809 results about "Antigen-presenting cell" patented technology

The present invention comprises compositions and methods for treating a tumor or neoplastic disease in a host, The methods employ conjugates comprising superantigen polypeptides or nucleic acids with other structures that preferentially bind to tumor cells and are capable of inducing apoptosis. Also provided are superantigen-glycolipid conjugates and vesicles that are loaded onto antigen presenting cells to activate both T cells and NKT cells. Cell-based vaccines comprise tumor cells engineered to express a superantigen along with glycolipids products which, when expressed, render the cells capable of eliciting an effective anti-tumor immune response in a mammal into which these cells are introduced. Included among these compositions are tumor cells, hybrid cells of tumor cells and accessory cells, preferably dendritic cells. Also provided are T cells and NKT cells activated by the above compositions that can be administered for adoptive immunotherapy.

Nanoparticles that activate complement in the absence of biological molecules are described. The nanoparticles are shown to specifically target antigen presenting cells in specifically in lymph nodes, without the use of a biological molecule for targeting. These particles are useful vehicles for delivering immunotherapeutics. Surface chemistries and chemical formulations for the nanoparticles are described.

The present invention relates to methods and compositions for eliciting an immune response and the prevention and treatment of primary and metastatic neoplastic diseases and infectious diseases. The methods of the invention comprise administering a composition comprising an effective amount of a complex, in which the complex consists essentially of a heat shock protein (hsp) noncovalently bound to an antigenic molecule. Optionally, the methods further comprise administering antigen presenting cells sensitized with complexes of hsps noncovalently bound to an antigenic molecule. "Antigenic molecule" as used herein refers to the peptides with which the hsps are endogenously associated in vivo as well as exogenous antigens/immunogens (i.e., with which the hsps are not complexed in vivo) or antigenic/immunogenic fragments and derivatives thereof. In a preferred embodiment, the complex is autologous to the individual. In a specific embodiment, the effective amounts of the complex are in the range of 0.1 to 9.0 micrograms for complexes comprising hsp70, 5 to 49 micrograms for hsp90, and 0.1 to 9.0 micrograms for gp96.

This invention provides a process for producing major histocompatibility antigen class II protein (hereinafter referred to as "MHC class II" for short) which occurs on the surfaces of antigen-presenting cells and the like, and MHC class II-bound materials in which MHC class II, alpha and/or beta subunit of MHC class II, or a part thereof is bound to a carrier such as beads, fibers and hollow fibers via covalent bond, as well as a module for removing superantigen using the same. This invention also provides a method for detecting or quantifying superantigens using MHC class II or a part thereof having an affinity to the superantigens, as well as an assay kit therefor.

Disclosed herein are methods and compositions for enhancing the immunogenicity of a preselected protein or peptide antigen in a mammal. Immunogenicity is enhanced by fusing the preselected antigen to an immunoglobulin heavy chain constant region to produce an Fc-antigen fusion protein. The Fc-antigen fusion proteins bind Fc receptors on the surface of antigen presenting cells, thereby targeting the antigen to the antigen presenting cells in the mammal. In addition, disclosed is a family of adjuvants, for example, an Fc-adjuvant fusion protein, for use in combination with the Fc-antigen fusion proteins to enhance or modulate a particular immune response against the preselected antigen.

The present invention relates to methods and compositions for use in mediating an immunosuppressive reaction. The compositions of the invention comprise exosomes having immunosuppressive activity. Such exosomes may be derived from a variety of different cell types, including antigen presenting cells such as dendritic cells and macrophages. Prior to isolation of exosomes, the cells may be genetically engineered to express molecules capable of enhancing the immunosuppressive activity of said exosomes and/or may be exposed to one or more agents, such as cytokines or cytokine inhibitors, which are also capable of enhancing the immunosuppressive activity of exosomes. The present invention also relates to the use of such exosomes for the treatment of diseases and disorders associated with undesirable activation of the immune system. The present invention also includes exosomes isolated directly from serum that have been shown to be immunosuppressive.

A method is disclosed for inducing cell-mediated immunity against cellular antigens. More specifically, the invention provides for a method for inducing cytotoxic T-lymphocyte immunity against weak antigens, notably self-proteins. The method entails that antigen presenting cells are induced to present at least one CTL epitope of the weak antigen and at the same time presenting at least one foreign T-helper lymphocyte epitope. In a preferred embodiment, the antigen is a cancer specific antigen, e.g. PSM, Her2, or FGF8b. The method can be exercised by using traditional polypeptide vaccination, but also by using live attenuated vaccines or nucleic acid vaccination. The invention furthermore provides immunogenic analogues of PSM, Her2 and FGF8b, as well as nucleic acid molecules encoding these analogues. Also vectors and transformed cells are disclosed. The invention also provides for a method for identification of immunogenic analogues of weak or non-immunogenic antigens.

The present invention provides compositions and methods for modulating immune responses to antigens. One aspect of the present invention relates to a particle-based antigen delivery system (vaccination node) that comprises a hydrogel particle capable of both antigen presentation and DC activation. The VN may further comprise a chemoattractant-loaded microsphere capable of attracting DCs to the site of administration. Another aspect of the present invention relates to the use of the VN to modulate antigen presenting cells activation for the prevention and/treatment of various diseases, such as infectious diseases, cancers and autoimmune diseases.

A method is described whereby dendritic cells derived from the CD34+ and CD 34−hematopoietic cell lineages are directed to become programmable antigen presenting cells. The programmed cells may be pulsed with tumor cell RNA or tumor cell RNA expression products. The protocol provides for directing the maturation of dendritic cells to become antigen presenting cells. The protocol further provides for isolating tumor cell RNA from biopsy material that has been prepared in paraffin block storage. The directed dendritic cell is provided with a plurality of tumor markers by using tumor RNA in toto, the poly A+RNA fraction or the expression product of such RNA. Once activated the dendritic cells are incubated with T4 and T8 lymphocytes to stimulate and sensitize the T lymphocytes which upon introduction either into a donor host or a nondonor recipient will provide immune response protection.

The invention relates to antigen-presenting cells having specificity against a selected antigen and methods for making the cells. The invention also relates to a method of selecting efficient antigen-presenting cells using reporter fusion constructs. The highly efficient antigen-presenting cells of the invention will provide a therapeutic strategy of modulating immune responses for a variety of diseases.

Compositions and methods for the therapy and diagnosis of Inflammatory Bowel Disease (IBD), including Crohn's Disease and Ulcerative Colitis, are disclosed. Illustrative compositions comprise one or more bacterial polypeptides, immunogenic portions thereof, polynucleotides that encode such polypeptides, antigen presenting cell that expresses such polypeptides, and T cells that are specific for cells expressing such polypeptides. The disclosed compositions are useful, for example, in the diagnosis, prevention and/or treatment of IBD.

The present invention includes compositions and methods for increasing the effectiveness of antigen presentation using a DCIR-specific antibody or fragment thereof to which an antigen is attached that forms an antibody-antigen complex, wherein the antigen is processed and presented by a dendritic cell that has been contacted with the antibody-antigen complex.

The present invention relates to methods and compositions for enhancing immunological responses and for the prevention and treatment of infectious diseases or primary and metastatic neoplastic diseases based on the administration of macrophages and/or other antigen presenting cells (APC) sensitized with heat shock proteins non-covalently bound to peptide complexes and/or antigenic components. APC are incubated in the presence of hsp-peptide complexes and/or antigenic components in vitro. The sensitized cells are reinfused into the patient with or without treatment with cytokines including but not limited to interferon- alpha , interferon- alpha , interleukin-2, interleukin-4, interleukin-6 and tumor neurosis factor.

Disclosed herein are compositions and methods for eliciting immune responses against antigens. In particular embodiments, the compounds and methods elicit immune responses against antigens that are otherwise recognized by the host as “self” antigens. The immune response is enhanced by presenting the host immune system with a chimeric antigen comprising an immune response domain and a target binding domain, wherein the target binding domain comprises a xenotypic antibody fragment. By virtue of the target binding domain, antigen presenting cells take up, process, and present the chimeric antigen, eliciting both a humoral and cellular immune response.

Free-living microbes are provided in which the nucleic acid has been modified so that the microbe is attenuated for proliferation and/or which comprise genetic mutations that attenuate the ability of the microbe to repair its nucleic acid. Methods of using the modified microbes for the loading, activation, and/or maturation of antigen-presenting cells are also provided. Vaccine compositions comprising the modified microbes and/or the antigen-presenting cells and methods of using the vaccines are also provided. The microbes may be further modified to include heterologous antigens, such as tumor antigens or infectious disease antigens, for use as a vaccine against cancer or infectious diseases.

Antibodies to antigen presenting cells may be utilized to interfere with the interaction of the antigen presenting cell and immune cells, including T cells. Peptides may be linked to said antibodies thereby generating an immune response to such peptides. Preferably peptides linked to the antibodies are associated with autoimmunity.

The present invention relates to pharmaceutical compositions and methods for the prevention and treatment of autoimmune diseases, infectious diseases, neurodegenerative diseases, and primary and metastatic neoplastic diseases. In the practice of the invention, the compositions are employed comprising: (a) a heat shock protein (hsp) or an alpha(2)macroglobulin (alpha2M); (b) a saponin; and, optionally, (c) an antigenic molecule. The antigenic molecule displays the antigenicity of an antigen of: (a) a cell that elicits an autoimmune response; (b) an agent of an infectious disease; (c) a cancerous cell; or (d) a cell or structure associated with a neurodegenerative or amyloid disease. The hsps that can be used in the practice of the invention include but are not limited to hsp70, hsp90, gp96, calreticulin, hsp 110, grp 170, and PDI, alone or in combination with each other. The antigenic molecule can be covalently or noncovalently bound to the hsp or alpha2M, free in solution, and/or covalently bound to the saponin. The compositions of the invention can be administered alone or in combination with the administration of antigen presenting cells sensitized with an hsp- or alpha2M-antigenic molecule complex.

Single chain trimer (SCT) molecules are disclosed, comprising an MHC antigen peptide sequence, a β₂-microglobulin sequence and a full-length MHC class I heavy chain sequence, joined by linker sequences. Further described are nucleic acids encoding single chain trimers. Methods for expansion of antigen-specific T cell populations using single chain trimer molecules are also disclosed. In some configurations, these methods comprise co-culturing, in a first stage, CD8+ T cells from a donor with antigen presenting cells comprising an MHC antigen peptide, and co-culturing, in a second stage, the CD8+ T cells with cells comprising an SCT which has an MHC antigen peptide sequence identical to the sequence of the antigen peptide in the first stage. The methods can provide 10,000-100,000 fold expansion of antigen-specific CD8+ T cells within about 28 days after establishing culture, and can yield over 1 billion antigen-specific CD8+ T cells expanded from an individual donor.

Compositions and methods for the therapy and diagnosis of cancer, particularly breast cancer, are disclosed. Illustrative compositions comprise one or more breast tumor polypeptides, immunogenic portions thereof, polynucleotides that encode such polypeptides, antigen presenting cell that expresses such polypeptides, and T cells that are specific for cells expressing such polypeptides. The disclosed compositions are useful, for example, in the diagnosis, prevention and/or treatment of diseases, particularly breast cancer.