TAU peptide immunogen constructs

Abstract

The present disclosure relates to individual peptide immunogen constructs directed against tau protein moieties for use in the treatment and / or prevention of tauopathies. The disclosure also relates to compositions containing the peptide immunogen constructs, methods of making and using the peptide immunogen constructs, and antibodies produced by the peptide immunogen constructs.

Description

[0001] This application is a PCT international application claiming the benefit of U.S. Provisional Application Serial No. 62 / 578,124, filed on October 27, 2017, which is incorporated herein by reference in its entirety. Technical Field

[0002] The present disclosure relates to peptide immunogen constructs based on Tau protein portions and their preparations, which can be used to prevent and treat Tau diseases. Background Art

[0003] Tau (or tau) is a protein that stabilizes microtubules (see website: en.wikipedia.org / wiki / Tau_protein). Tau is abundant in neurons of the central nervous system and less abundant elsewhere, but is also expressed at very low levels in CNS astrocytes and oligodendrocytes. Neurological pathologies and dementias, such as Alzheimer's and Parkinson's, are associated with Tau proteins that have become defective and can no longer properly stabilize microtubules.

[0004] Tau protein is a product of alternative splicing from a single gene, which in humans is called MAPT (microtubule-associated protein Tau), located on chromosome 17. Tau protein was identified in 1975 as a heat-stable protein essential for microtubule assembly and has since been characterized as an intrinsically disordered protein.

[0005] The Tau protein is a highly soluble microtubule-associated protein (MAP). In humans, these proteins are primarily found in neurons compared to non-neuronal cells. One of the main functions of Tau is to regulate the stability of axonal microtubules. Other nervous system MAPs may exhibit similar functions, as Tau gene knockout mice have shown no abnormalities in brain development - possibly because other MAPs compensate for the loss of Tau. Tau is not present in dendrites and acts primarily in the distal parts of the axon, where it provides microtubule stabilization but also has flexibility depending on demand. In contrast, the MAP6 (STOP) protein located in the proximal part of the axon essentially fixes microtubules, while MAP2 stabilizes microtubules in dendrites.

[0006] Tau proteins interact with tubulin to stabilize microtubules and promote the assembly of tubulin into microtubules. Tau has two ways of controlling microtubule stability: isoforms and phosphorylation.

[0007] Six Tau isoforms ranging in length from 352 to 441 amino acids are expressed in the adult human brain; these are generated by alternative mRNA splicing from the MAPT transcript (Fitzpatrick, et al., 2017; UniProtKB-P10636).

[0008] Isotypes are characterized by the number of their binding domains. Three isotypes have three binding domains, while the other three have four. The binding domain is located at the carboxyl terminus of the protein and is positively charged (making it bind to negatively charged microtubules). Isotypes with four binding domains are better at stabilizing microtubules than isotypes with three binding domains. The difference between the isotypes is the presence or absence of an insert of 29 or 58 amino acids in the amino terminal half, and the presence or absence of a 31-amino acid microtubule binding repeat encoded by exon 10 of MAPT in the carboxyl terminal half. The inclusion of exon 10 leads to the production of three Tau isotypes, each with four repeats (4R). In the other three isotypes, it is excluded, and each isotype has three repeats (3R). Four repeats (R1-R4) are included in residues 244-368 in the 441 amino acid Tau isotype.

[0009] Tau is a phosphorylated protein with 79 potential serine (Ser) and threonine (Thr) phosphorylation sites on the longest Tau isoform. It is reported that about 30 of these sites in normal Tau protein are phosphorylated. The phosphorylation of Tau is regulated by many kinases, including PKN (a serine / threonine kinase). When PKN is activated, it phosphorylates Tau, leading to the destruction of microtubule organization. The phosphorylation of Tau is also developmentally regulated. For example, fetal Tau is more highly phosphorylated in the embryonic CNS than adult Tau. Due to the activation of phosphatases, the phosphorylation degree of all six isoforms decreases with age. Like kinases, phosphatases also play a role in regulating the phosphorylation of Tau. For example, both PP2A and PP2B are present in human brain tissue and have the ability to dephosphorylate Ser396. The binding of these phosphatases to Tau affects the binding of Tau to MT.

[0010] Hyperphosphorylation of Tau protein (Tau inclusions, pTau) can lead to the self-assembly of tangled paired helical filaments and straight filaments, which is involved in the pathogenesis of Alzheimer's disease, frontotemporal dementia and other Tau diseases. All six Tau isoforms often exist in a hyperphosphorylated state in paired helical filaments of Alzheimer's brain. In other neurodegenerative diseases, the deposition of aggregates rich in certain Tau isoforms has been reported. When misfolded, this very soluble protein can form extremely insoluble aggregates, which cause many neurodegenerative diseases.

[0011] Recent studies suggest that Tau may be released extracellularly in Alzheimer's disease through an exosome-based mechanism. Sex-specific Tau gene expression in different regions of the human brain has recently been linked to sex differences in the expression pattern and risk of tauopathies. Certain aspects of how the disease works also suggest some similarities to prions.

[0012] Neurodegenerative diseases with abundant filamentous Tau inclusions are called Tauopathies. In addition to Alzheimer's disease, these diseases include tangle-only dementia, chronic traumatic encephalopathy (CTE), argyrophilic grain disease, progressive supranuclear palsy, corticobasal degeneration, globular glial tauopathy, and Pick's disease. Unlike Alzheimer's disease, these other diseases lack amyloid-β plaques. In Alzheimer's disease, tangle-only dementia, and chronic traumatic encephalopathy, all six Tau isoforms (3R and 4R) are present in the disease filaments. In argyrophilic grain disease, progressive supranuclear palsy, corticobasal degeneration, and pan-glial tauopathies, only the 4R Tau isoform is found, while in Pick's disease only 3R Tau inclusions are present. The occurrence of human tauopathies with distinct filament morphology has led to the view that different molecular conformers of aggregated Tau exist. The presence of multiple molecular conformers may also explain why filaments from the brains of individuals with Alzheimer's disease are more effective than in vitro assembled filaments from recombinant proteins in inducing Tau pathology in mouse brain.

[0013] Repetitive mild traumatic brain injury (TBI) is now recognized as a core component of brain damage in contact sports (particularly American football) as well as the concussive forces of military blasts. It can lead to chronic traumatic encephalopathy (CTE), which is characterized by fibrillar tangles of hyperphosphorylated Tau. High levels of Tau protein in brain fluid are associated with poor recovery after head trauma.

[0014] The Tau hypothesis believes that excessive or abnormal phosphorylation of Tau causes normal adult Tau to be converted into paired helical filaments (paired helical filaments, PHF-Tau) and neurofibrillary tangles (neurofibrillary tangles, NFTs). Tau protein is a highly soluble microtubule-associated protein (MAP). Through its isoforms and phosphorylation, Tau protein interacts with tubulin to stabilize microtubule assembly. Tau protein constitutes a family of six isoforms, which have a range of 352-441 amino acids. The longest isoform in CNS has four repeats (R1, R2, R3 and R4) and two inserts (a total of 441 amino acids), while the shortest isoform has three repeats (R1, R3 and R4) and no inserts (a total of 352 amino acids). All six Tau isoforms are often present in a hyperphosphorylated state in paired helical filaments from AD.

[0015] Mutations that alter Tau function and isoform expression lead to hyperphosphorylation. The process of Tau aggregation in the absence of mutations is unclear, but may be caused by increased phosphorylation, protease action, or exposure to polyanions (e.g., glycosaminoglycans). Hyperphosphorylated Tau depolymerizes microtubules and sequesters normal Tau, MAP 1 (microtubule-associated protein 1), MAP 2, and ubiquitin to form tangles of PHFs. This insoluble structure disrupts cytoplasmic function and interferes with axonal transport, which can lead to cell death.

[0016] To date, there remains an unmet need for the development of cost-effective site-directed peptide immunogens and their formulations for the treatment of patients with tauopathies.

[0017] References

[0018] 1."Tau protein,"Wikipedia,The Free Encyclopedia,website address:en.wikipedia.org / wiki / Tau_protein(accessed September 29,2017).

[0019] 2. Fitzpatrick, AWP, et al., "Cryo-EM structures of Tau filaments from Alzheimer's disease", Nature, 547(7662):185-190(2017). SUMMARY OF THE INVENTION

[0021] The present disclosure relates to individual peptide immunogen constructs for treating and / or preventing Tau diseases, which target portions of Tau proteins. The present disclosure also relates to compositions containing such peptide immunogen constructs, methods for preparing and using such peptide immunogen constructs, and antibodies generated using such peptide immunogen constructs.

[0022] The disclosed peptide immunogen construct contains about 15 or more amino acids. This peptide immunogen construct contains a B cell epitope, which is derived from the longest isoform of the human Tau protein (GenBank: AGF 19246.1) with the amino acid sequence of SEQ ID NO: 100 as shown in Table 8. The B cell epitope can be connected to a heterologous T helper cell (Th) epitope derived from a pathogenic protein by an optional heterologous spacer. The disclosed peptide immunogen construct can stimulate the production of highly specific antibodies against Tau. The disclosed peptide immunogen construct can be used as an immunotherapy for patients with Tau protein disease.

[0023] The B cell epitope portion of the peptide immunogen construct has an amino acid sequence from the full-length Tau protein (SEQ ID NO: 100). In some embodiments, the B cell epitope has a sequence containing any one of SEQ ID NOs: 1-21 and 101-124 as shown in Table 1.

[0024] The peptide immunogen constructs disclosed herein may contain heterologous Th epitope amino acid sequences derived from pathogenic bacteria proteins as shown in Table 2 (e.g., SEQ ID NOs: 22 to 50). In certain embodiments, the heterologous Th epitopes are derived from pathogenic bacteria in nature, such as diphtheria toxin (SEQ ID NO: 26), Plasmodium falciparum (SEQ ID NO: 27), cholera toxin (SEQ ID NO: 29). In other embodiments, the heterologous Th epitopes are idealized artificial Th epitopes derived from measles virus fusion protein (MVF 1 to 5) or hepatitis B surface antigen (HBsAg 1 to 3), which are in the form of single sequences or combined sequences (e.g., SEQ ID NOs: 33, 32, and 34).

[0025] In some embodiments, the peptide immunogen construct comprises a B cell epitope from Tau, which is connected to a heterologous T helper cell (Th) epitope via an optional heterologous spacer. In certain embodiments, the peptide immunogen construct comprises a B cell antigenic determinant having an amino acid sequence from Tau (SEQ ID NOs: 1-21 and 101-124), which is connected to a heterologous Th epitope derived from a pathogenic protein via an optional heterologous spacer (e.g., SEQID NOs: 22 to 50). In some embodiments, the optional heterologous spacer is a molecule or chemical structure capable of connecting two amino acids and / or peptides together. In certain embodiments, the spacer is a naturally occurring amino acid, a non-naturally occurring amino acid, or a combination thereof. In a specific embodiment, the peptide immunogen construct has an amino acid sequence of SEQ ID NOs: 51-71 and 125-155 as shown in Table 3.

[0026] The present disclosure is also about compositions comprising Tau peptide immunogen constructs. In some embodiments, the disclosed compositions comprise more than one Tau peptide immunogen construct to cover multiple B cell epitopes from Tau. In certain embodiments, the composition comprises a mixture of Tau peptide immunogen constructs (e.g., any combination of SEQ ID NOs: 51-71 and 125-155), which has more than one heterologous Th epitope derived from a pathogenic protein to cover a wide range of genetic backgrounds of patients. Compared to compositions comprising only a single Th peptide immunogen construct, compositions comprising a mixture of peptide immunogen constructs can result in a higher percentage of response rate after immunization to treat Tau protein disease.

[0027] The present disclosure also relates to pharmaceutical compositions for treating and / or preventing Tau protein diseases. In some embodiments, the pharmaceutical composition comprises a disclosed peptide immunogen construct, which is present in the form of a stable immunostimulatory complex, which is formed by mixing CpG oligomers and a composition comprising a peptide immunogen complex through electrostatic binding. This stable immunostimulatory complex can further enhance the immunogenicity of the peptide immunogen construct. In some embodiments, the pharmaceutical composition comprises an adjuvant, such as a mineral salt, including alum gel (ALHYDROGEL), aluminum phosphate (ADJUPHOS), or an oil-in-water emulsion including MONTANIDE ISA 51 or 720.

[0028] The present disclosure also relates to antibodies against the disclosed Tau peptide immunogen constructs. Specifically, when administered to a subject, the peptide immunogen constructs of the present disclosure can stimulate the production of highly specific antibodies that can cross-react with Tau amino acid sequences (SEQ ID NOs: 1-21 and 101-124). Highly specific antibodies made using peptide immunogen constructs can cross-react with recombinant Tau-containing proteins. The disclosed antibodies bind to Tau with high specificity, without much, if any, targeting heterologous Th epitopes for immunogenic enhancement, which is in sharp contrast to antibodies made using conventional proteins or other biological carriers for peptide antigenic enhancement.

[0029] The present disclosure also includes methods for treating and / or preventing Tau diseases using disclosed peptide immunogen constructs and / or antibodies against peptide immunogen constructs. In some embodiments, the method for treating and / or preventing Tau diseases comprises administering a composition comprising a disclosed peptide immunogen construct to a host. In certain embodiments, the composition used in this method comprises a disclosed peptide immunogen construct, which is present in the form of a stable immunostimulatory complex, which is formed by electrostatic binding using negatively charged oligonucleotides (e.g., CpG oligomers), and this complex can be further supplemented with an adjuvant (optionally a mineral salt or oil as an adjuvant) for administration to patients with Tau diseases. The disclosed method also includes administering a peptide immunogen construct to a host at risk of Tau diseases or already ill, a dosage regimen, a dosage form, and a route. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1A shows the log-fold increase in immune sera obtained from multiple Tau immunogen constructs at 6 weeks post-primary immunization (wpi) against non-phosphorylated Tau peptide when analyzed on the antigenic region of Tau. 10 Titer expressed as ELISA results.

[0032] Figure 1B shows the log-fold increase in immune sera obtained from multiple Tau immunogen constructs at 6 weeks post-primary immunization (wpi) against phosphorylated Tau peptide when analyzed on the antigenic region of Tau. 10 Titer expressed as ELISA results.

[0033] Figure 2 shows a Western blot analysis of cell lysates containing Tau protein monomers, dimers, trimers and oligomers. Different lanes represent IgG antibodies (left side) triggered by non-phosphorylated Tau peptide immunogen constructs shown above each lane. These peptide immunogen constructs correspond to the structures shown in Table 3. The binding profile of each antibody was analyzed and summarized in a histogram (right side). Representative immune sera against Tau immunogen constructs demonstrated binding reactivity against a variety of Tau (monomers, dimers, trimers, oligomers and polymers).

[0034] Figure 3A shows a graph of the extent of full-length Tau (Tau has 441 amino acids) aggregation after exposure to various antibodies against phosphorylated Tau peptide immunogens (Tau peptide immunogens used were as indicated above each graph at concentrations ranging from 0 to 5 μg / mL) compared to antibodies from pre-immune sera. The extent of Tau aggregation was measured using Thioflavin T (ThT) staining of aggregates.

[0035] FIG. 3B shows a histogram of in vitro Tau aggregation levels in the presence of 5 μg / mL of antibodies against phosphorylated Tau peptide immunogen constructs and methylene blue (methylene blue is known to decluster Tau in vitro and serves as a positive control).

[0036] Figure 4 shows a graph of the extent of Tau aggregation following exposure to antibodies against phosphorylated or non-phosphorylated Tau peptide immunogens (as indicated above each figure). The extent of Tau aggregation was measured using Thioflavin T (ThT) staining of aggregates. Different degrees of inhibition were found for antibodies against phosphorylated or non-phosphorylated Tau immunogens.

[0037] Figure 5 shows a graph of the extent of Tau deaggregation of preformed artificial Tau fibers after exposure to antibodies against phosphorylated or non-phosphorylated representative Tau peptide immunogens (as indicated below each figure). The extent of Tau aggregation was measured using Thioflavin T (ThT) staining of aggregates. Different degrees of deaggregation were found using antibodies from immune sera derived from representative phosphorylated or non-phosphorylated Tau immunogens.

[0038] Figure 6 shows Western blot analysis (under denaturing conditions) of anti-phosphorylated Tau and anti-non-phosphorylated Tau IgGs generated using the disclosed Tau peptide immunogens (as shown on the left). Dot blot analysis (under non-denaturing conditions) of anti-phosphorylated Tau and anti-non-phosphorylated Tau IgGs generated using representative Tau peptide immunogens of the disclosure (as shown on the right). Antibodies elicited by phosphorylated Tau peptide immunogens show preferential binding to fibers and oligomers of Tau.

[0039] Figure 7 shows immunohistochemical staining using representative antibodies generated using phosphorylated and non-phosphorylated Tau peptide immunogens of the present disclosure. The left panel shows the binding profiles in Alzheimer's disease specific and normal brain sections; while the right panel shows no cross-reactivity in normal tissues.

[0040] FIG. 8A shows tissue staining for neuronal protection against fibrillar Tau using representative antibodies raised against phosphorylated and non-phosphorylated Tau peptide immunogens of the present disclosure.

[0041] FIG. 8B shows a graph quantifying neuronal protection against fibrillar Tau using representative antibodies raised against phosphorylated and non-phosphorylated Tau peptide immunogens of the present disclosure.

[0042] [Implementation Method]

[0043] The present disclosure relates to individual peptide immunogen constructs for treating and / or preventing Alzheimer's disease and / or Tauopathy, which target a portion of the Tau protein. The present disclosure also relates to compositions containing the peptide immunogen constructs, methods for preparing and using the peptide immunogen constructs, and antibodies generated using the peptide immunogen constructs.

[0044] The disclosed peptide immunogen construct contains about 15 or more amino acids. This peptide immunogen construct contains a B cell epitope, which is derived from a portion of the longest isoform of the human Tau protein (GenBank: AGF 19246.1) having an amino acid sequence of SEQ ID NO: 100 as shown in Table 8. The B cell epitope can be linked to a heterologous T helper cell (Th) epitope derived from a pathogenic protein via an optional heterologous spacer. The disclosed peptide immunogen construct can stimulate the production of antibodies with high specificity for Tau. The disclosed peptide immunogen construct can be used as an immunotherapy for patients suffering from Alzheimer's disease and / or Tauopathy.

[0045] The B cell epitope portion of the peptide immunogen construct has an amino acid sequence from the full-length Tau protein (SEQ ID NO: 100). In some embodiments, the B cell epitope has a sequence containing any one of SEQ ID NOs: 1-21 and 101-124 as shown in Table 1.

[0046] The peptide immunogen constructs disclosed herein may contain heterologous Th epitope amino acid sequences derived from pathogenic bacteria proteins as shown in Table 2 (e.g., SEQ ID NOs: 22 to 50). In certain embodiments, the heterologous Th epitopes are derived from pathogenic bacteria in nature, such as diphtheria toxin (SEQ ID NO: 26), Plasmodium falciparum (SEQ ID NO: 27), cholera toxin (SEQ ID NO: 29). In other embodiments, the heterologous Th epitopes are idealized artificial Th epitopes derived from measles virus fusion protein (MVF 1 to 5) or hepatitis B surface antigen (HBsAg 1 to 3), which are in the form of single sequences or combined sequences (e.g., SEQ ID NOs: 33, 32, and 34).

[0047] In some embodiments, the peptide immunogen construct comprises a B cell epitope from Tau, which is connected to a heterologous T helper cell (Th) epitope via an optional heterologous spacer. In certain embodiments, the peptide immunogen construct comprises a B cell antigenic determinant having an amino acid sequence from Tau (SEQ ID NOs: 1-21 and 101-124), which is connected to a heterologous Th epitope derived from a pathogenic protein via an optional heterologous spacer (e.g., SEQ ID NOs: 22 to 50). In some embodiments, the optional heterologous spacer is a molecule or chemical structure that can connect two amino acids and / or peptides together. In certain embodiments, the spacer is a naturally occurring amino acid, a non-naturally occurring amino acid, or a combination thereof. In a specific embodiment, the peptide immunogen construct has an amino acid sequence of SEQ ID NOs: 51-71 and 125-155 as shown in Table 4.

[0048] The present disclosure also relates to compositions comprising Tau peptide immunogen constructs. In some embodiments, the disclosed compositions comprise more than one Tau peptide immunogen construct to cover multiple B cell epitopes from Tau. In certain embodiments, the composition comprises a mixture of Tau peptide immunogen constructs (e.g., any combination of SEQ ID NOs: 51-71 and 125-155) having more than one heterologous Th epitope derived from a pathogenic protein to cover a wide range of genetic backgrounds of patients. Compared to compositions comprising only a single peptide immunogen construct, compositions comprising a mixture of peptide immunogen constructs can result in a higher percentage of response rate after immunization to treat Alzheimer's disease and / or Tau protein disease.

[0049] The present disclosure also relates to pharmaceutical compositions for treating and / or preventing Alzheimer's disease and / or Tau protein disease. In some embodiments, the pharmaceutical composition comprises a disclosed peptide immunogen construct, which is in the form of a stable immunostimulatory complex, which is formed by mixing CpG oligomers and a composition comprising the peptide immunogen complex through electrostatic binding. This stable immunostimulatory complex can further enhance the immunogenicity of the peptide immunogen construct. In some embodiments, the pharmaceutical composition comprises an adjuvant, such as a mineral salt, including alum gel (ALHYDROGEL), aluminum phosphate (ADJUPHOS), or an oil-in-water emulsion including MONTANIDE ISA 51 or 720.

[0050] The present disclosure also relates to antibodies against the disclosed Tau peptide immunogen constructs. Specifically, when administered to a subject, the peptide immunogen constructs of the present disclosure can stimulate the production of highly specific antibodies that can cross-react with Tau amino acid sequences (SEQ ID NOs: 1-21 and 101-124). Highly specific antibodies made using peptide immunogen constructs can cross-react with recombinant Tau-containing proteins. The disclosed antibodies bind to Tau with high specificity, without much, if any, targeting heterologous Th epitopes for immunogenic enhancement, which is in sharp contrast to antibodies made using conventional proteins or other biological carriers for peptide antigenic enhancement.

[0051] The present disclosure also includes methods for treating and / or preventing Alzheimer's disease and / or Tau protein disease using disclosed peptide immunogen constructs and / or antibodies to peptide immunogen constructs. In some embodiments, the method for treating and / or preventing Alzheimer's disease and / or Tau protein disease comprises administering a composition comprising a disclosed peptide immunogen construct to a host. In certain embodiments, the composition used in this method comprises a disclosed peptide immunogen construct, which is present in the form of a stable immunostimulatory complex, which is formed by electrostatic binding using negatively charged oligonucleotides (e.g., CpG oligomers), which can be compounded with further supplemented adjuvants (optionally mineral salts or oils as adjuvants) for administration to patients with Alzheimer's disease and / or Tau protein disease. The disclosed method also includes administering a peptide immunogen construct to a host with a risk of Alzheimer's disease and / or Tau protein disease or who is already ill, dosage regimen, dosage form, and route.

[0052] The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.All references, or portions of references, cited in this application are expressly incorporated herein by reference in their entirety for any purpose.

[0053] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those with ordinary knowledge in the art to which the present invention belongs. Unless the context clearly indicates otherwise, the words "a", "an" and "the" include plural forms. Similarly, the word "or" is meant to include "and", unless the context clearly indicates otherwise. Therefore, "comprising A or B" means including A, or B, or A and B. It should be further understood that all amino acid sizes and all molecular weight or molecular mass values ​​for a given polypeptide are approximate and are provided for description purposes. However, methods and materials similar or equivalent to those described herein can be used in the practice or testing of the disclosed methods, suitable methods and materials described below. All publications, patent applications, patents and other references mentioned herein are incorporated herein by reference as a whole. In the event of a conflict, this specification (including the explanation of the terms) shall prevail. In addition, materials, methods and embodiments are illustrative only and are not intended to be limited.

[0054] Tau peptide immunogen constructs

[0055] The present disclosure provides peptide immunogen constructs comprising a B cell epitope having an amino acid sequence from Tau covalently linked to a heterologous T helper cell (Th) epitope either directly or through an optional heterologous spacer.

[0056] The terms "Tau peptide immunogen construct" or "peptide immunogen construct" as used herein refer to a peptide comprising (a) a B cell epitope having about 15 or more amino acid residues from the full-length sequence of the longest Tau isoform (SEQ ID NO: 100); (b) a heterologous Th epitope; and (c) an optional heterologous spacer.

[0057] In certain embodiments, a Tau peptide immunogen construct may be represented by the formula:

[0058] (Th) m –(A) n –(Tau fragment)–X

[0059] or

[0060] (Tau fragment) – (A) n –(Th) m –X

[0061] in

[0062] Th is a heterologous T helper cell epitope;

[0063] A is a heterologous spacer;

[0064] (Tau fragment) is a B cell epitope having about 15 to about 40 amino acid residues from SEQ ID NO: 100;

[0065] X is α-COOH or α-CONH2 of an amino acid;

[0066] m is from 1 to about 4; and

[0067] n is 0 to about 10.

[0068] The various components of the disclosed Tau peptide immunogen constructs are described below.

[0069] a. Tau fragment

[0070] The disclosed peptide immunogen construct contains about 15 or more amino acids. This peptide immunogen construct contains a B cell epitope, which is derived from a portion of the longest isoform of the human Tau protein (GenBank: AGF 19246.1) having an amino acid sequence of SEQ ID NO: 100 as shown in Table 8. The B cell epitope can be linked to a heterologous T helper cell (Th) epitope derived from a pathogenic protein via an optional heterologous spacer. The disclosed peptide immunogen construct can stimulate the production of antibodies with high specificity for Tau. The disclosed peptide immunogen construct can be used as an immunotherapy for patients suffering from Alzheimer's disease and / or Tauopathy.

[0071] The B cell epitope portion of the peptide immunogen construct has an amino acid sequence from the full-length Tau protein (SEQ ID NO: 100). In some embodiments, the B cell epitope has a sequence containing any one of SEQ ID NOs: 1-21 and 101-124 as shown in Table 1.

[0072] In some embodiments, the Tau fragments contain non-phosphorylated amino acids (e.g., SEQ ID NOs: 2, 4, 6, 8, 11, 13, 15, 17, 19, and 21), as shown in Table 1. In other embodiments, the Tau fragments contain phosphorylated serine and / or threonine amino acids (e.g., SEQ ID NOs: 1, 3, 5, 7, 9, 10, 12, 14, 16, 18, and 20), as shown in Table 1. The Tau fragments and phosphorylation sites shown in the peptides of Table 1 are exemplary, and the present disclosure includes any other fragments and / or phosphorylation sites of the full-length Tau protein of SEQ ID NO: 100.

[0073] b. Heterologous T helper cell epitopes (Th epitopes)

[0074] The present disclosure provides peptide immunogen constructs comprising a B cell epitope from Tau covalently linked to a heterologous T helper cell (Th) epitope, either directly or through an optional heterologous spacer.

[0075] Heterologous Th epitopes in Tau peptide immunogen constructs can enhance the immunogenicity of Tau fragments, which promote the generation of specific high-titer antibodies against optimized target B cell epitopes (i.e., Tau fragments) through rational design.

[0076] The term "heterologous" as used herein refers to an amino acid sequence derived from an amino acid sequence that is not part of or homologous to the wild-type sequence of Tau. Therefore, a heterologous Th epitope is a Th epitope derived from an amino acid sequence that is not naturally present in Tau (i.e., the Th epitope is not autologous to Tau). Because the Th epitope is heterologous to Tau, when the heterologous Th epitope is covalently linked to a Tau fragment, the native amino acid sequence of Tau does not extend toward the amino terminal or carboxyl terminal.

[0077] The heterologous Th epitope disclosed herein may be any Th epitope that does not have an amino acid sequence naturally present in Tau. The Th epitope may have an amino acid sequence derived from any species (e.g., human, pig, cattle, dog, rat, mouse, guinea pig, etc.). The Th epitope may also have a promiscuous binding motif for class 2 MHC molecules of various species. In certain embodiments, the Th epitope comprises a plurality of promiscuous class 2 MHC binding motifs to allow maximum activation of T helper cells, thereby leading to the initiation and regulation of an immune response. The preferred Th epitope itself is non-immunogenic (i.e., if any, antibodies generated using Tau peptide immunogen constructs are rarely directed against Th epitopes), thereby allowing a very focused immune response against the target B cell epitope of the Tau fragment.

[0078] Th epitopes disclosed herein include, but are not limited to, amino acid sequences derived from foreign pathogens, as exemplified in Table 2 (SEQ ID NOs: 22 to 50). In addition, Th epitopes include idealized artificial Th epitopes and combined idealized artificial Th epitopes (e.g., SEQ ID NOs: 23 and 30-36). Heterologous Th epitope peptides are presented in a combination sequence (e.g., SEQ ID NOs: 31-34), comprising a mixture of amino acid residues represented at specific positions within the peptide backbone based on the variable residues of the homologs of a specific peptide. A collection of combined peptides can be synthesized in a single process by adding a mixture of selected protected amino acids at specific positions during the synthesis process, rather than a specific amino acid. Such a combination heterologous Th epitope peptide collection can allow for a wide range of Th epitope coverage for animals with different genetic backgrounds. Representative combination sequences of heterologous Th epitope peptides include SEQ ID NOs: 31-34 as shown in Table 2. The Th epitope peptides of the present invention provide a wide range of reactivity and immunogenicity to animals and patients from genetically diverse populations.

[0079] Tau peptide immunogen constructs comprising Th epitopes can be produced simultaneously in a single solid phase peptide synthesis in tandem with Tau fragments. Th epitopes can also include immunological analogs of Th epitopes. Immunological Th analogs include immunopotentiating analogs, cross-reactive analogs, and fragments of any of these Th epitopes that are sufficient to enhance or stimulate an immune response to Tau fragments.

[0080] Functional immunological analogs of Th epitope peptides are also effective and are included as part of the present invention. Functional immunological Th analogs may include conservative substitutions, additions, deletions and insertions of from 1 to about 5 amino acid residues in the Th epitope, which do not substantially change the Th stimulating function of the Th epitope. As described above for Tau fragments, conservative substitutions, additions and insertions can be accomplished using natural or non-natural amino acids. Table 2 identifies another variant of functional analogs of Th epitope peptides. Specifically, SEQ ID NOs: 23 and 30 of MvF 1 and MvF2 Th are functional analogs of SEQ ID NOs: 33 and 35 of MvF4 and MvF5, because the amino acid skeletons are distinguished by deleting (SEQ ID NOs: 23 and 30) or inserting (SEQ ID NOs: 33 and 35) two amino acids at the amino and carboxyl termini. The difference between these two series of similar sequences does not affect the function of the Th epitopes contained in these sequences. Thus, functional immune Th analogs include various versions of Th epitopes derived from the measles virus fusion protein MvF 1-4Ths (SEQ ID NOs: 23, 30, 31, 33 and 35) and from the hepatitis surface protein HBsAg 1-3Ths (SEQ ID NOs: 32, 34 and 36).

[0081] The Th epitope in the Tau peptide immunogen construct may be covalently linked to the amino terminus or carboxyl terminus of the Tau peptide. In some embodiments, the Th epitope is covalently linked to the amino terminus of the Tau peptide. In other embodiments, the Th epitope is covalently linked to the carboxyl terminus of the Tau peptide. In certain embodiments, more than one Th epitope is covalently linked to the Tau fragment. When more than one Th epitope is linked to the Tau fragment, each Th epitope may have the same amino acid sequence or a different amino acid sequence. In addition, when more than one Th epitope is linked to the Tau fragment, the Th epitope may be arranged in any order. For example, the Th epitope may be continuously linked to the amino terminus of the Tau fragment, or continuously linked to the carboxyl terminus of the Tau fragment, or when different Th epitopes are covalently linked to the carboxyl terminus of the Tau fragment, the Th epitope may be covalently linked to the amino terminus of the Tau fragment. There is no restriction on the arrangement of the Th epitope relative to the Tau fragment.

[0082] In some embodiments, the Th epitope is covalently linked directly to the Tau fragment. In other embodiments, the Th epitope is covalently linked to the Tau fragment via a heterologous spacer described in further detail below.

[0083] c. Heterologous spacer

[0084] The disclosed Tau peptide immunogen constructs optionally comprise a heterologous spacer that covalently links a B cell epitope from Tau to a heterologous T helper cell (Th) epitope.

[0085] As described above, the term "heterologous" refers to an amino acid sequence that is derived from an amino acid sequence that is not part of or homologous to the wild-type sequence of Tau. Thus, when a heterologous spacer is covalently attached to a B cell epitope from Tau, the native amino acid sequence of Tau is not extended in the amino-terminal or carboxyl-terminal direction because the spacer is heterologous to the Tau sequence.

[0086] A spacer is any molecule or chemical structure that can link two amino acids and / or peptides together. Depending on the application, the length or polarity of the spacer may vary. Spacer linkages may be through amide or carboxyl linkages, but other functional groups are also possible. Spacers may include chemical compounds, naturally occurring amino acids, or non-naturally occurring amino acids.

[0087] Spacers can provide structural features to Tau peptide immunogen constructs. Structurally, spacers provide physical separation of Th epitopes from B cell epitopes of Tau fragments. Physical separation by spacers can destroy any artificial secondary structures generated by linking Th epitopes to B cell epitopes. In addition, physical separation of epitopes by spacers can eliminate interference between Th cell and / or B cell responses. In addition, spacers can be designed to generate or modify the secondary structure of peptide immunogen constructs. For example, spacers can be designed to act as flexible hinges to enhance the separation of Th epitopes and B cell epitopes. Flexible hinge spacers can also allow for more efficient interactions between presented peptide immunogens and appropriate Th cells and B cells to enhance immune responses to Th epitopes and B cell epitopes. Examples of sequences encoding flexible hinges are found in the hinge region of immunoglobulin heavy chains, which are generally rich in proline. A particularly useful flexible hinge as a spacer is provided by the sequence Pro-Pro-Xaa-Pro-Xaa-Pro (SEQ ID NO: 101), wherein Xaa is any amino acid, with aspartic acid being preferred.

[0088] Spacers can also provide functional features for Tau peptide immunogen constructs. For example, spacers can be designed to change the overall charge of the Tau peptide immunogen construct, which can affect the solubility of the peptide immunogen construct. In addition, changing the overall charge of the Tau peptide immunogen construct can affect the ability of the peptide immunogen construct to bind to other compounds and agents. As discussed in further detail below, the Tau peptide immunogen construct can form a stable immunostimulatory complex with a highly charged oligonucleotide (e.g., a CpG oligomer) through electrostatic binding. The overall charge of the Tau peptide immunogen construct is important for the formation of these stable immunostimulatory complexes.

[0089] Chemical compounds that can be used as spacers include, but are not limited to, (2-aminoethoxy)acetic acid (AEA), 5-aminovaleric acid (AVA), 6-aminohexanoic acid (Ahx), 8-amino-3,6-dioxaoctanoic acid (AEEA, mini-PEG 1), 12-amino-4,7,10-trioxadodecanoic acid (mini-PEG2), 15-amino-4,7,10,13-tetraoxapentadecanoic acid (mini-PEG3), trioxatridecan-succinamic acid (Ttds), 12-aminododecanoic acid, Fmoc-5-amino-3-oxovaleric acid (O1Pen), etc.

[0090] Naturally occurring amino acids include alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, and valine.

[0091] Non-naturally occurring amino acids include, but are not limited to, ε-N-lysine, β-alanine, ornithine, norleucine, norvaline, hydroxyproline, thyroxine, γ-aminobutyric acid, homoserine, citrulline, aminobenzoic acid, 6-aminohexanoic acid (Aca; 6-aminohexanoic acid), mercaptopropionic acid (MPA), 3-nitrotyrosine, pyroglutamic acid, and the like.

[0092] The spacer in the Tau peptide immunogen construct can be covalently linked to the Th epitope and the amino or carboxyl terminus of the Tau peptide. In some embodiments, the spacer is covalently linked to the carboxyl terminus of the Th epitope and the amino terminus of the Tau peptide. In other embodiments, the spacer is covalently linked to the carboxyl terminus of the Tau peptide and the amino terminus of the Th epitope. In certain embodiments, more than one spacer can be used, for example, when there is more than one Th epitope in the peptide immunogen construct. When more than one spacer is used, each spacer can be the same or different from each other. In addition, when there is more than one Th epitope in the peptide immunogen construct, the Th epitope can be separated by a spacer, which can be the same or different, and the Th epitope is separated from the B cell epitope by a spacer. There is no limitation on the arrangement of the spacer relative to the Th epitope or Tau fragment.

[0093] In certain embodiments, the heterologous spacer is a naturally occurring amino acid or a non-naturally occurring amino acid. In other embodiments, the spacer comprises more than one naturally occurring or non-naturally occurring amino acid. In a specific embodiment, the spacer is Lys-, Gly-, Lys-Lys-Lys-, (α, ε-N) Lys or ε-N-Lys-Lys-Lys-Lys (SEQ ID NO: 102).

[0094] Specific Embodiments of Tau Peptide Immunogen Constructs

[0095] The Tau peptide immunogen construct can be represented by the following molecular formula:

[0096] (Th) m –(A) n –(Tau fragment)–X

[0097] or

[0098] (Tau fragment) – (A) n –(Th) m –X

[0099] in

[0100] Th is a heterologous T helper cell epitope;

[0101] A is a heterologous spacer; (Tau fragment) is a B cell epitope having about 15 to about 40 amino acid residues from the full-length Tau protein of SEQ ID NO: 100;

[0102] X is α-COOH or α-CONH2 of an amino acid;

[0103] m is from 1 to about 4; and

[0104] n is 0 to about 10.

[0105] In certain embodiments, the heterologous Th epitope in the Tau peptide immunogen construct has an amino acid sequence selected from any one of SEQ ID NOs: 51-71 and 125-155 and combinations thereof, as shown in Table 3. In a specific embodiment, the Th epitope has an amino acid sequence selected from any one of SEQ ID NOs: 30-36. In certain embodiments, the Tau peptide immunogen construct comprises more than one Th epitope.

[0106] In certain embodiments, the optional heterologous spacer is selected from any one of Lys-, Gly-, Lys-Lys-Lys-, (α,ε-N)Lys, ε-N-Lys-Lys-Lys-Lys (SEQ ID NO: 102), and combinations thereof. In specific embodiments, the heterologous spacer is ε-N-Lys-Lys-Lys-Lys (SEQ ID NO: 102).

[0107] In certain embodiments, the Tau fragment has about 15 to about 40 amino acid residues from the full-length Tau protein of SEQ ID NO: 100. In specific embodiments, the Tau fragment has an amino acid sequence as shown in Table 1 as SEQ ID NOs: 1-21 and 101-124.

[0108] In certain embodiments, the Tau peptide immunogen construct has an amino acid sequence selected from any one of SEQ ID NOs: 51-71 and 125-155, as shown in Table 3.

[0109] a. Variants, homologues and functional analogs

[0110] Variants and analogs of the above-mentioned immunogenic peptides can also be used, which can induce antibodies and / or cross-react with antibodies, and this antibody is a preferred epitope for the Tau protein. Analogs (including alleles, species, and induced variants) are usually different from naturally occurring peptides at one, two, or several positions, usually due to conservative substitutions. Analogs usually show at least 80 or 90% sequence identity with natural peptides. Some analogs also include non-natural amino acids or modifications of the amino-terminal or carboxyl-terminal amino acids at one, two, or several positions.

[0111] Variants that are functional analogs may have conservative substitutions at amino acid positions, changes in overall charge, covalent linkages with other functional groups or additions, insertions or deletions of amino acids and / or any combination thereof.

[0112] Conservative substitutions refer to the replacement of one amino acid residue by another amino acid residue with similar chemical properties. For example, nonpolar (hydrophobic) amino acids include alanine, leucine, isoleucine, valine, proline, phenylalanine, tryptophan, and methionine; polar neutral amino acids include glycine, serine, threonine, cysteine, tyrosine, asparagine, and glutamine; positively charged (basic) amino acids include arginine, lysine, and histidine; and negatively charged (acidic) amino acids include aspartic acid and glutamic acid.

[0113] In a specific embodiment, the functional analog has at least 50% identity with the original amino acid sequence. In another embodiment, the functional analog has at least 80% identity with the original amino acid sequence. In yet another embodiment, the functional analog has at least 85% identity with the original amino acid sequence. In yet another embodiment, the functional analog has at least 90% identity with the original amino acid sequence.

[0114] Variants also include changes in phosphorylated residues. For example, a variant may include different residues within a phosphorylated peptide. Variant immunogenic Tau peptides may also include pseudophosphorylated peptides. Pseudophosphorylated peptides are generated by replacing one or more phosphorylated serine, threonine, and tyrosine residues of a Tau peptide with acidic amino acid residues (e.g., glutamic acid and aspartic acid).

[0115] Composition

[0116] The present disclosure also provides compositions comprising the disclosed Tau immunogen constructs.

[0117] a. Peptide Composition

[0118] Compositions comprising the disclosed Tau peptide immunogen constructs may be in liquid or solid form. Liquid compositions may include water, buffers, solvents, salts, and / or any other acceptable agents that do not alter the structural or functional properties of the Tau peptide immunogen constructs. Peptide compositions may contain one or more disclosed Tau peptide immunogen constructs.

[0119] b. Pharmaceutical Compositions

[0120] The present disclosure also relates to pharmaceutical compositions comprising the disclosed Tau peptide immunogen constructs.

[0121] The pharmaceutical composition may contain a carrier and / or other additives in a pharmaceutically acceptable delivery system. Therefore, the pharmaceutical composition may contain a pharmaceutically effective dose of the Tau peptide immunogen construct and a pharmaceutically acceptable carrier, adjuvant and / or other excipient (e.g., diluent, additive, stabilizer, preservative, solubilizer, buffer, etc.).

[0122] The pharmaceutical composition may contain one or more adjuvants, which function to accelerate, prolong or enhance the immune response to the Tau peptide immunogen construct without having any specific antigenic effect itself. Adjuvants used in the pharmaceutical composition may include oils, aluminum salts, virosomes, aluminum phosphates (e.g. ), aluminum hydroxide (e.g. ), lipo syn, saponin, squalene, L 121, Monophosphoryl lipid A (MPL), QS21, ISA 35, ISA 206, ISA 50V, ISA 51, ISA 720, and other adjuvants and emulsifiers.

[0123] In some embodiments, the pharmaceutical composition contains MONTANIDE TM ISA 51 (an oily adjuvant composition consisting of vegetable oil and mannide oleate for the preparation of a water-in-oil emulsion), 80 (also known as polysorbate 80 or polyoxyethylene (20) sorbitan monooleate), CpG oligonucleotides and / or any combination thereof. In other embodiments, the pharmaceutical composition is a water-in-oil-in-water (i.e., w / o / w) emulsion with Emulsigen or Emulsigen D as an adjuvant.

[0124] The pharmaceutical composition can be formulated into an immediate release or sustained release dosage form. In addition, the pharmaceutical composition can be formulated for inducing systemic or local mucosal immunity by encapsulation of immunogens and co-administration with microparticles. Such delivery systems are easily determined by those with ordinary knowledge in the art.

[0125] The pharmaceutical composition can be formulated as an injection in the form of a liquid solution or suspension. A liquid carrier containing a Tau peptide immunogen construct can also be prepared before injection. The pharmaceutical composition can be administered using any suitable method, such as id, iv, ip, im, intranasal, oral, subcutaneous, etc., and can be administered in any suitable delivery device. In certain embodiments, the pharmaceutical composition can be formulated for intravenous, subcutaneous, intradermal or intramuscular administration. Pharmaceutical compositions suitable for other modes of administration can also be prepared, including oral and intranasal applications.

[0126] The pharmaceutical composition can be formulated into an immediate release or sustained release dosage form. In addition, the pharmaceutical composition can be formulated for inducing systemic or local mucosal immunity by encapsulation of immunogens and co-administration with microparticles. Such delivery systems are easily determined by those with ordinary knowledge in the art.

[0127] The pharmaceutical composition can also be formulated in a suitable dosage unit form. In some embodiments, the pharmaceutical composition contains about 0.5 μg to about 1 mg of Tau peptide immunogen construct per kilogram of body weight. The effective dose of the pharmaceutical composition depends on many different factors, including the mode of administration, the target, the physiological state of the patient, whether the patient is human or animal, other drugs administered, and whether the treatment is for prevention or treatment. Typically, the patient is human, but non-human mammals including genetically modified mammals can also be treated. When delivered in multiple doses, the pharmaceutical composition can be conveniently divided into appropriate amounts for each dosage unit form. The dose administered depends on the age, weight and general health of the subject, which are well known in the therapeutic field.

[0128] In some embodiments, the pharmaceutical composition contains more than one Tau peptide immunogen construct. Pharmaceutical compositions containing a mixture of more than one Tau peptide immunogen construct allow for synergistic enhancement of the immunological efficacy of the construct. Pharmaceutical compositions containing more than one Tau peptide immunogen construct may be more effective in a larger genetic population due to broad class 2 MHC coverage, thus providing an improved immune response to the Tau peptide immunogen construct.

[0129] In some embodiments, the pharmaceutical composition contains a Tau peptide immunogen construct selected from SEQ ID NOs: 51-71 and 125-155, and homologs, analogs and / or combinations thereof. In a specific embodiment, the pharmaceutical composition contains a Tau peptide immunogen construct selected from SEQ ID NOs: 51-71 and 125-155, and any combination thereof.

[0130] Pharmaceutical compositions containing Tau peptide immunogen constructs can be used to induce an immune response and produce antibodies in a host after administration.

[0131] c. Immunostimulatory complex

[0132] The present disclosure also relates to pharmaceutical compositions containing Tau peptide immunogen constructs that form immunostimulatory complexes with CpG oligonucleotides. Such immunostimulatory complexes are particularly suitable as adjuvants and peptide immunogen stabilizers. The immunostimulatory complexes are in the form of microparticles that can effectively present Tau peptide immunogens to cells of the immune system to produce an immune response. The immunostimulatory complexes can be formulated as suspensions for parenteral administration. The immunostimulatory complexes can also be formulated in the form of w / o emulsions as suspensions combined with mineral salts or in situ gelling polymers for effective delivery of Tau peptide immunogens to cells of the host immune system after parenteral administration.

[0133] Stable immunostimulatory complexes can be formed by complexing a Tau peptide immunogen construct with an anionic molecule, oligonucleotide, polynucleotide, or a combination thereof through electrostatic binding. Stable immunostimulatory complexes can be incorporated into pharmaceutical compositions as immunogen delivery systems.

[0134] In certain embodiments, a Tau peptide immunogen construct is designed to include a cationic moiety that has a positive charge at a pH in the range of 5.0 to 8.0. The net charge of the cationic moiety of a Tau peptide immunogen construct or mixture of structures is calculated based on each lysine (K), arginine (R), or histidine (H) having a charge of +1, each aspartic acid (D) or glutamic acid (E) having a charge of -1, and the charge of the other amino acids in the sequence being 0. The charges of the cationic moieties in the Tau peptide immunogen construct are added together and expressed as a net average charge. Suitable peptide immunogens have cationic moieties with a net average positive charge of +1. Preferably, the peptide immunogen has a net positive charge in the range of greater than +2. In some embodiments, the cationic moiety of the Tau peptide immunogen construct is a heterologous spacer. In certain embodiments, when the spacer sequence is (α,ε-N)Lys,ε-N-Lys-Lys-Lys-Lys (SEQ ID NO: 102), the cationic portion of the Tau peptide immunogen construct has a charge of +4.

[0135] As described herein, "anionic molecule" refers to any molecule with a negative charge at a pH in the range of 5.0 to 8.0. In certain embodiments, the anionic molecule is an oligomer or polymer. The net negative charge calculation on the oligomer or polymer is based on the fact that each phosphodiester or thiophosphate group in the oligomer carries a -1 charge. Suitable anionic oligonucleotides are single-stranded DNA molecules with 8 to 64 nucleotide bases, and the number of repeats of the CpG motif is in the range of 1 to 10. Preferably, the CpG immunostimulatory single-stranded DNA molecule contains 18 to 48 nucleotide bases, and the number of repeats of the CpG motif is in the range of 3 to 8.

[0136] More preferably, the anionic oligonucleotide may have the formula 5'X1 CGX 2 3' means, wherein C and G are unmethylated; and X 1 is selected from the group consisting of A (adenine), G (guanine) and T (thymine); and X 2 is C (cytosine) or T (thymine). Alternatively, anionic oligonucleotides may have a molecular formula of 5'(X 3 )2CG(X 4 )2 3' represents, wherein C and G are unmethylated; and X 3 is selected from the group consisting of A, T or G; and X 4 It is C or T.

[0137] The resulting immunostimulatory complex is in particulate form, the size of which is typically in the range of 1-50 microns and is a function of many factors, including the relative charge stoichiometry and molecular weight of the interacting components. Microparticulate immunostimulatory complexes have the advantage of providing adjuvantation and upregulation of specific immune responses in vivo. In addition, the stable immunostimulatory complex is suitable for preparing pharmaceutical compositions by various methods, including water-in-oil emulsions, mineral salt suspensions, and polymeric gels.

[0138] Antibody

[0139] The present disclosure also provides antibodies elicited using Tau peptide immunogen constructs.

[0140] The disclosed Tau peptide immunogen construct comprises a Tau fragment, a heterologous Th epitope, and an optional heterologous spacer, and when administered to a host, the Tau peptide immunogen construct can induce an immune response and the production of antibodies. The Tau peptide immunogen construct is designed to break immune tolerance against autologous Tau and induce the production of site-specific antibodies that can recognize conformational epitopes (rather than linear epitopes).

[0141] Antibodies generated from Tau peptide immunogen constructs can recognize and bind to Tau in the form of monomers, dimers, trimers, and oligomers.

[0142] Surprisingly, antibodies elicited by Tau peptide immunogen constructs can prevent Tau aggregation (anti-aggregation activity) and can disaggregate preformed Tau aggregates (declustering activity).

[0143] The immune response generated by immunizing animals with the Tau peptide immunogen constructs of the present invention demonstrated that the constructs have the ability to generate effective site-directed antibodies that react with monomers, dimers, trimers and oligomers of Tau.

[0144] method

[0145] The present disclosure also relates to methods for making and using Tau peptide immunogen constructs, compositions, and pharmaceutical compositions.

[0146] a. Method for producing Tau peptide immunogen construct

[0147] The Tau peptide immunogen constructs disclosed herein can be prepared using chemical synthesis methods well known to those of ordinary skill (see, for example, Fields et al., Chapter 3 in Synthetic Peptides: A User's Guide, ed. Grant, WH Freeman & Co., New York, NY, 1992, p. 77). Tau peptide immunogen constructs can be synthesized using automated Merrifield solid phase synthesis, using side chain protected amino acids, α-NH2 chemically protected with t-Boc or F-moc, for example, on an Applied Biosystems Peptide Synthesizer Model 430A or 431. Preparation of Tau peptide immunogen constructs containing combinatorial database peptides of Th epitopes can be achieved by providing a mixture of alternative amino acids for coupling at a given variable position.

[0148] After the desired Tau peptide immunogen construct is assembled, the resin is treated according to standard procedures to cleave the peptide from the resin and remove the functional groups on the amino acid side chains. The free peptide can be purified by HPLC and characterized by, for example, amino acid analysis or sequencing. Methods for purification and characterization of peptides are well known to those of ordinary skill in the art to which the present invention belongs.

[0149] The quality of the peptides produced by this chemical process can be controlled and determined, and as a result the reproducibility, immunogenicity and yield of the Tau peptide immunogen constructs can be guaranteed. A detailed description of the manufacture of Tau peptide immunogen constructs by solid phase peptide synthesis is shown in Example 1.

[0150] The range of structural variation that allows retention of the desired immunological activity has been found to be more inclusive than the range of structural variation that allows retention of specific drug activity of small molecule drugs or the presence of desired activity and undesired toxicity in macromolecules co-produced with biologic drugs. Thus, peptide analogs with similar chromatographic and immunological properties to the desired peptide, whether intentionally designed or produced as a mixture of sequence deletion byproducts unavoidably due to errors in the synthetic process, generally have the same effect as the purified desired peptide preparation. Mixtures of designed analogs and unintended analogs are also effective as long as strict QC procedures are established to monitor the manufacturing process and product evaluation process to ensure the reproducibility and effectiveness of the final product using these peptides.

[0151] Tau peptide immunogen constructs can also be prepared using recombinant DNA technology including nucleic acid molecules, vectors and / or host cells. Therefore, nucleic acid molecules encoding Tau peptide immunogen constructs and immunologically functional analogs thereof are also included in the present disclosure as part of the present invention. Similarly, vectors (including expression vectors) containing nucleic acid molecules and host cells containing vectors are also included in the present disclosure as part of the present invention.

[0152] Various exemplary embodiments also include methods for making Tau peptide immunogen constructs and immunologically functional analogs thereof. For example, the method may include the step of culturing a host cell under conditions of expressing the peptide and / or analogs, the host cell comprising an expression vector containing a nucleic acid molecule encoding the Tau peptide immunogen construct and / or its immunologically functional analogs. Longer synthetic peptide immunogens can be synthesized using well-known recombinant DNA techniques. These techniques can be provided in well-known standard manuals with detailed experimental plans. In order to construct a gene encoding a peptide of the present invention, the amino acid sequence is reversely translated to obtain a nucleic acid sequence encoding the amino acid sequence, preferably using the most suitable codons for the organism in which the gene to be expressed is present. Next, a synthetic gene is usually made by synthesizing oligonucleotides encoding the peptide and any regulatory factors (if necessary). The synthetic gene is inserted into a suitable cloning vector and transfected into a host cell. The peptide is then expressed under suitable conditions suitable for the selected expression system and host. The peptide is purified using standard methods and its properties are described.

[0153] b. Method for producing immunostimulatory complex

[0154] Various exemplary embodiments also include methods for making immunostimulatory complexes comprising Tau peptide immunogen constructs and CpG oligodeoxynucleotide (ODN) molecules. Stable immunostimulatory complexes (ISCs) are derived from the cationic portion of the Tau peptide immunogen construct and the polyanionic CpG ODN molecules. The self-assembly system is driven by electrostatic neutralization of charges. The stoichiometry of the molar charge ratio of the cationic portion of the Tau peptide immunogen construct to the anionic oligomer determines the degree of association. The non-covalent electrostatic binding of the Tau peptide immunogen construct and the CpG ODN is a completely reproducible process. This peptide / CpGODN immunostimulatory complex aggregate facilitates presentation to "professional" antigen presenting cells (APCs) in the immune system, thereby further enhancing the immunogenicity of the complex. During the manufacturing process, the characteristics of these complexes can be easily characterized to control quality. The peptide / CpG ISC has good tolerance in vivo. This novel microparticle system comprising CpG ODN and a Tau fragment-derived peptide immunogen construct was designed to exploit the generalized B cell mitogenicity associated with the use of CpG ODN, but to promote a balanced Th-1 / Th-2 type response.

[0155] The CpG ODN in the disclosed pharmaceutical composition is 100% bound to the immunogen in a process mediated by electrostatic neutralization of opposite charges, resulting in the formation of micron-sized particles. The microparticle format allows for a significant reduction in the CpG dose conventionally used with CpG adjuvants, a lower likelihood of adverse innate immune responses, and promotes alternative immunogen processing pathways including antigen presenting cells (APCs). Therefore, this dosage form is conceptually novel and offers potential advantages by promoting stimulation of immune responses through alternative mechanisms.

[0156] c. Method for producing a pharmaceutical composition

[0157] Various exemplary embodiments also include pharmaceutical compositions containing Tau peptide immunogen constructs. In certain embodiments, the pharmaceutical compositions use water-in-oil emulsions and suspensions with mineral salts.

[0158] In order to make the pharmaceutical composition available to a wide range of people, and to avoid Tau aggregation as part of the dosing goal, safety becomes another important factor to consider. Although water-in-oil emulsions are used in humans for many dosage forms in clinical trials, alum is still the main adjuvant used in formulations based on its safety. Therefore, alum or its mineral salt aluminum phosphate (ADJUPHOS) is often used as an adjuvant in formulations for clinical use.

[0159] Other adjuvants and immunostimulants include 3De-O-acylatedmonophosphoryl lipid A (MPL) or 3-DMP, polymeric or monomeric amino acids, such as polyglutamic acid or polylysine. Such adjuvants can be used with or without other specific immunostimulants, such as muramylpeptides (e.g., N-acetylmuramyl-L-threonyl-D-isoglutamine (thr-MDP), N-acetyl-normuramyl-L-alanyl-D-isoglutamine (nor-MDP),

[0160] N-acetylmuramyl-L-alanyl-D-isoglutaminyl-L-alanine-2-(1′-2′

[0161] dipalmitoyl-sn-glycero-3-hydroxyphosphoryloxy)-ethylamine (MTP-PE),

[0162] N-acetylglucsaminyl-N-acetylmuramyl-L-Al-D-isoglu-L-Ala-dipalmitoxypropylamide(DTP-DPP)Theramide TM ), or other bacterial cell wall components. The oil-in-water emulsion includes MF59 (see patent application WO 90 / 14837 of Van Nest et al., which is incorporated herein by reference in its entirety), including 5% squalene, 0.5% Tween 80, and 0.5% Span 85 (optionally containing different amounts of MTP-PE), which is formulated into submicron particles using a microfluidizer; SAF, which includes 10% squalene, 0.4% Tween 80, 5% pluronic-block copolymer L 121, and thr-MDP, which is formed into a submicron emulsion using microfluidization or vortexed to produce a large particle emulsion; and Ribi TM Adjuvant system (RAS) (Ribi ImmunoChem, Hamilton, Mont.), which comprises 2% squalene, 0.2% Tween 80, and one or more bacterial cell wall components, the bacterial cell wall components are selected from the group consisting of monophosphoryl lipid A (MPL), trehalose dimycolate (TDM) and cell wall skeleton (CWS), preferably MPL + CWS (Detox TMOther adjuvants include complete Freund's adjuvant (CFA), incomplete Freund's adjuvant (IFA), and cytokines such as interleukins (IL-1, IL-2, and IL-12), macrophage colony stimulating factor (M-CSF), and tumor necrosis factor (TNF).

[0163] The choice of adjuvant depends on the stability of the immunogen preparation containing the adjuvant, the route of administration, the dosing schedule, the efficacy of the adjuvant on the species to be vaccinated, and pharmaceutically acceptable adjuvants in humans refer to adjuvants that have been approved or can be approved for human administration by relevant regulatory agencies. For example, alum, MPL or Freund's incomplete adjuvant (Chang et al., Advanced Drug Delivery Reviews 32: 173-186 (1998), which is incorporated herein by reference in its entirety) alone or optionally all combinations thereof suitable for human administration.

[0164] The composition may include a pharmaceutically acceptable non-toxic carrier or diluent, which is defined as a carrier commonly used in formulating pharmaceutical compositions for administration to animals or humans. The diluent is selected so as not to affect the biological activity of the combination. Examples of such diluents are distilled water, physiological phosphate buffered saline, Ringer's solution, dextrose solution, and Hank's solution. In addition, the pharmaceutical composition or dosage form may also include other carriers, adjuvants, or non-toxic, non-therapeutic, non-immunogenic stabilizers, etc.

[0165] Pharmaceutical compositions may also include large, slowly metabolized macromolecules (e.g., proteins, polysaccharides (e.g., chitin), polylactic acid, polyglycolic acid, and copolymers (e.g., latex functionalized sepharose, agarose, cellulose, etc.), polymeric amino acids, amino acid copolymers, and lipid aggregates (e.g., oil droplets or liposomes). In addition, these carriers may act as immunostimulants (i.e., adjuvants).

[0166] The pharmaceutical composition of the present invention may further comprise a suitable delivery vehicle. Suitable delivery vehicles include, but are not limited to, viruses, bacteria, biodegradable microspheres, microparticles, nanoparticles, liposomes, collagen microspheres and cochleates.

[0167] d. Methods of using the pharmaceutical composition

[0168] The present disclosure also includes methods of using pharmaceutical compositions comprising Tau peptide immunogen constructs.

[0169] In certain embodiments, pharmaceutical compositions comprising Tau peptide immunogen constructs may be used to:

[0170] (a) Inhibit Tau aggregation in the host;

[0171] (b) inducing the disaggregation of preformed Tau aggregates in the host;

[0172] (c) reducing neurodegeneration induced by exogenous Tau aggregates in the host;

[0173] (d) Reduced neurodegeneration in Tau-overexpressing cells;

[0174] (e) reducing serum Tau levels in the host;

[0175] (f) reducing the content of Tau oligomers in the host brain;

[0176] (g) Reducing neuropathology and restoring motor function in the host.

[0177] The above method comprises administering a pharmaceutical composition comprising a pharmaceutically effective dose of a Tau peptide immunogen construct to a host in need thereof.

[0178] As used herein, "Tauopathy" includes any neurodegenerative disease involving pathological aggregation of the microtubule protein Tau in the brain. Thus, in addition to familial and sporadic Alzheimer's disease, other tauopathies that can be treated using the methods of the invention include, but are not limited to, frontotemporal dementia, Parkinson's disease associated with chromosome 17 (FTDP-17), progressive supranuclear palsy, corticobasal degeneration, Pick's disease, progressive subcortical gliosis, tangle-only dementia, diffuse neurofibrillary tangles with calcification, argyrophilic grain dementia, amyotrophic lateral sclerosis parkinsonism-dementia complex, dementia pugilistica, Down syndrome, Gerstmann-Straussler-Scheinker disease, Hallerworden-Spatz disease, inclusion body myositis, Creutzfeld-Jakob disease, multiple system atropy, Niemann-Pick disease type C, prion protein cerebral amyloidangiopathy, subacute sclerosing panencephalitis, myotonic dystrophy, non-guanamian motor neurondisease with neurofibrillary tangles, postencephalitic parkinsonism, and chronic traumatic encephalopathy.

[0179] Another aspect of the present disclosure is a method for promoting the clearance of Tau aggregates from the brain of a subject. The method involves administering to the subject any one or more immunogenic Tau peptides having an amino acid sequence selected from the group consisting of SEQ ID NOs: 1-21 and 101-124, or administering one or more antibodies that recognize an immunogenic Tau epitope comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 1-21 and 101-124 and 51-71 and 125-155, under conditions effective to promote the clearance of Tau aggregates from the brain of the subject.

[0180] The clearance of tau aggregates includes the clearance of neurofibrillary tangles and / or pathological tau precursors of neurofibrillary tangles. Neurofibrillary tangles are often associated with neurodegenerative diseases, including, for example, sporadic and familial Alzheimer's disease, amyotrophic lateral sclerosis, argyrophilic grain dementia, dementia pugilistica, chronic traumatic encephalopathy, diffuse neurofibrillary tangles with calcifications, Down syndrome, Giestmann-Strauss disease, Hallervorden-Spatz disease, hereditary frontotemporal dementia, Parkinson's disease associated with chromosome 17 (FTDP-17), inclusion body myositis, Creutzfeldt-Jakob disease, multiple system atrophy, Niemann-Pick disease type C, Pick's disease, prion amyloid angiopathy, sporadic corticobasal degeneration, progressive supranuclear palsy, subacute sclerosing encephalitis, myotonic dystrophy, motor neuron disease with neurofibrillary tangles, dementia with tangles only, and progressive subcortical gliosis.

[0181] Another aspect of the present disclosure is a method for slowing the progression of a behavioral phenotype associated with Tau pathology in a subject. The method involves administering to the subject any one or more immunogenic Tau peptides comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 1-21 and 101-124 and 51-71 and 125-155, or administering one or more antibodies that recognize an immunogenic Tau epitope comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 1-21 and 101-124 and 51-71 and 125-155, under conditions effective to slow the progression of a behavioral phenotype associated with Tau pathology in the subject.

[0182] As described herein, behavioral phenotypes associated with tau pathology include, but are not limited to, cognitive dysfunction, early personality changes and disinhibition, apathy, avolition, mutism, apraxia, perseveration, stereotyped movements / behaviors, oral hyperorality, confusion, inability to plan or organize sequential tasks, selfishness / apathy, antisocial traits, lack of empathy, hesitancy, agrammatic speech with frequent semantic errors but relatively well-preserved comprehension, impaired comprehension and word selection disorders, slowly progressive gait instability, retropulsions, immobility, frequent falls, trunk rigidity that is non-responsive to levodopa, supranuclear gaze palsy, square wave jerks, slowed vertical eye movements, pseudobulbar palsy, limb apraxia, dystonia, cortical sensory loss, and tremor.

[0183] According to the methods disclosed herein, in one embodiment, an immunogenic Tau peptide or a combination of immunogenic Tau peptides is administered to a subject in need thereof. Suitable immunogenic Tau peptide fragments of Tau protein contain one or more epitopes that mimic the pathological form of Tau protein. Exemplary immunogenic Tau epitopes are phosphorylated at one or more amino acids that are phosphorylated in pathological forms of Tau but not phosphorylated in normal or non-pathological forms of Tau.

[0184] In some embodiments, administration of immunogenic Tau peptides induces an active immune response in a subject against immunogenic Tau peptides and pathological forms of Tau, thereby promoting clearance of relevant Tau aggregates, slowing the progression of Tau pathology-related behaviors, and treating underlying Tauopathy. According to this aspect of the invention, the immune response involves the development of beneficial humoral (antibody-mediated) and / or cellular (mediated by antigen-specific T cells or their secretory products) responses against immunogenic Tau peptides.

[0185] The presence of a humoral immune response can be measured and monitored by testing a biological sample (e.g., blood, plasma, serum, urine, saliva, feces, CSF, or lymph) from a subject to determine whether antibodies to immunogenic Tau peptides are present. Methods for detecting antibodies in biological samples are well known in the art, such as ELISA, dot blot, SDS-PAGE gel, or ELISPOT. The presence of a cell-mediated immune response can be measured by a proliferation assay (CD4+T cells) or a CTL (cytotoxic T lymphocyte) assay that is readily known in the art.

[0186] The isolated immunogenic Tau peptides of the present invention include any of the amino acid sequences of SEQ ID NOs: 1-21 and 101-124 and 51-71 and 125-155 shown in Tables 1 and 3 below. The phosphorylated amino acid residues of each sequence are shown in bold and underlined. The names of the peptides in Table 1 correspond to the amino acid positions of these peptides in the longest isoform of the human Tau protein having the amino acid sequence of SEQ ID NO: 100 as shown in Table 8. Specific implementation plan

[0187] The present invention comprises the following specific embodiments:

[0188] (1) A Tau peptide immunogen construct, which can be represented by the following molecular formula:

[0189] (Th) m –(A) n –(Tau fragment)–X

[0190] or

[0191] (Tau fragment) – (A) n –(Th) m –X

[0192] in

[0193] Th is a heterologous T helper cell epitope;

[0194] A is a heterologous spacer;

[0195] (Tau fragment) is a B cell epitope having about 15 to about 40 amino acid residues from the full-length Tau protein of SEQ ID NO: 100;

[0196] X is α-COOH or α-CONH2 of an amino acid;

[0197] m is from 1 to about 4; and

[0198] n is 0 to about 10.

[0199] (2) The Tau peptide immunogen construct of (1), wherein the Tau fragment is selected from the group consisting of SEQ ID NOs: 1-21 and 101-124.

[0200] (3) The Tau peptide immunogen construct of any one of (1) or (2), wherein the T helper cell epitope is selected from the group consisting of SEQ ID NOs: 22-50.

[0201] (4) The Tau peptide immunogen construct of (1), wherein the peptide immunogen construct is selected from the group consisting of SEQ ID NOs: 51-71 and 125-155.

[0202] (5) A Tau peptide immunogen construct, comprising:

[0203] A B cell epitope comprising about 15 to about 40 amino acid residues from the full-length Tau protein sequence of SEQ ID NO: 100;

[0204] A T helper cell epitope comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 22-50; and

[0205] an optional heterologous spacer selected from the group consisting of amino acids, Lys-, Gly-, Lys-Lys-Lys-, (α,ε-N)Lys, and ε-N-Lys-Lys-Lys-Lys (SEQ ID NO: 102),

[0206] The B cell epitope is covalently linked to the T helper cell epitope directly or via an optional heterologous spacer.

[0207] (6) The Tau peptide immunogen construct of (5), wherein the B cell epitope is selected from the group consisting of SEQ ID NOs: 1-21 and 101-124.

[0208] (7) The Tau peptide immunogen construct of (5), wherein the T helper cell epitope is selected from the group consisting of SEQ ID NOs: 22-50.

[0209] (8) The Tau peptide immunogen construct of (5), wherein the optional heterologous spacer is (α,ε-N)Lys or ε-N-Lys-Lys-Lys-Lys (SEQ ID NO: 102).

[0210] (9) The Tau peptide immunogen construct of (5), wherein the T helper cell epitope is covalently linked to the amino terminus of the B cell epitope.

[0211] (10) The Tau peptide immunogen construct of (5), wherein the T helper cell epitope is covalently linked to the amino terminus of the B cell epitope via an optional heterologous spacer.

[0212] (11) A composition comprising the peptide immunogen construct according to any one of (1) to (4).

[0213] (12) A pharmaceutical composition comprising:

[0214] a. A peptide immunogen construct as described in any one of (1) to (4); and

[0215] b. Pharmaceutically acceptable delivery vehicles and / or adjuvants.

[0216] (13) The pharmaceutical composition of (12), wherein

[0217] a. Tau peptide immunogen construct is selected from the group consisting of SEQ ID NOs: 51-71 and 125-155; and

[0218] b. Tau peptide immunogen constructs were mixed with CpG oligodeoxynucleotides (ODN) to form a stable immunostimulatory complex.

[0219] (14) An isolated antibody or an epitope-binding fragment thereof that can specifically bind to a B cell epitope of a Tau peptide immunogen construct as described in any one of (1) to (10).

[0220] (15) The isolated antibody or epitope-binding fragment thereof of (14) is bound to a Tau peptide immunogen construct.

[0221] (16) An isolated antibody or an epitope-binding fragment thereof that can specifically bind to a B cell epitope of a Tau peptide immunogen construct as described in any one of (1) to (10).

[0222] (17) A composition comprising the isolated antibody or epitope-binding fragment thereof according to any one of (14) to (16).

[0223] Example 1. Antibodies elicited by non-phosphorylated TAU peptide immunogen constructs and binding profiles

[0224] a. Synthesis and immunization of Tau fragments

[0225] Methods for synthesizing designed Tau fragments are described in the detailed description, which are included in the development of non-phosphorylated and phosphorylated Tau peptide immunogen constructs. Typically, peptides are synthesized on a small scale for serological testing, on a laboratory pilot scale for field or clinical studies, and on a large scale (kilograms) for industrial / commercial production of pharmaceutical compositions. A large library of Tau-associated antigenic B-cell epitope peptides with sequences ranging in length from about 10 to about 40 amino acids is designed for broad serological screening and selection as candidate B-cell epitopes to be incorporated into Tau peptide immunogen construct design for immunogenicity and functional testing of Tau vaccine formulations.

[0226] Full-length Tau (Table 8) as a recombinant protein in these serological studies was purchased from rPeptide Company (Tau-441, T-1001-2). Table 1 (SEQ ID NOs: 1 to 21 and 101-124) identifies Tau peptide fragments used for epitope identification in various serological assays. Selected Tau peptide fragments were made into Tau peptide immunogen constructs by synthetically linking Tau peptides with carefully designed T helper cell (Th) epitopes derived from pathogenic bacterial proteins including measles virus fusion protein (MVF), hepatitis B surface antigen protein (HBsAg), influenza virus, Clostridium tetani, and Epstein-Barr virus (EBV). The designed Th epitopes are shown in Table 2 (SEQ ID NOs: 22 to 50).

[0227] Formulations using water-in-oil emulsions and suspensions with mineral salts are prepared as described in the detailed description. In designing suitable pharmaceutical compositions for use by a large population for the prevention of disease, it is important to consider the safety of the composition. Although water-in-oil emulsions are used in humans for many pharmaceutical compositions in clinical trials, alum remains the primary adjuvant used in pharmaceutical compositions due to its safety. Alum or its mineral salts, such as ADJUPHOS (aluminum phosphate), are often used as adjuvants in formulations for clinical use. (i) Utilizing Seppic MONTANIDE, an oil approved for human use TM ISA 51 was formulated as a water-in-oil emulsion, or (ii) mixed with mineral salts ADJUPHOS (aluminum phosphate) or ALHYDROGEL (alum) to formulate non-phosphorylated Tau peptide immunogen constructs, and the peptide structure was formulated in different amounts as specified. Tau peptide immunogen constructs were usually dissolved in water at a concentration of about 400 μg / mL and mixed with MONTANIDE TM ISA 51 is formulated as a water-in-oil emulsion (1:1 volume) or as a composition with mineral salts (1:1 volume). The composition is placed at room temperature for about 30 minutes and mixed by vortexing for about 10 to 15 seconds before immunization. Some animals are immunized with more than 1 dose of a particular composition, which is administered at time 0 (primary immunization) and 3 weeks after the primary immunization (wpi) (boost immunization), and optionally a second boost immunization at 6wpi, which is administered by the intramuscular route. These immunized animals are then tested with selected B cell epitope peptides to evaluate the immunogenicity of various Tau peptide immunogen constructs present in the formulation, as well as their cross-reactivity with related target peptides or proteins. Thereafter, those Tau peptide immunogen constructs that are effectively immunogenic in the initial screening of guinea pigs are further tested in primates in water-in-oil emulsions, mineral salts, and alum-based formulations for dosing regimens within a specific period specified by the immunization schedule.

[0228] Dissolved in solvent (ISA 51VG, CpG3 50μg / mL, 0.2% ) were injected into guinea pigs at a specific schedule, and immune sera were collected for extensive serological analysis.

[0229] b. ELISA assay and results

[0230] Sera from immunized animals were collected at various time points after the primary immunization and initially analyzed for binding profiles by ELISA to determine the immunogenicity of the corresponding structures to their own B cell epitope targets. Serological cross-reactivity between Tau peptides from other functional regions was extensively assessed by ELISA using plates coated with different peptides selected from those shown in Tables 9a-9e.

[0231] An ELISA assay for evaluating immune serum samples was developed and described in the following examples. Briefly, the wells of a 96-well plate were coated with target peptide Tau fragments A145-P160, P172-P189, P182-P200, S195-P213, R209-L224, V228-L243, K257-K274, R379-L408, V275-K311, and V393-L425 peptides (SEQ ID NOs: 2, 4, 6, 8, 11, 13, 15, 17, 19, and 21, respectively) at a concentration of 2 μg / mL (unless otherwise stated) in 10 mM sodium bicarbonate buffer, pH 9.5 (unless otherwise stated) in a volume of 100 μL at 37° C. for 1 hour. The peptide-coated wells were reacted with 250 μL of 3 wt % gelatin in PBS at 37°C for 1 hour to block nonspecific protein binding sites. The wells were washed three times with PBS containing 20% ​​normal goat serum, 1% gelatin and 0.05% 20% PBS was diluted to a ratio of 1:20 (unless otherwise specified). 100 μL of diluted sample (e.g., serum, plasma) was added to each well and reacted at 37°C for 60 minutes. 20 Wash the wells 6 times to remove unbound antibody. Use horseradish peroxidase (HRP) conjugated species (e.g., mouse, guinea pig, or human) specific goat anti-IgG as a labeled tracer to bind to the antibody / peptide antigen complex formed in the positive wells. Add 100 μL of peroxidase-labeled goat anti-IgG (prepared at a pre-titrated optimal dilution in a solution containing 1% by volume normal goat serum and 0.05% by volume 20% PBS) was added to each well and reacted at 37°C for another 30 minutes. The wells were washed 6 times with 20% PBS to remove unbound antibodies and reacted with 100 μL of a substrate mixture containing 0.04 weight percent 3',3',5',5'-tetramethylbenzidine (TMB) and 0.12 volume percent hydrogen peroxide in sodium citrate buffer for another 15 minutes. The substrate mixture was used to detect the peroxidase label by forming a colored product. The reaction was terminated by adding 100 μL of 1.0 M sulfuric acid and the absorbance at 450 nm (A 450 To determine the antibody titers of vaccinated animals receiving various Tau-derived peptide immunogens, 10-fold serial dilutions of sera from 1:100 to 1:10,000 were tested and A 450 A with a threshold of 0.5 450 The titer of the test serum was calculated by linear regression analysis, with Log 10 The ELISA results shown in Tables 9a-9e were further analyzed by plotting histograms as shown in Figure 1A.

[0232] In general, high immunogenicity was found to be associated with each selected Tau peptide structure when tested against its own B cell epitope (Tables 9a-9e and Figure 1A). High cross-reactivity of antibodies elicited by peptide immunogen constructs of SEQ ID Nos: 52, 54, 56, 58 and 61 was found (see Figure 1A).

[0233] Interestingly, it was found that SEQ ID NO: 65 containing the B cell epitope K257-K274 (SEQ ID NO: 15) was a highly immunogenic sequence in the designed Tau peptide structure, but the antibodies elicited by this structure were the most specific, not having much cross-reactivity with any other B cell epitope (see Figure 1A). In contrast, the Tau peptide immunogen construct of SEQ ID NO: 67 containing the B cell epitope R379-L408 (SEQ ID NO: 17) was the most immunogenic, with high reactivity to self B cell epitopes, but also reasonable cross-reactivity with other Tau B cell epitopes (see Figure 1A).

[0234] Example 2. Antibodies and Binding Profiles Elicited by Phosphorylated TAU Peptide Immunogen Constructs

[0235] At 6 weeks post-primary immunization (wpi), the ability of antibodies generated against the phosphorylated Tau peptide immunogen constructs to bind to their phosphorylated B cell epitopes was assessed by ELISA.

[0236] a. Immunity

[0237] Phosphorylated Tau peptide immunogens (SEQ ID NOs: 51, 53, 55, 57, 59, 60, 62, 64, 66, 68, and 70) were formulated and administered to guinea pigs under the same conditions as for the non-phosphorylated Tau peptide immunogens as discussed in Example 1. Formulations containing phosphorylated Tau peptide immunogens were administered at 0, 3, and 6 wpi.

[0238] b. ELISA assay and results

[0239] Phosphorylated Tau target peptide fragments A145-P160, P172-P189, P182-P200, S195-P213, R209-L224, V228-L243, K257-K274, R379-L408, V275-K311 and V393-L425 peptides (SEQ ID NOs: 1, 3, 5, 7, 9, 10, 12, 14, 16, 18 and 20, respectively) were used at a concentration of 2 μg / mL (unless otherwise stated) in 10 mM sodium bicarbonate buffer, pH 9.5 (unless otherwise stated) and were acted on the wells of a 96-well plate in a volume of 100 μL at 37° C. for 1 hour. The peptide-coated wells were reacted with 250 μL of 3 wt % gelatin in PBS at 37°C for 1 hour to block nonspecific protein binding sites. The wells were washed three times with PBS containing 20% ​​normal goat serum, 1% gelatin and 0.05% 20% PBS was used to dilute the test serum at a ratio of 1:20 (unless otherwise specified). 100 μL of the diluted sample (e.g., serum, plasma) was added to each well and reacted at 37°C for 60 minutes. 20 Wash the wells 6 times to remove unbound antibody. Use horseradish peroxidase (HRP) conjugated species (e.g., mouse, guinea pig, or human) specific goat anti-IgG as a labeled tracer to bind to the antibody / peptide antigen complex formed in the positive wells. Add 100 μL of peroxidase-labeled goat anti-IgG (prepared at a pre-titrated optimal dilution in a solution containing 1% by volume normal goat serum and 0.05% by volume 20% PBS) was added to each well and reacted at 37°C for another 30 minutes. The wells were washed 6 times with 20% PBS to remove unbound antibodies and reacted with 100 μL of a substrate mixture containing 0.04 weight percent 3',3',5',5'-tetramethylbenzidine (TMB) and 0.12 volume percent hydrogen peroxide in sodium citrate buffer for another 15 minutes. The substrate mixture was used to detect the peroxidase label by forming a colored product. The reaction was terminated by adding 100 μL of 1.0 M sulfuric acid and the absorbance at 450 nm (A 450 To determine the antibody titers of vaccinated animals receiving various Tau-derived peptide immunogens, 10-fold serial dilutions of sera from 1:100 to 1:10,000 were tested and A 450 A with a threshold of 0.5 450 The titer of the test serum was calculated by linear regression analysis, with Log 10 Serum from immunized animals was collected at different time points after injection and the binding profile was analyzed by ELISA. ELISA plates were coated with different Tau fragments and the results are shown in Tables 10a-10d.

[0240] The ELISA results shown in Tables 10a-10d were further analyzed by plotting histograms as shown in Figure 1 B. Similar immunogenicity and serological profiles were found when phosphorylated Tau peptide constructs were used as immunogens, including cross-reactivity between B cell epitopes.

[0241] Example 3. Binding profiles of antibodies elicited by phosphorylated TAU peptide immunogen constructs and against their non-phosphorylated peptide counterparts

[0242] As described in further detail below, at 6 weeks post injection (wpi), the ability of antibodies raised against phosphorylated Tau peptides to bind to their corresponding non-phosphorylated counterparts was assessed by ELISA.

[0243] a. Immunity

[0244] Phosphorylated Tau peptide immunogens (SEQ ID NOs: 51, 53, 55, 57, 59, 60, 62, 64, 66, 68 and 70) were formulated and administered to guinea pigs under the conditions described in Example 1 for non-phosphorylated Tau peptide immunogens.

[0245] b. ELISA assay and results

[0246] The target peptide Tau fragments A145-P160, P172-P189, P182-P200, S195-P213, R209-L224, V228-L243, K257-K274, R379-L408, V275-K311 and V393-L425 peptides (SEQ ID NOs: 2, 4, 6, 8, 11, 13, 15, 17, 19 and 21, respectively) were prepared in 10 mM sodium bicarbonate buffer, pH 9.5 (unless otherwise stated) at a concentration of 2 μg / mL (unless otherwise stated) and were acted on the wells of a 96-well plate in a volume of 100 μL at 37° C. for 1 hour. The peptide-coated wells were reacted with 250 μL of 3 wt % gelatin in PBS at 37°C for 1 hour to block nonspecific protein binding sites. The wells were washed three times with PBS containing 20% ​​normal goat serum, 1% gelatin and 0.05% 20% PBS was used to dilute the test serum at a ratio of 1:20 (unless otherwise specified). 100 μL of the diluted sample (e.g., serum, plasma) was added to each well and reacted at 37°C for 60 minutes. 20 Wash the wells 6 times to remove unbound antibody. Use horseradish peroxidase (HRP) conjugated species (e.g., mouse, guinea pig, or human) specific goat anti-IgG as a labeled tracer to bind to the antibody / peptide antigen complex formed in the positive wells. Add 100 μL of peroxidase-labeled goat anti-IgG (prepared at a pre-titrated optimal dilution in a solution containing 1% by volume normal goat serum and 0.05% by volume 20% PBS) was added to each well and reacted at 37°C for another 30 minutes. The wells were washed 6 times with 20% PBS to remove unbound antibodies and reacted with 100 μL of a substrate mixture containing 0.04 weight percent 3',3',5',5'-tetramethylbenzidine (TMB) and 0.12 volume percent hydrogen peroxide in sodium citrate buffer for another 15 minutes. The substrate mixture was used to detect the peroxidase label by forming a colored product. The reaction was terminated by adding 100 μL of 1.0 M sulfuric acid and the absorbance at 450 nm (A 450 To determine the antibody titers of vaccinated animals receiving various Tau-derived peptide immunogens, 10-fold serial dilutions of sera from 1:100 to 1:10,000 were tested and A 450 A with a threshold of 0.5 450 The titer of the test serum was calculated by linear regression analysis, with Log 10 Sera from immunized animals were collected at different time points after injection and the binding profiles were analyzed by ELISA.

[0247] ELISA plates were coated with different non-phosphorylated Tau fragments and the results are shown in Tables 11a-11e. Similar serological binding profiles were obtained for all antibodies raised against phosphorylated Tau peptide structures when immune sera were tested against the corresponding non-phosphorylated Tau B cell epitope peptides. Based on the extensive immunogenicity and serological studies performed in Examples 1, 2 and 3, antibodies elicited by Tau peptide immunogen constructs clearly exhibit similar properties. Most of these properties can be attributed to the amino acid sequence. Conformational evaluation using cross-reactivity studies indicated that phosphorylation of the peptides caused only minor differences, indicating that these immune sera elicited by their corresponding phosphorylated and non-phosphorylated peptide immunogen constructs have similar functional properties.

[0248] Example 4. Binding profiles of antibodies against non-phosphorylated TAU peptide immunogen

[0249] a. Specificity of anti-non-phosphorylated Tau antibodies purified from antisera of guinea pigs immunized with different Tau peptide immunogen constructs of different sizes

[0250] As described in Example 1, guinea pigs were immunized with non-phosphorylated Tau peptide immunogen constructs. Western blotting was used to screen anti-non-phosphorylated Tau antibodies (anti-non-p-Tau antibodies) for binding specificity to Tau molecular complexes of different sizes. This anti-non-phosphorylated Tau antibody was purified from the antisera of guinea pigs immunized with different Tau peptide immunogen constructs. After photoinduced cross-linking (PICUP) treatment, various forms of Tau (20 μM) (monomers, dimers, trimers, oligomers and polymers) were separated on 12% Tris-glycine SDS-PAGE and transferred to nitrocellulose (NC) membranes. The membrane was reacted with anti-non-phosphorylated Tau antibodies purified from guinea pig antiserum at a concentration of 1 μg / mL, and then donkey anti-guinea pig antibodies conjugated to HRP (706-035-148, Jackson) were reacted with the membrane. Blots were visualized using the chemiluminescent reagent Western Lightning ECL Pro (PerkinElmer).

[0251] b. Results

[0252] Western blot analysis of lysates containing monomers, dimers, trimers, and oligomers of Tau is shown in Figure 2 (left). Monomeric Tau appears at approximately 60 kDa, and dimers, trimers, and oligomers appear at their corresponding molecular weights. Commercially available monoclonal antibodies Mab Tau 5 and Mab Tau 46 are able to detect monomeric Tau, and to a lesser extent, dimeric forms of Tau (Figure 2, lanes 1 and 2). Mab Tau5 was used as a total Tau marker, while Tau46 was a marker for Tau 404-441.

[0253] IgG antibodies elicited by non-phosphorylated peptide immunogen constructs (SEQ ID NOs: 52, 54, 56, 58, 61, 63, 65, 67, 69 and 71) detected Tau monomers, dimers, trimers and oligomers with different efficiencies (Figure 2, lanes 4-13). The binding profile of each antibody was analyzed and quantitatively summarized in a histogram (Figure 2, right). In general, antibodies derived from Tau peptide immunogen constructs from the carboxyl-terminal region were able to elicit antibodies with higher preferential binding characteristics compared to those derived from Tau peptide immunogen constructs from the amino-terminal region (data not shown).

[0254] Example 5. Antibodies against non-phosphorylated TAU peptide immunogens can inhibit TAU ​​aggregation

[0255] a. Immunization and exposure to Tau

[0256] Animals were immunized with non-phosphorylated Tau immunogen constructs (SEQ ID NOs: 52, 54, 56, 58, 61, 63, 65, 67, 69, and 71) as described in Example 1, or with phosphorylated Tau immunogen constructs (SEQ ID NOs: 51, 53, 55, 57, 60, 62, 64, 66, 68, and 70) as described in Example 2.

[0257] The antibodies produced by the immunization were then exposed to samples containing commercially available full-length Tau441 recombinant protein under conditions that promote Tau aggregation. Aggregation was performed using 60 μg of Tau in 100 μL of 1xPBS containing 10 unit / mL heparin at 37°C for 7 days to produce Tau441 β-folded fibers, which were then transferred to a 300 kDa cutoff filter (Pall) at 4°C to separate the β-folded fibers. These aggregations were verified using Thioflavin T (ThT, Sigma) fluorescence.

[0258] Tau was aggregated in 200 μL of PBS buffer solution containing 5 μM heparin in the presence or absence of IgG antibodies elicited by Tau peptide immunogen constructs for 3 days. After centrifugation (13,000×g, 4°C, 30 minutes), Tau aggregates were harvested and confirmed by ThT assay.

[0259] b. Results

[0260] Figure 3A contains multiple charts showing the extent of full-length Tau (Tau441) aggregation in the presence of antibodies against the non-phosphorylated Tau peptide immunogen constructs shown above each chart. The dashed line shown in Figure 3A represents a control sample for assessing Tau aggregation using pre-immune IgG. The results show that all antibodies against the non-phosphorylated Tau peptide immunogens inhibit Tau aggregation compared to the pre-immune serum control sample. Antibodies are able to inhibit Tau aggregation to varying degrees.

[0261] Figure 3B quantifies the degree of full-length Tau (Tau441) aggregation measured by ThT staining of aggregates in the presence of antibodies against the non-phosphorylated Tau peptide immunogen constructs shown below the histogram. The results show that antibodies against the non-phosphorylated Tau peptide immunogens can inhibit Tau aggregation compared to pre-immune serum control samples. Antibodies can inhibit Tau aggregation to varying degrees.

[0262] The results showed that when a Tau peptide immunogen construct with a B cell epitope closer to the carboxyl-terminal region of Tau was used, it had greater anti-aggregation ability against Tau aggregation.

[0263] Example 6. Antibodies against TAU ​​peptide immunogens can inhibit TAU ​​aggregation

[0264] a. Immunization and exposure to Tau

[0265] Animals were immunized with non-phosphorylated Tau immunogen constructs as described in Example 1. Animals were also immunized with phosphorylated Tau immunogen constructs as described in Example 2.

[0266] The immunized antibodies were then exposed to cell lysates from (a) neuronal cells (SH-SY5Y cells) treated with okadaic acid (OKA) as hyperphosphorylated Tau or (b) neuronal cells without okadaic acid treatment as non-phosphorylated Tau. In the presence of antiserum at time points wpi 6 and 9, OKA was added to the culture medium to a final concentration of 100 nM for 3 hours to determine the dose-dependent effect of the antiserum in inhibiting Tau aggregation.

[0267] b. Results

[0268] FIG4 contains multiple graphs showing the extent of Tau aggregation of different lysates after exposure to antibodies against the Tau peptide immunogen shown above each graph. The extent of Tau aggregation was determined using ThT staining of aggregates. Again, antibodies from either phosphorylated or non-phosphorylated Tau peptide immunogen constructs can inhibit Tau aggregation, which is consistent with the serological analysis described in the previous examples.

[0269] The results showed that the use of Tau epitopes derived from the central and carboxyl-terminal regions of Tau had greater resistance to Tau aggregation.

[0270] Example 7. Disaggregation of Preformed Tau Aggregates Following Exposure to Antibodies Against TAU ​​Peptide Immunogen

[0271] a. Immunization and Exposure to Preformed Tau Aggregates

[0272] Animals were immunized with non-phosphorylated Tau immunogen constructs as described in Example 1. Animals were also immunized with phosphorylated Tau immunogen constructs as described in Example 2.

[0273] The immunized antibodies were then exposed to preformed Tau fibrils. The preformed Tau aggregates were then reacted with or without anti-p-Tau antibodies or anti-non-p-Tau antibodies purified from guinea pig antiserum for 2 and 4 days. After the reaction, the aggregates were collected after centrifugation at 13,000 x g for 30 minutes at 4°C and then quantified using the ThT assay.

[0274] b. Results

[0275] Figure 5 contains multiple graphs showing the extent of Tau deaggregation after exposure to antibodies against Tau peptide immunogens (representative peptide structures of SEQ ID NOs: 66 and 67) as shown above in Figure 5 (right panel). The extent of Tau aggregation was determined using ThT staining and Western blotting.

[0276] Data from Western blot and ThT assays showed that anti-non-p / p-Tau 379-408 IgGs elicited by SEQ ID NOs: 67 and 66, respectively, had the ability to disrupt Tau fibril aggregation.

[0277] Example 8. Dot blot analysis of specific binding to native forms of TAU fibrils, oligomers, and monomers by representative antibodies generated using phosphorylated TAU and non-phosphorylated TAU peptide immunogen constructs

[0278] a. Western blot and dot blot analysis of binding profiles of immunization and anti-Tau antibodies

[0279] Animals were immunized with non-phosphorylated Tau immunogen constructs as described in Example 1. Animals were also immunized with phosphorylated Tau immunogen constructs as described in Example 2.

[0280] Different types of Tau proteins (i.e., α-helical monomers, β-sheet monomers, β-sheet oligomers, and β-sheet fibers) were prepared as described in Example 5. Western blot and dot blot analysis were performed using different types of Tau proteins, using anti-p-Tau or anti-non-p-Tau antibodies purified from guinea pig antisera immunized with different Tau peptide immunogen constructs as primary antibodies. For strict specificity controls, various forms of β-sheet fibers, oligomers, monomers, α-helical monomers, and other control reagents were dotted on the blots. Detailed procedures for preparing these reagents for use in serological testing and evaluation are further described in Example 11.

[0281] b. Results

[0282] Figure 6 (left) contains Western blot analysis (under denaturing conditions) of anti-p-Tau IgG produced by Tau peptide immunogens (SEQ ID NOs: 59, 66 and 70) and anti-non-p-Tau IgG produced by Tau peptide immunogen (SEQ ID NO: 67). The results of Western blot analysis show that anti-p-Tau IgGs against the carboxyl terminus of Tau can specifically recognize high molecular weight Tau aggregates, but not Tau monomers.

[0283] Figure 6 (right) contains dot blot analysis (under non-denaturing conditions) of anti-p-Tau and anti-non-p-Tau IgGs generated by Tau peptide immunogens SEQ ID NOs: 66 and 67, respectively. The results show that both anti-non-p- / p-Tau 379-408 IgGs can specifically bind to various forms of Tau, but not other amyloidogenic proteins (i.e., Aβ1-42 and alpha-synuclein). In addition, when compared with the monoclonal antibody Mab Tau 5 and another IgG against the non-carboxyl terminal region of Tau, the anti-p- / anti-non-p-Tau 379-408 IgGs derived from the present invention (SEQ ID NOs: 66 and 67, respectively) have a higher affinity for fibers and oligomers rather than monomers. In addition, the anti-p-Tau 379-408 IgG does not bind to β-sheet monomers.

[0284] Example 9. Tissue Binding Profiles of Antibodies Against TAU ​​Peptide Immunogen

[0285] a. Immuno- and Histological Staining

[0286] Animals were immunized with non-phosphorylated Tau immunogen constructs as described in Example 1. Animals were also immunized with phosphorylated Tau immunogen constructs as described in Example 2.

[0287] The immunization-generated antibodies were then used to stain tissue from healthy (normal) brain and Alzheimer's disease (AD) brain. Before applying anti-Tau 349-408 (SEQ ID NOs: 66 or 67) or pre-immune serum to the tissue, the human tissue group (Pantomics) was dewaxed with xylene, rehydrated in ethanol, and then treated with PBS containing 0.25% trypsin solution and 0.5% CaCl2 for 30 minutes, and reacted in methanol containing 1% hydrogen peroxide to block endogenous peroxidase activity, followed by reaction with PBS containing 10% Block Ace (Sigma). Sections were developed with 3-3'-diaminobenzidine (DAB) and counterstained with hematoxylin before microscopic examination.

[0288] b. Results

[0289] Figure 7 shows the staining images of this experiment. Antibodies against non-phosphorylated Tau 379-408 (SEQ ID NO: 67) and phosphorylated Tau 379-408 (SEQ ID NO: 66) had no cross-reactivity with sections from normal tissue, but had cross-reactivity with Alzheimer's disease brain tissue. Antibodies against the phosphorylated peptide (SEQ ID NO: 66) showed stronger binding to the hippocampus region of AD brains.

[0290] Example 10. Antibodies elicited by TAU peptide immunogen constructs and their preparations: Neuroprotective effects in reducing neurodegeneration induced by exogenous TAU fibers

[0291] To evaluate the neuroprotective effects of anti-Tau antibodies purified from guinea pig antisera immunized with different Tau peptide immunogen constructs, an in vitro neurodegeneration model was employed in which exogenous preformed Tau aggregates were treated in neuronally differentiated PC 12 cells treated with NGF.

[0292] PC 12 cells were treated with NGF (100 ng / mL) for 6 days to induce neuronal differentiation. 3 The iMagerduos high-throughput imaging system (Screen) confirms and analyzes the morphology of neuronal differentiation cells. Cell death was marked with a fluorescent dye, and cells were counted using a cell counting software. Antibodies triggered by Tau peptide immunogen constructs can enter cells and bind to Tau aggregates (data not shown). The neurotrophic effect of NGF reflected in the number of neurite growth and neuronal differentiation cells was quantified. After standardization, the degree of neurite growth and the number of neuronal differentiation cells were expressed as percentages (mean ± SEM). The neurite lengths of PC 12 cells with and without NGF treatment were considered as 100% and 0%, respectively. The number of PC 12 cells with neuronal differentiation treated with NGF for 6 days was standardized to 100%.

[0293] Neurodegeneration was observed by adding exogenous preformed Tau aggregates treated with heparin to neuron-differentiated PC 12 cells for one week at 37°C. In the presence of preformed Tau aggregates, neurite length in neuron-differentiated PC 12 cells was shortened and cell number was reduced. This Tau fiber-driven neurodegeneration was proportional to the amount of exogenous Tau aggregates added in a concentration-dependent manner. Commercially available anti-Tau antibodies (e.g., Mab Tau 5 and Mab Tau46), rather than untreated Antibodies purified from guinea pigs attenuate Tau fiber-driven neurodegeneration. This model was used as a screening platform to identify which anti-Tau antibodies purified from guinea pig antisera immunized with different Tau peptide immunogen constructs have a concentration-dependent neuroprotective effect in restoring neuronal survival (Figures 8A and B).

[0294] As a result, anti-Tau antibodies purified from guinea pig antisera immunized with more than half of the different Tau peptide immunogen constructs can restore neurite growth. Tau fibers are provided at a concentration of 5 μg / mL, which was previously optimized to cause damage (Figure 8A). Anti-Tau antibodies purified from guinea pig antisera immunized with phosphorylated or non-phosphorylated Tau peptide structures can protect neuron-differentiated PC 12 cells from neuronal death caused by Tau fibers. Figure 8B shows data from anti-non-p-Tau antibodies provided by immunization with SEQ ID NOs: 65, 67 and 69.

[0295] The results of Figures 8A and 8B demonstrate that anti-Tau antibodies (e.g., SEQ ID NOs: 65, 67, and 69) can protect neurons from the neurotoxicity of Tau fibers. 3 Imager duos software (Miteklab) was used to count the number of viable cells in the culture, and the anti-neurodegenerative effects of anti-Tau antibodies elicited by Tau peptide immunogen constructs (SEQ ID Nos: 65, 67, and 69) were observed and quantified.

[0296] Regarding the evaluation of the neuroprotective effects of anti-Tau antibodies by in vitro functional assays, it has been shown that inhibition of Tau aggregation seeding in vitro can significantly reduce pathology and improve cognition in vivo, as reported by Yanamandra, K, et al. (Neuron 80: 402-414, 2013). Tau monomers are considered to be naturally non-structural and may not have much functional role in Tau aggregation and related cell cytotoxicity. Recent findings suggest that the initiation of pathological aggregation can start from the conversion of Tau monomers from inert to seed-competent forms (Mirbaha, H., et al., eLife 2018; 7: e36584; doi: 10.7554 / eLife.36584). Based on these findings, we tested the ability of anti-Tau antibodies elicited by Tau peptide immunogen constructs to reduce seeding activity. Specifically, anti-Tau antibodies against Tau peptide immunogen constructs were reacted with brain homogenates from Alzheimer's disease (AD) patients and found to have the ability to reduce such vaccination activity (data not shown). Immunogenicity and serological analysis facilitate the development of neuroprotective interventions, and our broad range of Tau immunogens are designed as vaccines at both molecular and serological levels to treat devastating tauopathies.

[0297] Example 11. Other serological tests and reagents

[0298] Serological assays and reagents used to assess the functional immunogenicity of synthetic peptide constructs and their preparations are described in detail below.

[0299] a. Fine-scale specificity analysis and epitope identification of Tau fragments using ELISA assay based on B cell epitope cluster peptides

[0300] Fine-scale specificity analysis of anti-Tau antibodies in immunized hosts using epitope identification assays. Briefly, individual Tau fragment peptides (SEQ ID NOs: 115 and 156-171) from the Tau 275-311 region (SEQ ID NO: 19) to be identified were coated in a 96-well plate, with each well containing 0.5 μg of Tau fragment peptide per 0.1 mL volume, and then 100 μL of serum samples (diluted 1:100 in PBS) were added to the wells of the plate in duplicate according to the steps of the above antibody ELISA method. For additional reactivity and specificity confirmation, the B cell epitopes of the Tau peptide immunogen constructs and the related fine specificity analysis of the immune serum anti-Tau antibodies in the immunized hosts were also tested, which was performed using the corresponding Tau peptides without spacer and Th sequences (e.g., SEQ ID NOs: 1-21, 101-124 shown in Table 1 and SEQ ID NOs: 72-99 shown in Tables 4 to 7, and SEQ ID NO: 100 shown in Table 8).

[0301] b. Immunogenicity Assessment

[0302] Pre-immune and immune serum samples from animals were collected according to the experimental immunization protocol and heated at 56°C for 30 minutes to inactivate serum complement factors. After administration of the Tau peptide immunogen constructs, blood samples were obtained according to the protocol and evaluated for their immunogenicity against the specific target. Serial dilutions of sera were tested and positive titers were expressed as the Log reciprocal of the dilution. 10 The immunogenicity of a particular Tau peptide immunogen construct is assessed by its ability to elicit high titer B cell antibody responses specific for the desired epitope within the target antigen, while maintaining low to negligible antibody reactivity against "helper T cell epitopes" that serve to provide enhancement of the desired B cell response.

[0303] c. Preparation of Tau aggregates (dimers, trimers, oligomers and fibers) using recombinant Tau protein

[0304] To prepare aggregated Tau, purified recombinant Tau protein (concentration 0.1 μg / μL) in 100 μL PBS / KCl aggregation buffer (1x PBS containing 2.5 mM magnesium chloride, 50 mM HEPES and 150 mM potassium chloride at pH 7.4) in a 1.5 mL microcentrifuge tube was placed in a thermostatic shaker (Eppendorf) at 37°C for 7 days without shaking. Aggregated Tau was immediately frozen at -80°C for later use.

[0305] d. Purification of Anti-Tau Antibodies

[0306] Anti-Tau antibodies were purified from serum collected from guinea pigs 3 to 15 weeks after primary immunization (wpi) using affinity columns (Thermo Scientific, Rockford), which were immunized with Tau peptide immunogen constructs (SEQ ID NOs: 51-71 and 125-155) containing peptides of different sequences. In brief, after equilibration in buffer (0.1M phosphoric acid and 0.15M sodium chloride, pH 7.2), 400 μL of serum was added to the Nab Protein G Spin column, followed by end-over-end mixing for 10 minutes and centrifugation at 5,800 x g for 1 minute. The column was washed three times with binding buffer (400 μL). Subsequently, elution buffer (400 μL, 0.1M glycine, pH 2.0) was added to the spin column to elute the antibody after centrifugation at 5,800 x g for 1 minute. The eluted antibody was mixed with neutralization buffer (400 μL, 0.1 M Tris, pH 8.0) and quantified by using Nano-Drop OD 280 Assays were performed to measure the concentrations of these purified antibodies, using BSA (bovine serum albumin) as a standard.

[0307] e. Specificity of anti-Tau antibodies purified from guinea pig antisera immunized with different Tau peptide immunogen constructs of different sizes

[0308] Western blot was used to screen anti-Tau antibodies purified from guinea pig antisera immunized with different Tau peptide immunogen constructs for binding specificity to Tau molecular complexes of different sizes. After photoinduced cross-linking (PICUP) treatment, various forms of Tau (20 μM) were separated on 12% Tris-glycine SDS-PAGE and transferred to nitrocellulose (NC) membranes. The membranes were reacted with anti-Tau antibodies purified from guinea pig antisera at a concentration of 1 μg / mL, and then donkey anti-guinea pig antibodies conjugated with HRP (706-035-148, Jackson) were reacted with the membranes. The blots were visualized using the chemiluminescent reagent Western Lightning ECL Pro (PerkinElmer). Monomeric Tau blots were located around 60 kDa, while dimers, trimers or oligomers had molecular weights several times larger than that of monomeric Tau. Commercial antibodies (eg, Mab Tau 5 or Mab Tau 46) capable of detecting various oligomer species (eg, dimers, trimers, and larger oligomers) were used as positive controls.

[0309] f. Dot blot analysis using different types of amyloidogenic proteins

[0310] Aβ 1-42 The preparation of α-helical monomers, β-sheet monomers, β-sheet oligomers and β-sheet fibers of α-Syn, Tau and α-Syn is described below.

[0311] Aβ 1-42 α-helical monomer: 20 μg of Aβ 1-42 The β-sheet monomer (50 μL) was added to 1×PBS (10 μL) containing 20% ​​trifluoroacetic acid and 20% hexafluoroisopropanol and reacted at 4°C for 24 hours to form an α-helical monomer.

[0312] Aβ 1-42 β-sheet monomer: 60 μg of Aβ prepared in 120 μL of 1xPBS containing 5% TFA and reacted at 37°C for 24 hours for aggregation 1-42 The β-sheet monomers were recovered by transfer onto a 10 kDa cut-off filter (Millipore).

[0313] Aβ 1-42 β-sheet oligomers: 60 μg of Aβ prepared in 120 μL 1xPBS and reacted at 37°C for 3 days for aggregation 1-42 The pellet was sonicated on ice and transferred to 10 and 30 kDa cut-off filters (Millipore) to recover β-pleated oligomeric fibers less than 35 kDa.

[0314] Aβ 1-42 β-pleated fibers: 60 μg of Aβ prepared in 120 μL 1xPBS and reacted at 37°C for 3 days for aggregation 1-42 The β-pleated fibers were isolated by sonication on ice and transferred to a 30 kDa cut-off filter (Millipore).

[0315] α-Syn α-helical monomers: 40 μg of freshly prepared α-Syn was dissolved in cold 100 μL 1× PBS at 4°C and immediately transferred onto a 10 kDa cutoff filter (Millipore) to recover the α-helical monomers.

[0316] α-Syn β-sheet monomers: 40 μg of α-Syn prepared in 100 μL PBS / KCl buffer and reacted at 37°C for 24 hours was transferred to a 10 kDa cut-off filter (Millipore) to recover β-sheet monomers.

[0317] α-Syn β-sheet oligomers: 40 μg of α-Syn prepared in 100 μL PBS / KCl buffer at 37°C for 8 days for aggregation was sonicated on ice and then transferred to 30 and 100 kDa cut-off filters to recover β-sheet oligomers.

[0318] α-Syn β-pleated fibers: 40 μg of α-Syn aggregated in 100 μL PBS / KCl buffer at 37°C for 8 days was sonicated on ice and then transferred to 30 and 100 kDa cut-off filters to separate β-pleated fibers.

[0319] Tau441 α-helical monomers: 60 μg of Tau in 100 μL 1×PBS was transferred onto a 100 kDa cutoff filter at 4° C. to recover α-helical monomers.

[0320] Tau441 β-sheet monomers: 60 μg of Tau aggregated in 100 μL 1x PBS containing 10 unit / mL heparin at 25°C for 48 hours was transferred to a 100 kDa cut-off filter at 4°C to recover β-sheet monomers.

[0321] Tau441 β-sheet oligomers: 60 μg of Tau prepared in 100 μL 1xPBS containing 10 unit / mL heparin at 37°C for 48 hours for aggregation was transferred to 100 and 300 kDa cut-off filters (Pall) at 4°C to recover β-sheet oligomers.

[0322] Tau441 β-pleated fibers: 60 μg of Tau aggregated in 100 μL 1×PBS containing 10 unit / mL heparin at 37°C for 6 days was transferred to a 300 kDa cutoff filter (Pall) at 4°C to separate β-pleated fibers.

[0323] These monomers and aggregates were verified by ThT fluorescence or PAGE (polyacrylamide gel electrophoresis). 1-42 The concentration of amyloid protein was measured by stock solution. 1-42 , 4 μg of α-Syn and 7 μg of Tau, and these monomers and oligomers were spotted on PVDF membranes. The membranes were reacted with anti-Tau antibodies purified from guinea pig antiserum (as primary antibodies) (dilution factor 1:1,000), and then hybridized with anti-guinea pig HRP-conjugated secondary antibodies (dilution factor 1:5,000; Vector Laboratories). The membranes were treated with Luminata Western HRP substrate (Bio-Rad, Hercules, CA, USA), and the signals were detected using the ChemiDoc-It 810 digital imaging system (UVP Inc., Upland, CA, USA).

[0324] Example 12. Animals used for immunogenicity and efficacy studies

[0325] a. Guinea Pig:

[0326] In mature without antibodies Immunogenicity studies were conducted in adult male and female Duncan-Hartley guinea pigs (300-350 g / BW). At least three guinea pigs were used per group for this experiment. The experimental protocol involving Duncan-Hartley guinea pigs (8-12 weeks old; Covance Research Laboratories, Denver, PA, USA) was conducted in a contract laboratory animal facility and United Biomedical, Inc. (UBI) as the trial sponsor under an application reviewed and approved by the Institutional Animal Care Group (IACUC).

[0327] Example 13. Identification of focused antibody responses elicited by TAU peptide immunogen constructs directed against target B cell epitopes: Representative studies

[0328] In a representative fine epitope identification study (Table 16), antibody binding sites against specific residues elicited by a Tau peptide immunogen construct directed against its Tau 275-311 region (SEQ ID NO: 19) were determined, and overlapping peptides of increasing length from this region (SEQ ID NOs: 115 and 156-171) were synthesized and coated onto the wells of a 96-well microtiter plate as solid phase immunosorbents. The peptides (0.5 μg of peptide per well per 0.1 mL volume) were coated onto the microtiter plate, and then 100 μL of serum samples (diluted 1:100 in PBS) were added to the wells of the plate in duplicate according to the steps of the antibody ELISA method described above.

[0329] Pooled 6wpi guinea pig antisera to SEQ ID NO: 68 Tau peptide immunogen construct (prepared in sample dilution buffer at a dilution factor of 1:100) were added to the wells of a microtiter plate coated with Tau overlapping peptides from this region (at a concentration of 2.0 μg / mL) and then reacted at 37°C for 1 hour. After washing the wells of the microtiter plate with wash buffer, horseradish peroxidase-conjugated protein A / G was added and reacted for 30 minutes. After washing again with PBS, the substrate was added to the wells and the absorbance at 450 nm was measured using an ELISA plate reader, which analyzed the samples in duplicate. The binding of the antiserum to the corresponding long Tau peptide of the B cell epitope immunogen construct represents the maximum binding.

[0330] As shown in Table 16, the pooled 6wpi guinea pig immune sera showed high precision binding characteristics, where the two Tau peptides with SEQ ID NOs 164 and 115 sequences differed in length by only two amino acids, but the longer peptide SEQ ID NO: 115 could present a strong Tau epitope from this hyperphosphorylated and aggregated region. However, due to the deletion of two amino terminal amino acids (I297 and K298), the pooled immune sera could not recognize the peptide SEQ ID NO: 164, indicating that these two amino acids are critical in presenting this region as an immunodominant epitope.

[0331] As shown in Tables 12, 13a, 13b and 15, this region was subjected to further careful design of Tau peptide structures for immunogenicity studies, including the incorporation of a trans configuration of a proline at amino acid position 301 for immunogenicity assessment. In general, in this hyperphosphorylated and aggregated region, high immunogenicity was found in the carefully designed Tau immunogenic peptide structures of SEQ ID NOs: 126-132, 135, 136, 140 and 141, in addition to SEQ ID NO: 128.

[0332] Additional Tau peptide immunogen constructs were designed to target the "fuzzy coat" region of Tau, which is located in the amino-terminal region that is often deleted from Tau isoforms. Tau peptide immunogen constructs from this region (SEQ ID Nos: 137-139) were also designed as shown in Table 3, and their corresponding immunogenicity was evaluated.

[0333] Table 14 shows that the Tau peptide immunogen constructs from the villous coat region are highly immunogenic. These results suggest that the Tau peptide immunogen constructs from the amino-terminal villous coat region can be used to incorporate into compositions to elicit antibodies to prevent Tau aggregation, and may also reduce the initiation of monomeric Tau inoculation that leads to Tau aggregation.

[0334] All the technical features of the invention disclosed in the specification can be combined in any way. Each technical feature disclosed in the specification can be replaced by other methods that provide the same, equivalent or similar purpose. Therefore, unless otherwise specified, all the features disclosed in the text are only examples of a general series of equivalent or similar features.

[0335] From the above, it can be seen that those skilled in the art can easily understand the essential characteristics of the present invention and can make many changes and adjustments to the present invention to apply it to different uses and conditions without departing from the spirit and scope thereof.

[0336] Table 1. Amino acid sequences of Tau and phosphorylated Tau (pTau) fragments

[0337]

[0338]

[0339] 1 Phosphorylated residues are indicated in bold and underlined

[0340] Table 2. Amino acid sequences of pathogenic bacteria protein-derived Th epitopes used in the design of Tau peptide immunogen constructs containing idealized artificial Th epitopes

[0341]

[0342]

[0343]

[0344]

[0345]

[0346]

[0347] Table 8. Full-length (441 amino acids) Tau protein sequences with 4R and 2N isoforms (GenBank: AGF19246.1)

[0348]

[0349] Table 9a. Immunogenicity analysis of Tau peptide structures (data corresponding to Figure 1A)

[0350] Adjuvant: ISA 51VG; CpG3 50μg / ml; 0.2% tween 80

[0351] Immunogen dose: Primary immunization: 400 μg / 1.0 ml / dose / IM (4 injection sites, 0.25 ml / site); Booster immunization: 100 μg / 0.25 ml / dose / IM

[0352] Immunization schedule: 0, 3 and 6 weeks of gestation

[0353]

[0354] Table 9b. Immunogenicity analysis of Tau peptide structures (data corresponding to Figure 1A)

[0355] Adjuvant: ISA 51VG; CpG3 50μg / ml; 0.2% tween 80

[0356] Immunogen dose: Primary immunization: 400 μg / 1.0 ml / dose / IM (4 injection sites, 0.25 ml / site); Booster immunization: 100 μg / 0.25 ml / dose / IM

[0357] Immunization schedule: 0, 3 and 6 weeks of gestation

[0358]

[0359] Table 9c. Immunogenicity analysis of Tau peptide structures (data corresponding to Figure 1A)

[0360] Adjuvant: ISA 51VG; CpG3 50μg / ml; 0.2% tween 80

[0361] Immunogen dose: Primary immunization: 400 μg / 1.0 ml / dose / IM (4 injection sites, 0.25 ml / site); Booster immunization: 100 μg / 0.25 ml / dose / IM

[0362] Immunization schedule: 0, 3 and 6 weeks of gestation

[0363]

[0364] Table 9d. Immunogenicity analysis of Tau peptide structures (data corresponding to Figure 1A)

[0365] Adjuvant: ISA 51VG; CpG3 50μg / ml; 0.2% tween 80

[0366] Immunogen dose: Primary immunization: 400 μg / 1.0 ml / dose / IM (4 injection sites, 0.25 ml / site); Booster immunization: 100 μg / 0.25 ml / dose / IM

[0367] Immunization schedule: 0, 3 and 6 weeks of gestation

[0368]

[0369] Table 9e. Immunogenicity analysis of Tau peptide structures (data corresponding to Figure 1A)

[0370] Adjuvant: ISA 51VG; CpG3 50μg / ml; 0.2% tween 80

[0371] Immunogen dose: Primary immunization: 400 μg / 1.0 ml / dose / IM (4 injection sites, 0.25 ml / site); Booster immunization: 100 μg / 0.25 ml / dose / IM

[0372] Immunization schedule: 0, 3 and 6 weeks of gestation

[0373]

[0374] Table 10a. Immunogenicity analysis of phosphorylated Tau peptide structures (data corresponding to Figure 1B)

[0375] Adjuvant: ISA 51VG; CpG3 50μg / ml; 0.2% tween 80

[0376] Immunogen dose: Primary immunization: 400 μg / 1.0 ml / dose / IM (4 injection sites, 0.25 ml / site); Booster immunization: 100 μg / 0.25 ml / dose

[0377]

[0378] Table 10b. Immunogenicity analysis of phosphorylated Tau peptide structures (data corresponding to Figure 1 B)

[0379] Adjuvant: ISA 51VG; CpG3 50μg / ml; 0.2% tween 80

[0380] Immunogen dose: Primary immunization: 400 μg / 1.0 ml / dose / IM (4 injection sites, 0.25 ml / site); Booster immunization: 100 μg / 0.25 ml / dose / IM

[0381]

[0382] Table 10c. Immunogenicity analysis of phosphorylated Tau peptide structures (data corresponding to Figure 1B)

[0383] Adjuvant: ISA 51VG; CpG3 50μg / ml; 0.2% tween 80

[0384] Immunogen dose: Primary immunization: 400 μg / 1.0 ml / dose / IM (4 injection sites, 0.25 ml / site); Booster immunization: 100 μg / 0.25 ml / dose / IM

[0385] Immunization schedule: 0, 3 and 6 weeks of gestation

[0386]

[0387] Table 10d. Immunogenicity analysis of phosphorylated Tau peptide structures (data corresponding to Figure 1B)

[0388] Adjuvant: ISA 51VG; CpG3 50μg / ml; 0.2% tween 80

[0389] Immunogen dose: Primary immunization: 400 μg / 1.0 ml / dose / IM (4 injection sites, 0.25 ml / site); Booster immunization: 100 μg / 0.25 ml / dose / IM

[0390] Immunization schedule: 0, 3 and 6 weeks of gestation

[0391]

[0392]

[0393] Table 11a. Immunogenicity analysis of phosphorylated Tau peptide structures

[0394] Adjuvant: ISA 51VG; CpG3 50μg / ml; 0.2% tween 80

[0395] Immunogen dose: Primary immunization: 400 μg / 1.0 ml / dose / IM (4 injection sites, 0.25 ml / site); Booster immunization: 100 μg / 0.25 ml / dose / IM

[0396] Immunization schedule: 0, 3 and 6 weeks of gestation

[0397]

[0398] Table 11b. Immunogenicity analysis of phosphorylated Tau peptide structures

[0399] Adjuvant: ISA 51VG; CpG3 50μg / ml; 0.2% tween 80

[0400] Immunogen dose: Primary immunization: 400 μg / 1.0 ml / dose / IM (4 injection sites, 0.25 ml / site); Booster immunization: 100 μg / 0.25 ml / dose / IM

[0401] Immunization schedule: 0, 3 and 6 weeks of gestation

[0402]

[0403] Table 11c. Immunogenicity analysis of phosphorylated Tau peptide structures

[0404] Adjuvant: ISA 51VG; CpG3 50μg / ml; 0.2% tween 80

[0405] Immunogen dose: Primary immunization: 400 μg / 1.0 ml / dose / IM (4 injection sites, 0.25 ml / site); Booster immunization: 100 μg / 0.25 ml / dose / IM

[0406] Immunization schedule: 0, 3 and 6 weeks of gestation

[0407]

[0408] Table 11d. Immunogenicity analysis of phosphorylated Tau peptide structures

[0409] Adjuvant: ISA 51VG; CpG3 50μg / ml; 0.2% tween 80

[0410] Immunogen dose: Primary immunization: 400 μg / 1.0 ml / dose / IM (4 injection sites, 0.25 ml / site); Booster immunization: 100 μg / 0.25 ml / dose / IM

[0411] Immunization schedule: 0, 3 and 6 weeks of gestation

[0412]

[0413] Table 11e. Immunogenicity analysis of phosphorylated Tau peptide structures

[0414] Adjuvant: ISA 51VG; CpG3 50μg / ml; 0.2% tween 80

[0415] Immunogen dose: Primary immunization: 400 μg / 1.0 ml / dose / IM (4 injection sites, 0.25 ml / site); Booster immunization: 100 μg / 0.25 ml / dose / IM

[0416] Immunization schedule: 0, 3 and 6 weeks of gestation

[0417]

[0418] Table 12. Immunogenicity analysis of Tau peptide constructs containing B cell epitopes from Tau hyperphosphorylation and aggregation sites

[0419] Adjuvant: ISA 51VG; CpG3: 50 μg / ml; 0.2% tween 80

[0420] Immunogen dose: Primary immunization: 400 μg / 1.0 ml / dose / IM (4 injection sites, 0.25 ml / site); Booster immunization: 100 μg / 0.25 ml / dose / IM

[0421] Immunization schedule: 0, 3 and 6 weeks of gestation

[0422]

[0423] Table 13a. Immunogenicity analysis of Tau peptide structures derived from B cell epitopes from the Tau 275-311 region

[0424] Adjuvant: ISA 51VG; CpG3: 50 μg / ml; 0.2% tween 80

[0425] Immunogen dose: Primary immunization: 400 μg / 1.0 ml / dose / IM (4 injection sites, 0.25 ml / site); Booster immunization: 100 μg / 0.25 ml / dose / IM

[0426] Immunization schedule: 0, 3 and 6 weeks of gestation

[0427]

[0428] Table 13b

[0429]

[0430] Table 14. Immunogenicity analysis of Tau peptide structures derived from the amino-terminal 'villi coat' of Tau

[0431] Adjuvant: ISA 51VG; CpG3: 50 μg / ml; 0.2% tween 80

[0432] Immunogen dose: Primary immunization: 400 μg / 1.0 ml / dose / IM (4 injection sites, 0.25 ml / site); Booster immunization: 100 μg / 0.25 ml / dose / IM

[0433] Immunization schedule: 0, 3 and 6 weeks of gestation

[0434]

[0435]

[0436] Table 16. Localization of immunogenic regions within Tau 275-311 by fine epitope identification

[0437]

Claims

1. A Tau peptide immunogen construct represented by the following molecular formula: (Th)m–(A)n–(Tau fragment)–X or (Tau fragment)–(A)n–(Th) m –X in Th is a heterologous T helper cell epitope; A is a heterologous spacer; (Tau fragment) is a B cell epitope having about 15 to about 40 amino acid residues from the full-length Tau protein of SEQ ID NO: 100; X is α-COOH or α-CONH2 of an amino acid; m is from 1 to about 4; and n is 0 to about 10.

2. The Tau peptide immunogen construct of claim 1, wherein the Tau fragment is selected from the group consisting of SEQ ID NOs: 1-21 and 101-124.

3. The Tau peptide immunogen construct of any one of claims 1 or 2, wherein the T helper cell epitope is selected from the group consisting of SEQ ID NOs: 22-50.

4. The Tau peptide immunogen construct of claim 1, wherein the peptide immunogen construct is selected from the group consisting of SEQ ID NOs: 51-71 and 125-155.

5. A Tau peptide immunogen construct, comprising: A B cell epitope comprising about 15 to about 40 amino acid residues from the full-length Tau protein sequence of SEQ ID NO: 100; A T helper cell epitope comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 22-50; and an optional heterologous spacer selected from the group consisting of amino acids, Lys-, Gly-, Lys-Lys-Lys-, (α,ε-N)Lys, and ε-N-Lys-Lys-Lys-Lys (SEQ ID NO: 102), wherein the B cell epitope is covalently linked to the T helper cell epitope directly or via the optional heterologous spacer.

6. The Tau peptide immunogen construct of claim 5, wherein the B cell epitope is selected from the group consisting of SEQ ID NOs: 1-21 and 101-124.

7. The Tau peptide immunogen construct of claim 5, wherein the T helper cell epitope is selected from the group consisting of SEQ ID NOs: 22-50.

8. The Tau peptide immunogen construct of claim 5, wherein the optional heterologous spacer is (α,ε-N)Lys or ε-N-Lys-Lys-Lys-Lys (SEQ ID NO: 102).

9. The Tau peptide immunogen construct of claim 5, wherein the T helper cell epitope is covalently linked to the amino terminus of the B cell epitope.

10. The Tau peptide immunogen construct of claim 5, wherein the T helper cell epitope is covalently linked to the amino terminus of the B cell epitope via the optional heterologous spacer.

11. A composition comprising the peptide immunogen construct according to any one of claims 1 to 4.

12. A pharmaceutical composition comprising: a. A peptide immunogen construct as described in any one of claims 1 to 4; and b. Pharmaceutically acceptable delivery vehicles and / or adjuvants.

13. The pharmaceutical composition according to claim 12, wherein a. The Tau peptide immunogen construction system is selected from the group consisting of SEQ ID NOs: 51-71 and 125-155; and b. The Tau peptide immunogen construct is mixed with CpG oligodeoxynucleotide (ODN) to form a stable immunostimulatory complex.

14. An isolated antibody or epitope-binding fragment thereof, which can specifically bind to the B cell epitope of the Tau peptide immunogen construct as claimed in any one of claims 1 to 10.

15. The isolated antibody or epitope-binding fragment thereof of claim 14 binds to the Tau peptide immunogen construct.

16. An isolated antibody or epitope-binding fragment thereof, which can specifically bind to the B cell epitope of the Tau peptide immunogen construct as claimed in any one of claims 1 to 10.

17. A composition comprising the isolated antibody or epitope-binding fragment thereof as claimed in any one of claims 14 to 16.

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