Polymersomes containing soluble encapsulated polynucleotides and ionizable lipids and methods of making and using same - Patents.com

Abstract

The present invention relates to a polymersome comprising a soluble encapsulated antigen, said soluble encapsulated antigen being a polynucleotide selected from a DNA molecule or an mRNA molecule, said polymersome further comprising an ionizable lipid.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to European Patent Application No. 21167911, filed with the European Patent Office on April 12, 2021, the entire contents of which are incorporated herein by reference for all purposes.

[0002] Sequence Listing This application contains a Sequence Listing in computer readable format, which is incorporated herein by reference.

[0003] Technical Field The present invention relates to polymersomes, including oxidatively stable polymersomes comprising a soluble or solubilized antigen (e.g., a polynucleotide, such as a DNA molecule, an RNA molecule, and / or a combination of one or more thereof) and an ionizable lipid. [Background technology]

[0004] 2. Background of the Invention Immunization is a well-established process, but different immunogens or antigens induce different levels of response. For example, membrane proteins form a class of antigens that produce low response levels, which means that a large amount of membrane protein is required to generate or induce an immune response to the desired level. Membrane proteins are notoriously difficult to synthesize and are insoluble in water unless detergent is present. Therefore, membrane proteins are expensive and it is difficult to obtain sufficient amounts of membrane proteins for immunization. Furthermore, membrane proteins require proper folding to function properly. The immunogenicity of correctly folded native membrane proteins is usually much better than their solubilized forms, which may not be folded in a physiologically meaningful way. Therefore, even if adjuvants can be used to boost the immunogenicity of such solubilized antigens, it is an inefficient method without much advantage (e.g. WO2014 / 077781A1).

[0005] To increase the chances of isolating antibodies that may be efficient in vivo, transfected cell and lipid-based systems have been used to present membrane protein antigens, but these systems are often unstable (e.g., oxidation sensitive), laborious, and costly. Moreover, for such membrane protein antigens, the current state of the art is to use inactive virus-like particles for immunization.

[0006] On the other hand, vaccines are the most efficient way to prevent diseases, mainly infectious diseases [e.g., Liu et al., 2016]. At present, the majority of licensed vaccines are made of either live or killed viruses. Although such vaccines are effective in generating humoral immunity (antibody-mediated responses) with the aim of preventing viral transmission and cell entry, concerns remain regarding the safety of such vaccines. In the past decades, scientific advances have helped to overcome such issues by engineering vaccine vectors that are non-replicating recombinant viruses. In parallel, protein-based or subunit antigens have been explored as a safer alternative. However, the immunity (both humoral and cellular responses) induced by such protein-based vaccines is typically insufficient. Several approaches have been used to improve the immunogenic properties of antigens. For example, microencapsulation of antigens in polymers has been extensively studied, which could enhance immunogenicity, but antigen aggregation and denaturation remain unsolved [e.g., Hilbert et al., 1999]. Furthermore, adjuvants (e.g., oil-in-water emulsions or polymer emulsions) [e.g., US 9636397 B2, US 2015 / 0044242 A1] are used together with antigens to induce more pronounced humoral and cellular responses. Despite these advances, they have low uptake and cross-presentation efficiency. Based on available information on the immune system during viral infection, virus-like particles have been developed to mimic such properties to promote cross-presentation. Synthetic architectures such as liposomes in which antigens are encapsulated are particularly attractive. Liposomes are self-assembled unilamellar structures made of lipids, and cationic liposomes are more attractive and promising as delivery vehicles because they are efficiently taken up by antigen-presenting cells (APCs) [e.g., Maji et al., 2016].Furthermore, liposomes can also be loaded with immunomodulators, such as monophosphoryl lipid A (MPL), CpG oligodeoxynucleotides, etc., which are toll-like receptor (TLR) agonists that stimulate immune cells via their receptors. Despite these favorable conditions for such delivery vehicles, one of the limiting factors is the stability of liposomes in the presence of serum components. The stability issue of liposomes can be somewhat mitigated by PEGylation and loading of high melting point lipids. One such well-characterized example is the interbilayered-crosslinked multilamellar vesicle (ICMV), which is formed by stabilizing multilamellar vesicles with short covalent bridges linking lipids [e.g., Moon et al., 2011]. Other nanoparticle architectures have also led to successful immunization using nanodiscs [e.g., Kuai et al., 2017] or pH-sensitive particles [e.g., Luo et al., 2017]. However, such strategies still require adjuvants or are not very efficient outside the prototypic ovalbumin (OVA) model.

[0007] In addition, polymersomes have emerged as a stable alternative to liposomes, and they have been used to incorporate membrane proteins to induce immune responses [e.g. Quer et al., 2011, WO2014 / 077781A1]. Protein antigens have also been encapsulated in the chemically modified (but oxidation-sensitive) membrane of polymersomes to release antigens and adjuvants to dendritic cells [e.g. Stano et al., 2013].

[0008] Even with the advances made through the use of polymers, it remains to be seen whether it is possible to overcome or at least alleviate the above-mentioned problems and to improve the ability of the polymers to inhibit CD8, which is of particular importance in the treatment and / or prevention of infectious diseases, cancer and autoimmune diseases, among others. (+)There remains a need to provide cross-presentation delivery vehicles and methods that are efficient in uptake and stable, with improved functionality in that they are also capable of eliciting T cell-mediated immune responses. Summary of the Invention

[0009] The present invention relates to a polymersome comprising a soluble encapsulated antigen, the soluble encapsulated antigen being a polynucleotide (e.g., single-stranded or double-stranded) selected from an RNA (e.g., mRNA) molecule or a DNA molecule, the polymersome further comprising an ionizable lipid.

[0010] The present invention relates to a method for inducing an immune response, i) a polypeptide, ii) carbohydrates, iii) a polynucleotide, which is preferably not an antisense oligonucleotide, and more preferably is a DNA molecule or an mRNA molecule, or iv) a combination of i) and / or ii) and / or iii) The present invention also relates to the use of polymersomes having a diameter of about 120 nm or 140 nm or more, comprising a soluble encapsulated antigen selected from the group consisting of:

[0011] 2. Use of an assembly of polymersomes having an average diameter of about 120 nm or 140 nm or more to induce an immune response, the polymersomes of the assembly comprising: i) a polypeptide, ii) carbohydrates, iii) a polynucleotide, which is preferably not an antisense oligonucleotide, and more preferably is a DNA molecule or an mRNA molecule, or iv) a combination of i) and / or ii) and / or iii) The use of the present invention, comprising a soluble encapsulated antigen selected from the group consisting of:

[0012] Furthermore, by providing polymersomes of the present invention, encapsulated soluble (or solubilized) antigens generate stronger humoral immune responses (compared to free antigens with or without adjuvant) and enhance CD8 (+) It was found in the course of the present invention that it is possible to induce a T cell-mediated immune response. As a result, an increase in the efficiency of antibody production in the subject is achieved. The increase in efficiency can be obtained with or without the use of an adjuvant. Furthermore, it has been found that the polymersomes of the present invention are capable of inducing a CD8 T cell-mediated immune response. (+) The ability to induce T cell-mediated immune responses dramatically increases their potential as antigen delivery and presentation systems for immunotherapy.

[0013] Because soluble (e.g., solubilized) encapsulated antigens are presented by polymersomes, the use of polymersomes of the invention and antibodies produced by the methods of the invention will not only have a higher production success rate, higher affinity for their respective in vitro or in vivo targets, and correspondingly improved sensitivity when used in various solution-based antibody applications, but will also facilitate the generation of antibodies against difficult antigens that could not trigger antibody production using conventional methods using injection of free antigen, and / or reduce the amount of antigen required for such antibody production procedures, thereby reducing the cost of such production. Furthermore, the soluble (e.g., solubilized) encapsulated antigens presented by the polymersomes of the invention will be capable of binding to CD8 (+) They can also induce T cell-mediated immune responses, which extends the use of the corresponding polymersomes to cell-mediated immunity, thus improving their immunotherapeutic and antigen delivery and presentation capabilities.

[0014] The present application therefore meets this need by providing oxidatively stable polymersomes that improve the immunogenic properties of antigens, methods for their production and compositions comprising such polymersomes, as described hereinafter, characterized in the claims, and illustrated by the accompanying examples and figures.

[0015] Sequence Listing Overview As used herein, references are made to UniProtKB accession numbers (available at http: / / www.uniprot.org / , e.g., UniProt Release 2021_01, published February 10, 2021).

[0016] As used herein, references are made to NCBI GenBank accession numbers (http: / / www.ncbi.nlm.nih.gov / genbank / release / current, available, e.g., in Release 242.0, published February 15, 2021).

[0017] SEQ ID NO:1 is the amino acid sequence of the tumor neo-antigen polypeptide Reps1 P45A from the MC-38 mouse model of colon cancer.

[0018] SEQ ID NO:2 is the amino acid sequence of the tumor neo-antigenic peptide Adpgk R304M derived from the MC-38 mouse model of colon cancer.

[0019] SEQ ID NO:3 is the amino acid sequence of the tumor neo-antigen peptide Dpagt1 V213L derived from the MC-38 mouse model of colon cancer.

[0020] SEQ ID NO:4 is the amino acid sequence of chicken ovalbumin (OVA), UniProtKB Accession No. P01012.

[0021] SEQ ID NO:5 is the amino acid sequence of Influenza A virus (A / New York / 38 / 2016 (H1N1)) hemagglutinin, UniProtKB accession number A0A192ZYK0.

[0022] SEQ ID NO:6 is the amino acid sequence of Influenza A virus (A / Swine / 4 / Mexico / 2009 (H1N1)) hemagglutinin, UniProtKB Accession No. D2CE65.

[0023] SEQ ID NO:7 is the amino acid sequence of Influenza A virus (A / Puerto Rico / 8 / 1934 (H1N1)) hemagglutinin.

[0024] SEQ ID NO:8 is the amino acid sequence of Influenza A virus (A / California / 07 / 2009 (H1N1)) hemagglutinin.

[0025] SEQ ID NO:9 is the amino acid sequence of the tumor neo-antigen polypeptide CD8 Trp2 173-196 from the melanoma B16-F10 mouse model.

[0026] SEQ ID NO:10 is the amino acid sequence of the tumor neo-antigen polypeptide CD4 M30 Kif18b K739N from the melanoma B16-F10 mouse model.

[0027] SEQ ID NO:11 is the amino acid sequence of the tumor neo-antigen polypeptide CD4 M44 Cpsf3l D314N from the melanoma B16-F10 mouse model.

[0028] SEQ ID NO:12 is the amino acid sequence of the soluble portion (amino acid residues 19 to 1327) of the porcine epidemic diarrhea virus (PEDv) spike protein (S protein) (UniProtKB Accession No. V5TA78).

[0029] SEQ ID NO:13 is the amino acid sequence of the S1 region (amino acid residues 19 to 739) of the PEDv spike protein (S protein).

[0030] SEQ ID NO:14 is the amino acid sequence of the S2 region (amino acid residues 739 to 1327) of the PEDv spike protein (S protein).

[0031] SEQ ID NO:15 is the amino sequence of enhanced green fluorescent protein (eGFP).

[0032] SEQ ID NO:16 is the OVA mRNA nucleotide sequence. [Brief description of the drawings]

[0033] [Figure 1] FIG. 1 is a schematic diagram of immunization with polymersomes of the invention encapsulating antigen and measuring humoral and cellular responses. [Figure 2A] The results of dynamic light scattering results for polymersomes of the present invention are shown. Figure 2A is a dynamic light scattering plot of OVA-encapsulated polymersomes, which are a monodisperse population of 173.1 nm (diameter). Figure 2B is a table of the average diameter (Z-average) measured by DLS for various polymersomes encapsulating various antigens. [Figure 2B] See legend to Figure 2A. [Diagram 3] FIG. 1 shows the elution profile of OVA-encapsulated polymersomes in size-exclusion chromatography. [Figure 4] FIG. 1 shows sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of OVA-encapsulated polymersomes. [Figure 5A] The results of encapsulation of nucleic acid (here, the gene encoding enhanced green fluorescent protein (eGFP)) into polymersomes of the present invention and uptake of the nucleic acid-encapsulated polymer into cells are shown. FIG. 5A shows the fluorescence intensity uptake of various polymersomes into the cell interior and eGFP expression based on DNA encapsulated in the polymersomes. FIG. 5B shows the fluorescence image of a cell transfected with DNA-encapsulated polymersomes. FIG. 5C shows the fluorescence image of a cell transfected with DNA-encapsulated polymersomes. [Figure 5B] See legend to Figure 5A. [Figure 5C] See legend to Figure 5A. [Figure 6]Antibody titers from mouse sera immunized with PBS, OVA alone, OVA with SAS adjuvant, and OVA-encapsulated polymersomes without adjuvant are shown. Only ACM encapsulating OVA (hereinafter, "ACM" refers to the polymersomes of the present invention) was able to induce IgG titers. [Figure 7] Figure 1 shows antibody titers from mouse sera immunized with PBS, HA only, and HA-encapsulated polymersomes without adjuvant. HA-encapsulated ACM (polymersomes of the invention) was able to induce IgG titers. [Figure 8] Results are shown for the MC-38 mouse tumor model. Tumor volume was monitored in mice immunized with free peptide (open circles), peptide encapsulated in ACM (closed squares, polymersomes of the invention) or peptide encapsulated in ACM with anti-PD1 antibody treatment (closed triangles). Tumor growth was modified by peptide encapsulated in ACM (polymersomes of the invention) compared to free peptide, and it was further enhanced by the addition of anti-PD1 antibody. No adjuvant was added to any group. [Figure 9] IgG antibody titers and virus neutralization responses (against PEDv USA / Colorado / 2013 (CO / 13) strain) from mouse sera immunized with PBS and a soluble fragment of PEDv S protein encapsulated in polymersomes used as described herein ("spike protein encapsulated polymersomes"), as well as, for comparison, from mouse sera immunized with killed PED virus ("killed PEDv") and ACM polymersomes only (i.e., no antigen, "polymersomes only"). From the IgG titers in FIG. 9, it is clear that both the ACM encapsulated PEDv S protein fragment and the killed virus induce IgG titers. The virus neutralization data shows that only the ACM encapsulated PEDv S protein resulted in significant neutralization titers, while the negative control (ACM polymersomes without any antigen) and the killed PED virus showed negligible neutralization responses. [Figure 10]Virus neutralization data (against the PEDv USA / Colorado / 2013 (CO / 13) strain) from sera generated from mice following immunization with PBS and various polymersomes (e.g., BD21 (described below), PDMS46-PEO37 (simply referred to as "PDMS" in the figures), PDMS46-PEO37 with DSPE-PEG (distearoylphosphatidylethanolamine [DSPE] polyethylene glycol) as added lipid, and polyethylene glycol-polylactic acid (PLA-PEG) with added asolectin lipid (a commercially available phospholipid derived from soybean) encapsulating either the full-length soluble PED spike protein ("BD21 with soluble S protein") or its S1 or S2 fragments (all other cases)) are shown. It is evident from FIG. 10 that the group of mice immunized with PBS samples does not show any virus neutralization response, whereas the polymersome formulations, irrespective of whether they encapsulate the full-length protein or its fragment, all show varying degrees of virus neutralization response. [Figure 11] 11 shows IgA antibody titers from pigs orally immunized with PEDv S protein encapsulated in ACM without adjuvant. Titers are from fecal swabs. As can be seen in FIG. 11, the titers increase over time. This indicates that the polymersomes of the present invention encapsulating PEDv S protein and administered orally can induce an immune response in pigs. [Figure 12] Schematic representation of the Porcine Epidemic Diarrhea Virus (PEDv) spike protein (S protein) (UniProtKB Accession No. V5TA78) and soluble fragments of SEQ ID NO:12 (amino acid residues 19-1327), SEQ ID NO:13 (amino acid residues 19-739) and SEQ ID NO:14 (amino acid residues 739-1327) used for encapsulation of soluble S protein in polymersomes and subsequent immunization / vaccination of mice and pigs as described herein. [Figure 13-1]1 shows DLS profiles demonstrating that the stability of OVA-mRNA loaded in ACM-polymersomes (BD / DOTAP as a reference example) is superior to that of OVA-mRNA loaded in LNPs (Onpattro composition) at −80° C. A- LNPs; B- ACM-polymersomes. [Figure 13-2] See description of Figure 13-1. [Figure 14] The DLS profile of empty polymersomes made with BD / DLin-MC3-DMA (A) ionizable lipid is shown compared to empty BD / DOTAP (B) polymersomes as a reference, demonstrating that both form in a similar manner. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] Detailed Description of the Invention In the following detailed description, reference is made to the accompanying examples and drawings, which show, by way of illustration, specific details and embodiments that may be taken in carrying out the present invention. These embodiments are described in sufficient detail to enable one skilled in the art to practice the invention. Other embodiments may be utilized, such that structural, logical and optional changes may be made without departing from the scope of the present invention. The various aspects of the present invention described herein are not necessarily mutually exclusive, as aspects of the present invention may be combined with one or more other aspects to form new embodiments of the present invention.

[0035] In the present context, polymersomes are vesicles with polymeric membranes, which are typically, but not necessarily, formed by self-assembly of dilute solutions of one or more amphiphilic block copolymers, which can be of various types, such as diblock and triblock (ABA or ABC). The polymersomes of the present invention can also be formed from tetrablock or pentablock copolymers. In the case of triblock copolymers, the central block is often shielded from the environment by its neighboring blocks, but diblock copolymers self-assemble into bilayers, with the two hydrophobic blocks arranged tail-to-tail to achieve much the same effect. In most cases, the vesicle membrane has an insoluble middle layer and a soluble outer layer. The driving force for the formation of polymersomes by self-assembly is believed to be the microphase separation of the insoluble blocks, which tend to associate to shield themselves from contact with water. The polymersomes of the present invention have remarkable properties due to the large molecular weight of the constituent copolymers. Increasing the total molecular weight of the block copolymers favors vesicle formation. As a result, the diffusion of (polymeric) amphiphiles is much less than that of vesicles formed by lipids and surfactants. This low mobility of polymer chains aggregated into vesicle structures allows stable polymersome morphology to be obtained. Unless otherwise stated, the terms "polymersome" and "vesicle" used herein are construed as similar and may be used interchangeably. Importantly, the polymersomes of the present invention may be formed from one type of block copolymer or from two or more types of block copolymers. That is, the polymersomes may be formed from a mixture of polymersomes and thus contain two or more types of block copolymers. In some aspects, the polymersomes of the present invention are oxidatively stable.

[0036] In some aspects, the present invention relates to a method for eliciting an immune response against a soluble (e.g., solubilized) encapsulated antigen in a subject. The method is suitable for injecting a composition comprising a polymersome (e.g., carrier or vehicle) having a membrane (e.g., surrounding membrane) of an amphiphilic polymer into a subject. The composition comprises a soluble (e.g., solubilized) antigen encapsulated by the membrane (e.g., surrounding membrane) of an amphiphilic polymer of the polymersome of the present invention. The antigen can be one or more of the following: (i) a polypeptide, (ii) a carbohydrate, (iii) a polynucleotide (e.g., the polynucleotide is not an antisense oligonucleotide, preferably the polynucleotide is a DNA molecule or a messenger RNA (mRNA) molecule), or a combination of (i) and / or (ii) and / or (iii).

[0037] In some further aspects, the invention relates to polymersomes capable of eliciting a CD8(+) T cell-mediated immune response.

[0038] In some aspects, the present invention relates to polymersomes capable of targeting lymph node resident macrophages and / or B cells. Exemplary non-limiting targeting mechanisms envisioned by the present invention include (i) delivery of encapsulated antigens (such as polypeptides) to dendritic cells (DCs) for T cell activation (CD4 and / or CD8). Another mechanism is (ii) delivery of whole folded antigens (such as proteins) that will be routed to DCs and also trigger titers (B cells).

[0039] In some aspects, the present invention relates to polymersomes encapsulating an antigen selected from the group consisting of: (i) an autoantigen, (ii) a non-self antigen, (iii) a non-self immunogen, and (iv) an autoimmunogen. Thus, the products and methods of the present invention are suitable for use in the context of induced tolerance (e.g., in clinical settings), for example, to target autoimmune diseases.

[0040] In some aspects, the present invention relates to polymersomes of the present invention comprising lipid polymers.

[0041] The polymersomes of the present invention may be co-encapsulated (i.e., encapsulated in addition to the antigen) with one or more adjuvants. Specific examples of adjuvants include synthetic oligodeoxynucleotides (ODNs) containing unmethylated CpG motifs that can trigger cells expressing Toll-like receptor 9 (including human plasmacytoid dendritic cells and B cells) to initiate an innate immune response characterized by the production of Th1 and proinflammatory cytokines, cytokines such as interleukin-1, interleukin-2, or interleukin-12, keyhole limpet hemocyanin (KLH), serum albumin, bovine thyroglobulin, or soybean trypsin inhibitor, to name just a few.

[0042] The polymersomes of the present invention can be of any size as long as the polymersomes can induce an immune response. For example, the polymersomes may have a diameter of more than 70 nm. The diameter of the polymersomes may range from about 100 nm to about 1 μm, or from about 100 nm to about 750 nm, or from about 100 nm to about 500 nm. The diameter of the polymersomes may further range from about 125 nm to about 175 nm, or from about 125 nm to about 250 nm, from about 140 nm to about 240 nm, from about 150 nm to about 235 nm, from about 170 nm to about 230 nm, or from about 220 nm to about 180 nm, or from about 190 nm to about 210 nm. The diameter of the polymersomes may be, for example, about 200 nm, about 205 nm, or about 210 nm. When used as an assembly for inducing an immune response, the polymersome assembly is typically a monodisperse assembly. The average diameter of the polymersome aggregates / populations used is typically greater than 70 nm, or greater than 120 nm, or greater than 125 nm, or greater than 130 nm, or greater than 140 nm, or greater than 150 nm, or greater than 160 nm, or greater than 170 nm, or greater than 180 nm, or greater than 190 nm (see also FIG. 2 in this respect). The average diameter of the polymersome aggregates may be, for example, in the range of the individual polymersomes mentioned above. That is, the average diameter of the polymersome aggregates may be in the range of 100 nm to about 1 μm, or in the range of about 100 nm to about 750 nm, or in the range of about 100 nm to about 500 nm, or in the range of about 125 nm to about 250 nm, about 140 nm to about 240 nm, about 150 nm to about 235 nm, about 170 nm to about 230 nm, or about 220 nm to about 180 nm, or about 190 nm to about 210 nm. The average diameter of a population of polymersomes may be, for example, about 200 nm, about 205 nm, or about 210 nm. The diameter can be determined, for example, by a dynamic light scattering (DLS) instrument using the preferred DLS parameter Z-average (d, nm). The Z-average size is the intensity weighted harmonic mean particle diameter (see Examples 1 and 2).In this context, it should be noted that according to US Patent No. 8,323,696 to Hubbel et al., polymersome aggregates should have an average diameter of less than 70 nm in order to be able to induce an immune response. Similarly, Stano et al., 2013, supra, would have preferred to use smaller polymersomes, but due to technical limitations used polymersomes with a diameter of 125 nm ± 15 nm to induce an immune response. Thus, it is surprising that a population / aggregate of polymersomes of the invention, for example with an average diameter of more than 150 nm, can induce both a cellular and a humoral immune response (see Examples). Such polymersome aggregates may be in a form suitable for inducing an immune response, for example by injection or oral administration.

[0043] In some aspects, the present invention relates to compositions of the present invention suitable for intradermal, intraperitoneal, subcutaneous, intravenous, or intramuscular injection or non-invasive administration, such as oral or nasal administration, of the antigens of the present invention. The compositions may comprise the polymersomes (e.g., carriers) of the present invention having a membrane (e.g., a surrounding membrane) of an amphiphilic polymer. The compositions further comprise a soluble (e.g., solubilized) antigen encapsulated by the membrane of the amphiphilic polymer of the polymersome. The compositions of the present invention may be used for therapeutic purposes (e.g., treating a diseased subject or preventing disease, such as by vaccination), or for antibody discovery, vaccine discovery, or targeted delivery.

[0044] In some aspects, the polymersomes of the invention have hydroxyl groups on their surface. In some further aspects, the polymersomes of the invention have no hydroxyl groups on their surface.

[0045] In the context of this application, the term "encapsulated" means surrounded by a membrane (e.g., the membrane of a polymersome of the invention) (e.g., contained within the lumen of the polymersome). The term "encapsulated" in reference to an antigen further means that the antigen is not incorporated, covalently attached, or conjugated to a membrane (e.g., the membrane of a polymersome of the invention). In reference to the compartmentalization of the polymersome vesicle structures described herein, the term "encapsulated" means that the inner vesicle is completely contained within the outer vesicle and surrounded by the vesicle membrane of the outer vesicle. The closed space surrounded by the vesicle membrane of the outer vesicle forms one compartment. The closed space surrounded by the vesicle membrane of the inner vesicle forms another compartment.

[0046] In the context of this application, the term "antigen" refers to any substance that can be specifically bound by immune system components. Only antigens that are capable of eliciting (or eliciting or inducing) an immune response are considered immunogenic and are called "immunogens." Exemplary, non-limiting antigens are polypeptides derived from the soluble portion of a protein, hydrophobic polypeptides that have been made soluble for inclusion, and aggregated polypeptides that are soluble as aggregates. Antigens can originate from within the body ("self-antigens") or from the external environment ("non-self").

[0047] Membrane proteins form a class of antigens that typically generate low levels of immune response. Of particular interest, soluble (e.g., solubilized) membrane proteins (MPs) as well as membrane-associated peptides (MAPs) and fragments (i.e., portions) thereof (e.g., antigens as referred to herein) can be encapsulated by polymersomes, which allows them to fold in a physiologically meaningful manner. This strongly boosts the immunogenicity of such antigens, so that a smaller amount of the corresponding antigen can be used to generate the same level of immune response when compared to free antigen. Furthermore, the large size of polymersomes (compared to free membrane proteins) allows them to be more easily detected by the immune system.

[0048] For purposes of this application, the term "B16 peptide" refers to any neo-antigen polypeptide derived from a spontaneous C57BL / 6-derived B16 melanoma model (e.g., the B16-F10 melanoma mouse model), non-limiting examples of which include peptides of SEQ ID NOs:9, 10, and 11.

[0049] For purposes of this application, the term "MC38 peptide" refers to any neo-antigen polypeptide derived from the MC38 mouse model of colon cancer, including, but not limited to, the peptides of SEQ ID NOs: 1, 2, and 3.

[0050] For purposes of this application, the term "influenza hemagglutinin (HA)" refers to a glycoprotein found on the surface of influenza viruses. HA has at least 18 different antigens, all of which are within the scope of the present invention. These subtypes are designated H1 through H18. Non-limiting examples of "influenza hemagglutinin (HA)" subtype H1 include the polypeptides of SEQ ID NOs:5, 6, 7, and 8.

[0051] As used herein, the term "swine influenza hemagglutinin (HA)" refers to a glycoprotein found on the surface of swine influenza viruses, a family of influenza viruses specific to pigs. A non-limiting example of a "swine influenza hemagglutinin (HA)" is subtype H1 of SEQ ID NO:6.

[0052] In the context of this application, the term "PEDv S protein" refers to the spike glycoprotein present on the surface of the porcine epidemic diarrhea virus (PEDV), a family of coronaviruses in pigs. Non-limiting examples of soluble "PEDv S protein" that may be used herein include the entire soluble fragment of the porcine epidemic diarrhea virus (PEDv) spike protein (S protein) (UniProtKB Accession No. V5TA78) consisting of the S1 and S2 regions having the amino acid sequence of SEQ ID NO: 12, the soluble fragment of the S1 region of SEQ ID NO: 13, or the soluble fragment of the S2 region of SEQ ID NO: 14. It is of course possible to use shorter fragments of the entire soluble fragment of the S1 and S2 regions, or only of either the S1 or S2 regions (see FIG. 12 in this regard). It is of course possible to use fragments containing part of S1 and part of S2 in the polymersomes of the invention, for example amino acids 500 to 939 of the deposited sequence of the spike protein. It is also noted that the polymersomes of the invention may encapsulate one or more different soluble fragments of the spike protein, such as the entire S1 region, the S2 region, and / or the entire S1 and S2 regions. In exemplary embodiments of the polymersomes of the invention, the polymersomes of the invention encapsulate therein one type of soluble fragment (e.g., only the S1 region), two different types of soluble fragments (e.g., the S1 and S2 regions), three different types of soluble fragments (the S1 region, the S2 region, and the entire soluble fragment of S1 and S2 of SEQ ID NO:12 (amino acid residues 19-1327)), or even four different types of fragments (e.g., the S1 region, the S2 region, and the entire soluble fragment of S1 and S2 of SEQ ID NO:12 (amino acid residues 19-1327), and a fourth type of fragment as described above that contains a portion of S1 and a portion of S2, e.g., amino acids 500-939 of the spike protein sequence).It should also be noted here that the polymersomes of the present invention encapsulating one or more different soluble fragments of the spike protein are used in a preferred embodiment as oral vaccines against porcine epidemic diarrhea virus.

[0053] In the context of this application, the term "oxidative stability" refers to a measure of the resistance of polymersomes (or corresponding polymers or membranes) to oxidation, using, for example, the method described by Scott et al., 2012. In this method, polymersomes with encapsulated antigens are incubated in a 0.5% solution of hydrogen peroxide, and the amount of free antigen (released) can be quantified by UV / fluorescence HPLC. Polymersomes that release a substantial portion or all of the encapsulated antigen under these oxidizing conditions are considered to be oxidation-sensitive. Another method for determining whether a block copolymer, and therefore the resulting polymersome, is oxidation-stable or oxidation-sensitive is described in column 16 of US Pat. No. 8,323,696. According to this method, polymers with oxidation-sensitive functional groups are chemically modified by a mild oxidizing agent, and the test is the enhanced solubility in 10% hydrogen peroxide in vitro for 20 hours. For example, poly(propylene sulfide) (PPS) is an oxidation-sensitive polymer (see, for example, Scott et al. 2012 supra and US Pat. No. 8,323,696). PPS can serve as a standard for determining whether the polymer of interest and each polymersome of interest are oxidation-susceptible or oxidation-stable. For example, if the same or more amount of antigen is released from the polymersome of interest, or about 90% or more, or about 80% or more, or about 70% or more, or about 60% or more, compared to the amount released from the PPS polymersome containing the same antigen, the polymersome is considered to be oxidation-susceptible. If the same or less amount of antigen is released from the polymersome of interest, less than about 0.5%, or less than about 1.0%, or less than about 2%, or less than about 5%, or less than about 10%, or less than about 20%, or less than about 30%, or less than about 40%, or less than about 50% compared to the amount released from the PPS polymersome containing the same antigen, the polymersome is considered to be oxidation-stable.In line with this, therefore, PPS polymersomes as described in US Pat. No. 8,323,696, or PPS-bl-PEG polymersomes, such as those made of poly(propylene sulfide) (PPS) and poly(ethylene glycol) (PEG) as components as described in Stano et al., are not oxidatively stable polymersomes in the sense of the present invention. Similarly, PPS30-PEG17 polymersomes are not oxidatively stable polymersomes in the sense of the present invention. Other non-limiting examples of oxidative stability measurements include measurements of stability in the presence of serum components (e.g., components of mammalian serum, e.g., human serum), or for example, measurements of stability inside endosomes.

[0054] For purposes of this application, the term "reductive stability" refers to a measure of a polymersome's resistance to reduction in a reducing environment.

[0055] As used herein, the term "serum" refers to plasma from which the clotting proteins have been removed.

[0056] For purposes of this application, the term "oxidation-independent release" refers to the release of polymersome contents without, or essentially without, oxidation of the polymer forming the polymersome.

[0057] The term "polypeptide" is used herein equivalently to the term "protein". Proteins (including fragments thereof, preferably biologically active fragments, and peptides, usually those having less than 30 amino acids) comprise one or more amino acids coupled together (resulting in a chain of amino acids) via covalent peptide bonds. The term "polypeptide" as used herein refers to a group of molecules, e.g., those consisting of more than 30 amino acids. Polypeptides can further form multimers, i.e., consisting of two or more polypeptide molecules, such as dimers, trimers and higher oligomers. The polypeptide molecules forming such dimers, trimers, etc. may or may not be identical. The corresponding higher order structures of such multimers are therefore called homodimers or heterodimers, homotrimers or heterotrimers, etc. An example of a heteromultimer is an antibody molecule, which in its native form consists of two identical light polypeptide chains and two identical heavy polypeptide chains. The terms "polypeptide" and "protein" also refer to naturally modified polypeptides / proteins, where the modification is achieved by post-translational modifications such as, for example, glycosylation, acetylation, phosphorylation, etc. Such modifications are well known in the art.

[0058] As used herein, the term "sugar" refers to compounds such as aldoses and ketoses having the stoichiometric formula C(H2O)n (i.e., and therefore "carbohydrates"). The collective term "sugar" includes, but is not limited to, monosaccharides, oligosaccharides, and polysaccharides, as well as substances derived from monosaccharides by reduction of the carbonyl group (alditols), oxidation of one or more terminal groups to carboxylic acids, or replacement of one or more hydroxyl groups by groups such as hydrogen atoms, amino groups, thiol groups, and the like. Derivatives of these compounds are also included.

[0059] For purposes of this application, the term "polynucleotide" (also referred to as "nucleic acid" which may be used interchangeably with the term "polynucleotide") refers to a polymer composed of nucleotide units that may be hydrolyzable, for example, to certain pyrimidine or purine bases (usually adenine, cytosine, guanine, thymine, uracil), d-ribose or 2-deoxy-d-ribose, and phosphate. Non-limiting examples of "polynucleotides" include DNA molecules (e.g., cDNA or genomic DNA), RNA (mRNA), combinations thereof, or hybrid molecules composed of DNA and RNA. Nucleic acids can be double-stranded or single-stranded and can contain both double-stranded and single-stranded fragments. Most preferred are double-stranded DNA molecules and mRNA molecules.

[0060] As used herein, the term "antisense oligonucleotide" refers to a nucleic acid polymer, at least a portion of which is complementary to a nucleic acid present in a normal cell or a diseased cell. Exemplary "antisense oligonucleotides" include antisense RNA, siRNA, and RNAi.

[0061] In this application, the term "CD8(+) T cell-mediated immune response" refers to an immune response mediated by cytotoxic T cells (TCs, also known as cytotoxic T lymphocytes, CTLs, T killer cells, cytolytic T cells, CD8(+) T cells or killer T cells). Examples of cytotoxic T cells include, but are not limited to, antigen-specific effector CD8(+) T cells. For the T cell receptor (TCR) to bind to class I MHC molecules, it must be associated with a glycoprotein called CD8, which binds to the constant portion of class I MHC molecules. These T cells are therefore called CD8(+) T cells. Once activated, TC cells undergo "clonal expansion" with the help of the cytokine interleukin-2 (IL-2), which is a growth and differentiation factor for T cells. This increases the number of cells specific to the target antigen, which can then migrate throughout the body in search of antigen-positive somatic cells.

[0062] As used herein, the term "clonal expansion of antigen-specific CD8(+) T cells" refers to an increase in the number of CD8(+) T cells specific for a target antigen.

[0063] As used herein, the term "cellular immune response" refers to an immune response that does not involve antibodies, but rather involves the activation of phagocytes, antigen-specific cytotoxic T lymphocytes, and the release of various cytokines in response to an antigen.

[0064] As used herein, the term "cytotoxic phenotype of an antigen-specific CD8(+) T cell" refers to a set of observable characteristics of an antigen-specific CD8(+) T cell that are relevant to the cytotoxic function of the cell.

[0065] As used herein, the term "lymph node resident macrophages" refers to macrophages, large white blood cells that are an integral part of our immune system and reside in lymph nodes, small bean-like glands found throughout the body, where they engulf particles and then digest them using a process called phagocytosis.

[0066] As used herein, the term "humoral immune response" refers to immune responses mediated by macromolecules found in extracellular fluids, such as secreted antibodies, complement proteins, and certain antimicrobial peptides. Aspects that involve antibodies are often referred to as antibody-mediated immunity.

[0067] As used herein, the term "B cells", also known as B lymphocytes, are a type of white blood cell of the lymphocyte subtype. They function in the humoral immune component of the adaptive immune system by secreting antibodies.

[0068] As used herein, an "antibody" is a protein comprising one or more polypeptides (including one or more binding domains, preferably antigen-binding domains) substantially or partially encoded by immunoglobulin genes or fragments of immunoglobulin genes. "Immunoglobulin" (Ig) is used interchangeably herein with "antibody". Recognized immunoglobulin genes include the kappa, lambda, alpha, gamma, delta, epsilon and mu constant region genes, as well as a myriad of immunoglobulin variable region genes. In particular, as used herein, an "antibody" is typically a tetrameric, glycosylated protein composed of two light (L) chains, each of approximately 25 kDa, and two heavy (H) chains, each of approximately 50 kDa. Two types of light chains, called lambda and kappa, can be found in antibodies. Depending on the amino acid sequence of the constant domain of the heavy chain, immunoglobulins can be assigned to five major classes, A, D, E, G, and M, some of which can be further divided into subclasses (isotypes), e.g., IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2. IgG is preferred in the context of the present invention. Antibodies related to the present invention are also envisaged that have an IgE constant domain or a part thereof that is bound by the Fc epsilon receptor I. IgM antibodies consist of five basic heterotetramer units and an additional polypeptide called the J chain, and contain ten antigen-binding sites. IgA antibodies, on the other hand, contain two to five basic four-chain units, which can multimerize to form multivalent assemblies in combination with the J chain. In the case of IgG, the four-chain unit is generally about 150,000 daltons. Each light chain comprises an N-terminal variable (V) domain (VL) and a constant (C) domain (CL). Each heavy chain contains an N-terminal V domain (VH), three or four C domains (CH) and a hinge region. The constant domains are not directly involved in binding the antibody to an antigen, but can exhibit various effector functions, such as participating in antibody-dependent cellular cytotoxicity (ADCC).If the antibody is to exert ADCC, it is preferable that the antibody is an IgG1 subtype; IgG4 subtypes will not have the ability to exert ADCC.

[0069] The term "antibody" also includes, but is not limited to, monoclonal, monospecific, polyspecific or multispecific antibodies, such as bispecific antibodies, humanized antibodies, camelized antibodies, human antibodies, single-chain antibodies, chimeric antibodies, synthetic antibodies, recombinant antibodies, hybrid antibodies, mutated antibodies, grafted antibodies, and in vitro generated antibodies, with chimeric or humanized antibodies being preferred. The term "humanized antibody" is generally defined for antibodies in which the CDRs encoding the HC and LC specificities have been transferred into a suitable human variable framework ("CDR grafting"). The term "antibody" also includes scFvs, single-chain antibodies, diabodies or tetrabodies, domain antibodies (dAbs) and nanobodies. In the context of the present invention, the term "antibody" is also intended to include dimeric, trimeric or multimeric forms having several antigen binding sites or bifunctional, trifunctional or multifunctional antibodies.

[0070] Furthermore, the term "antibody" as used in the present invention also relates to derivatives (including fragments) of the antibodies described herein. A "derivative" of an antibody includes an amino acid sequence that has been altered by introducing substitutions, deletions, or additions of amino acid residues. In addition, derivatives also include antibodies that have been modified by covalently binding any type of molecule to the antibody or protein. Examples of such molecules include, but are not limited to, sugars, PEG, hydroxyl groups, ethoxy groups, carboxy groups, or amine groups. In short, covalent modification of antibodies leads to, but is not limited to, glycosylation, PEGylation, acetylation, phosphorylation, amidation, etc.

[0071] The antibodies related to the present invention are preferably "isolated" antibodies. "Isolated", when used to describe the antibodies disclosed herein, means an antibody that has been identified, separated and / or recovered from components of its production environment. Preferably, an isolated antibody is free of association with any other components from its production environment. Contaminating components of the production environment, such as those resulting from recombinant transfected cells, are materials that would typically interfere with diagnostic or therapeutic uses of the polypeptide, and may include enzymes, hormones and other proteinaceous or non-proteinaceous solutes. In a preferred embodiment, the antibody will be (1) purified to a sufficient extent to obtain at least 15 residues of N-terminal or internal amino acid sequence using a spinning cup sequenator, or (2) purified to homogeneity by SDS-PAGE under non-reducing or reducing conditions, using Coomassie blue staining or preferably silver staining. Ordinarily, however, an isolated antibody will be prepared by at least one purification step.

[0072] The term "essentially non-immunogenic" means that the block copolymer or amphiphilic polymer of the present invention does not induce an adaptive immune response, i.e., compared to the encapsulated immunogen, the block copolymer or amphiphilic polymer exhibits less than 30%, preferably less than 20%, more preferably less than 10%, and particularly preferably less than 9, 8, 7, 6 or 5% of the immune response.

[0073] The term "essentially non-antigenic" means that the block copolymer or amphiphilic polymer of the present invention does not specifically bind to a certain group of products of adaptive immunity (e.g. T cell receptors or antibodies), i.e., compared to the encapsulated antigen, the block copolymer or amphiphilic polymer exhibits less than 30%, preferably less than 20%, more preferably less than 10%, and particularly preferably less than 9, 8, 7, 6 or 5% binding.

[0074] Typically, binding affinities are around 10-6 Binding is considered specific when the binding affinity is greater than M. Preferably, the binding affinity is greater than about 10 -11 ~10 -8 M(KD), preferably about 10 -11 ~10 -9 Binding is considered specific when M. If necessary, the binding conditions can be altered to reduce non-specific binding without substantially affecting specific binding.

[0075] The term "amino acid" or "amino acid residue" typically refers to an amino acid having its art-recognized definition, e.g., an amino acid selected from the group consisting of alanine (Ala or A), arginine (Arg or R), asparagine (Asn or N), aspartic acid (Asp or D), cysteine ​​(Cys or C), glutamine (Gln or Q), glutamic acid (Glu or E), glycine (Gly or G), histidine (His or H), isoleucine (He or I), leucine (Leu or L), lysine (Lys or K), methionine (Met or M), phenylalanine (Phe or F), proline (Pro or P), serine (Ser or S), threonine (Thr or T), tryptophan (Trp or W), tyrosine (Tyr or Y), and valine (Val or V), although modified, synthetic, or rare amino acids may be used as desired. In general, amino acids can be classified as having nonpolar side chains (e.g., Ala, Cys, He, Leu, Met, Phe, Pro, Val), negatively charged side chains (e.g., Asp, Glu), positively charged side chains (e.g., Arg, His, Lys), or uncharged polar side chains (e.g., Asn, Cys, Gln, Gly, His, Met, Phe, Ser, Thr, Trp, and Tyr).

[0076] "Polyclonal antibody" or "polyclonal antiserum" refers to an immune serum that can be prepared from the blood of an animal immunized with one or more antigens and contains a mixture of antibodies specific for said one (monovalent or specific antiserum) or several (polyvalent antiserum) antigens.

[0077] Furthermore, the term "antibody" as used in the present invention also relates to derivatives or variants of the antibodies described herein that exhibit the same specificity as the antibodies described herein. Examples of "antibody variants" include humanized variants of non-human antibodies, "affinity matured" antibodies (see, e.g., Hawkins et al. J. Mol. Biol. 254, 889-896 (1992) and Lowman et al., Biochemistry 30, 10832-10837 (1991)), and antibody mutants with altered effector functions (see, e.g., U.S. Patent No. 5,648,260).

[0078] The term "monoclonal antibody" as used herein refers to an antibody obtained from a population of substantially homogeneous antibodies; that is, the individual antibodies constituting the population are identical except for possible natural mutations and / or post-translational modifications (e.g., isomerization, amidation) that may be present in minor amounts. Monoclonal antibodies are highly specific, being directed against a single antigenic site. Furthermore, in contrast to conventional (polyclonal) antibody preparations, which typically contain different antibodies against different determinants (epitopes), each monoclonal antibody is directed against a single determinant on the antigen. In addition to their specificity, monoclonal antibodies are advantageous in that they are synthesized by hybridoma cultures uncontaminated by other immunoglobulins. The modifier "monoclonal" indicates the character of the antibody as being obtained from a substantially homogeneous population of antibodies and is not to be construed as requiring production of the antibody by any method. For example, the monoclonal antibodies to be used in accordance with the present invention may be made by the hybridoma method first described by Kohler et al., Nature, 256:495 (1975), or may be made by recombinant DNA methods (see, e.g., U.S. Pat. No. 4,816,567). The "monoclonal antibodies" may also be isolated from phage antibody libraries using, for example, the techniques described in Clackson et al., Nature, 352:624-628 (1991) and Marks et al., J. Mol. Biol., 222:581-597 (1991).

[0079] Monoclonal antibodies herein specifically include "chimeric" antibodies (immunoglobulins) in which a portion of the heavy and / or light chain is identical or homologous to a corresponding sequence in an antibody from a particular species or belonging to a particular antibody class or subclass, while the remainder of the chain is identical or homologous to a corresponding sequence in an antibody from another species or belonging to another antibody class or subclass, as well as fragments of such antibodies, so long as they exhibit the desired biological activity (U.S. Pat. No. 4,816,567; Morrison et al., Proc. Natl. Acad. Sci. USA, 81:6851-6855 (1984)). Chimeric antibodies of interest herein include "primitized" antibodies that contain variable domain antigen-binding sequences derived from a non-human primate (e.g., Old World monkeys, apes, etc.) and human constant region sequences.

[0080] "Humanized" forms of non-human (e.g., murine) antibodies are chimeric immunoglobulins, chimeric immunoglobulin chains or fragments thereof (e.g., Fv, Fab, Fab', F(ab')2 or other antigen-binding subsequences of antibodies) that contain mostly human sequences with minimal sequence derived from non-human immunoglobulin. Humanized antibodies are mostly human immunoglobulins (recipient antibody) in which residues from a hypervariable region (also CDR) of the recipient are replaced by residues from a hypervariable region of a non-human species (donor antibody) such as mouse, rat or rabbit having the desired specificity, affinity, and capacity. In some cases, Fv framework region (FR) residues of the human immunoglobulin are replaced by corresponding non-human residues. Furthermore, "humanized antibodies" as used herein can also include residues that are not found in the recipient antibody or in the donor antibody. These modifications are made to further refine and optimize antibody performance. Humanized antibodies optimally will also contain at least a portion of an immunoglobulin constant region (Fc), typically that of a human immunoglobulin. For further details, see Jones et al., Nature, 321:522-525 (1986); Reichmann et al., Nature, 332:323-329 (1988); and Presta, Curr. Op. Struct. Biol., 2:593-596 (1992).

[0081] The term "human antibody" includes antibodies having variable and constant regions substantially corresponding to human germline immunoglobulin sequences known in the art, such as those described by Kabat et al. (Kabat, et al. (1991) supra). The human antibodies of the invention can include, for example in the CDRs, and particularly in CDR3, amino acid residues not encoded by human germline immunoglobulin sequences (e.g., mutations introduced by random or site-specific mutagenesis in vitro or by somatic mutation in vivo). A human antibody can have at least one, two, three, four, five or more positions replaced with an amino acid residue not encoded by a human germline immunoglobulin sequence.

[0082] As used herein, an "in vitro generated antibody" refers to an antibody in which all or part of the variable region (e.g., at least one CDR) is generated by a non-immune cell selection method (e.g., in vitro phage display, protein chip, or any other method in which candidate sequences can be tested for their antigen binding ability). Thus, preferably, the term excludes sequences generated by genomic rearrangement in immune cells.

[0083] A "bispecific" or "bifunctional antibody" is an artificial hybrid antibody having two different heavy / light chain pairs and two different binding sites. Bispecific antibodies can be produced by a variety of methods, including fusion of hybridomas or linking of Fab' fragments. See, for example, Songsivilai & Lachmann, Clin. Exp. Immunol. 79:315-321 (1990); Kostelny et al., J. Immunol. 148, 1547-1553 (1992). In one embodiment, a bispecific antibody comprises a first binding domain polypeptide, such as a Fab' fragment, linked via an immunoglobulin constant region to a second binding domain polypeptide.

[0084] Numerous methods known to those skilled in the art can be used to obtain antibodies or antigen-binding fragments thereof. For example, antibodies can be produced using recombinant DNA techniques (U.S. Patent No. 4,816,567). Monoclonal antibodies may be produced by generation of hybridomas (see, e.g., Kohler and Milstein (1975) Nature, 256:495-499) according to known methods. Hybridomas formed in this manner are then screened by standard methods, e.g., enzyme-linked immunosorbent assay (ELISA) or surface plasmon resonance (BIACORE™) analysis, to identify one or more hybridomas that produce an antibody that specifically binds to the designated antigen. The designated antigen can be used as an immunogen in any form, e.g., recombinant antigen, native form, any variant or fragment thereof, and antigenic peptides thereof.

[0085] In addition to using display libraries, the designated antigens can also be used to immunize non-human animals, e.g., rodents such as mice, hamsters, or rats. In one embodiment, the non-human animals contain at least a portion of a human immunoglobulin gene. For example, it is possible to engineer mouse strains with large fragments of the human Ig loci that are deficient in mouse antibody production. Hybridoma technology can be used to produce and select antigen-specific monoclonal antibodies derived from genes with the desired specificity. See, e.g., XENOMOUSE™, Green et al. (1994) Nature Genetics 7:13-21, US2003-0070185, WO 96 / 34096, and WO96 / 33735.

[0086] In another embodiment, monoclonal antibodies can be obtained from non-human animals and then modified antibodies, such as humanized, deimmunized, and chimeric antibodies, can be produced using recombinant DNA techniques known in the art. Various approaches to making chimeric antibodies have been described. See, for example, Morrison et al., Proc. Natl. Acad. ScL USA 81:6851, 1985; Takeda et al., Nature 314:452, 1985; U.S. Patent No. 4,816,567 to Cabilly et al.; U.S. Patent No. 4,816,397 to Boss et al.; EP 171496, EP 173494, and GB 2177096 to Tanaguchi et al. Humanized antibodies can also be produced, for example, using transgenic mice that express human heavy and light chain genes but are incapable of expressing endogenous mouse immunoglobulin heavy and light chain genes. Winter describes an exemplary CDR grafting method that can be used to prepare the humanized antibodies described herein (U.S. Patent No. 5,225,539). All of the CDRs of a particular human antibody can be replaced with at least a portion of a non-human CDR, or only a portion of the CDRs can be replaced with non-human CDRs. Only the number of CDRs necessary for the binding of the humanized antibody to a predetermined antigen need be replaced.

[0087] Humanized antibodies or fragments thereof can be generated by replacing sequences of Fv variable domains that are not directly involved in antigen binding with equivalent sequences from human Fv variable domains. Exemplary methods for generating humanized antibodies or fragments thereof are provided by Morrison (1985) Science 229:1202-1207, Oi et al. (1986) BioTechniques 4:214, and US 5,585,089, US 5,693,761, US 5,693,762, US 5,859,205, and US 6,407,213. These methods include isolating, manipulating, and expressing nucleic acid sequences that encode all or part of immunoglobulin Fv variable domains from at least one of the heavy or light chains. Such nucleic acids can be obtained from hybridomas producing antibodies against a predetermined target as described above, or from other sources. The recombinant DNA encoding the humanized antibody molecule can then be cloned into an appropriate expression vector.

[0088] In certain embodiments, humanized antibodies are optimized by introducing conservative substitutions, consensus sequence substitutions, germline substitutions and / or back mutations. Such modified immunoglobulin molecules can be produced by any of several techniques known in the art (e.g., Teng et al., Proc. Natl. Acad. Sci. USA, 80:7308-7312, 1983; Kozbor et al., Immunology Today, 4:7279, 1983; Olsson et al., Meth. Enzymol., 92:3-16, 1982), or may be produced according to the teachings of WO 92 / 06193 or EP 239400.

[0089] Antibodies or fragments thereof can also be modified by specific deletion of human T cell epitopes, i.e., "deimmunization," by the methods disclosed in WO 98 / 52976 and WO 00 / 34317. Briefly, the heavy and light chain variable domains of an antibody can be analyzed for peptides that bind to MHC class II. These peptides are potential T cell epitopes (as defined in WO 98 / 52976 and WO 00 / 34317). A computer modeling approach called "peptide threading" can be applied to detect potential T cell epitopes, and databases of human MHC class II binding peptides can be searched for motifs present in the VH and VL sequences, as described in WO 98 / 52976 and WO 00 / 34317. These motifs bind to any of the 18 major MHC class II DR allotypes, thus constituting potential T cell epitopes. Potential T cell epitopes detected can be eliminated by substituting a small number of amino acid residues in the variable domain, or preferably by single amino acid substitutions. Typically, conservative substitutions are made. In many cases, amino acids common to positions in human germline antibody sequences can be used, but not always. Human germline sequences are disclosed, for example, in Tomlinson, et al. (1992) J.MoI.Biol.227:776-798, Cook,GP et al. (1995) Immunol.Today Vol.16(5):237-242, Chothia,et al. (1992) J.MoI.Biol.227:799-817, and Tomlinson et al. (1995) EMBO J.14:4628-4638. The V BASE directory provides a comprehensive directory of human immunoglobulin variable region sequences (compiled by Tomlinson, L. A. et al., MRC Protein Engineering Centre, Cambridge, UK). These sequences can be used as a source of human sequences, e.g., for framework regions and CDRs.Consensus human framework regions can also be used, for example, as described in US Pat. No. 6,300,064.

[0090] "Effector cells", preferably human effector cells, are leukocytes that express one or more FcRs to perform effector functions. Preferably, these cells express at least FcyRm and perform ADCC effector functions. Examples of human leukocytes that mediate ADCC include peripheral blood mononuclear cells (PBMCs), natural killer (NK) cells, monocytes, cytotoxic T cells and neutrophils. Effector cells can be isolated from native sources, such as blood.

[0091] Techniques for producing antibodies, including polyclonal, monoclonal, humanized, bispecific and heteroconjugate antibodies, are known in the art, some of which are exemplified below.

[0092] 1) Polyclonal antibodies Polyclonal antibodies are generally raised in animals by multiple subcutaneous (sc) or intraperitoneal (ip) injections of the relevant antigen (e.g., encapsulated in polymersomes) and adjuvants. It may be useful to conjugate the relevant antigen to a protein that is immunogenic in the species being immunized, such as keyhole limpet hemocyanin (KLH), serum albumin, bovine thyroglobulin, or soybean trypsin inhibitor, using bifunctional agents or derivatizing agents, such as maleimidobenzoyl sulfosuccinimide ester (conjugation through cysteine ​​residues), N-hydroxysuccinimide (through lysine residues), glutaraldehyde, succinic anhydride, and the like. Examples of adjuvants that may be used include Freund's complete adjuvant and MPL-TDM adjuvant (monophosphoryl lipid A, synthetic trehalose dicorynomycolate). Those skilled in the art will be able to select the immunization protocol without undue experimentation. For example, animals are immunized against an antigen, immunogenic conjugate, or derivative by mixing the protein or conjugate (for rabbits or mice, respectively) with 3 volumes of Freund's complete adjuvant and injecting the solution intradermally at multiple sites. One month later, the animals are boosted with 1 / 5 to 1 / 10 the original amount of peptide or conjugate in Freund's complete adjuvant by subcutaneous injection at multiple sites. Seven to 14 days later, the animals are bled and the serum is assayed for antibody titer. Animals are boosted until the titer plateaus. Conjugates can be made as protein fusions in recombinant cell culture. Agglutinating agents such as alum are also suitable for use in enhancing the immune response.

[0093] The term "immunizing" refers to one or more steps of administering to a non-human animal one or more antigens such that antibodies can be generated in the animal.

[0094] Specifically, non-human animals are immunized, preferably at least twice, more preferably at least three times, with a polypeptide (antigen) that may be mixed with an adjuvant. An "adjuvant" is a non-specific stimulator of the immune response. An adjuvant may take the form of a composition that includes either or both of the following components: (a) a substance intended to form a deposit that protects the antigen from rapid catabolism (e.g., mineral oil, alum, aluminum hydroxide, liposomes, or surfactants (e.g., pluronic polyols)) and (b) a substance that non-specifically stimulates the immune response of the immunized host animal (e.g., by increasing lymphokine levels therein).

[0095] Exemplary molecules for increasing lymphokine levels include lipopolysaccaride (LPS) or its lipid A portion, Bordetalla pertussis, pertussis toxin, Mycobacterium tuberculosis, and muramyl dipeptide (MDP). Examples of adjuvants include Freund's adjuvant (optionally containing killed M. tuberculosis; complete Freund's adjuvant), aluminum hydroxide adjuvant, and monophosphoryl lipid A-synthetic trehalose dicorynomycolate (MPL-TDM).

[0096] The "non-human animal" immunized herein is preferably a rodent. "Rodent" refers to an animal belonging to the order Rodentia, a placental mammal. Exemplary rodents include mice, rats, guinea pigs, squirrels, hamsters, ferrets, etc., with mice being the preferred rodent for immunization according to the methods herein. Other non-human animals that can be immunized herein include non-human primates such as Old World monkeys (e.g., baboons or macaques, including rhesus and cynomolgus monkeys; see U.S. Patent No. 5,658,570), birds (e.g., chickens), rabbits, goats, sheep, cows, horses, pigs, donkeys, dogs, etc.

[0097] "Screening" means subjecting one or more monoclonal antibodies (e.g., purified antibodies and / or hybridoma culture supernatants containing the antibodies) to one or more assays that qualitatively and / or quantitatively determine the ability of the antibodies to bind an antigen of interest.

[0098] By "immunoassay" is meant an assay which determines the binding of an antibody to an antigen, optionally where either the antibody or the antigen or both are adsorbed to a solid phase at some stage of the assay (i.e., an "immunoadsorbent" assay). Exemplary such assays include ELISA, radioimmunoassay (RIA), and FACS assay. In view of the above, the present invention thus provides monoclonal or polyclonal antibodies which can be obtained by the above-mentioned antibody production method, i.e., by immunizing a non-human animal as described above.

[0099] 2) Monoclonal antibodies Monoclonal antibodies are obtained from a population of substantially homogeneous antibodies, i.e., the individual antibodies comprising the population are identical except for possible naturally occurring mutations and / or post-translational modifications (e.g., isomerization, amidation) that may be present in minor amounts. Thus, the modifier "monoclonal" indicates the character of the antibody as not being a mixture of discrete antibodies. For example, monoclonal antibodies may be produced using the hybridoma method first described by Kohler et al., Nature, 256:495 (1975), or may be produced by recombinant DNA methods (U.S. Patent No. 4,816,567).

[0100] In the hybridoma method, a mouse or other suitable host animal, such as a hamster, is immunized as described herein above to elicit lymphocytes that produce, or have the capacity to produce, antibodies that will specifically bind to the protein used for immunization.

[0101] Alternatively, lymphocytes may be immunized in vitro and then fused with myeloma cells using a suitable fusing agent, such as polyethylene glycol, to form a hybridoma cell (Goding, Monoclonal Antibodies: Principles and Practice, pp. 59-103 (Academic Press, 1986)).

[0102] The immunizing agent will typically include the antigen protein or a fusion variant thereof. If cells of human origin are desired, peripheral blood lymphocytes ("PBLs") are generally used, whereas if non-human mammalian sources are desired, spleen cells or lymph node cells are used. The lymphocytes are then fused with an immortalized cell line using a suitable fusing agent, such as polyethylene glycol, to form a hybridoma cell. Goding, Monoclonal Antibodies: Principles and Practice, Academic Press (1986), pp. 59-103.

[0103] Immortalized cell lines are usually transformed mammalian cells, especially myeloma cells from rodents, cows and humans. Usually, rat or mouse myeloma cell lines are used. The hybridoma cells thus prepared are seeded and grown in a suitable culture medium, preferably containing one or more substances that inhibit the growth or survival of unfused parental myeloma cells. For example, if parental myeloma cells lack the enzyme hypoxanthine guanine phosphoribosyltransferase (HGPRT or HPRT), the culture medium for hybridomas will typically contain hypoxanthine, aminopterin and thymidine, which are substances that inhibit the growth of HGPRT-deficient cells (HAT medium).

[0104] Preferred immortalized myeloma cells are those that fuse efficiently, support stable high-level production of antibodies by selected antibody-producing cells, and are sensitive to media such as HAT medium. Among these, mouse myeloma lines are preferred, such as those derived from MOPC-21 and MPC-11 mouse tumors available from the Salk Institute Cell Distribution Center, San Diego, Calif., USA, and SP-2 cells (and their derivatives, e.g., X63-Ag8-653) available from the American Type Culture Collection, Manassas, Va., USA. Human myeloma cell lines and mouse-human heteromyeloma cell lines have also been described for the production of human monoclonal antibodies (Kozbor, J. Immunol., 133:3001 (1984); Brodeur et al., Monoclonal Antibody Production Techniques and Applications, pp.51-63 (Marcel Dekker, Inc., New York, 1987)).

[0105] The culture medium in which the hybridoma cells are growing is assayed for production of monoclonal antibodies against the antigen. Preferably, the binding specificity of the monoclonal antibodies produced by the hybridoma cells is determined by immunoprecipitation or by an in vitro binding assay, such as radioimmunoassay (RIA) or enzyme-linked immunoabsorbent assay (ELISA).

[0106] The culture medium in which hybridoma cells are cultured can be assayed for the presence of monoclonal antibodies against the desired antigen.Preferably, the binding affinity and binding specificity of monoclonal antibodies can be determined by immunoprecipitation or by in vitro binding assays such as radioimmunoassay (RIA) or enzyme-linked assay (ELISA).Such techniques and assays are known in the art.For example, binding affinity can be determined by the Scatchard analysis of Munson et al., Anal.Biochem.,107:220(1980).

[0107] After hybridoma cells that produce antibodies of the desired specificity, affinity, and / or activity are identified, the clones can be subcloned by limiting dilution and grown by standard methods (Goding, supra). Suitable culture media for this purpose include, for example, D-MEM medium or RPMI-1640 medium. In addition, hybridoma cells can be grown in vivo as ascites tumors in a mammal.

[0108] The monoclonal antibodies secreted by the subclones are suitably separated from the culture medium, ascites fluid, or serum by conventional immunoglobulin purification procedures, such as, for example, protein A-Sepharose, hydroxylapatite chromatography, gel electrophoresis, dialysis, or affinity chromatography.

[0109] Monoclonal antibodies may be produced as described above by recombinant DNA methods such as those described in U.S. Pat. No. 4,816,567. DNA encoding the monoclonal antibodies is easily isolated and sequenced using conventional procedures (e.g., by using oligonucleotide probes capable of specifically binding to genes encoding the heavy and light chains of mouse antibodies). Hybridoma cells serve as a preferred source of such DNA. Once isolated, the DNA can be placed into an expression vector that is then transfected into host cells that do not naturally produce immunoglobulin proteins, such as E. coli cells, monkey COS cells, Chinese hamster ovary (CHO) cells, or myeloma cells, to synthesize the monoclonal antibodies in such recombinant host cells. Reviews on recombinant expression in bacteria of DNA encoding the antibody include Skerra et al., Curr. Opinion in Immunol., 5:256-262 (1993) and Pluckthun, Immunol. Revs. 130:151-188 (1992).

[0110] 3) Humanized antibodies The antibody of the present invention may further include humanized or human antibodies. Humanized forms of non-human (e.g., murine) antibodies are chimeric immunoglobulins, chimeric immunoglobulin chains or fragments thereof (e.g., Fv, Fab, Fab', F(ab')2 or other antigen-binding subsequences of antibodies) that contain minimal sequence derived from non-human immunoglobulin. Humanized antibodies include human immunoglobulins (recipient antibodies) in which residues of the recipient complementarity determining regions (CDRs) are replaced by residues of the CDRs of a non-human species (donor antibody) such as mouse, rat or rabbit that has the desired specificity, affinity and capacity. In some cases, Fv framework residues of the human immunoglobulin are replaced by corresponding non-human residues.

[0111] A "humanized antibody" may also comprise residues that are found neither in the recipient antibody nor in the imported CDR or framework sequences. In general, a humanized antibody will comprise substantially all of at least one, and typically two, variable domains, with all or substantially all of the CDR regions corresponding to a non-human immunoglobulin and all or substantially all of the FR regions being those of a human immunoglobulin consensus sequence. A humanized antibody will optimally also comprise at least a portion of an immunoglobulin constant region (Fc), typically that of a human immunoglobulin. Jones et al., Nature 321:522-525 (1986), Riechmann et al., Nature 332:323-329 (1988) and Presta, Curr. Opin. Struct. Biol. 2:593-596 (1992).

[0112] Methods for humanizing non-human antibodies are well known in the art. In general, a humanized antibody has one or more amino acid residues introduced therein from a non-human source. These non-human amino acid residues are often called "import" residues, and they are usually adopted from an "import" variable domain. Humanization can be essentially performed according to the method of Winter and coworkers, Jones et al., Nature 321:522-525 (1986), Riechmann et al., Nature 332:323-327 (1988), Verhoeyen et al., Science 239:1534-1536 (1988), or by substituting rodent CDRs or CDR sequences for the corresponding sequences of human antibodies. Thus, such "humanized" antibodies are chimeric antibodies in which substantially less than an intact human variable domain is replaced with the corresponding sequence from a non-human species (U.S. Patent No. 4,816,567). In practice, humanized antibodies are typically human antibodies in which some CDR residues and possibly some FR residues are substituted by residues from analogous sites in rodent antibodies.

[0113] To reduce antigenicity, the selection of both light and heavy human variable domains used in the production of humanized antibodies is crucial. According to the so-called "best-fit" method, the sequence of the variable domain of rodent antibodies is screened against the entire library of known human variable domain sequences. The human sequence that is closest to the rodent sequence is then accepted as the human framework (FR) for the humanized antibody. Sims et al., J.Immunol., 151:2296 (1993); Chothia et al., J.Mol.Biol., 196:901 (1987).

[0114] Another method uses a particular framework derived from the consensus sequence of all human antibodies of a particular subgroup of light or heavy chains. The same framework can be used for several different humanized antibodies. Carter et al., Proc. Natl. Acad. Sci. USA, 89:4285 (1992); Presta et al., J. Immunol., 151:2623 (1993).

[0115] It is further important that antibodies are humanized while retaining high affinity for the antigen and other favorable biological properties. To this end, in one preferred method, humanized antibodies are prepared by a process of analyzing parental sequences and various conceptual humanized products using three-dimensional models of the parental and humanized sequences. Three-dimensional immunoglobulin models are commonly available and are familiar to those skilled in the art. Computer programs are available that illustrate and display probable three-dimensional conformational structures of selected candidate immunoglobulin sequences. Inspection of these displays allows analysis of the likely role of the residues in the functioning of the candidate immunoglobulin sequence, i.e., analysis of residues that affect the antigen-binding ability of the candidate immunoglobulin. In this way, FR residues can be selected and combined from the recipient and import sequences to achieve desired antibody characteristics, such as increased affinity for the target antigen. In general, CDR residues are directly and most substantially involved in influencing antigen binding.

[0116] Various forms of the humanized antibody are contemplated, for example, the humanized antibody may be an antibody fragment, such as a Fab, which may be conjugated to one or more cytotoxic agents to generate an immunoconjugate.

[0117] Alternatively, the humanized antibody may be an intact antibody, such as an intact IgG1 antibody.

[0118] 4) Human antibodies As an alternative to humanization, human antibodies can be generated. For example, it is now possible to generate transgenic animals (e.g., mice) that, upon immunization, have the ability to produce a full repertoire of human antibodies in the absence of endogenous immunoglobulin production. For example, homozygous deletion of the antibody heavy chain joining region (JH) gene in chimeric and germ-line mutant mice has been described to result in complete inhibition of endogenous antibody production. Transfer of the human germ-line immunoglobulin gene array into such germ-line mutant mice will result in the production of human antibodies upon antigen exposure. See, e.g., Jakobovits et al., Proc. Natl. Acad. Sci. USA, 90:2551 (1993); Jakobovits et al., Nature, 362:255-258 (1993); Bruggermann et al., Year in Immun., 7:33 (1993); U.S. Patent No. 5,591,669; and WO 97 / 17852.

[0119] Alternatively, phage display technology can be used to produce human antibodies and human antibody fragments in vitro from immunoglobulin variable (V) domain gene repertoires of unimmunized donors. McCafferty et al., Nature 348:552-553 (1990); Hoogenboom and Winter, J. Mol. Biol. 227:381 (1991). In this technique, antibody V domain genes are cloned in frame into either the major or minor coat protein genes of a filamentous bacteriophage, such as M13, and displayed as functional antibody fragments on the surface of the phage particle. Because the filamentous particle contains a single-stranded DNA copy of the phage genome, selections based on the functional properties of the antibody also result in selection of the gene encoding the antibody exhibiting those properties. Thus, the phage mimics some of the properties of the B cell. Phage display can be performed in a variety of formats, as reviewed, for example, in Johnson, Kevin S. and Chiswell, David J., Curr. Opin Struct. Biol. 3:564-571 (1993). Several sources of V gene segments can be used for phage display. Clackson et al., Nature 352:624-628 (1991) isolated a wide variety of anti-oxazolone antibodies from a random recombinant library V genes derived from the spleens of immunized mice. A repertoire of V genes can be constructed from unimmunized human donors, and antibodies against a wide variety of antigens, including self-antigens, can be isolated essentially following the techniques described in Marks et al., J. Mol. Biol. 222:581-597 (1991) or Griffith et al., EMBO J. 12:725-734 (1993). See also U.S. Patent Nos. 5,565,332 and 5,573,905.

[0120] For the preparation of human monoclonal antibodies, the techniques of Cole et al. and Boerner et al. can also be used (Cole et al., Monoclonal Antibodies and Cancer Therapy, Alan R. Liss, p. 77 (1985) and Boerner et al. al., J. Immunol. 147(1):86-95 (1991). Similarly, human antibodies can be generated by introducing human immunoglobulin loci into transgenic animals, e.g., mice, in which the endogenous immunoglobulin genes have been partially or completely inactivated. Upon antigen exposure, human antibody production is observed that closely resembles that seen in humans in all respects, including gene rearrangement, assembly, and antibody repertoire. This approach is described, for example, in U.S. Pat. Nos. 5,545,807, 5,545,806, 5,569,825, 5,625,126, 5,633,425, 5,661,016, and in the following scientific publications: Marks et al., Bio / Technology 10:779-783 (1992); Lonberg et al., Nature 10:779-783 (1993); 368:856-859 (1994), Morrison, Nature 368:812-13 (1994), Fishwild et al., Nature Biotechnology 14:845-51 (1996), Neuberger, Nature Biotechnology 14:826 (1996), and Lonberg and Huszar, Intern. Rev. Immunol. 13:65-93 (1995). Finally, human antibodies can also be generated in vitro by activated B cells (see U.S. Patent Nos. 5,567,610 and 5,229,275).

[0121] 5) Bispecific and multispecific antibodies Bispecific antibodies (BsAbs) are antibodies that have binding specificities for at least two different epitopes, including those on the same protein or on different proteins. Alternatively, one arm is equipped to bind to a target antigen, and the other arm can be combined with an arm that binds to a triggering molecule on a white blood cell, such as a T cell receptor molecule (e.g., CD3) or an Fc receptor for IgG (FcyR), such as FcyRI (CD64), FcyRII (CD32) and FcyRin (CD16), so that the cellular defense mechanism is focused and localized to the target antigen-expressing cell. Such antibodies can be derived from full-length antibodies or antibody fragments (e.g., F(ab')2 bispecific antibodies).

[0122] Bispecific antibodies may also be used to localize cytotoxic agents to cells expressing a target antigen. Such antibodies have one arm that binds the desired antigen and another arm that binds the cytotoxic agent (e.g., methotrexate).

[0123] Methods for making bispecific antibodies are known in the art. Traditional production of full-length bispecific antibodies is based on the co-expression of two immunoglobulin heavy-light chain pairs, where the two chains have different specificities. Millstein et al., Nature, 305:537-539 (1983). Because the immunoglobulin heavy and light chains are randomly assorted, these hybridomas (quadromas) produce a potential mixture of 10 different antibody molecules, only one of which has the correct bispecific structure. Purification of the correct molecule, usually performed by affinity chromatography steps, is quite laborious and the product yield is low. Similar procedures are disclosed in WO 93 / 08829 and Traunecker et al., EMBO J., 10:3655-3659 (1991).

[0124] In a different approach, antibody variable domains with the desired binding specificity (antibody-antigen binding site) are fused to immunoglobulin constant domain sequences. The fusion is preferably with an immunoglobulin heavy chain constant domain, including at least a portion of the hinge, CH2 and CH3 regions. The first heavy chain constant region (CH1), containing the site necessary for light chain binding, is preferably present in at least one of the fusions. DNAs encoding the immunoglobulin heavy chain fusions and, if desired, the immunoglobulin light chain are inserted into separate expression vectors, which are co-transfected into a suitable host organism. This allows great freedom to adjust the mutual ratios of the three polypeptide fragments used in the construction in those embodiments where an unequal ratio of the three polypeptide chains provides optimal yields. However, it is possible to insert the coding sequences for two or all three polypeptide chains into one expression vector, in cases where an equal ratio of at least two polypeptide chains results in high yields, or where the ratio is not particularly important.

[0125] In a preferred embodiment of this approach, the bispecific antibody is composed of a hybrid immunoglobulin heavy chain with a first binding specificity in one arm and a hybrid immunoglobulin heavy-light chain pair (providing a second binding specificity) in the other arm. This asymmetric structure has been found to facilitate separation of the desired bispecific compound from unwanted immunoglobulin chain combinations, since the immunoglobulin light chain is present in only one half of the bispecific molecule, resulting in a simple separation method. This approach is disclosed in WO 94 / 04690. For further details regarding the generation of bispecific antibodies, see, for example, Suresh et al., Methods in Enzymology 121:210 (1986).

[0126] According to another approach described in WO 96 / 27011 or US 5,731,168, the interface between a pair of antibody molecules can be engineered to maximize the percentage of heterodimers recovered from recombinant cell culture. A preferred interface comprises at least a portion of the CH3 region of the antibody constant domain. In this method, one or more small amino acid side chains at the interface of the first antibody molecule are replaced with larger side chains (e.g., tyrosine or tryptophan). Compensatory "cavities" of the same or similar size as the large side chains are created at the interface of the second antibody molecule by replacing the large amino acid side chains with smaller ones (e.g., alanine or threonine). This provides a mechanism for increasing the yield of heterodimers relative to other unwanted end-products, such as homodimers.

[0127] Techniques for generating bispecific antibodies from antibody fragments have been described in the literature. For example, bispecific antibodies can be prepared by chemical linkage. Brennan et al., Science 229:81 (1985) describe a procedure in which intact antibodies are proteolytically cleaved to generate F(ab')2 fragments. These fragments are reduced in the presence of the dithiol complexing agent sodium arsenite to stabilize vicinal dithiols and prevent intermolecular disulfide formation. The Fab' fragments generated are then converted to thionitrobenzoate (TNB) derivatives. One of the Fab'-TNB derivatives is then reconverted to the Fab'-TNB derivative to form the bispecific antibody. The bispecific antibodies produced can be used as agents for the selective immobilization of enzymes.

[0128] Fab' fragments may be directly recovered from E. coli and chemically coupled to form bispecific antibodies. Shalaby et al., J. Exp. Med. 175:217-225 (1992) describe the production of fully humanized bispecific antibody F(ab')2 molecules. Each Fab' fragment was secreted separately from E. coli and subjected to directed chemical coupling in vitro to form bispecific antibodies. The bispecific antibodies thus formed were capable of binding to cells overexpressing the ErbB2 receptor and normal human T cells, and were also capable of triggering the lytic activity of human cytotoxic lymphocytes against human breast tumor targets.

[0129] Various techniques for making and isolating bivalent antibody fragments directly from recombinant cell culture have also been described. For example, divalent heterodimers have been produced using leucine zippers. Kostelny et al., J. Immunol., 148(5):1547-1553 (1992).

[0130] Leucine zipper peptides from Fos and Jun proteins were linked to the Fab' portions of two different antibodies by genetic fusion. Antibody homodimers were reduced at the hinge region to form monomers and then reoxidized to form antibody heterodimers. The "diabody" technology described by Hollinger et al., Proc. Natl. Acad. Sci. USA, 90:6444-6448 (1993) represents an alternative mechanism for generating bispecific / bivalent antibody fragments. These fragments contain a heavy-chain variable domain (VH) connected to a light-chain variable domain (VL) by a linker that is too short to allow pairing between the two domains on the same chain. Thus, the VH and VL domains of one fragment are forced to pair with the complementary VL and VH domains of the other fragment, thereby forming two antigen-binding sites. Another strategy for generating bispecific / bivalent antibody fragments using single-chain Fv (sFv) dimers has also been reported. See Gruber et al., J. Immunol., 152:5368 (1994).

[0131] Antibodies with more than two valencies are contemplated. For example, trispecific antibodies can be prepared. Tutt et al., J. Immunol. 147:60 (1991).

[0132] Exemplary bispecific antibodies may bind to two different epitopes on a given molecule. Alternatively, an anti-protein arm may be combined with an arm that binds to a triggering molecule on a leukocyte, such as a T cell receptor molecule (e.g., CD2, CD3, CD28 or B7) or an Fc receptor for IgG (FcyR), such as FcyRI (CD64), FcyRII (CD32) and FcyRIII (CD16), so that cellular defense mechanisms are focused on cells expressing a particular protein.

[0133] Another bispecific antibody of interest binds a protein of interest and also binds human serum albumin.

[0134] The "diabody" technology described by Hollinger et al., Proc. Natl. Acad. Sci. USA, 90:6444-6448 (1993) provides an alternative mechanism for making bispecific fragments. These fragments contain a VH connected to a VL by a linker that is too short to allow pairing between the two domains on the same chain. Thus, the VH and VL domains of one fragment are forced to pair with the complementary VL and VH domains of another fragment, thereby forming two antigen-binding sites. Another strategy for making bispecific antibody fragments using single-chain Fv (sFv) dimers has also been reported. See Gruber et al., J. Immunol., 152:5368 (1994).

[0135] Antibodies with more than two valencies are contemplated. For example, trispecific antibodies can be prepared. Tutt et al. J. Immunol. 147:60 (1991).

[0136] Multivalent antibodies may be internalized (and / or catabolized) more quickly than bivalent antibodies by cells expressing the antigen to which the antibody binds. The antibodies of the present invention may be multivalent antibodies (other than IgM class) with three or more antigen binding sites (e.g., tetravalent antibodies), which may be readily produced by recombinant expression of nucleic acids encoding the polypeptide chains of the antibody. The multivalent antibody may comprise a dimerization domain and three or more antigen binding sites. A preferred dimerization domain comprises (or consists of) an Fc region or a hinge region. In this scenario, the antibody would comprise an Fc region and three or more antigen binding sites amino-terminal to the Fc region. A preferred multivalent antibody herein comprises (or consists of) three to about eight, but preferably four, antigen binding sites. A multivalent antibody comprises at least one polypeptide chain (preferably two polypeptide chains), which (they) comprise two or more variable domains. For example, the polypeptide chains may comprise a VDI (X1 n-VD2-(X2)n-Fc, where VDI is the first variable domain, VD2 is the second variable domain, Fc is one Fc region polypeptide chain, X1 and X2 represent amino acids or polypeptides, and n is 0 or 1. For example, the polypeptide chain may comprise a VH-CHI-flexible linker-VH-CHI-Fc region chain or a VH-CHI-VH-CHI-Fc region chain. The multivalent antibody herein preferably further comprises at least two (preferably four) light chain variable domain polypeptides. The multivalent antibody herein may comprise, for example, about two to about eight light chain variable domain polypeptides. The light chain variable domain polypeptides contemplated herein comprise a light chain variable domain and, optionally, further comprise a CL domain.

[0137] Heteroconjugate antibodies are also within the scope of the present invention.

[0138] Heteroconjugate antibodies are composed of two covalently joined antibodies. For example, one of the antibodies in the heteroconjugate can be coupled to avidin, and the other to biotin. These antibodies could be prepared in vitro using known methods in synthetic protein chemistry, including those that require cross-linking agents. For example, immunotoxins can be constructed using a disulfide exchange reaction or by forming a thioether bond. Examples of suitable reagents for this purpose include iminothiolate and methyl-4-mercaptobutyrimidate, and those disclosed, for example, in U.S. Pat. No. 4,676,980. Heteroconjugate antibodies can be made using any conventional cross-linking method. Suitable cross-linking agents are well known in the art and are disclosed in U.S. Pat. No. 4,676,980, along with several cross-linking techniques.

[0139] For other antibody production techniques, see Antibodies: A Laboratory Manual, eds. Harlow et al., Cold Spring Harbor Laboratory, 1988. The present invention is not necessarily limited to any particular source, method of production or other special characteristics of the antibodies.

[0140] The antibodies related to the present invention are preferably "isolated" antibodies. "Isolated", when used to describe the antibodies disclosed herein, means an antibody that has been identified, separated and / or recovered from components of its production environment. Preferably, an isolated antibody is free of association with any other components from its production environment. Contaminating components of its production environment, such as those resulting from recombinant transfected cells, are materials that would typically interfere with diagnostic or therapeutic uses of the polypeptide, and may include enzymes, hormones and other proteinaceous or non-proteinaceous solutes. In a preferred embodiment, the antibody will be (1) purified to a sufficient extent to obtain at least 15 residues of N-terminal or internal amino acid sequence using a spinning cup sequenator, or (2) purified to homogeneity by SDS-PAGE under non-reducing or reducing conditions, using Coomassie blue staining or preferably silver staining. Ordinarily, however, an isolated antibody will be prepared by at least one purification step.

[0141] As used herein, "cancer" refers to a broad group of diseases characterized by the uncontrolled growth of abnormal cells in the body. Unregulated cell division can lead to the formation of malignant tumors or cells that invade adjacent tissues and can metastasize to distant parts of the body via the lymphatic system or bloodstream.

[0142] Non-limiting examples of cancers include squamous cell carcinoma, small cell lung cancer, non-small cell lung cancer, squamous non-small cell lung cancer (NSCLC), non-NSCLC, glioma, gastrointestinal cancer, renal cancer (e.g., clear cell carcinoma), ovarian cancer, liver cancer, colorectal cancer, endometrial cancer, renal cancer (e.g., renal cell carcinoma (RCC)), prostate cancer (e.g., hormone refractory prostate adenocarcinoma), thyroid cancer, neuroblastoma, pancreatic cancer, glioblastoma (glioblastoma multiforme), cervical cancer, gastric cancer, bladder cancer, hepatoma, breast cancer, colon cancer, and head and neck cancer (or cancer), stomach cancer, germ cell tumors. , pediatric sarcoma, sinonasal natural killer, melanoma (e.g. metastatic melanoma, e.g. subcutaneous or intraocular melanoma), bone cancer, skin cancer, uterine cancer, anal region cancer, testicular cancer, fallopian tube cancer, endometrial cancer, cervical cancer, vaginal cancer, vulvar cancer, esophageal cancer, small intestine cancer, endocrine system cancer, parathyroid cancer, adrenal gland cancer, soft tissue sarcoma, urethral cancer, penile cancer, childhood solid tumors, ureteral cancer, renal pelvis cancer, central nervous system (CNS) neoplasms, primary CNS lymphoma, tumor angiogenesis, spinal axis tumor, brain stem glioma, pituitary adenoma, Kaposi's sarcoma, epidermoid carcinoma, Squamous cell carcinomas, T-cell lymphomas, environmentally induced cancers, e.g. those induced by asbestos, virus-associated cancers (e.g. human papillomavirus (HPV)-associated tumors), hematological malignancies derived from either of the two major blood cell lineages, i.e. myeloid lineage (producing granulocytes, erythrocytes, platelets, macrophages and mast cells) or lymphoid lineage (producing B cells, T cells, NK cells and plasma cells), e.g. all types of leukemias, lymphomas and myelomas, e.g. acute, chronic, lymphocytic and / or myeloid leukemias, such as acute myeloid leukemia (ALL), acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), and chronic myeloid leukemia (CML), anaplastic AML (M0), myeloblastic leukemia (M1), myeloblastic leukemia (M2; with cellular maturation), promyelocytic leukemia (M3 or M3 variant [M3V]), myelomonocytic leukemia (M4 or M4 variant with eosinophilicity [M4E]), monocytic leukemia (M5), erythroleukemia (M6), megakaryoblastic leukemia (M7), isolated granulocytic sarcoma, and chloroma;Lymphomas, e.g. Hodgkin's lymphoma (HL), non-Hodgkin's lymphoma (NHL), B-cell lymphoma, T-cell lymphoma, lymphoplasmacytic lymphoma, monocytoid B-cell lymphoma, mucosa-associated lymphoid tissue (MALT) lymphoma, anaplastic (e.g. Ki1+) large cell lymphoma, adult T-cell lymphoma / leukemia, mantle cell lymphoma, angioimmunoblastic T-cell lymphoma, hemocentric lymphoma, intestinal T-cell lymphoma, primary mediastinal B-cell lymphoma, precursor T-lymphoblastic lymphoma Lymphoma, T-lymphoblastic lymphoma / leukemia (T-Lbly / T-ALL), peripheral T-cell lymphoma, lymphoblastic lymphoma, post-transplant lymphoproliferative disorder, histiocytic lymphoma, primary central nervous system lymphoma, primary effusion lymphoma, lymphoblastic lymphoma (LBL), hematopoietic neoplasms of the lymphatic system, acute lymphoblastic leukemia, diffuse large B-cell lymphoma, Burkitt lymphoma, follicular lymphoma, diffuse histiocytic lymphoma (DHL), immunoblastic large cell lymphoma, precursor B-lymphoblastic lymphoma, cutaneous T-cell lymphoma (CTLC) (also called mycosis fungoides or Sézary syndrome), and lymphoplasmacytic lymphoma (LPL) with Waldenström macroglobulinemia; myelomas, such as IgG myeloma, light chain myeloma, nonsecretory myeloma, smoldering myeloma (also called indolent myeloma), solitary plasmacytoma, and multiple myeloma; chronic lymphocytic leukemia (CLL), hairy cell lymphoma; hematopoietic tumors of the myeloid lineage; fibromyalgia. tumors of mesenchymal origin including sarcoma and rhabdomyosarcoma; seminoma, teratocarcinoma, tumors of the central and peripheral nervous system, e.g. astrocytoma, schwannoma; tumors of mesenchymal origin including fibrosarcoma, rhabdomyosarcoma and osteosarcoma; and other tumors, e.g. melanoma, xeroderma pigmentosum, keratoacanthoma, seminoma, follicular and teratocarcinoma of the thyroid gland, hematopoietic tumors of the lymphatic system, e.g. T-cell tumors and B-cell tumors, T-cell disorders such as, but not limited to, T-prolymphocytic leukemia (T-PLL), including small cell and cerebriform cell types; large granular lymphocyte leukemia (LGL), preferably of the T-cell type; a / d T-NHL hepatosplenic lymphoma; peripheral / post-thymic T-cell lymphoma (pleomorphic and immunoblastic subtypes); angiocentric (nasal) T-cell lymphoma; head and neck cancer, renal cancer, rectal cancer, thyroid cancer;acute myeloid lymphoma, and any combination of the above cancers. The methods described herein can also be used to treat metastatic cancers, refractory cancers (e.g., cancers that are refractory to previous immunotherapy, e.g., with CTLA-4 or PD-1 or PD-L1 blocking antibodies), and recurrent cancers;

[0143] The term "subject" is intended to include living organisms. Examples of subjects include mammals, such as humans, dogs, cows, horses, pigs, sheep, goats, cats, mice, rabbits, rats, and transgenic non-human animals. However, the subject (animal) may also be a non-mammalian animal, such as a bird or a fish. In some preferred embodiments of the present invention, the subject is a human, and in some other preferred embodiments, the subject may be an agricultural animal, which may be either a mammal or a non-mammalian animal. Examples of such non-mammalian animals are birds (e.g., poultry such as chickens, ducks, geese, or turkeys), fish (e.g., farmed fish such as salmon, trout, or tilapia), or crustaceans (such as shrimp or prawns). Examples of mammalian (livestock) animals include goats, sheep, cows, horses, pigs, or donkeys. Other mammals include, for example, cats, dogs, mice, and rabbits. In an exemplary embodiment, the polymersomes of the invention are used for vaccination or immunization of the above-mentioned agricultural animals, both mammalian and non-mammalian agricultural animals (birds, fish, crustaceans), against viral infection (see the Examples). Thus, in such cases, the polymersomes of the invention may encapsulate therein soluble full-length viral proteins or soluble fragments of full-length viral proteins.

[0144] For use in vaccination of both humans and non-human animals, the polymersomes of the invention or compositions comprising the polymersomes of the invention may be dissolved in an appropriate (pharmaceutical acceptable) buffer, such as phosphate buffered saline (PBS) or 0.9% saline (isotonic solution of 0.90% w / v NaCl with an osmolality of 308 mOsm / L) and administered orally to the respective subject (see again the Examples). Alternatively, the polymersomes may be modified, such as by coating with a natural polymer, or formulated in particles of natural polymers such as alginate or chitosan, or in particles of synthetic polymers such as poly(d,l-lactide-co-glycolide) (PLG), poly(d,l-lactic-co-glycolic acid) (PLGA), poly(g-glutamic acid) (g-PGA) [31,32] or poly(ethylene glycol) (PEG). These particles can be either particles in the micrometer range ("macrobeads") or nanoparticles, or nanoparticles incorporated into macrobeads, both of which are well known in the art.See, for example, Hari et al. "Chitosan / calcium-alginate beads for oral delivery of insulin" Applied Polymer Science, Volume 59, Issue 11, 14 March 1996, pp. 1795-1801, Sosnik's review "Alginate Particles as Platform for Drug Delivery by the Oral Route: State-of-the-Art" ISRN Pharmaceutics Volume 2014, Article ID 926157, Machado et al. "Encapsulation of DNA in Macroscopic and Nanosized Calcium Alginate Gel Particles" Langmuir 2013, 29, 15926-15935, International Patent Application WO2015 / 110656, Liang Zhao et al.'s review "Nanoparticle vaccines" Vaccine 32 (2014) 327-337 or Li et al. "Chitosan-Alginate Nanoparticles as a Novel Drug Delivery System" Vaccine 32 (2014) 327-337. See, "Delivery System for Nifedipine" Int J Biomed Sci vol. 4 no. 3 September 2008,221-228. In exemplary embodiments of these polymersomes and oral formulations, the polymersomes used for vaccination have encapsulated therein a viral antigen, including influenza hemagglutinin, swine influenza hemagglutinin, foot and mouth disease (FMD) viral proteins such as VP1, VP2 or VP3 coat proteins (VP1 coat protein contains the major antigenic determinants of the FMD virion, so variations in its sequence should account for the high antigenic diversity of this virus), ovalbumin (OVA), or a soluble portion of the porcine epidemic diarrhea (PED) virus spike protein.As evidenced by the use of polymersomes containing soluble portions of foot and mouth disease (FMD) viral proteins such as influenza hemagglutinin or VP1, VP2 or VP3 coat proteins, viral diseases can affect any animal, including birds and mammals, which can also be humans.

[0145] The term "effective amount" or "effective dosage" is defined as an amount sufficient to achieve a desired effect or an amount sufficient to at least partially achieve a desired effect. The term "therapeutically effective amount" is defined as an amount sufficient to cure or at least partially arrest the disease and its complications in a patient already affected by the disease. Amounts effective for this use will depend on the severity of the infection and the general state of the subject's own immune system. The term "patient" includes human and other mammalian subjects receiving either prophylactic or therapeutic treatment.

[0146] The appropriate dosage or therapeutically effective amount of the antibody or antigen-binding portion thereof will depend on the condition being treated, the severity of the condition, previous treatments, and the patient's clinical history and response to the therapeutic agent. The appropriate dose can be adjusted according to the judgment of the attending physician so that it can be administered to the patient once or as a series of doses. The pharmaceutical composition can be administered as the sole therapeutic agent or in combination with additional therapeutic agents as needed.

[0147] If the pharmaceutical composition is lyophilized, the lyophilized material is first reconstituted in a suitable liquid prior to administration, for example, bacteriostatic water for injection (BWFI), saline, phosphate buffered saline (PBS), or the same formulation in which the protein was present prior to lyophilization.

[0148] Pharmaceutical compositions for injection can be presented in unit dosage form, for example in ampoules or in multi-dose containers with added preservatives.In addition, several new drug delivery approaches have been developed, and the pharmaceutical compositions of the present invention are suitable for administration using these new methods, for example, pen-type injectors such as Inject-ease, Genject, Genen, and needleless devices such as MediJector and BioJector.The pharmaceutical compositions can also be adapted to administration methods that have not yet been discovered.See also Langer, 1990, Science, 249:1527-1533.

[0149] Pharmaceutical compositions can also be formulated as depot preparations.Such long-acting formulations can be administered by implantation (e.g. subcutaneous, intraligamentous or intratendinous, subsynovial or intramuscular), subsynovial injection or intramuscular injection.Thus, for example, the formulation can be modified with suitable polymeric or hydrophobic materials (e.g. as emulsion in acceptable oil) or ion exchange resin, or modified as sparingly soluble derivatives, for example as sparingly soluble salts.

[0150] The pharmaceutical compositions may be in a variety of conventional depot forms used for administration to provide the reactive composition, including, for example, solid, semi-solid and liquid dosage forms such as solutions or suspensions, slurries, gels, creams, balms, emulsions, lotions, powders, sprays, foams, pastes, ointments, salves, balms and drops.

[0151] If desired, pharmaceutical composition can be presented in a vial, pack or dispenser device, which can contain one or more unit dosage forms containing active ingredient.In one embodiment, dispenser device can contain a syringe with a single dose of liquid formulation ready for injection.Syringe can be accompanied by instructions on administration.

[0152] Pharmaceutical compositions may further comprise additional pharmaceutically acceptable components. The proteins described herein may also comprise other pharmaceutically acceptable carriers, excipients, or stabilizers, such as those described in Remington's Pharmaceutical Sciences 16th edition, Osol, A. Ed. (1980), as long as they do not adversely affect the desired characteristics of the formulation. As used herein, "pharmaceutically acceptable carriers" refers to any and all solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents that are compatible with pharmaceutical administration. The use of such media and agents for pharmaceutically active substances is well known in the art. Acceptable carriers, excipients or stabilizers are nontoxic to recipients at the dosages and concentrations employed and may include additional buffering agents; preservatives; co-solvents; antioxidants, such as ascorbic acid and methionine; chelating agents, such as EDTA; metal complexes (e.g., Zn-protein complexes); biodegradable polymers, such as polyesters; salt-forming counterions, such as sodium, polyhydric sugar alcohols; amino acids, such as alanine, glycine, asparagine, 2-phenylalanine, and threonine; sugars or sugar alcohols, such as lactitol, stachyose, mannose, sorbose, xylose, These include ribose, ribitol, myoinisitose, myoinisitol, galactose, galactitol, glycerol, cyclitols (e.g., inositol), polyethylene glycol; sulfur-containing reducing agents, such as glutathione, thioctic acid, sodium thioglycolate, thioglycerol, [alpha]-monothioglycerol, and sodium thiosulfate; low molecular weight proteins, such as human serum albumin, bovine serum albumin, gelatin, or other immunoglobulins; and hydrophilic polymers, such as polyvinylpyrrolidone.

[0153] The formulations described herein are useful as pharmaceutical compositions in the treatment and / or prevention of the pathological medical conditions described herein in patients in need thereof. The term "treatment" refers to both therapeutic treatment and prophylactic or preventative measures. Treatment includes application or administration of the formulation to the body, isolated tissue or cells of a patient having a disease / disorder, a symptom of a disease / disorder, or a predisposition to a disease / disorder, with the purpose of curing, healing, alleviating, relieving, altering, correcting, improving, ameliorating, or affecting the disease, the symptom of a disease, or the predisposition to a disease.

[0154] As used herein, the terms "treat" and "treatment" refer to administering a therapeutically effective amount of a pharmaceutical composition of the present invention to a subject. A "therapeutically effective amount" refers to an amount of a pharmaceutical composition or antibody sufficient to treat or ameliorate a disease or disorder, delay the onset of a disease, or provide some therapeutic benefit in the treatment or management of a disease.

[0155] As used herein, the term "prevention" refers to the use of an agent to prevent the onset of a disease or disorder. A "prophylactically effective amount" defines the amount of an active component or pharmaceutical agent sufficient to prevent the onset or recurrence of a disease.

[0156] As used herein, the terms "disorder" and "disease" are used interchangeably to refer to a condition in a subject. In particular, the term "cancer" is used interchangeably with the term "tumor."

[0157] Kits of the present invention will typically include the containers described above, as well as one or more other containers containing materials desirable from a commercial and user standpoint, such as buffers, diluents, filters, needles, syringes, and package inserts with instructions for use.

[0158] For purposes of this application, the term "liposome" refers to a spherical vesicle having at least one lipid bilayer.

[0159] For purposes of this application, the term "endosome" refers to a membrane-bound compartment (ie, a vacuole) within a eukaryotic cell into which material taken up by endocytosis is delivered.

[0160] For the purposes of this application, the term "late endosome" refers to a pre-lysosomal endocytic organelle that is distinct from early endosomes by its lower luminal pH and different protein composition. Late endosomes are more spherical than early endosomes, are mostly located near the nucleus, and are concentrated near the microtubule-organizing center.

[0161] For the purposes of this application, the term "T helper cells" (also called TH cells or "effector CD4(+) T cells") refers to T lymphocytes that assist other white blood cells in immunological processes, including B cell maturation into plasma cells and memory B cells, and activation of cytotoxic T cells and macrophages. These cells are also known as "CD4(+) T cells" because they express the CD4 glycoprotein on their surface. Helper T cells are activated when presented with, for example, peptide antigens, by MHC class II molecules expressed on the surface of antigen-presenting cells (APCs).

[0162] As used herein, the term "autoantigen" refers to any molecule or chemical group in one organism that acts as an antigen in inducing antibody formation in another organism, but to which the healthy immune system of the parent organism is tolerant.

[0163] The term "% identity" used herein refers to the percentage of identical amino acid residues at corresponding positions in sequences when comparing two amino acid sequences in optimal sequence alignment, as exemplified by the ClustalW method or ClustalX method available at www.clustal.org or equivalent techniques.Thus, align both sequences (reference sequence and sequence of interest), identify the identical amino acid residues between both sequences, and divide the total number of identical amino acids by the total number of amino acids (amino acid length).The result of this division is a percentage value, i.e., percentage identity value / percent identity.

[0164] Since the immunization method of the present invention can be carried out by using a full-length soluble encapsulated antigen (e.g., a protein) or a fragment of said protein in a synthetic environment that allows its proper folding, the probability of isolating an antibody capable of detecting the corresponding antigen (e.g., a membrane protein) in vivo will be high. Moreover, the immunization and antibody generation can be carried out without any prior knowledge of the membrane protein structure, which would otherwise be required when using a peptide-based immunization approach.

[0165] Furthermore, in comparison to other techniques, the methods of the present invention allow for the rapid and cost-effective production of membrane proteins encapsulated in an oxidatively stable membrane environment.

[0166] In some aspects, the present invention relates to a method for eliciting an immune response against an antigen (e.g., an immunogen) in a subject. The method may comprise administering to a subject a composition comprising a polymersome of the present invention having a membrane (e.g., a surrounding membrane) of an amphiphilic polymer. The composition further comprises a soluble antigen encapsulated by the membrane of the amphiphilic polymer of the polymersome of the present invention. The immunogen may be a membrane-bound protein. In some further aspects, the polymersome of the present invention comprises a lipid polymer. Administration may be performed in any suitable manner, for example, orally, topically, or by injection.

[0167] One of skill in the art can determine and adjust the frequency of administration (e.g., oral administration or injection) depending on the level of response desired. For example, a control (which may include a mammal) can be given a weekly or biweekly administration (e.g., oral administration or injection) of a polymersome of the invention. The immune response can be measured by quantifying the blood concentration level (titer) of antibodies in the mammal to an initial amount of antigen encapsulated in a polymersome of the invention (see "Examples").

[0168] Polymersome structures can include amphiphilic block copolymers that self-assemble into vesicles to encapsulate various antigens (e.g., soluble proteins) using solvent re-hydration methods, direct dispersion, or spontaneous self-assembly (e.g., Example 1 described herein).

[0169] In the context of this application, the term "soluble antigen" as used herein means an antigen that can be dissolved or made liquified. The term "soluble antigen" encompasses "solubilized" antigens, i.e., antigens that have been rendered soluble or have increased solubility, particularly in water, by the action of detergents or other agents. Exemplary, non-limiting, soluble antigens of the present invention include polypeptides derived from insoluble portions of proteins, hydrophobic polypeptides that have been rendered soluble for inclusion, as well as aggregated polypeptides that are soluble as aggregates.

[0170] In some aspects, the antigens of the present invention (e.g., membrane proteins) are solubilized using detergents, surfactants, temperature changes, or pH changes. The vesicle structure provided by the amphiphilic block copolymers allows the antigens (e.g., membrane proteins) to fold in a physiologically correct and functional manner, thereby allowing the immune system of the target mammal to detect the antigen and thereby generate a strong immune response.

[0171] In some aspects, injection of the compositions of the invention can include intraperitoneal injection, subcutaneous or intravenous injection, intramuscular injection, or non-invasive administration. In other aspects, injection of the compositions of the invention can include intradermal injection.

[0172] In some other aspects, the level of the immune response can be further enhanced or boosted by including an adjuvant in the composition comprising the polymersomes of the invention, hi such aspects, the polymersomes and the adjuvant can be administered to the subject simultaneously.

[0173] In some aspects, the block copolymers or amphiphilic polymers of the polymersomes of the invention are not immunostimulants or adjuvants.

[0174] In some other aspects, the block copolymers or amphiphilic polymers of the present invention are immunostimulants and / or adjuvants.

[0175] In some further aspects, the polymersomes of the invention are immunogenic.

[0176] In some further aspects, the polymersomes of the invention are non-immunogenic.

[0177] In some aspects, the adjuvant may be administered separately from the administration of the composition of the invention comprising the polymersomes of the invention. The adjuvant may be administered before, simultaneously with, or after the administration of the composition comprising the polymersomes encapsulating the antigen of the invention. For example, the adjuvant may be injected into a subject after the injection of the composition comprising the polymersomes encapsulating the antigen of the invention. In some aspects, the adjuvant may be encapsulated in the polymersome along with the antigen.

[0178] Those skilled in the art will readily recognize and understand that the type of adjuvant to be injected depends on the type of antigen to be injected. The antigen can be of bacterial, viral or fungal origin. For example, if the antigen is OVA, the adjuvant can be Sigma Adjuvant System (SAS). Other antigen-adjuvant pairs are also suitable for use in the method of the present invention. In certain aspects, the use of an adjuvant is not necessary. In yet other aspects, the method works better, i.e., a stronger immune response is elicited, without the use of an adjuvant.

[0179] In some aspects, the membrane protein can be a transmembrane protein, a G protein-coupled receptor, a neurotransmitter receptor, a kinase, a porin, an ABC transporter, an ion transporter, an acetylcholine receptor and a cell adhesion receptor.The membrane protein can be fused or coupled to a tag, or can be tag-free.When the membrane protein is tagged, the tag can be selected from well-known affinity tags, such as VSV, His-tag, Strep-tag, Flag-tag, intein-tag or GST-tag, or anti-affinity binding pair partners, such as biotin or avidin, or labels such as fluorescent labels, enzyme labels, NMR labels or isotopic labels.

[0180] In some aspects, the membrane protein or a fragment (or portion) thereof may be provided prior to encapsulation or may be encapsulated simultaneously with production of the protein by a cell-free expression system, which may be an in vitro transcription-translation system.

[0181] The cell-free expression system can also be a eukaryotic cell-free expression system, such as the TNT system based on rabbit reticulocytes, wheat germ extracts or insect extracts, a prokaryotic cell-free expression system or an archaeal cell-free expression system.

[0182] As described above, the polymersomes can be formed from amphiphilic diblock or triblock copolymers. In various aspects, the amphiphilic polymer can include at least one carboxylic acid, amide, amine, alkylene, dialkylsiloxane, ether, or alkylene sulfide monomer unit.

[0183] In some aspects, the amphiphilic polymer can be a polyether block selected from the group consisting of an oligo(oxyethylene) block, a poly(oxyethylene) block, an oligo(oxypropylene) block, a poly(oxypropylene) block, an oligo(oxybutylene) block, and a poly(oxybutylene) block. Further examples of blocks that may be included in the polymer include, but are not limited to, poly(acrylic acid), poly(methyl acrylate), polystyrene, poly(butadiene), poly(2-methyloxazoline), poly(dimethylsiloxane), poly(e-caprolactone), poly(propylene sulfide), poly(N-isopropylacrylamide), poly(2-vinylpyridine), poly(2-(diethylamino)ethyl methacrylate), poly(2-diisopropylamino)ethyl methacrylate), poly(2-methacryloyloxy)ethyl phosphorylcholine, poly(isoprene), poly(isobutylene), poly(ethylene-co-butylene), and poly(lactic acid). Examples of suitable amphiphilic polymers include poly(ethylethylene)-b-poly(ethylene oxide) (PEE-b-PEO), poly(butadiene)-b-poly(ethylene oxide) (PBD-b-PEO), poly(styrene)-b-poly(acrylic acid) (PS-PAA), poly(dimethylsiloxane)-poly(ethylene oxide), also known as poly(dimethylsiloxane-b-ethylene oxide) (referred to herein as PDMS-PEO), e.g., PMOXA, as used by May et al., 2013. 20 -PDMS 54 -PMOXA 20Examples of block copolymers include, but are not limited to, poly(2-methyloxazoline)-b-poly(dimethylsiloxane)-b-poly(2-methyloxazoline) (PMOXA-bPDMS-bPMOXA), poly(2-methyloxazoline)-b-poly(dimethylsiloxane)-b-poly(ethylene oxide) (PMOXA-b-PDMS-b-PEO), poly(ethylene oxide)-b-poly(propylene sulfide)-b-poly(ethylene oxide) (PEO-b-PPS-b-PEO), and poly(ethylene oxide)-poly(butylene oxide) block copolymers, including triblock copolymers such as (ABA). Block copolymers can be further specified by the average block length of each block contained in the copolymer. Thus, PB M PEO N indicates the presence of a polybutadiene block (PB) of length M and a polyethylene oxide (PEO) block of length N. M and N are independently selected integers, which may be selected, for example, within the range of about 6 to about 60. Thus, PB 35 PEO 18 indicates the presence of polybutadiene blocks of average length 35 and polyethylene oxide blocks of average length 18. In certain aspects, the PB-PEO diblock copolymer comprises 5-50 blocks PB and 5-50 blocks PEO. Similarly, PB 10 PEO 24 indicates the presence of polybutadiene blocks of average length 10 and polyethylene oxide blocks of average length 24. Specific examples of suitable PB-PEO diblock copolymers that can be used in the present invention include the diblock copolymer PBD 21 -PEO 14 (also commercially available) and [PBD] 21 -[PEO] 12 (See WO2014 / 077781A1 and Nallani et al., 2011). As a further example, E O B Pindicates the presence of an ethylene oxide block (E) of length O and a butadiene block (B) of length P. Thus, O and P are independently selected integers, ranging, for example, from about 10 to about 120. Thus, E 16 E 22 indicates the presence of ethylene oxide blocks of average length 16 and butadiene blocks of average length 22.

[0184] Turning now to another preferred block copolymer used to form the polymersomes of the present invention, poly(dimethylsiloxane-b-ethylene oxide) (PDMS-PEO), it is noted that both linear and comb-shaped PDMS-PEO can be used here (see Gaspard et al. "Mechanical Characterization of Hybrid Vesicles Based on Linear Poly(Dimethylsiloxane-b-Ethylene Oxide)and Poly(Butadiene-b-Ethylene Oxide)Block Copolymers," Sensors 2016,16(3),390, which describes polymersomes formed from PDMS-PEO).

[0185] The structure of linear PDMS-PEO is shown below as formula (I): The structure of the comb-shaped PDMS-PEO is shown as formula (II): Shown as TIFF2024518710000002.tif42128. PDMS according to structural formula (I) n -PEO m The term "polydimethylsiloxane" refers to the presence of a polydimethylsiloxane (PDMS) block of length n and a polyethylene oxide (PEO) block of length m, where m and n are independently selected integers and can each be selected in the ranges, for example, from about 5 or about 6 to about 100, from about 5 to about 60, or from about 6 to about 60, or from about 5 to about 50. For example, PDMS 12 -PEO 46 or PDMS 47 PEO36 Linear PDMS-PEO such as PDMS-PEO-1, PDMS-PEO-2, PDMS-PEO-3, PDMS-PEO-4, PDMS-PEO-5, PDMS-PEO-6, PDMS-PEO-7, PDMS-PEO-8, PDMS-PEO-9, PDMS-PEO-10, PDMS-PEO-20, PDMS-PEO-30, PDMS-PEO-40, PDMS-PEO-50, PDMS-PEO-60, PDMS-PEO-70, PDMS-PEO-80, PDMS-PEO-90, PDMS-PEO-10, PDMS-PEO-11, PDMS-PEO-12, PDMS-PEO-13, PDMS-PEO-14, PDMS-PEO-15, PDMS-PEO-16, PDMS-PEO-17, PDMS-PEO-18, PDMS-PEO-19, PDMS-PEO-20, PDMS-PEO-21, PDMS-PEO-22, PDMS-PEO-23, PDMS-PEO-24, PDMS-PEO-25, PDMS-PEO-26, PDMS-PEO-27, PDMS-PEO-28, PDMS-PEO-29 ...9, PDMS-PEO-29, PDMS-PEO-29, PDMS-PEO-24,

[0186] In accordance with the above, the present invention in one aspect relates to a method for inducing an immune response in a subject, comprising administering to the subject a polymersome formed from PDMS-PEO carrying an antigen. The antigen can be associated / physically linked to the PDMS-PEO polymersome in any suitable manner. For example, the PDMS-PEO polymersome can have a soluble antigen encapsulated therein, as described in the present invention. Alternatively or additionally, the polymersome can have an antigen incorporated / incorporated into the surrounding membrane of the polymersome, as described in WO2014 / 077781A1. In this case, the antigen is a membrane protein whose transmembrane domain(s) is incorporated into the surrounding membrane of the PDMS-PEO-polymersome. Incorporation can be achieved as described in WO2014 / 077781A1 or Nallani et al. "Proteopolymersomes: in vitro production of a membrane protein in polymersome membranes", Biointerphases, 1 December 2011, page 153. When an antigen is encapsulated in a PDMS-PEO polymersome, it may be a soluble antigen selected from the group consisting of polypeptides, carbohydrates, polynucleotides, and combinations thereof. The present invention further relates to a method for producing such encapsulated antigens in PDMS-PEO polymersomes and the polymersomes produced by said method.

[0187] The present invention further relates to compositions comprising PDMS-PEO polymersomes carrying an antigen. Again, in these compositions, the antigen can be associated / physically linked to the PDMS-PEO polymersome in any suitable manner. For example, the PDMS-PEO polymersomes can have a soluble antigen encapsulated therein, as described in the present invention. Alternatively or additionally, the polymersomes can have an antigen incorporated / incorporated into the membrane surrounding the polymersome, as described in WO2014 / 077781A1. The present invention also relates to a vaccine comprising such PDMS-PEO polymersomes carrying an antigen, a method of eliciting an immune response, or a method for treating, ameliorating, preventing or diagnosing cancer, an autoimmune disease or an infectious disease, comprising the step of administering to a subject in need thereof a PDMS-PEO polymersome carrying an antigen.

[0188] In accordance with the above, the present invention also relates to the in vitro and in vivo use of PDMS-PEO polymersomes carrying (or carrying) antigens in a form suitable for eliciting an immune response. The antigens can be encapsulated in the PDMS-PEO polymersomes or incorporated in the surrounding membrane of the polymersomes, for example as described in WO2014 / 077781A1.

[0189] In certain aspects, the polymersomes of the present invention may contain one or more compartments (also referred to as "multicompartments"). The compartmentalization of the vesicular structure of polymersomes allows the coexistence of complex reaction pathways in living cells and helps to separate many activities in the cell spatially and temporally. Thus, two or more types of antigens may be encapsulated in the polymersomes of the present invention. The different antigens may have the same or different isoforms. Each compartment may be formed of the same or different amphiphilic polymers. In various aspects, two or more different antigens are incorporated into the surrounding membrane of the amphiphilic polymer. Each compartment may encapsulate at least one of a peptide, a protein, and a nucleic acid. The peptide, protein, polynucleotide, or carbohydrate may be immunogenic.

[0190] Further details of suitable multi-compartmental polymersomes can be found in WO20121018306, the contents of which are incorporated herein by reference in their entirety for all purposes.

[0191] Additionally, polymersomes may be free-standing or immobilized on a surface, for example as described in WO2010 / 1123462, the contents of which are incorporated herein by reference in their entirety for all purposes.

[0192] When the polymersome carrier contains two or more compartments, the compartments may include an outer block copolymer vesicle and at least one inner block copolymer vesicle encapsulated inside the outer block copolymer vesicle. In some aspects, each of the block copolymers of the outer vesicle and the inner vesicle includes a polyether block, such as a poly(oxyethylene) block, a poly(oxypropylene) block, and a poly(oxybutylene) block. Further examples of blocks that may be included in the copolymer include, but are not limited to, poly(acrylic acid), poly(methyl acrylate), polystyrene, poly(butadiene), poly(2-methyloxazoline), poly(dimethylsiloxane), poly(L-isocyanoalanine(2-thiophen-3-yl-ethyl)amide), poly(e-caprolactone), poly(propylene sulfide), poly(N-isopropylacrylamide), poly(2-vinylpyridine), poly(2-(diethylamino)ethyl methacrylate), poly(2-(diisopropylamino)ethyl methacrylate), poly(2-(methacryloyloxy)ethyl phosphorylcholine), and poly(lactic acid).Examples of suitable outer and inner vesicles include poly(ethylethylene)-b-poly(ethylene oxide) (PEE-b-PEO), poly(butadiene)-b-poly(ethylene oxide) (PBD-b-PEO), poly(styrene)-b-poly(acrylic acid) (PS-b-PAA), poly(ethylene oxide)-poly(caprolactone) (PEO-b-PCL), poly(ethylene oxide)-poly(lactic acid) (PEO-b-PLA), poly(isoprene)-poly(ethylene oxide) (PI-b-PEO), poly(2-vinylpyridine)-poly(ethylene oxide) (P2VP-b-PEO), poly(ethylene oxide)-poly(N-isopropylacrylamide) (PEO-b-PNIPAm), poly(ethylene glycol)-poly(propylene sulfide) (PEG-b-PPS), poly(methylphenylsilane)-poly (ethylene oxide) (PMPS-b-PEO-b-PMPS-b-PEO-b-PMPS), poly(2-methyloxazoline)-b-poly-(dimethylsiloxane)-b-poly(2-methyloxazoline) (PMOXA-b-PDMS-b-PMOXA), poly(2-methyloxazoline)-b-poly(dimethylsiloxane)-b-poly(ethylene oxide) (PMOXA-b-PDMS-b-PEO), poly[styrene-b-poly(L-isocyanoalanine(2-thiophen-3-yl-ethyl)amide)] (PS-b-PIAT), poly(ethylene oxide)-b-poly(propylene sulfide)-b-poly(ethylene oxide) (PEO-b-PPS-b-PEO) and poly(ethylene oxide)-poly(butylene oxide) (PEO-b-PBO) block copolymers. Block copolymers may be further specified by the average number of each block contained in the copolymer, thus PS. M -PIAT N indicates the presence of a polystyrene block (PS) having M repeat units and a poly(L-isocyanoalanine(2-thiophen-3-yl-ethyl)amide) (PIAT) block having N repeat units. M and N are thus independently selected integers, which may be selected, for example, within the range of about 5 to about 95. Thus, PS 40-PIAT 50 indicates the presence of PS blocks with an average of 40 repeat units and PIAT blocks with an average of 50 repeat units.

[0193] In some aspects, the present invention relates to a method for producing an encapsulated antigen in a polymersome, comprising the steps of: (i) dissolving an amphiphilic polymer of the present invention in chloroform, preferably the amphiphilic polymer is polybutadiene-polyethylene oxide (BD); (ii) drying the dissolved amphiphilic polymer to form a polymer film; (iii) adding a solubilized antigen to the dried amphiphilic polymer film of step (ii), wherein the antigen is selected from the group consisting of: (a) a polypeptide, preferably a polypeptide which is an antigen of the present invention; (b) a carbohydrate; (c) a combination of (a) and / or (b) and / or (c); (iv) rehydrating the polymer film of step (iii) to form a polymer vesicle; (v) optionally filtering the polymer vesicles of step (iv) to purify the polymer vesicles into monodisperse vesicles; and / or (vi) optionally isolating the polymer vesicles of step (iv) or step (v) from non-encapsulated antigen.

[0194] In some other aspects, the present invention relates to other methods for producing encapsulated antigens in polymersomes, including methods based on mixing a non-aqueous solution of a polymer into an aqueous solution of an antigen, sonicating the corresponding polymer-antigen mixed solution, or extruding the corresponding polymer-antigen mixed solution. Exemplary methods include those described in Rameez et al, Langmuir 2009 and Neil et al Langmuir 2009,25(16),9025-9029. In some other aspects, the present invention relates to a polymersome (or an assembly of multiple polymersomes or polymersomes) comprising a soluble encapsulated antigen, where the soluble encapsulated antigen is a polynucleotide (e.g., single-stranded or double-stranded) selected from an RNA molecule (e.g., mRNA, self-amplifying mRNA or siRNA) or a DNA molecule or a DNA / RNA hybrid, and the polymersome further comprises an ionizable lipid.

[0195] In other aspects of the invention, the ionizable lipid is a cationic ionizable lipid.

[0196] In some other aspects of the invention, the ionizable lipid (i) is a tertiary amine (e.g., not a quaternary amine) and / or contains one or more tertiary amine moieties (e.g., does not contain a cationic quaternized ammonium moiety), and / or (ii) contains a free electron pair at a nitrogen atom (e.g., an ionizable nitrogen atom).

[0197] In some other aspects of the invention, the ionizable lipid comprises or consists of the following: the ionizable lipid DLin-MC3-DMA having formula I (i.e., (6Z,9Z,28Z,31Z)-heptatriaconta-6,9,28,31-tetraen-19-yl 4-(dimethylamino)butanoate); the ionizable lipid 319 having formula II; the ionizable lipid C12-200 having formula III; the ionizable lipid 5A2-SC8 having formula IV; the ionizable lipid 306Oi10 having formula VI; the ionizable lipid SM-102 having formula VII (i.e., heptadecane-9-yl 8-((2-hydroxyethyl)(6-oxo-6-(undecyloxy)hexyl)amino)octanoate; ionizable lipid A9 having formula VIII; ionizable lipid ALC-0315 having formula IX (i.e., [(4-hydroxybutyl)azanediyl]di(hexane-6,1-diyl)bis(2-hexyldecanoate); ionizable lipid Arcturus 2.2(8.8)4C CH3 having formula X; ionizable lipid Genevant CL1 having formula XI; ionizable lipid ALC-0159 having formula XII (i.e., 2-[(polyethylene glycol)-2000]-N,N-ditetradecylacetamide); any one of the above, wherein one or more of the alkyl chains thereof are further esterified.

[0198] In some preferred aspects of the invention, the ionizable lipid is a cationic ionizable lipid that comprises or consists of DLin-MC3-DMA ((6Z,9Z,28Z,31Z)-heptatriaconta-6,9,28,31-tetraen-19-yl 4-(dimethylamino)butanoate).

[0199] In some other aspects of the invention, the polymersomes can increase the thermal and / or storage stability and / or immunogenicity of a polynucleotide (e.g., mRNA) and / or one or more polypeptides encoded by the polynucleotide (e.g., mRNA) within the polymersome, preferably compared to the same polynucleotide (e.g., mRNA) and / or one or more polypeptides encoded by the same polynucleotide (e.g., mRNA) within another polymersome not having an ionizable substance or within an ionizable lipid nanoparticle (LNP) comprising cholesterol under the same conditions, more preferably the thermal and / or storage stability is increased within a temperature range of about -80°C to about 4°C (e.g., at -80°C, -20°C or 4°C, preferably at -80°C), and most preferably the immunogenicity is increased within a temperature range of about 36.5°C to about 37.5°C, and even most preferably the increase is an increase of at least about 5% (e.g., at least 10%, at least 20% or at least 30%).

[0200] In some other aspects of the invention, the polymersomes are made of polybutadiene-polyethylene oxide (BD) and DLin-MC3-DMA ((6Z,9Z,28Z,31Z)-heptatriaconta-6,9,28,31-tetraen-19-yl 4-(dimethylamino)butanoate); and / or PBD-PEO (poly(butadiene)-poly(ethylene oxide)) and DLin-MC3-DMA ((6Z,9Z,28Z,31Z)-heptatriaconta-6,9,28,31-tetraen-19-yl 4-(dimethylamino)butanoate). 4-(dimethylamino)butanoate), preferably with 15% or 30% Dlin-MC3-DMA; and / or polybutadiene-polyethylene oxide (BD) and ionizable lipid 319 having formula II; and / or polybutadiene-polyethylene oxide (BD) and ionizable lipid C12-200 having formula III; and / or polybutadiene-polyethylene oxide (BD) and ionizable lipid 5A2-SC8 having formula IV; and / or polybutadiene-polyethylene oxide (BD) and ionizable lipid 306Oi10 having formula V; and / or polybutadiene-polyethylene oxide ( BD) and an ionizable lipid 5 having formula VI; and / or polybutadiene-polyethylene oxide (BD) and an ionizable lipid SM-102 having formula VII; and / or polybutadiene-polyethylene oxide (BD) and an ionizable lipid A9 having formula VIII; and / or polybutadiene-polyethylene oxide (BD) and an ionizable lipid ALC-0315 having formula IX (i.e., [(4-hydroxybutyl)azanediyl]di(hexane-6,1-diyl)bis(2-hexyldecanoate); and / or polybutadiene-polyethylene oxide (BD) and an ionizable lipid Arcturus having formula X 2.2(8.8)4C CH3; and / or polybutadiene-polyethylene oxide (BD) and an ionizable lipid Genevant CL1 having formula XI; and / or polybutadiene-polyethylene oxide (BD) and an ionizable lipid ALC-0159 having formula XII (i.e., 2-[(polyethylene glycol)-2000]-N,N-ditetradecylacetamide).

[0201] Compared to existing uptake and cross-presentation vehicles and methods based on them, the polymersomes of the invention have, inter alia, the following advantages, which are also aspects of the invention: The polymersomes are highly efficient in uptake and cross-presentation to the immune system. · Immune response is CD8 (+) including T cell-mediated immune responses, Polymersomes are oxidatively stable; - the humoral response is stronger than that generated by free antigen-based techniques with or without adjuvant; The immune response induced by the polymersomes of the present invention can be further boosted using adjuvants. The polymers of the polymersomes of the invention are inherently robust and can be adapted or functionalized to increase circulation time in the body; The polymersomes of the present invention are stable in the presence of serum components; Polymersome polymers are inexpensive and rapidly synthesized. The amount of antigen required to induce an immune response by the method of the present invention is less compared to free antigen-based techniques with or without adjuvant.

[0202] The present invention is also characterized by the following items. 1. Polymersomes (e.g., oxidatively stable polymersomes comprising a soluble encapsulated antigen), The soluble encapsulated antigen is (i) a polypeptide, (ii) carbohydrates, (iii) a polynucleotide, which is preferably not an antisense oligonucleotide, and more preferably is a DNA molecule or an mRNA molecule; (iv) a combination of (i) and / or (ii) and / or (iii) Selected from the group consisting of: Polymersomes. 2. Polymersomes bind to CD8(+) The polymersome according to any one of the preceding paragraphs, having the ability to induce a T cell mediated immune response, preferably said induction being in vivo, ex vivo or in vitro. 3. The antigen comprises a soluble portion of a membrane protein (MP) or membrane associated peptide (MAP), preferably the antigen comprises a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, ovalbumin (OVA), porcine epidemic diarrhea virus spike protein, B16 peptide or MC38 peptide, more preferably the antigen comprises a soluble portion of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, and SEQ ID The polymersome of any one of the preceding items, comprising a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of NO:12-14. 4. The polymersome according to any one of the preceding paragraphs, wherein the polymersome is stable in the presence of serum components, preferably said stability being in vivo, ex vivo or in vitro. 5. The polymersome according to any one of the preceding paragraphs, wherein the polymersome is stable within an endosome, preferably said stability being in vivo, ex vivo or in vitro. 6. The polymersome according to any one of the preceding paragraphs, wherein the polymersome has improved oxidative stability compared to the corresponding oxidative stability of a liposome, preferably said improved stability being in vivo, ex vivo or in vitro. 7. Polymersomes release their contents, including soluble encapsulated antigens, in an oxidation-independent manner to target CD8 (+)The polymersome according to any one of the preceding items, having the ability to trigger a T cell mediated immune response, preferably wherein said release is in vivo, ex vivo or in vitro release. 8. Polymersomes Conjugates for CD8 (+) The polymersome according to any one of the preceding paragraphs, having the ability to induce a cellular immune response, including a T cell mediated immune response, preferably said immune response being an in vivo, ex vivo or in vitro immune response. 9. The polymersomes have the ability to induce a cellular and / or humoral immune response, and the cellular immune response is (+) The polymersome of any one of the preceding paragraphs, comprising a T cell mediated immune response, preferably wherein the immune response is an in vivo, ex vivo or in vitro immune response. 10. The polymersome according to any one of the preceding paragraphs, wherein the humoral immune response comprises the production of specific antibodies, more preferably said immune response is an in vivo, ex vivo or in vitro immune response. 11. Polymersomes bind to effector CD4 (+) The polymersome according to any one of the preceding paragraphs, having the ability to enhance the frequency of T cells, preferably said enhancement being in vivo, ex vivo or in vitro. 12. The polymersome according to any one of the preceding paragraphs, wherein the cellular immune response comprises a T cell mediated immune response, preferably wherein the immune response is an in vivo, ex vivo or in vitro immune response. 13. Polymersomes increase antigen-specific CD8 activity compared to free antigen (+) The polymersome according to any one of the preceding paragraphs, having the ability to enhance clonal expansion of T cells, preferably said expansion being in vivo, ex vivo or in vitro expansion. 14. Polymersomes bind antigen-specific effector CD8 (+) The polymersome according to any one of the preceding items, having the ability to induce T cells, preferably said induction being in vivo, ex vivo or in vitro. 15. Polymersomes bind antigen-specific CD8 (+)The polymersome according to any one of the preceding paragraphs, having the ability to enhance the cytotoxic phenotype of T cells, preferably said enhancement being in vivo, ex vivo or in vitro. 16. The polymersome according to any one of the preceding items, wherein the polymersome is capable of targeting lymph node resident macrophages and / or B cells, preferably said targeting being in vivo, ex vivo or in vitro targeting. 17. The polymersome according to any one of the preceding items, wherein the polymersome is reduction-stable, preferably the polymersome is reduction-stable in the presence of serum components, more preferably the reduction-stability is in vivo, ex vivo or in vitro. 18. The polymersome according to any one of the preceding items, wherein the polymersome has reduced permeability, preferably the reduced permeability is compared to the corresponding permeability of a liposome, and more preferably the permeability is in vivo, ex vivo or in vitro permeability. 19. The polymersome according to any one of the preceding paragraphs, wherein the polymersome is capable of releasing its contents within an endosome, preferably the endosome is a late endosome, and more preferably the release is in vivo, ex vivo or in vitro. 20. The following: (i) the ability to induce a cellular immune response, preferably the cellular immune response being CD8 (+) More preferably, the cellular immune response comprises a CD8 (+)and most preferably, the cellular immune response is a response to a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, ovalbumin (OVA), porcine epidemic diarrhea virus spike protein, B16 peptide or MC38 peptide, and most preferably, the cellular immune response is a response to a soluble portion of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17, SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, SEQ ID NO:21, SEQ ID NO:22, SEQ ID NO:23, SEQ ID NO:24, SEQ ID NO:25, SEQ ID NO:26, SEQ ID NO:27, SEQ ID NO:28, SEQ ID NO:29, SEQ ID NO:30, SEQ ID NO:31, SEQ ID NO:32, SEQ ID NO:33, SEQ ID NO:34, SEQ ID NO:35, SEQ ID NO:36, SEQ ID NO:37, SEQ ID NO:38, SEQ ID NO:39, SEQ ID NO:40, SEQ ID NO:41, SEQ ID NO:42, SEQ ID NO:43, SEQ ID NO:44, SEQ ID NO:45, SEQ ID NO:46, SEQ ID NO:47, SEQ ID NO:48, SEQ ID NO:49, SEQ ID NO:50, SEQ ID NO:51, SEQ ID NO:52, SEQ ID NO:53, SEQ ID NO:54, SEQ the ability to elicit a cellular immune response in response to a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of NO:12-14; (ii) the ability to release polymersome contents within an endosome, preferably the endosome is a late endosome, more preferably the contents comprises a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, ovalbumin (OVA), porcine epidemic diarrhea virus spike protein, B16 peptide or MC38 peptide, and most preferably the contents comprises a soluble portion of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17, SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, SEQ ID NO:21, SEQ ID NO:22, SEQ ID NO:23, SEQ ID NO:24, SEQ ID NO:25, SEQ ID NO:26, SEQ ID NO:27, SEQ ID NO:28, SEQ ID NO:29, SEQ ID NO:30, SEQ ID NO:31, SEQ ID NO:32, SEQ ID NO:33, SEQ ID NO:34, SEQ ID NO:35, SEQ ID NO:36, SEQ ID NO:37, SEQ ID NO:38, SEQ ID NO:39, SEQ ID NO:40, SEQ ID NO:41, SEQ ID NO:42, SEQ ID NO:43, SEQ ID NO:44, SEQ ID NO:45, SEQ ID NO:46, SEQ ID NO:47, SEQ ID NO:48, SEQ ID NO:49, SEQ ID NO:50, SEQ ID NO:51, SEQ ID NO:52, SEQ ID NO:53, the ability to release polymersome contents within an endosome comprising a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of NO:12-14; (iii) Oxidation-independent release of polymersome contents to CD8 (+)and the ability to trigger a T cell mediated immune response, preferably the content comprises a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, ovalbumin (OVA), porcine epidemic diarrhea virus spike protein, B16 peptide or MC38 peptide, more preferably the content comprises a soluble portion of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17, SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, SEQ ID NO:21, SEQ ID NO:22, SEQ ID NO:23, SEQ ID NO:24, SEQ ID NO:25, SEQ ID NO:26, SEQ ID NO:27, SEQ ID NO:28, SEQ ID NO:29, SEQ ID NO:30, SEQ ID NO:31, SEQ ID NO:32, SEQ ID NO:33, SEQ ID NO:34, SEQ ID NO:35, SEQ ID NO:36, SEQ ID NO:37, SEQ ID NO:38, SEQ ID NO:39, SEQ ID NO:40, SEQ ID NO:41, SEQ ID NO:42, SEQ ID NO:43, SEQ ID NO:44, SEQ ID NO:45, SEQ ID NO:46, SEQ ID NO:47, SEQ ID NO:48, SEQ ID NO:49, SEQ ID NO:50, SEQ ID NO:51, SEQ ID NO:52, SEQ ID NO:53, SEQ ID NO:54, SEQ ID NO:5 A method for the oxidation-independent release of polymersome contents comprising administering to CD8 cells a polypeptide having at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of NO:12 to 14. (+) the ability to trigger a T cell-mediated immune response; (iv) the ability to stimulate an immune response against an antigen, preferably the antigen comprises a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, ovalbumin (OVA), porcine epidemic diarrhea virus spike protein, B16 peptide or MC38 peptide, more preferably the antigen comprises a soluble portion of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, SEQ ID NO:12, SEQ ID NO:13, SEQ ID NO:14, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:17, SEQ ID NO:18, SEQ ID NO:19, SEQ ID NO:20, SEQ ID NO:21, SEQ ID NO:22, SEQ ID NO:23, SEQ ID NO:24, SEQ ID NO:25, SEQ ID NO:26, SEQ ID NO:27, SEQ ID NO:28, SEQ ID NO:29, SEQ ID NO:30, SEQ ID NO:31, SEQ ID NO:32, SEQ ID NO:33, SEQ ID NO:34, SEQ ID NO:35, SEQ ID NO:36, SEQ ID NO:37, SEQ ID NO:38, SEQ ID NO:39, SEQ ID NO:40, SEQ ID NO:41, SEQ ID NO:42, SEQ ID NO:43, SEQ ID NO:44, SEQ ID NO:45, SEQ ID NO:46, SEQ ID NO:47, SEQ ID NO:48, SEQ ID NO:49, SEQ ID NO:50, SEQ ID NO:51, SEQ ID NO:52, SEQ ID NO:53, SEQ ID NO:54, SEQ ID NO: the ability to stimulate an immune response to an antigen, comprising a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of NOs:12-14; (v) CD8 (+) and the ability to trigger cross-protection induced by a T cell mediated immune response, preferably the response is a response to a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, porcine epidemic diarrhea virus spike protein, ovalbumin (OVA), B16 peptide or MC38 peptide, more preferably the response is a response to a soluble portion of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11 and SEQ ID NO: A CD8 response to a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of NO:12-14. (+) the ability to trigger cross-protection induced by T cell-mediated immune responses; (vi) the ability to deliver a peptide or protein to an antigen presenting cell (APC), preferably the peptide or protein comprises or is derived from a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, ovalbumin (OVA), porcine epidemic diarrhea virus spike protein, B16 peptide or MC38 peptide, more preferably the peptide or protein is selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11 and SEQ ID NO: the ability to deliver a peptide or protein to an antigen-presenting cell, comprising or derived from a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of NOs:12-14; (vii) CD8 (+) T cell-mediated immune response and / or CD4 (+)and the ability to trigger an immune response, including a T cell mediated immune response, preferably the response is a response to a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, ovalbumin (OVA), porcine epidemic diarrhea virus spike protein, B16 peptide or MC38 peptide, more preferably the response is a response to a soluble portion of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11 and SEQ ID NO: A CD8 response to a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of NO:12-14. (+) T cell-mediated immune response and / or CD4 (+) the ability to trigger immune responses, including T cell-mediated immune responses; (viii) the ability to stimulate an immune response in a subject, preferably the response is a response to a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, ovalbumin (OVA), porcine epidemic diarrhea virus spike protein, B16 peptide or MC38 peptide, and more preferably the response is a response to a soluble portion of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11 and SEQ ID NO: the ability to stimulate an immune response in a subject to a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of NO:12-14; (ix) the ability to immunize a non-human animal, preferably the immunization is against a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, ovalbumin (OVA), porcine epidemic diarrhea virus spike protein, B16 peptide or MC38 peptide, more preferably the immunization is against a soluble portion of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11 and SEQ ID NO: the ability to immunize a non-human animal against a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of NOs:12-14; (x) the polymersome has an altered antigenicity compared to the corresponding antigenicity of the antigen without the polymersome, preferably the antigen is a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, ovalbumin (OVA) porcine epidemic diarrhea virus spike protein, B16 peptide or MC38 peptide, more preferably the antigen is any of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11 and SEQ ID NO: having altered antigenicity, which is a polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of SEQ ID NOs: 12 to 14; (xi) the polymersome has altered immunogenicity compared to the corresponding immunogenicity of the antigen without the polymersome, preferably the immunogen is a soluble portion of influenza hemagglutinin, porcine influenza hemagglutinin, ovalbumin (OVA), porcine epidemic diarrhea virus spike protein, B16 peptide or MC38 peptide, more preferably the immunogen is any of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11 and SEQ ID NO:12. A polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of NOs: 12 to 14, and has altered immunogenicity. The polymersome of any one of the preceding claims, having one or more of the following capabilities: 21. The following characteristics: (i) the polymersome comprises an oxidatively stable membrane, and / or (ii) the polymersome is synthetic, and / or (iii) the polymersomes are free of non-encapsulated antigen or are mixed with free non-encapsulated antigen, and / or (iv) the polymersome comprises a membrane of an amphiphilic polymer; and / or (v) the polymersome comprises an amphiphilic synthetic block copolymer that forms a vesicle membrane; and / or (vi) the polymersome has a diameter of more than 70 nm, preferably in the range of about 100 nm to about 1 μm, or about 120 nm to about 250 nm, or about 125 nm to about 250 nm, about 140 nm to about 240 nm, about 150 nm to about 235 nm, about 170 nm to about 230 nm, or about 220 nm to about 180 nm, or about 190 nm to about 210 nm; and / or (vii) the polymersome has a vesicle morphology; (viii) The polymersomes are self-assembling. The polymersome of any one of the preceding claims, comprising one or more of: 22. The polymersome according to item 21, wherein the polymersome is in the form of a polymersome aggregate, and the average diameter of the polymersome aggregate is in the range of about 100 nm to about 1 μm, or about 100 nm to about 750 nm, or about 100 nm to about 500 nm, or about 120 nm to about 250 nm, or about 125 nm to about 250 nm, about 140 nm to about 240 nm, about 150 nm to about 235 nm, about 170 nm to about 230 nm, or about 220 nm to about 180 nm, or about 190 nm to about 210 nm. 23. The polymersome of any one of the preceding claims, wherein the antigen is an immunogen. 24. The polymersome of any one of the preceding claims, wherein the antigen is selected from the group consisting of (i) an autoantigen, (ii) a non-self antigen, (iii) a non-self immunogen, and (iv) an autoimmunogen. 25. The antigen is: (i) a polypeptide that is at least 80% or more (e.g., at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a viral polypeptide sequence, preferably the viral polypeptide sequence is influenza hemagglutinin or swine influenza hemagglutinin, and more preferably the viral polypeptide sequence is selected from the group consisting of SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7 and SEQ ID NO:8; (ii) a polypeptide that is at least 80% or more identical (e.g., at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) to a bacterial polypeptide sequence; (iii) A polypeptide having at least 80% or more (e.g., at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identity to a mammalian or avian polypeptide sequence, preferably the mammalian or avian polypeptide sequence is at least 80% or more (e.g., at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to ovalbumin (OVA), spike protein, B16 peptide or MC38 peptide, more preferably the mammalian or avian polypeptide sequence is selected from the group consisting of SEQ ID NO:4, SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11 and SEQ ID NO:12-14. The polymersome of any one of the preceding claims, selected from the group consisting of: 26. The polymersome of any one of the preceding claims, wherein the mammalian polypeptide sequence is selected from the group consisting of human, rodent, rabbit and horse polypeptide sequences. 27. The polymersome of any one of the preceding items, wherein the antigen is an antibody or a fragment thereof. 28. The antigen is: (i) influenza hemagglutinin (HA), preferably selected from the group consisting of SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7 and SEQ ID NO:8; (ii) swine influenza hemagglutinin (HA), preferably SEQ ID NO:6; (iii) ovalbumin (OVA), preferably SEQ ID NO:4; (iv) Porcine epidemic diarrhea virus (PED) spike protein, preferably SEQ ID NO: 12-14; (v) B16 peptide, preferably selected from the group consisting of SEQ ID NO:9, SEQ ID NO:10 and SEQ ID NO:11; (vi) MC38 peptides, preferably selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2 and SEQ ID NO:3; (vii) B16 peptide and MC38 peptide, preferably the peptide is independently selected from the group: (i) SEQ ID NO: 1-3 and (ii) SEQ ID NO: 9-11; The polymersome of any one of the preceding claims, selected from the group consisting of: 29. The polymersome of any one of the preceding claims, selected from the group consisting of cationic, anionic and nonionic polymersomes, and mixtures thereof. 30. The polymersome according to any one of the preceding items, wherein the block copolymer or amphiphilic polymer is essentially non-immunogenic or essentially non-antigenic, preferably the block copolymer or amphiphilic polymer is non-immunogenic or non-antigenic. 31. The polymersome of any one of the preceding claims, wherein the block copolymer or amphiphilic polymer is oxidatively stable. 32. The polymersome of any one of the preceding claims, wherein the block copolymer or amphiphilic polymer is not an immunostimulant or adjuvant. 33. The polymersome of any one of the preceding claims, wherein the amphiphilic polymer comprises a diblock or triblock (ABA or ABC) copolymer. 34. The polymersome of any one of the preceding claims, wherein the amphiphilic polymer comprises the copolymer poly(N-vinylpyrrolidone)-b-PLA. 35. The polymersome of any one of the preceding paragraphs, wherein the amphiphilic polymer comprises at least one carboxylic acid, amide, amine, alkylene, dialkylsiloxane, ether, or alkylene sulfide monomer unit. 36. The polymersome of any one of the preceding paragraphs, wherein the amphiphilic polymer is a polyether block selected from the group consisting of an oligo(oxyethylene) block, a poly(oxyethylene) block, an oligo(oxypropylene) block, a poly(oxypropylene) block, an oligo(oxybutylene) block, and a poly(oxybutylene) block. 37. The polymersome of any one of the preceding claims, wherein the amphiphilic polymer is a poly(butadiene)-poly(ethylene oxide) (PB-PEO) diblock copolymer. 38. The polymersome according to any one of the preceding items, wherein the PB-PEO diblock copolymer comprises 5-50 block PB and 5-50 block PEO. 39. The polymersome according to any one of the preceding items, wherein the amphiphilic polymer is a poly(dimethylsiloxane)-poly(ethylene oxide) (PDMS-PEO) diblock copolymer, preferably the PB-PEO diblock copolymer preferably comprising 5-100 blocks PDMS and 5-100 blocks PEO. 40. A polymersome according to any one of the preceding items, wherein the polymersome may be composed of block copolymers or amphiphilic polymers alone or may be composed of block copolymers or amphiphilic polymers mixed with lipids. 41. The polymersome of any one of the preceding items, wherein the lipid is composed of a synthetic or natural lipid, or a mixture of synthetic or natural lipids, or a combination of synthetic and natural lipids. 42. The polymersome of any one of the preceding paragraphs, wherein the amphiphilic polymer is a poly(lactide)-poly(ethylene oxide) / 1-palmitoyl-2-oleyl-sn-glycero-3-phospho-L-serine (PLA-PEO / POPC) copolymer, preferably the PLA-PEO / POPC has a ratio of PLA-PEO to POPC (e.g., PLA-PEO / POPC) of 50:50 or more (e.g., 50 / 50 or 75 / 25 or 90 / 10). 43. The polymersome of any one of the preceding paragraphs, wherein the amphiphilic polymer is a poly(caprolactone)-poly(ethylene oxide) / 1-palmitoyl-2-oleyl-sn-glycero-3-phospho-L-serine (PCL-PEO / POPC) copolymer, preferably PCL-PEO / POPC having a ratio of PCL-PEO to POPC (e.g. PCL-PEO / POPC) of 50:50 or more (e.g. 50 / 50 or 75 / 25 or 90 / 10). 44. The polymersome of any one of the preceding claims, wherein the amphiphilic polymer is a polybutadiene-polyethylene oxide (BD) or poly(dimethylsiloxane)-poly(ethylene oxide) (PDMS-PEO) diblock copolymer. 45. Polymersomes are made of diblock copolymers (PBD 21 -PEO 14 (herein referred to as "BD21"), PDMS 47 -PEO 36 (PDMS-PEO) or triblock copolymer PMOXA 12 -PDMS 55 -PMOXA 12 The polymersome of any one of the preceding items, comprising: 46. ​​The polymersome of any one of the preceding paragraphs, comprising one or more compartments. 47. The polymersome according to any one of the preceding items, wherein the polymersome comprises one or more compartments, each of which encapsulates at least one peptide, protein, and nucleic acid, preferably at least one of the peptides, proteins, and nucleic acids being immunogenic or antigenic, and more preferably each of the one or more compartments being composed of the same or different amphiphilic polymers. 48. A polymersome comprising two or more compartments, the compartments comprising an outer block copolymer vesicle and at least one inner block copolymer vesicle, the at least one inner block copolymer vesicle being encapsulated within the outer block copolymer vesicle, preferably the outer block copolymer vesicle is (i) poly[styrene-b-poly(L-isocyanoalanine(2-thiophen-3-yl-ethyl)amide)] (PS-PIAT), (ii) poly(butadiene)-poly(ethylene oxide) (PBD-PEO); (iii) poly(ethylene oxide)-poly(caprolactone) (PEO-PCL); (iv) poly(ethylethylene)-poly(ethylene oxide) (PEE-PEO); (v) poly(ethylene oxide)-poly(lactic acid) (PEO-PLA); (vi) poly(isoprene)-poly(ethylene oxide) (PI-PEO); (vii) poly(2-vinylpyridine)-poly(ethylene oxide) (P2VP-PEO); (viii) poly(ethylene oxide)-poly(N-isopropylacrylamide) (PEO-PNIPAm); (ix) poly(styrene)-poly(acrylic acid) (PS-PAA); (x) poly(ethylene glycol)-polypropylene sulfide (PEG-PPS); (xi) poly(2-methyloxazoline)-poly(dimethylsiloxane)-poly(2-methyloxazoline) (PMOXA-PDMS-PMOXA); (xii) poly(ethylene oxide)-poly(dimethylsiloxane)-poly(2-methyloxazoline) (PEO-PDMS-PMOXA), and (xiii) Poly(methylphenylsilane)-poly(ethylene oxide) (PMPS-PEO-PMPS-PEO-PMPS) and more preferably, the at least one inner block copolymer vesicle is formed of a copolymer independently selected from the group consisting of: (xiv) poly[styrene-b-poly(L-isocyanoalanine(2-thiophen-3-yl-ethyl)amide)] (PS-PIAT); (xv) poly(butadiene)-poly(ethylene oxide) (PBD-PEO); (xvi) poly(ethylene oxide)-poly(caprolactone) (PEO-PCL); (xvii) Poly(ethylethylene)-poly(ethylene oxide) (PEE-PEO); (xviii) poly(ethylene oxide)-poly(lactic acid) (PEO-PLA); (xix) poly(isoprene)-poly(ethylene oxide) (PI-PEO); (xx) Poly(2-vinylpyridine)-poly(ethylene oxide) (P2VP-PEO), (xxi) Poly(ethylene oxide)-poly(N-isopropylacrylamide) (PEO-PNIPAm); (xxii) poly(styrene)-poly(acrylic acid) (PS-PAA); (xxiii) poly(ethylene glycol)-polypropylene sulfide (PEG-PPS); (xxiv) poly(2-methyloxazoline)-poly(dimethylsiloxane)-poly(2-methyloxazoline) (PMOXA-PDMS-PMOXA); (xxv) poly(ethylene oxide)-poly(dimethylsiloxane)-poly(2-methyloxazoline) (PEO-PDMS-PMOXA), and (xxvi) Poly(methylphenylsilane)-poly(ethylene oxide) (PMPS-PEO-PMPS-PEO-PMPS) The polymersome of any one of the preceding claims, which is a polymersome formed from a copolymer independently selected from the group consisting of: 49. The polymersome of any one of the preceding items, comprising a lipid polymer. 50. The polymersome of any one of the preceding claims, further comprising an encapsulated adjuvant. 51. A method for producing an encapsulated antigen in a polymersome, comprising the steps of: (i) dissolving an amphiphilic polymer in chloroform, preferably the amphiphilic polymer is polybutadiene-polyethylene oxide (BD); (ii) drying the dissolved amphiphilic polymer to form a polymer film; (iii) adding a solubilized antigen to the dry amphiphilic polymer film of step (ii), wherein the antigen is (a) a polypeptide, preferably the polypeptide antigen is as described in any one of the preceding paragraphs, more preferably the polypeptide antigen comprises a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, ovalbumin (OVA), porcine epidemic diarrhea virus spike protein, B16 peptide or MC38 peptide, most preferably the polypeptide antigen is selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11 and SEQ ID NO: A polypeptide that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of NOs: 12 to 14; (b) carbohydrates, (c) a polynucleotide which is not an antisense oligonucleotide and is preferably a DNA molecule or an mRNA molecule; (d) a combination of (a) and / or (b) and / or (c) A step selected from the group consisting of: (iv) rehydrating the polymer film of step (iii) to form polymer vesicles; (v) optionally filtering the polymer vesicles of step (iv) to purify the polymer vesicles into monodisperse vesicles; and / or (vi) optionally isolating the polymer vesicles of step (iv) or step (v) from unencapsulated antigen. A method comprising: 52. A method for producing an encapsulated antigen in a polymersome according to any one of the preceding items, wherein the polymersome is a polymersome according to any one of the preceding items. 53. A polymersome produced by the method for producing an encapsulated antigen in a polymersome described in any one of the preceding items. 54. A polymersome comprising a soluble encapsulated antigen, wherein the soluble encapsulated antigen is a polynucleotide (e.g., single-stranded or double-stranded) selected from an RNA molecule (e.g., mRNA, self-amplifying mRNA or siRNA, preferably mRNA), or a DNA molecule, or a combination thereof (e.g., a DNA / RNA hybrid), and the polymersome further comprises an ionizable lipid, preferably a polymersome according to any one of the preceding items. 55. The polymersome of any one of the preceding items, wherein the ionizable lipid is a cationic ionizable lipid. 56. The ionizable lipid is (i) is a tertiary amine (e.g., not a quaternary amine) and / or contains one or more tertiary amine moieties (e.g., does not contain a cationic quaternized ammonium moiety, i.e., the ionizable lipid is not DOTAP); and / or (ii) contains a free electron pair at the nitrogen atom (e.g., an ionizable nitrogen atom); and / or (iii) may or may not be protonated to a quaternary amine The polymersome according to any one of the preceding items. 57. The ionizable lipid is selected from the group consisting of: i) Formula I: the ionizable lipid DLin-MC3-DMA (i.e., (6Z,9Z,28Z,31Z)-heptatriaconta-6,9,28,31-tetraen-19-yl 4-(dimethylamino)butanoate) with TIFF2024518710000003.tif12128; ii) Formula II: 319 ionizable lipids with TIFF2024518710000004.tif18128, iii) Formula III: Ionizable lipid C12-200 with TIFF2024518710000005.tif25128, iv) Formula IV: ionizable lipid 5A2-SC8 with TIFF2024518710000006.tif36128, v) Formula V: Ionizable lipid 306Oi10 with TIFF2024518710000007.tif18128, vi) Formula VI: ionizable lipid 5 with TIFF2024518710000008.tif23128, vii) Formula VII: ionizable lipid SM-102 (i.e., heptadecan-9-yl 8-((2-hydroxyethyl)(6-oxo-6-(undecyloxy)hexyl)amino)octanoate) with TIFF2024518710000009.tif28128; viii) Formula VIII: Ionizable lipid A9 with TIFF2024518710000010.tif31128, ix) Formula IX: ionizable lipid ALC-0315 (i.e., [(4-hydroxybutyl)azanediyl]di(hexane-6,1-diyl)bis(2-hexyldecanoate), having TIFF2024518710000011.tif33128; x) Formula X: ionizable lipid Arcturus 2.2(8.8)4C CH3, with TIFF2024518710000012.tif34128 xi) Formula XI: ionizable lipid Genevant CL1 with TIFF2024518710000013.tif21128, xii) Formula XII: ionizable lipid ALC-0159 (i.e., 2-[(polyethylene glycol)-2000]-N,N-ditetradecylacetamide) with TIFF2024518710000014.tif20128; xiii) any one of (i) to (xii), wherein one or more of the alkyl chains are further esterified; The polymersome of any one of the preceding claims, comprising or consisting of: 58. The polymersome of any one of the preceding items, wherein the polynucleotide encodes one or more polypeptides, preferably the one or more polypeptides are viral polypeptides. 59. The polymersome can increase the thermal stability and / or storage stability and / or immunogenicity of the polynucleotide (e.g., mRNA) and / or one or more polypeptides encoded by the polynucleotide (e.g., mRNA) in the polymersome, preferably compared to the same polynucleotide (e.g., mRNA) and / or one or more polypeptides encoded by the same polynucleotide (e.g., mRNA) in another polymersome without an ionizable substance or in an ionizable lipid nanoparticle (LNP) comprising cholesterol, under the same conditions; More preferably, the thermal stability and / or storage stability is increased within a temperature range of about -80°C to about 4°C (e.g. at -80°C, -20°C or 4°C, preferably at -80°C), and most preferably, the immunogenicity is increased within a temperature range of about 36.5°C to about 37.5°C, and even most preferably, the increase is an increase of at least about 5% (e.g. at least 10%, at least 20% or at least 30%). 60. The polymersome of any one of the preceding items, which is an oxidatively stable polymersome. 61. The polymersome, (+) and having the ability to induce a T cell-mediated immune response, preferably the induction is in vivo, ex vivo or in vitro induction, more preferably the CD8 (+) The polymersome of any one of the preceding paragraphs, wherein the T cell-mediated immune response is a response to one or more polypeptides encoded by the polynucleotide. 62. The polymersome has the ability to induce a cellular immune response, the cellular immune response being a CD8 (+) Preferably, the immune response is an in vivo, ex vivo or in vitro immune response, and more preferably, the CD8 (+) The polymersome of any one of the preceding paragraphs, wherein the T cell-mediated immune response is a response to one or more polypeptides encoded by the polynucleotide. 63. The polymersome has the ability to induce a cellular and / or humoral immune response, the cellular immune response being a CD8 (+) and preferably, the immune response is an in vivo, ex vivo or in vitro immune response, more preferably, the cellular and / or humoral immunity is immunity to one or more polypeptides encoded by said polynucleotide, and most preferably, the CD8 (+) The polymersome of any one of the preceding paragraphs, wherein the T cell-mediated immune response is a response to one or more polypeptides encoded by the polynucleotide. 64. The polymersome according to any one of the preceding items, wherein the humoral immune response comprises the production of specific antibodies, more preferably, the immune response is an in vivo, ex vivo or in vitro immune response, most preferably, the humoral immunity is against one or more polypeptides encoded by the polynucleotide. 65. The polymersome comprises an effector CD4 (+) and having the ability to enhance the frequency of T cells, preferably said enhancement being in vivo, ex vivo or in vitro enhancement, more preferably effector CD4 (+) The polymersome of any one of the preceding paragraphs, wherein said frequency of T cells is for one or more polypeptides encoded by said polynucleotide. 66. The polymersome according to any one of the preceding items, wherein the cellular immune response comprises a T cell-mediated immune response, preferably, the immune response is an in vivo, ex vivo or in vitro immune response, more preferably, the cellular immune response comprising a T cell-mediated immune response is a response to one or more polypeptides encoded by the polynucleotide. 67. The polymersomes inhibit antigen-specific CD8 (+) The ability to enhance clonal expansion of T cells, preferably said expansion being in vivo, ex vivo or in vitro expansion, more preferably antigen-specific CD8 (+) The polymersome of any one of the preceding items, wherein the clonal expansion of T cells is clonal expansion for one or more polypeptides encoded by the polynucleotide. 68. The polymersome is an antigen-specific effector CD8 (+) and capable of inducing T cells, preferably the induction being in vivo, ex vivo or in vitro induction, more preferably antigen-specific effector CD8 (+) The polymersome of any one of the preceding claims, wherein said induction of T cells is to one or more polypeptides encoded by said polynucleotide. 69. The polymersome is an antigen-specific CD8 (+) and capable of enhancing the cytotoxic phenotype of T cells, preferably said enhancement being in vivo, ex vivo or in vitro enhancement, more preferably antigen-specific CD8 (+) The polymersome of any one of the preceding paragraphs, wherein the enhancement of the cytotoxic phenotype of a T cell is enhancement against one or more polypeptides encoded by the polynucleotide. 70. The polymersome according to any one of the preceding items, wherein the polymersome is capable of targeting lymph node resident macrophages and / or B cells, preferably, the targeting is in vivo, ex vivo or in vitro targeting, more preferably, the targeting of lymph node resident macrophages and / or B cells is targeting to one or more polypeptides encoded by the polynucleotide. 71. The following abilities: i) the ability to induce a cellular immune response, preferably the cellular immune response being a CD8 (+) and more preferably, the cellular immune response comprises a CD8 (+) a T cell mediated immune response, most preferably the immune response being a response to one or more polypeptides encoded by said polynucleotide; ii) release of polymersome contents in an oxidation-independent manner to CD8 (+) the ability to trigger a T cell-mediated immune response, preferably which immune response is a response to one or more polypeptides encoded by said polynucleotide; iii) the ability to stimulate an immune response against one or more polypeptides encoded by said polynucleotide; iv) CD8 (+) the ability to trigger cross-protection induced by a T cell-mediated immune response, preferably the immune response being a response to one or more polypeptides encoded by said polynucleotide; v) the ability to deliver one or more polypeptides encoded by said polynucleotides to antigen-presenting cells (APCs); vi) CD8 (+) T cell-mediated immune response and / or CD4 (+) the ability to trigger an immune response, including a T cell-mediated immune response, preferably the immune response being a response to one or more polypeptides encoded by said polynucleotide; vii) the ability to stimulate an immune response in a subject, preferably the immune response being a response to one or more polypeptides encoded by said polynucleotide; viii) the ability to immunize a non-human animal, preferably against one or more polypeptides encoded by said polynucleotide; ix) the polymersome has altered antigenicity compared to the corresponding antigenicity of the antigen without the polymersome; x) the polymersome has altered immunogenicity compared to the corresponding immunogenicity of the antigen without the polymersome. The polymersome of any one of the preceding claims, comprising one or more of: 72. The following characteristics: i) the polymersome comprises an oxidatively stable membrane; and / or ii) the polymersome is synthetic, and / or iii) the polymersomes are free of or mixed with non-encapsulated antigens, and / or iv) the polymersome comprises a membrane of an amphiphilic polymer; and / or v) the polymersome comprises an amphiphilic synthetic block copolymer that forms a vesicle membrane; and / or vi) the polymersome has a diameter of more than 70 nm, preferably the diameter is in the range of about 100 nm to about 1 μm, or about 100 nm to about 750 nm, or about 100 nm to about 500 nm, or about 125 nm to about 250 nm, about 140 nm to about 240 nm, about 150 nm to about 235 nm, about 170 nm to about 230 nm, or about 220 nm to about 180 nm, or about 190 nm to about 210 nm, and most preferably the diameter is about 200 nm; and / or vii) the polymersome has the morphology of a vesicle; viii) the polymersome is self-assembling; ix) the polymersome comprises an amphiphilic block copolymer that (a) has the ability to sense pH (e.g., has the ability to protonate or deprotonate in response to pH) and / or (b) has been modified and / or substituted to be a pH-sensitive moiety (e.g., has the ability to protonate or deprotonate in response to pH), preferably the modification and / or substitution comprises modification and / or replacement of hydroxyl groups (e.g., C-OH) with / by -NH3 groups and carboxyl groups (e.g., -COOH) (e.g., modification and / or replacement of PBD-PEO-OH functional groups with PBD-PEO-NH3 and PBD-PEO-COOH). The polymersome of any one of the preceding claims, comprising one or more of: 73. The polymersome according to any one of the preceding items, wherein the polymersome is in the form of a polymersome aggregate, and the average diameter of the polymersome aggregate is in the range of about 100 nm to about 1 μm, or about 100 nm to about 750 nm, or about 100 nm to about 500 nm, or about 125 nm to about 250 nm, about 140 nm to about 240 nm, about 150 nm to about 235 nm, about 170 nm to about 230 nm, or about 220 nm to about 180 nm, or about 190 nm to about 210 nm. 74. The polymersome of any one of the preceding items, wherein the polynucleotide encodes an immunogen. 75. The polymersome according to any one of the preceding items, wherein the polynucleotide is a polynucleotide encoding one or more viral polypeptides, preferably a polynucleotide encoding influenza hemagglutinin, porcine influenza hemagglutinin and / or porcine epidemic diarrhea virus spike protein, more preferably a polynucleotide encoding a polypeptide selected from the group consisting of SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7 and SEQ ID NO:8 and SEQ ID NO:12, 13 and 14. 76. The polynucleotide comprising: i) influenza hemagglutinin (HA), preferably selected from the group consisting of SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7 and SEQ ID NO:8; ii) swine influenza hemagglutinin (HA), preferably SEQ ID NO:6; iii) ovalbumin (OVA), preferably SEQ ID NO:4; iv) B16 peptides, preferably selected from the group consisting of SEQ ID NO:9, SEQ ID NO:10 and SEQ ID NO:11; v) MC38 peptides, preferably selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2 and SEQ ID NO:3; vi) B16 peptides and MC38 peptides, preferably those independently selected from the group: i) SEQ ID NOs:1-3 and ii) SEQ ID NOs:9-11, and / or vii) Porcine epidemic diarrhea virus spike protein and soluble fragments thereof, preferably fragments of SEQ ID NO: 12, 13 or 14. The polymersome of any one of the preceding paragraphs, wherein the polymersome encodes one or more of: 77. The polymersome according to any one of the preceding items, wherein the block copolymer or amphiphilic polymer is essentially non-immunogenic or essentially non-antigenic, preferably the block copolymer or amphiphilic polymer is non-immunogenic or non-antigenic. 78. The polymersome of any one of the preceding items, wherein the block copolymer or amphiphilic polymer is not an immunostimulant or adjuvant. 79. The polymersome of any one of the preceding items, wherein the amphiphilic polymer comprises a diblock or triblock (ABA or ABC) copolymer. 80. The polymersome of any one of the preceding items, wherein the amphiphilic polymer comprises the copolymer poly(N-vinylpyrrolidone)-b-PLA. 81. The polymersome of any one of the preceding items, wherein the amphiphilic polymer comprises at least one monomer unit of a carboxylic acid, an amide, an amine, an alkylene, a dialkylsiloxane, an ether or an alkylene sulfide, preferably wherein the amine has the ability to undergo protonation or deprotonation depending on the pH. 82. The polymersome of any one of the preceding items, wherein the amphiphilic polymer is a polyether block selected from the group consisting of an oligo(oxyethylene) block, a poly(oxyethylene) block, an oligo(oxypropylene) block, a poly(oxypropylene) block, an oligo(oxybutylene) block, and a poly(oxybutylene) block. 83. The polymersome of any one of the preceding items, wherein the amphiphilic polymer is a poly(butadiene)-poly(ethylene oxide) (PB-PEO) diblock copolymer, or the amphiphilic polymer is a poly(dimethylsiloxane)-poly(ethylene oxide) (PDMS-PEO) diblock copolymer. 84. The polymersome according to item 36, wherein the PB-PEO diblock copolymer comprises 5-50 block PB and 5-50 block PEO, or the PB-PEO diblock copolymer preferably comprises 5-100 block PDMS and 5-100 block PEO. 85. The polymersome of any one of the preceding items, wherein the amphiphilic polymer is a poly(lactide)-poly(ethylene oxide) / 1-palmitoyl-2-oleyl-sn-glycero-3-phospho-L-serine (PLA-PEO / POPC) copolymer, preferably, the PLA-PEO / POPC has a ratio of PLA-PEO to POPC (e.g., PLA-PEO / POPC) of 75 to 25 (e.g., 75 / 25). 86. The polymersome of any one of the preceding items, wherein the amphiphilic polymer is a poly(caprolactone)-poly(ethylene oxide) / 1-palmitoyl-2-oleyl-sn-glycero-3-phospho-L-serine (PCL-PEO / POPC) copolymer, preferably, the PCL-PEO / POPC has a ratio of PCL-PEO to POPC (e.g., PCL-PEO / POPC) of 75 to 25 (e.g., 75 / 25). 87. The polymersome of any one of the preceding claims, wherein the amphiphilic polymer is polybutadiene-polyethylene oxide (BD). 88. Diblock copolymer PBD 21 -PEO 14 (BD21) and triblock copolymer PMOXA 12 -PDMS 55 -PMOXA 12 The polymersome of any one of the preceding items, comprising: 89. The polymersome of any one of the preceding items, comprising a lipid polymer. 90. Below: i) polybutadiene-polyethylene oxide (BD), and DLin-MC3-DMA ((6Z,9Z,28Z,31Z)-heptatriaconta-6,9,28,31-tetraen-19-yl 4-(dimethylamino)butanoate) having formula I; ii) PBD-PEO (poly(butadiene)-poly(ethylene oxide)) and DLin-MC3-DMA ((6Z,9Z,28Z,31Z)-heptatriaconta-6,9,28,31-tetraen-19-yl 4-(dimethylamino)butanoate), preferably containing 15% or 30% DLin-MC3-DMA; iii) polybutadiene-polyethylene oxide (BD), and an ionizable lipid 319 having formula II; iv) polybutadiene-polyethylene oxide (BD), and an ionizable lipid C12-200 having formula III; v) polybutadiene-polyethylene oxide (BD) and the ionizable lipid 5A2-SC8 having formula IV; vi) polybutadiene-polyethylene oxide (BD), and an ionizable lipid 306Oi10 having formula V; vii) polybutadiene-polyethylene oxide (BD), and an ionizable lipid 5 having formula VI; viii) polybutadiene-polyethylene oxide (BD), and the ionizable lipid SM-102 having formula VII; ix) polybutadiene-polyethylene oxide (BD), and an ionizable lipid A9 having formula VIII; x) polybutadiene-polyethylene oxide (BD) and an ionizable lipid ALC-0315 having formula IX (i.e., [(4-hydroxybutyl)azanediyl]di(hexane-6,1-diyl)bis(2-hexyldecanoate), xi) polybutadiene-polyethylene oxide (BD), and the ionizable lipid Arcturus 2.2(8.8)4C CH3 having the formula X; xii) polybutadiene-polyethylene oxide (BD), and the ionizable lipid Genevant CL1 having formula XI; xiii) polybutadiene-polyethylene oxide (BD), and the ionizable lipid ALC-0159 having formula XII (i.e., 2-[(polyethylene glycol)-2000]-N,N-ditetradecylacetamide). The polymersome of any one of the preceding claims, comprising one or more of: 91. A composition comprising a polymersome according to any one of the preceding items. 92. The composition according to any one of the preceding items, which is a pharmaceutical composition or a diagnostic composition. 93. The composition of any one of the preceding items, which is an immunogenic composition, an antigenic composition or an immunotherapeutic composition. 94. The composition of any one of the preceding items, further comprising one or more immunostimulants and / or one or more adjuvants. 95. The composition of any one of the preceding items, which is a vaccine. 96. The composition of any one of the preceding items, formulated for intradermal, intraperitoneal, intramuscular, subcutaneous, intravenous injection, or non-invasive administration to a mucosal surface. 97. An isolated antigen-presenting cell or hybridoma cell exposed to a polymersome or composition according to any one of the preceding items. 98. The antigen-presenting cell of any one of the preceding items, comprising a dendritic cell. 99. The antigen-presenting cell of any one of the preceding items, comprising a macrophage. 100. An antigen-presenting cell according to any one of the preceding paragraphs, comprising a B cell. 101. A vaccine comprising the polymersome, composition, antigen-presenting cell or hybridoma according to any one of the preceding items, and further comprising a pharma- ceutically acceptable excipient or carrier. 102. (i) the antigen comprises influenza hemagglutinin (HA) and the vaccine is an influenza vaccine, preferably the influenza hemagglutinin (HA) is at least 60% or more (e.g. at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide selected from the group consisting of SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7 and SEQ ID NO:8; (ii) the antigen comprises swine influenza hemagglutinin (HA) and the vaccine is a swine influenza vaccine, preferably the swine influenza hemagglutinin (HA) is at least 60% or more (e.g. at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to SEQ ID NO:6; (iii) the antigen comprises ovalbumin (OVA) and the vaccine is a cancer vaccine, preferably the ovalbumin (OVA) is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to SEQ ID NO:4; (iv) the antigen comprises a spike protein (PEDv S) and the vaccine is a PED vaccine, preferably the porcine epidemic diarrhea virus spike protein (S protein) is at least 80% or more (e.g., at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide of SEQ ID NO:12-14; (v) the antigen comprises a B16 peptide, and the vaccine is a cancer vaccine, preferably the peptide is selected from the group consisting of SEQ ID NOs: 9 to 11; (vi) The antigen comprises an MC38 peptide, and the vaccine is a cancer vaccine, preferably the peptide is selected from the group consisting of SEQ ID NO: 1 to 3; (vii) the antigen comprises a B16 peptide and an MC38 peptide, and the vaccine is a cancer vaccine, preferably the peptides are independently selected from the group: (i) SEQ ID NOs: 1-3 and (ii) SEQ ID NOs: 9-11; (viii) the antigen is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, and the vaccine is a cancer vaccine. (ix) The antigen is a spike protein of a human pathogenic coronavirus, such as SEQ ID NO:43 The vaccine according to any one of the preceding items. 103. A kit comprising the polymersome, composition, antigen-presenting cell, hybridoma or vaccine of any one of the preceding items. 104. A method for inducing an immune response in a subject (e.g., a human), comprising the steps of: (i) providing to said subject a polymersome, composition, antigen presenting cell, hybridoma or vaccine according to any one of the preceding paragraphs; (ii) administering the polymersome, composition, antigen presenting cell, hybridoma or vaccine to the subject, preferably said administration being by intradermal, intraperitoneal, intramuscular, subcutaneous, intravenous injection, or non-invasive administration to a mucosal surface. A method comprising: 105. The method of inducing an immune response according to any one of the preceding items, wherein the immune response is a broad immune response. 106. Immune response is CD8 (+) T cell-mediated immune response and / or CD4 (+) A method of eliciting an immune response according to any one of the preceding paragraphs, comprising a T cell mediated immune response. 107. A method for treating or preventing an infectious disease, cancer or autoimmune disease in a subject (e.g., a human) in need thereof, comprising administering to the subject a therapeutically effective amount of a polymersome, composition, antigen-presenting cell, hybridoma or vaccine described in any one of the preceding items, preferably wherein the infectious disease is a viral infectious disease or a bacterial infectious disease. 108. A method for immunizing a non-human animal, comprising the steps of: (i) providing a polymersome, composition, antigen presenting cell, hybridoma or vaccine according to any one of the preceding paragraphs; (ii) immunizing a non-human animal with the polymersome, composition, antigen-presenting cell, hybridoma or vaccine. A method comprising: 109. A method for preparing an antibody, comprising the steps of: (i) immunizing a non-human mammal with the polymersome, composition, antigen presenting cell, hybridoma or vaccine according to any one of the preceding paragraphs; (ii) isolating the antibody obtained in step (i). A method comprising: 110. The method of any one of the preceding items, wherein the antibody is a monoclonal antibody (mAb). 111. A polymersome, composition, antigen-presenting cell, hybridoma or vaccine according to any one of the preceding items for use as a medicament. 112. The following methods: i) methods for discovering and / or screening and / or preparing antibodies; ii) methods for discovering and / or screening and / or preparing vaccines; iii) a method for producing or preparing an immunogenic or immunostimulatory composition; iv) A method for targeted delivery of proteins and / or peptides, preferably the targeted delivery is targeted delivery of an antigenic protein and / or antigenic peptide according to any one of the previous items, further preferably the antigenic protein and / or peptide comprises a soluble portion of a membrane protein (MP) or a membrane associated peptide (MAP), most preferably the antigen comprises a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, ovalbumin (OVA), porcine epidemic diarrhea virus spike protein, B16 peptide or MC38 peptide, further most preferably the antigen comprises a soluble portion of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11 and SEQ ID NO: a polypeptide sequence selected from the group consisting of NO:12-14, which is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to the polypeptide sequence selected from the group consisting of NO:12-14, and most preferably, targeted delivery is performed in a subject; v) A method for stimulating an immune response against an antigen, preferably the antigen is an antigen according to any one of the preceding items, more preferably the antigen comprises a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, ovalbumin (OVA), porcine epidemic diarrhea virus spike protein, B16 peptide or MC38 peptide, and most preferably the antigen is selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11 and SEQ ID NO:12. a polypeptide sequence selected from the group consisting of NO:12-14 that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to said polypeptide sequence, and most preferably for use in stimulating an immune response to said antigen in a subject; vi) CD8 (+) A method for triggering cross-protection induced by a T cell-mediated immune response, preferably comprising administering to a subject a CD8 (+)a method for triggering cross-protection induced by a T cell mediated immune response, more preferably wherein the antigen comprises a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, ovalbumin (OVA), porcine epidemic diarrhea virus spike protein, B16 peptide or MC38 peptide, and most preferably wherein the antigen is at least 60% or more (e.g. at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, and SEQ ID NOs:12-14; vii) A method for delivering a peptide and / or protein to an antigen presenting cell (APC) according to any one of the preceding paragraphs, preferably the peptide and / or protein is an antigen according to any one of the preceding paragraphs, more preferably the antigen comprises a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, ovalbumin (OVA), porcine epidemic diarrhea virus spike protein, B16 peptide or MC38 peptide, most preferably the antigen is selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11 and SEQ ID NO:12. A method in which the polypeptide sequence is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of NOs: 12 to 14; viii) CD8 (+) T cell-mediated immune response and / or CD4 (+) A method of triggering an immune response, including a T cell mediated immune response, preferably wherein the response is a response to an antigen according to any one of the preceding items, more preferably wherein the antigen comprises a soluble portion of influenza hemagglutinin, swine influenza hemagglutinin, ovalbumin (OVA), porcine epidemic diarrhea virus spike protein, B16 peptide or MC38 peptide, more preferably wherein the response is a response to an antigen according to SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:8, SEQ ID NO:9, SEQ ID NO:10, SEQ ID NO:11, and SEQ ID A method in response to an antigen that is at least 60% or more (e.g., at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100%) identical to a polypeptide sequence selected from the group consisting of NOs: 12 to 14; ix) A method for treating, ameliorating, preventing or diagnosing an infectious disease, preferably the infectious disease is a viral infectious disease or a bacterial infectious disease, more preferably the viral infectious disease is selected from the group consisting of influenza infection, respiratory syncytial virus infection and herpes virus infection; x) methods for the treatment, amelioration, prevention or diagnosis of cancer or autoimmune diseases; xi) methods for sensitizing cancer cells to chemotherapy; xii) methods for inducing apoptosis in cancer cells; xiii) a method for stimulating an immune response in a subject; xiv) methods for immunizing non-human animals; xv) methods for preparing hybridomas; xvi) the method according to any one of the preceding items, xvii) The method according to any one of i) to xvi), which is an in vivo and / or ex vivo and / or in vitro method; xviii) The method according to any one of i) to xvii) above, wherein the antigen is foreign to the environment in which it is used. The polymersome, composition, antigen presenting cell, hybridoma or vaccine according to any one of the preceding items for use in one or more of the following: 113. The following: (i) to discover and / or screen and / or prepare antibodies; (ii) to discover and / or screen and / or prepare vaccines; (iii) to produce or prepare an immunogenic or immunostimulatory composition; (iv) for targeted delivery of proteins and / or peptides, preferably targeted delivery of antigenic proteins and / or peptides, more preferably targeted delivery is performed in a subject; (v) for stimulating an immune response to an antigen, preferably for use in stimulating an immune response to an antigen in a subject; (vi) CD8 (+) To trigger cross-protection induced by T cell-mediated immune responses, (vii) for delivery of a peptide or protein to an antigen presenting cell (APC), preferably the peptide or protein is an antigen, more preferably the peptide or protein is immunogenic or immunotherapeutic; (viii) CD8 (+) T cell-mediated immune response and / or CD4 (+) To trigger immune responses, including T cell-mediated immune responses, (ix) A method for treating, ameliorating, preventing or diagnosing an infectious disease, preferably the infectious disease is a viral infectious disease or a bacterial infectious disease, more preferably the viral infectious disease is selected from the group consisting of influenza infection, respiratory syncytial virus infection and herpes virus infection, (x) To treat, ameliorate, prevent or diagnose cancer or an autoimmune disease; (xi) To sensitize cancer cells to chemotherapy; (xii) for induction of apoptosis in cancer cells; (xiii) stimulating an immune response in a subject; (xiv) for immunizing non-human animals, (xv) for the preparation of hybridomas, (xvi) In the method according to any one of the preceding paragraphs, (xvii) For the use according to any one of (i) to (xvi) above, which is for in vivo and / or ex vivo and / or in vitro use, (xviii) For the use according to any one of (i) to (xvii) above, wherein the antigen is foreign to the environment in which the antigen is used. Use of the polymersome, composition, antigen presenting cell, hybridoma or vaccine according to any one of the preceding items for one or more of the following: 114. A method for inducing an immune response in a subject, comprising administering to the subject a polymersome formed from PDMS-PEO carrying an antigen. 115. The method according to item 114, wherein the antigen is encapsulated within a PDMS-PEO polymersome. 116. The method according to item 115, wherein the antigen encapsulated in the PDMS-PEO polymersome is a soluble antigen. 117. The method according to item 116, wherein the antigen is selected from the group consisting of polypeptides, carbohydrates, polynucleotides and combinations thereof. 118. The method according to item 114, wherein the antigen is incorporated into the surrounding membrane of the PDMS-PEO polymersome. 119. Antigen-loaded PDMS-PEO polymersomes. 120. The polymersome according to item 119, wherein the antigen is encapsulated within the PDMS-PEO polymersome. 121. The polymersome according to item 120, wherein the antigen encapsulated in the PDMS-PEO polymersome is a soluble antigen. 122. The polymersome according to item 121, wherein the antigen is selected from the group consisting of polypeptides, carbohydrates, polynucleotides and combinations thereof. 123. The polymersome according to item 122, wherein the antigen is incorporated into the surrounding membrane of the PDMS-PEO polymersome. 124. The polymersome according to item 123, wherein the antigen is a membrane-bound protein or a lipid antigen. 125. The polymersome according to item 124, wherein the membrane-bound protein is selected from the group consisting of transmembrane proteins, G protein-coupled receptors, neurotransmitter receptors, kinases, porins, ABC transporters, ion transporters, acetylcholine receptors and cell adhesion receptors. 126. A pharmaceutical composition comprising a polymersome according to any one of items 119 to 125. 127. Use in vitro and in vivo of PDMS-PEO according to any one of items 119 to 125 or of the pharmaceutical composition according to item 126 for inducing an immune response. EXAMPLES

[0203] Example of the invention In order that the present invention may be readily understood and put into practice, certain aspects of the present invention are illustrated below by way of non-limiting examples.

[0204] material and method Example 1: Encapsulation of ovalbumin, peptides, soluble HA, PEDv spike protein and eGFP DNA into polymersomes A 100 mg / ml stock solution of polybutadiene-polyethylene oxide (herein referred to as "BD21") was dissolved in chloroform. 100 μL of the 100 mg / ml BD21 stock solution was then placed in a borosilicate (12×75 mm) culture tube and slowly dried under a stream of nitrogen gas to form a thin polymer film. The film was further dried under reduced pressure in a desiccator for 6 hours. 1 mL of solubilized ovalbumin (OVA) protein at 1-5 mg / ml in 1× PBS buffer was then added to the culture tube. The mixture was stirred at 600 rpm at 4° C. for at least 18 hours to rehydrate the film and form polymer vesicles. The turbid suspension was extruded through a Whatman Nucleopore membrane with a pore size of 200 nm using an extruder (Avanti 1 mL liposome extruder, 21 strokes) to obtain monodisperse vesicles [e.g. Fu et al., 2011, Lim. SK, et al., 2017]. The protein-containing BD21 polymer vesicles were purified from unencapsulated proteins by dialysis of the mixture against 1 L of 1× PBS using a dialysis membrane (300 kDa MWCO, cellulose ester membrane).

[0205] The final vesicle mixture was analyzed for unencapsulated protein using size exclusion chromatography. The fractions of the vesicle peak from SEC were used to quantify protein encapsulation by SDS-PAGE. Vesicle size and monodispersity were characterized with a dynamic light scattering instrument (Malvern, UK) (100-fold dilution in 1× PBS). To quantify OVA encapsulated in polymersomes, samples were pretreated with 20% DMSO and then treated with sample buffer before loading for SDS-PAGE analysis.

[0206] A similar protocol was followed for peptide encapsulation (exemplified with MC38 neo-antigen peptides of SEQ ID NO: 1, 2 and 3). The peptide concentration dissolved in PBS for encapsulation was 0.5-0.3mg / ml. After dialysis, the amount of encapsulated peptide was determined using phenylalanine fluorescence (excitation wavelength 270nm / emission wavelength 310nm) using a Cary Eclipse spectrophotometer (Agilent). The encapsulation of all three peptides was performed individually and the concentration was determined to be 20-30ug / ml for all peptides. Equal amounts of each of the three encapsulated peptides were mixed together just before injection into mice.

[0207] For encapsulation of HA, a similar protocol was followed. For encapsulation, recombinant HA (H1N1 / A / Puerto Rico / 8 / 1934 strain) was dissolved in PBS at a concentration of 10ug / ml. After dialysis, the amount of encapsulated peptide was determined by Western blot. The HA concentration after encapsulation was determined to be around 1ug / ml. 100ul was injected into mice.

[0208] For the encapsulation of PEDv spike protein into BD21 polymersomes, a similar protocol was followed, as described above. Baculovirus expression system was used to express PEDv spike protein (various constructs, SEQ ID NO: 12-14). Protein isolated from insect cells was added for encapsulation. Meanwhile, poly(dimethylsiloxane)-poly(ethylene oxide) (PDMS obtained from Polymer Source, Quebec, Canada) was used for encapsulation. 46 -PEO 37 ) or mixtures of block copolymers and lipids, e.g., PDMS 46 -PEO 37For the encapsulation of PEDv spike protein in polymersomes made with PLA / DSPE-PEG, PLA-PEG / POPC, and PLA-PEG / Azolectin, different protocols were followed to demonstrate the universality of the method. The polymer and / or polymer-lipid mixture was dissolved in ethanol or any water-miscible solvent and self-assembled by dropwise addition to the protein solution. The protein is encapsulated in the polymersomes during self-assembly. Non-encapsulated protein was removed by dialysis against PBS. The amount of encapsulated protein in each polymersome sample after dialysis was determined by densitometry. The concentration of protein after encapsulation was determined to be around 1 μg / ml for each of these polymersome formulations. The polymersomes were encapsulated with either soluble spike protein (SEQ 12) or the S1 region of spike protein (SEQ 13) and the S2 region of spike protein (SEQ 14). Mice were injected with 100–200 μl of polymersomes (containing either soluble spike protein alone or a mixture of polymersomes with the S1 and S2 regions of the spike protein), and pigs were orally administered 1 ml of the same polymersomes.

[0209] For eGFR DNA encapsulation, a similar protocol was followed as for OVA encapsulation. Briefly, block copolymers such as poly(butadiene)-poly(ethylene oxide) (BD21), poly(butadiene)-poly(ethylene oxide) with functional groups (e.g., NH2, COOH) at the ends of the poly(ethylene oxide) chains (BD21-NH2), and mixtures of block copolymers and lipids such as PLA-PEG / POPC, PLA-PEG / Azolectin, dimethylaminoethane-carbamoyl (DC)-cholesterol, and 1,2-dioleyl-3-trimethylammonium-propane (DOTAP) were dissolved in chloroform, transferred to glass tubes, and slowly dried under a stream of nitrogen gas to form thin films. The films were further dried in a desiccator for 6 hours and under reduced pressure. 1 μg of eGFP DNA was added to the films and allowed to rehydrate overnight. The samples were then extruded through 0.2 um polycarbonate filters and dialyzed in HEPES buffer.

[0210] Example 2: Transfection of eGFP DNA-encapsulating polymersomes with HEK293T cells HEK293T cells were seeded in 48-well plates at a density of 50,000 cells / well. For transfection (Lipofectamine 2000 transfection), 1,000 μL of Opti-MEM I (Invitrogen), 2 μL of Lipofectamine 2000 (Invitrogen), and 1 μg of SF-GFP PC DNA (or polymersome formulation containing 1 μg of SF-GFP PC DNA) were mixed. The transfection complex was formed during a 20-min incubation at RT. For transfection, the lipofectamine complex was added to the cells and incubated for 24 h to 72 h at 37 C and 5% CO2. The efficiency of transfection was measured by GFP fluorescence (excitation wavelength 485 nm, emission wavelength 520 nm). For cellular uptake, fluorescence was measured at an excitation wavelength of 530 nm and an emission wavelength of 560 nm. For imaging, after aspirating the cell medium, the cells were washed with DPBS (containing Ca2+ / Mg2+) and fixed with 4% p-formaldehyde. Then, the glass coverslips were removed and flicked onto a glass slide containing a drop of 20ul mounting medium containing DAPI. Finally, the coverslips were sealed with nail polish and stored at 4C for later imaging. Fluorescence microscopy was used for imaging.

[0211] Example 3: Immunization with OVA-encapsulated polymersomes for antibody titers C57bl / 6 mice were immunized with free OVA and OVA-encapsulated ACM (polymersomes) with or without Sigma Adjuvant System (SAS) by priming and boosting 21 days later. All immunizations were performed with a final OVA dose of 5-10ug OVA / injection / mouse. Final bleed was performed 42 days after prime. ELISA was then performed to assess titer. OVA was coated overnight on MaxiSorp plates (1ug / ml). Plates were blocked with 3% BSA in PBS for 1 hour at RT. All sera were diluted 1:100 and incubated on the plates for 1 hour at RT. After 3 washes with PBS+0.05% Tween 20, anti-mouse IgG-HRP-conjugated secondary antibody was incubated at 1:10,000 dilution for 1 hour at RT (room temperature). After 3 washes with PBS / Tween 20 buffer, TMB substrate was added and the reaction was stopped with 1M HCl. The optical density was quantified at 450 nm.

[0212] Example 4: Immunization with HA-encapsulated polymersomes for antibody titers Similarly, Balb / c mice were immunized with free HA protein (SEQ ID NO:7) in PBS, HA encapsulated in ACM (polymersomes) or PBS control. All immunizations were performed with the same final HA amount of 100ng HA / injection / mouse. A final bleed was taken 42 days after priming and ELISA was performed as above using 1ug / ml HA for plate coating.

[0213] Example 5: Immunization with MC38 neoantigen peptide-encapsulated polymersomes for cellular responses To observe specific CD8 T cell responses after immunization, we used the MC-38 syngeneic tumor model. To generate tumors, C57bl / 6 mice were injected subcutaneously into the right flank with MC-38 tumor cells (3 × 10 5Mice were inoculated with 100 μg / ml of peptide (100 μg / ml) per day. The day of inoculation is defined as day 0. Animals were randomized based on body weight, and immunization began on day 4 after inoculation. Immunization consisted of free peptide, peptide encapsulated in ACM (polymersomes) with and without co-treatment with a commercial anti-PD-1 antibody. The peptides were Reps1 P45A (SEQ ID NO:1), Adpgk R304M (SEQ ID NO:2) and Dpagt1 V213L (SEQ ID NO:3) and were obtained from Genscript. Mice were immunized subcutaneously with 200 ul of peptide and peptide in ACM on days 4, 11 and 18. The concentration of peptide in ACM was determined to be 20-30 μg / ml. Meanwhile, for peptide alone, 10 μg per injection per mouse was used. Anti-PD1 antibody was injected intraperitoneally on days 5, 8, 12, 15, 19 and 22 at a dosage of 5 mg / kg. The animals were checked for tumor growth and whether the treatment had any effect on normal behavior such as mobility, food and water consumption, weight gain / loss (body weight was measured three times a week). Tumor size was measured three times a week in two dimensions using calipers and calculated according to the formula: V=0.5a×b 2 where a and b are the long and short diameters of the tumor, respectively, to calculate the volume in mm 3 Expressed in units of.

[0214] Example 6: Immunization of mice and pigs with PEDv spike protein-encapsulated polymersomes Mice were immunized with PEDv spike protein encapsulated in ACM and boosted with a second dose 21 days later. 150ul-200ul of polymersomes encapsulated with PEDv spike protein were used for immunization. Sera were collected from the final bleed and used for ELISA. These sera were further tested for their ability to neutralize PEDV strain USA / Colorado / 2013 (CO / 13) by conventional virus neutralization assay. Furthermore, weanling pigs were orally vaccinated (after prime on day 1 and boost on day 14) with 1ml of polymersomes encapsulated with PED spike protein. Simple physiological solution was used for oral vaccination.

[0215] result Example 1 Protein and DNA Encapsulation: The OVA-encapsulated polymersomes were purified by dialysis and size-exclusion column (SEC) to remove non-encapsulated proteins and analyzed by dynamic light scattering. As shown in Figure 2A, Figure 3, and Figure 4, the elution profile of OVA-encapsulated polymersomes from SEC and a monodisperse population were observed.

[0216] Dynamic light scattering (DLS) data for various polymersomes encapsulating OVA, PEDv spike protein, or eGFP DNA are presented in Figure 2B. They all have an average diameter between 120 nm and 180 nm, as measured using the preferred DLS parameter Z-average (d, nm). The Z-average size is the intensity-weighted harmonic mean particle size, and these values ​​are in good agreement with previous data for polymersomes [Fu et al., 2011; Lim. SK, et al., 2017].

[0217] Encapsulated eGFP DNA and transfection data for Example 2: HEK293T cells were transfected with eGFP DNA-encapsulated polymersomes, and after transfection, ACM polymersome uptake was measured by a fluorescence plate reader at excitation wavelength 530 nm and emission wavelength 560 nm, and transfection efficiency was measured by GFP fluorescence (excitation wavelength 485 nm, emission wavelength 520 nm). As shown in Figure 5, it is clear that DNA-containing polymersomes can enter cells and release DNA to express the DNA into proteins, and all polymersome formulations can be taken up by cells and release DNA, while the ratio of polymersome release to protein expression correlates well with their stability and biodegradability (Figure 5A). Non-biodegradable polymersomes such as BD21 were taken up in lower amounts and had lower expression levels compared to biodegradable polymersomes. Similar results were also observed from the fluorescence images of cells (Figure 5B and Figure 5C).

[0218] Encapsulated OVA and titers for Example 3: OVA-encapsulated polymersomes were used to immunize C57bl / 6 mice with a prime and boost dose 21 days later. ELISA was performed with the last bleed. As shown in Figure 6, it is clear that OVA-encapsulated polymersomes is the only formulation that can trigger titers compared to free OVA, OVA with adjuvant, or control sample (PBS only). The reason why OVA with SAS did not produce titers may be due to the low amount of OVA used in the trial (around 5ug per injection). Therefore, OVA encapsulated in ACM was able to trigger a B cell response against OVA in the form of ovalbumin-specific IgG serum titers.

[0219] Encapsulated HA and titers for Example 4: HA (H1N1 / A / Puerto Rico / 8 / 1934 strain, SEQ ID NO:7) encapsulated polymersomes were used to immunize Balb / c mice with a prime and boost dose 21 days later. ELISA was performed with the last bleed. As shown in Figure 7, it is clear that HA encapsulated polymersomes is the only formulation that can trigger titers compared to free HA or control samples (PBS only). The reason why free HA did not produce titers may be due to the low amount of HA used in the trial (around 100 ng per injection). Thus, HA encapsulated in ACM was able to trigger a B cell response against HA in the form of HA-specific IgG serum titers.

[0220] Example 5 Encapsulated MC-38 Neo-antigenic Peptides and CD8 T Cell Responses: To demonstrate that antigens encapsulated in ACM can trigger CD8 T cell responses, we used the well-characterized MC-38 syngeneic mouse tumor model that relies on the delivery of known CD8 antigenic peptides. Large amounts of these peptides combined with adjuvants have been shown to trigger tumor control in therapeutic mouse models (e.g., Kuai et al., 2017; Luo et al., 2017). In addition, these effects clearly correlated with the presence of peptide-specific CD8 T cells in the mouse blood. Any differences in tumor growth between groups could therefore be directly attributed to the presence of a peptide-specific pool of CD8 T cells. Four days after inoculation with the MC-38 cell line, mice were immunized with either free peptide or peptide encapsulated in ACM (polymersomes) with and without anti-PD1 antibody treatment, as described in Materials and Methods herein. As shown in Figure 8, immunization with encapsulated peptide was able to trigger tumor growth inhibitory effects compared to free peptide. This effect was dramatically enhanced whenever anti-PD1 antibody injection was added. This data demonstrated that peptides (polymersomes) encapsulated in ACMs can trigger peptide-specific CD8 T cell responses, possibly by delivery of these peptides to dendritic cells, which results in tumor control. This effect was increased by the addition of checkpoint inhibitors such as anti-PD1 antibodies. In fact, MC-38 has been shown to express PD-L1 molecules on its cell surface, which are known to inhibit the killing activity of T cells inside tumors. Thus, inhibition of such interactions by antibodies blocking PD1 / PD-L1 interactions is known to further reveal the presence of tumor-specific T cells. Overall, this data clearly demonstrates that antigens (polymersomes) encapsulated in ACMs can trigger antigen-specific CD8 T cell responses without the addition of adjuvants.

[0221] Example 6 Encapsulated PEDv Spike Protein and IgG, IgA and Virus Neutralization Responses: Mice were immunized with PEDv spike protein encapsulated in ACM and boosted with a second dose 21 days later. Sera were collected from the final round and used for ELISA. As seen in Figure 8, antibody binding to spike protein coated on ELISA plates and titers were at similar levels in animals vaccinated with killed virus compared to ACM vaccinated mice. These sera were further tested for their ability to neutralize PEDV strain USA / Colorado / 2013 (CO / 13) in a conventional virus neutralization experiment (Figure 9). Here, it was observed that virus neutralization was found only in sera from mice immunized with the ACM vaccine (i.e., PED spike protein encapsulated in ACM) and not in sera from mice vaccinated with killed virus. Furthermore, various polymersomes (e.g., BD21, PDMS) encapsulated full-length soluble proteins were used to neutralize the PEDV strain USA / Colorado / 2013 (CO / 13) in a conventional virus neutralization experiment (Figure 9). Here, it was observed that virus neutralization was found only in sera from mice immunized with the ACM vaccine (i.e., PED spike protein encapsulated in ACM) and not in sera from mice vaccinated with killed virus. 46 -PEO 37 (In Figure 10, it is simply written "PDMS"), PDMS 46 -PEO 37 Polymersome mixtures containing PED / DSPE-PEG, PLA-PEG / Azolectin lipids) and S1 and S2 regions were used for immunization and sera were tested for virus neutralization (Figure 10). It is clear from Figure 10 that the group of mice immunized with PBS samples does not show any virus neutralization, whereas all other polymersome formulations show various degrees of virus neutralization. Furthermore, weaned pigs were orally vaccinated with PED spike protein encapsulated in ACM and an increase in specific IgA antibodies against the virus (after prime on day 1 and boost on day 14) was observed in collected fecal swabs and measured by ELISA (see Figure 11).

[0222] Example 7: Improved stability (e.g., storage) of polymersomes containing soluble encapsulated mRNA and ionizable lipids OVA mRNA (SEQ ID NO:16) was prepared using ACM-polymersomes according to the following protocols / conditions / compositions.

[0223] 10 μg / ml OVA mRNA was prepared in 20 mM Tris, 4.5 mM acetate, 5% sucrose (eg, based on the Moderna LNP formulation).

[0224] BD / DOTAP (85 / 15) 400 mg / ml ACM-polymersomes were prepared in THF. In Example 7, ACM-polymersomes prepared with BD / DOTAP are used as a reference example. Thus, ACM-polymersomes containing ionizable lipids can be prepared in the same manner as BD / DOTAP polymersomes.

[0225] 11ml (9ml homogenized, 1ml extruded, 1ml non-extruded).

[0226] Homogenization was performed as follows: 5 strokes, final pressure 75-80Mpa-153nm PdI 0.18.

[0227] Homogenization batch split-4 ml dialysis 1000 kDa membrane, split 4 ml between 4°C, -20°C and -80°C.

[0228] Extrusion batch split-0.5ml dialysis, 0.5ml split between 4°C, -20°C, -80°C.

[0229] Co-solvent batch split - 0.5 ml dialysis, split the remainder between 4 °C and -20 °C.

[0230] Next, the mRNA concentration was measured after homogenization and mRNA encapsulation in ACM-polymersomes (Tables 1 and 2).

[0231] Table 1. Measurement of mRNA concentration after homogenization and encapsulation of OVA-mRNA in ACM-polymersomes in the presence of detergent (Triton). TIFF2024518710000015.tif48150

[0232] Table 2. Measurement of mRNA concentration after homogenization and encapsulation of OVA-mRNA in ACM-polymersomes in the absence of detergent (Triton). TIFF2024518710000016.tif62150

[0233] The results in Table 2 demonstrate successful encapsulation of mRNA into ACM-polymersomes after homogenization in the absence of detergent.

[0234] Furthermore, the storage stability of ACM-polymersome encapsulated OVA-mRNA was also examined over a weekend at 4° C. (Table 3).

[0235] Table 3. Storage stability of OVA-mRNA encapsulated in ACM-polymersomes at 4°C. TIFF2024518710000017.tif62148

[0236] Therefore, to assess the stability of the mRNA samples, we compared the DLS profiles of OVA-mRNA-loaded ACM BD / DOTAP polymersomes (above) and LNPs (Onpattro composition, Tables 4-5 below).

[0237] To this end, the following protocols / conditions / compositions were used: Buffer: 20 mM Tris, 5% sucrose, pH 7.4. ACM / LNP molar content: 5 μM. OVA-mRNA (SEQ ID NO:16) content: 25 μg / ml. Storage temperature: -80℃.

[0238] The DLS results are shown in Figure 13. The results demonstrate that the stability of OVA-mRNA loaded in ACM-polymersomes at -80°C is superior to that of OVA-mRNA loaded in LNPs (Onpattro composition).

[0239] Table 4. Onpattro composition TIFF2024518710000018.tif49150

[0240] Table 5. Onpattro Composition (continued) TIFF2024518710000019.tif35150

[0241] In addition, the following empty ACM-polymersome compositions were prepared:

[0242] Empty ACM-polymersomes containing DOTAP (prepared as described above, BD / DOTAP polymersomes are used as a reference example): ACM concentration: 5 µM (7.7-8.6 mg / ml); polymer (mol%): 85 or 70; DOTAP (mol%): 15 or 30; buffer: 20 mM Tris, 4.5 mM acetate, 5% sucrose, pH 7.4.

[0243] Empty ACM-polymersomes containing DLin-MC3-DMA (BD / DLin-MC3-DMA): ACM concentration: 5 µM (7.6–8.6 mg / ml); polymer (mol%): 85 or 70; MC3 (mol%): 15 or 30; starting buffer: 20 mM sodium acetate, pH 5 or 20 mM Tris, 4.5 mM acetate, 5% sucrose, pH 7.4; final buffer: 20 mM Tris, 4.5 mM acetate, 5% sucrose, pH 7.4.

[0244] Next, empty ACM polymersomes prepared with DLin-MC3-DMA ionizable lipid (BD / DLin-MC3-DMA) were compared to reference DOTAP polymersomes (empty) by DLS, demonstrating that both formed similarly (Figure 14).

[0245] Additionally, ACM-polymersomes containing PBD-PEO and DLin-MC3-DMA were also prepared (Table 6).

[0246] Table 6. ACM-polymersomes containing PBD-PEO and DLin-MC3-DMA TIFF2024518710000020.tif95150

[0247] It will be readily apparent to those skilled in the art that the present invention is adapted to carry out and obtain the objects and advantages set forth above and inherent therein. Moreover, it will be apparent to those skilled in the art that various substitutions and modifications may be made to the invention disclosed herein without departing from the scope and spirit of the invention. The compositions, methods, procedures, procedures, molecules, and specific compounds described herein are presently representative of certain embodiments, are exemplary, and are not intended to limit the scope of the invention. Modifications therein and other uses will occur to those skilled in the art that are encompassed within the spirit of the invention and defined by the scope of the claims. The listing or discussion herein of a previously published document should not necessarily be construed as an acknowledgment that the document is part of the state of the art or is common general knowledge.

[0248] The invention illustratively described herein may be suitably implemented in the absence of one or more elements or one or more limitations not specifically disclosed herein. Thus, for example, terms such as "comprising," "including," and "containing" are to be read expansively and without limitation. In addition, the terms and expressions used herein are used as terms of description and not of limitation, and the use of such terms and expressions is not intended to exclude any equivalents of the features shown and described or portions thereof, and it is recognized that various modifications are possible within the scope of the claimed invention. Thus, although the present invention has been specifically disclosed by exemplary embodiments and optional features, it should be understood that those skilled in the art may resort to modifications and variations of the invention embodied herein, and such modifications and variations are considered to be within the scope of the present invention.

[0249] The invention has been described herein broadly in generic terms. Each of the subcategories and subclasses encompassed in the disclosure of the generic terms also form part of this disclosure. This includes describing the invention in generic terms with a provisos or negative limitation excluding any subject matter from the generic term, whether or not the excluded matter is specifically stated herein.

[0250] Other embodiments are within the scope of the following claims. Additionally, when features or aspects of the invention are described in terms of a Markush group, those skilled in the art will understand that the invention is also described thereby in terms of any individual members or subgroups of members of that Markush group.

[0251] References TIFF2024518710000021.tif111150TIFF2024518710000022.tif144150

Claims

1. 1. A polymersome comprising a soluble encapsulated antigen, the soluble encapsulated antigen being a polynucleotide selected from an RNA molecule or a DNA molecule, the polymersome further comprising an ionizable lipid, the ionizable lipid being a tertiary amine and / or comprising one or more tertiary amine moieties, the ionizable lipid not comprising a cationic quaternized ammonium moiety.

2. 2. The polymersome of claim 1, wherein the ionizable lipid is a cationic ionizable lipid.

3. The ionizable lipid is (i) is a tertiary amine and not a quaternary amine, and / or contains one or more tertiary amine moieties and does not contain a cationic quaternized ammonium moiety; and / or (ii) a nitrogen atom contains a free electron pair and is an ionizable nitrogen atom; The polymersome according to any one of the preceding claims.

4. The ionizable lipid may be selected from the group consisting of: i) Formula I: The ionizable lipid DLin-MC3-DMA ((6Z,9Z,28Z,31Z)-heptatriaconta-6,9,28,31-tetraen-19-yl 4-(dimethylamino)butanoate), ii) Formula II: 319, an ionizable lipid having iii) Formula III: ionizable lipid C12-200 having iv) Formula IV: ionizable lipid 5A2-SC8 having v) Formula V: ionizable lipid 306Oi10 having vi) Formula VI: 5, an ionizable lipid having vii) Formula VII: The ionizable lipid SM-102 (heptadecan-9-yl 8-((2-hydroxyethyl)(6-oxo-6-(undecyloxy)hexyl)amino)octanoate), viii) Formula VIII: Ionizable lipid A9 having the formula ix) Formula IX: ALC-0315 ([(4-hydroxybutyl)azanediyl]di(hexane-6,1-diyl)bis(2-hexyldecanoate), an ionizable lipid having x) Formula X: The ionizable lipid Arcturus 2.2 (8.8) 4C CH3, xi) Formula XI: Genevant CL1, an ionizable lipid having xii) Formula XII: ALC-0159 (2-[(polyethylene glycol)-2000]-N,N-ditetradecylacetamide), an ionizable lipid having xiii) any one of (i) to (xii), wherein one or more of the alkyl chains are further esterified; 20. The polymersome of claim 1, comprising or consisting of:

5. 20. The polymersome of any one of the preceding claims, wherein the polynucleotide encodes one or more polypeptides, preferably the one or more polypeptides are viral polypeptides.

6. said polymersomes may increase the thermal stability and / or storage stability and / or immunogenicity of said polynucleotide and / or one or more polypeptides encoded by said polynucleotide within said polymersomes, preferably compared to the same polynucleotide and / or one or more polypeptides encoded by said same polynucleotide within another polymersome without an ionizable substance or within an ionizable lipid nanoparticle (LNP) comprising cholesterol, under the same conditions; More preferably, the thermal stability and / or storage stability is increased within a temperature range of about -80°C to about 4°C, and most preferably, the immunogenicity is increased within a temperature range of about 36.5°C to about 37.5°C, and even most preferably, the increase is at least about 5%.

7. 20. The polymersome of any one of the preceding claims, which is an oxidatively stable polymersome.

8. The following characteristics: i) the polymersome comprises an oxidatively stable membrane; and / or ii) the polymersome is synthetic, and / or iii) the polymersomes are free of or mixed with non-encapsulated antigens, and / or iv) the polymersome comprises a membrane of an amphiphilic polymer; and / or v) the polymersome comprises an amphiphilic synthetic block copolymer that forms a vesicle membrane; and / or vi) the polymersomes have a diameter of more than 70 nm, preferably the diameter is in the range of about 100 nm to about 1 μm, or about 100 nm to about 750 nm, or about 100 nm to about 500 nm, or about 125 nm to about 250 nm, about 140 nm to about 240 nm, about 150 nm to about 235 nm, about 170 nm to about 230 nm, or about 220 nm to about 180 nm, or about 190 nm to about 210 nm, most preferably the diameter is about 200 nm; and / or vii) the polymersome has the morphology of a vesicle; viii) the polymersome is self-assembling; ix) the polymersome comprises an amphiphilic block copolymer, the amphiphilic block copolymer (a) having the ability to sense pH, and / or (b) modified and / or substituted to become a pH-sensitive moiety, preferably the modification and / or substitution comprises modifying and / or replacing hydroxyl groups with -NH3 groups and carboxyl groups. The polymersome of any preceding claim, comprising one or more of:

9. The polynucleotide comprises: i) influenza hemagglutinin (HA), preferably selected from the group consisting of SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:7 and SEQ ID NO:8; ii) swine influenza hemagglutinin (HA), preferably SEQ ID NO:6; iii) ovalbumin (OVA), preferably SEQ ID NO:4; iv) B16 peptides, preferably selected from the group consisting of SEQ ID NO:9, SEQ ID NO:10 and SEQ ID NO:11; v) MC38 peptides, preferably selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2 and SEQ ID NO:3; vi) B16 peptides and MC38 peptides, preferably those independently selected from the group: i) SEQ ID NOs:1-3 and ii) SEQ ID NOs:9-11; and / or vii) Porcine epidemic diarrhea virus spike protein and soluble fragments thereof, preferably fragments of SEQ ID NO: 12, 13 or 14. The polymersome of any one of the preceding claims, encoding one or more of:

10. The polymersome of claim 8, wherein (i) the amphiphilic polymer comprises a diblock or triblock (ABA or ABC) copolymer, (ii) the amphiphilic polymer is polybutadiene-polyethylene oxide (BD), (iii) the polymersome comprises a diblock copolymer PBD21-PEO14 (BD21) and a triblock copolymer PMOXA12-PDMS55-PMOXA12, and / or (iv) the polymersome comprises a lipid polymer.

11. below: i) polybutadiene-polyethylene oxide (BD) and the ionizable lipid DLin-MC3-DMA ((6Z,9Z,28Z,31Z)-heptatriaconta-6,9,28,31-tetraen-19-yl 4-(dimethylamino)butanoate); ii) PBD-PEO (poly(butadiene)-poly(ethylene oxide)) and the ionizable lipid DLin-MC3-DMA ((6Z,9Z,28Z,31Z)-heptatriaconta-6,9,28,31-tetraen-19-yl 4-(dimethylamino)butanoate), preferably comprising 15% or 30% DLin-MC3-DMA; iii) polybutadiene-polyethylene oxide (BD), and an ionizable lipid 319 having formula II; iv) polybutadiene-polyethylene oxide (BD), and an ionizable lipid C12-200 having formula III; v) polybutadiene-polyethylene oxide (BD) and the ionizable lipid 5A2-SC8 having formula IV; vi) polybutadiene-polyethylene oxide (BD), and an ionizable lipid 306Oi10 having formula V; vii) polybutadiene-polyethylene oxide (BD), and an ionizable lipid 5 having formula VI; viii) polybutadiene-polyethylene oxide (BD), and the ionizable lipid SM-102 having formula VII; ix) polybutadiene-polyethylene oxide (BD) and an ionizable lipid A9 having formula VIII; x) polybutadiene-polyethylene oxide (BD) and the ionizable lipid ALC-0315 having formula IX ([(4-hydroxybutyl)azanediyl]di(hexane-6,1-diyl)bis(2-hexyldecanoate); xi) polybutadiene-polyethylene oxide (BD) and the ionizable lipid Arcturus 2.2(8.8)4CCH3 having the formula X; xii) polybutadiene-polyethylene oxide (BD), and the ionizable lipid Genevant CL1 having the formula XI; xiii) Polybutadiene-polyethylene oxide (BD), and the ionizable lipid ALC-0159 having formula XII (2-[(polyethylene glycol)-2000]-N,N-ditetradecylacetamide) The polymersome of any one of the preceding claims, comprising one or more of:

12. 13. A composition comprising a polymersome according to any one of the preceding claims, preferably a pharmaceutical or diagnostic composition, more preferably formulated for intradermal, intraperitoneal, intramuscular, subcutaneous or intravenous injection or for non-invasive administration to a mucosal surface.

13. 13. A kit comprising the polymersome or composition of any preceding claim and further comprising one or more containers.

14. 20. A polymersome, composition or kit according to any preceding claim for use as a medicament.

15. Here's how to do it: i) methods for discovering and / or screening and / or preparing antibodies; ii) a method for producing or preparing an immunogenic or immunostimulatory composition; iii) A method for targeted delivery of said one or more polypeptides encoded by said polynucleotides, and most preferably, said targeted delivery is carried out in a subject; iv) stimulating an immune response against said one or more polypeptides encoded by said polynucleotides; v) CD8 （＋） Methods for triggering cross-protection induced by T cell-mediated immune responses vi) CD8 （＋） T cell-mediated immune response and / or CD4 （＋） Methods for triggering an immune response, including a T cell-mediated immune response, vii) A method for treating, ameliorating, preventing or diagnosing an infectious disease, preferably the infectious disease is a viral or bacterial infectious disease, more preferably the viral infectious disease is selected from the group consisting of influenza infection, PED virus infection, foot and mouth disease virus infection, respiratory syncytial virus infection and herpes virus infection; viii) methods for the treatment, amelioration, prevention or diagnosis of cancer or autoimmune diseases; ix) methods for sensitizing cancer cells to chemotherapy; x) methods for inducing apoptosis in cancer cells; xi) a method for stimulating an immune response in a subject; xii) methods for immunizing non-human animals; xiii) methods for the preparation of hybridomas; xiv) The method according to any one of i) to xiii) above, which is an in vivo and / or ex vivo and / or in vitro method.

20. The polymersome, composition or kit of any preceding claim for use in one or more of the following:

Images