Abstract: PD-1 antagonists are disclosed that can be used to reduce the expression or activity of PD-1 in a subject. An immune response specific to an infectious agent or to tumor cells can be enhanced using these PD-1 antagonists in conjunction with an antigen from the infectious agent or tumor. Thus, subjects with infections, such as persistent infections can be treated using PD-1 antagonists. In addition, subjects with tumors can be treated using the PD-1 antagonists. In several examples, subjects can be treated by transplanting a therapeutically effective amount of activated T cells that recognize an antigen of interest and by administering a therapeutically effective amount of a PD-1 antagonist.

Abstract: The invention provides isolated nucleic acids molecules, designated B7-4 nucleic acid molecules, which encode novel B7-4 polypeptides. The invention also provides antisense nucleic acid molecules, recombinant expression vectors containing B7-4 nucleic acid molecules, host cells into which the expression vectors have been introduced, and nonhuman transgenic animals in which a B7-4 gene has been introduced or disrupted. The invention still further provides isolated B7-4 proteins, fusion proteins, antigenic peptides and anti-B7-4 antibodies. Diagnostic, screening, and therapeutic methods utilizing compositions of the invention are also provided.

Abstract: The invention provides isolated nucleic acids molecules, designated PD-L2 nucleic acid molecules, which encode novel B7-related molecules which are ligands for PD-1. The invention also provides antisense nucleic acid molecules, recombinant expression vectors containing PD-L2 nucleic acid molecules, host cells into which the expression vectors have been introduced, and nonhuman transgenic animals in which a PD-L2 gene has been introduced or disrupted. The invention further provides isolated PD-L2 polypeptides, fusion proteins, antigenic peptides and anti-PD-L2 antibodies. The invention still further provides methods for promoting or inhibiting the interaction between PD-L2 and PD-1. The invention further provides methods of identifying compounds that upmodulate T cell activation in the presence of a PD-1-mediated signal. Diagnostic and treatment methods utilizing compositions of the invention are also provided.

Abstract: The invention provides isolated nucleic acids molecules, designated PD-L2 nucleic acid molecules, which encode novel B7-related molecules which are ligands for PD-1. The invention also provides antisense nucleic acid molecules, recombinant expression vectors containing PD-L2 nucleic acid molecules, host cells into which the expression vectors have been introduced, and nonhuman transgenic animals in which a PD-L2 gene has been introduced or disrupted. The invention further provides isolated PD-L2 polypeptides, fusion proteins, antigenic peptides and anti-PD-L2 antibodies. The invention still further provides methods for promoting or inhibiting the interaction between PD-L2 and PD-1. Diagnostic and treatment methods utilizing compositions of the invention are also provided.

Abstract: The invention identifies PD-1 as a receptor for B7-4. B7-4 can inhibit immune cell activation upon binding to an inhibitory receptor on an immune cell. Accordingly, the invention provides agents for modulating PD-1, B7-4, and the interaction between B7-4 and PD-1 in order to modulate a costimulatory or an inhibitory signal in a immune cell resulting in modulation of the immune response.

Abstract: The present invention provides methods and compositions for the treatment, prevention, or reduction of persistent infections, such as chronic infections, latent infections, and slow infections and cancer. The methods and compositions of the invention are also useful for the alleviation of one or more symptoms associated with such infections and cancer.

Abstract: Novel structural forms of T cell costimulatory molecules are described. These structural forms comprise a novel structural domain or have a structural domain deleted or added. The structural forms correspond to naturally-occurring alternatively spliced forms of T cell costimulatory molecules or variants thereof which can be produced by standard recombinant DNA techniques. In one embodiment, the T cell costimulatory molecule of the invention contains a novel cytoplasmic domain. In another embodiment, the T cell costimulatory molecule of the invention contains a novel signal peptide domain or has an immunoglobulin variable region-like domain deleted. The novel structural forms of T cell costimulatory molecules can be used to identify agents which stimulate the expression of alternative forms of costimulatory molecules and to identify components of the signal transduction pathway which results in costimulation of T cells.

Abstract: Disclosed are methods for identifying an agent that modulates an immune response. One such method comprises screening for agents which inhibit the interaction between a PD-1 ligand and a PD-1 polypeptide, and determining whether the agents inhibit the interaction between a PD-1 ligand and a B7 polypeptide, to identify an agent that inhibits PD-1 ligand and PD-1 polypeptide interaction, while not inhibiting the interaction between a PD-1 ligand and a B7 polypeptide, as an agent that modulates an immune response. Another such method comprises screening for agents which inhibit the interaction between a PD-1 ligand and a B7 polypeptide, and determining whether the agents inhibit the interaction between a PD-1 ligand and a PD-1 polypeptide, to identify an agent that inhibits the PD-1 ligand and B7 polypeptide interaction, which does not inhibit the interaction between a PD-1 ligand and a PD-1 polypeptide, as an agent that modulates the immune response.

Abstract: We teach a strategy to obtain large quantities of desired APCs, activated B cells, which are superior in their capacity to present tumor protein antigen in a multiadministration protocol. Human B cells can be obtained from peripheral blood in large numbers. These cells can be activated in vitro by coculture with CD40L (CD40-B cells) and an immunosuppressive agent such as cyclosporin A. They can expanded up to 1×103 to 1×104 fold in 2 weeks or 1×105 to 1×106 fold in 2 months. We demonstrate these cells are most efficient APCs comparable to DCs in stimulating allogeneic CD4+ CD45RA+, CD4+ CD45RO+, and CD8+ T cells. In contrast to DCs, CD40-B cells are fully functional even in the presence of immunosuppressive cytokines such as IL-10 and TGF?.

Abstract: Methods for selectively modulating a Th2-type response within a population of activated CD4+ T cells are provided. The methods of the invention involve contacting the CD4+ T cells with an agent which modulates a B7-2-induced signal in the CD4+ T cells, such that the Th2-type response is modulated. Methods for either stimulating or inhibiting Th2 type responses are provided by the invention.

Abstract: The invention provides isolated nucleic acids molecules, designated B7-4 nucleic acid molecules, which encode novel B7-4 polypeptides. The invention also provides antisense nucleic acid molecules, recombinant expression vectors containing B7-4 nucleic acid molecules, host cells into which the expression vectors have been introduced, and nonhuman transgenic animals in which a B7-4 gene has been introduced or disrupted. The invention still further provides isolated B7-4 proteins, fusion proteins, antigenic peptides and anti-B7-4 antibodies. Diagnostic, screening, and therapeutic methods utilizing compositions of the invention are also provided.

Abstract: Tumor cells modified to express a T cell costimulatory molecule are disclosed. In one embodiment, the costimulatory molecule is a CD28/CTLA4 ligand, preferably a B lymphocyte antigen B7. The tumor cells of the invention can be modified by transfection with nucleic acid encoding a T cell costimulatory molecule, by using an agent which induces or increases expression of a T cell costimulatory molecule on the tumor cell surface or by coupling a T cell costimulatory molecule to the tumor cell surface. Tumor cells further modified to express MHC class I and/or class II molecules or in which expression of an MHC associated protein, the invariant chain, is inhibited are also disclosed. The modified tumor cells of the invention can be used in methods for treating-a patient with a tumor, preventing or inhibiting metastatic spread of a tumor or preventing or inhibiting recurrence of a tumor.

Abstract: The invention provides isolated nucleic acids molecules, designated B7-4 nucleic acid molecules, which encode novel B7-4 polypeptides. The invention also provides antisense nucleic acid molecules, recombinant expression vectors containing B7-4 nucleic acid molecules, host cells into which the expression vectors have been introduced, and nonhuman transgenic animals in which a B7-4 gene has been introduced or disrupted. The invention still further provides isolated B7-4 proteins, fusion proteins, antigenic peptides and anti-B7-4 antibodies. Diagnostic, screening, and therapeutic methods utilizing compositions of the invention are also provided.

Abstract: The invention provides isolated nucleic acids molecules, designated B7-4 nucleic acid molecules, which encode novel B7-4 polypeptides. The invention also provides antisense nucleic acid molecules, recombinant expression vectors containing B7-4 nucleic acid molecules, host cells into which the expression vectors have been introduced, and nonhuman transgenic animals in which a B7-4 gene has been introduced or disrupted. The invention still further provides isolated B7-4 proteins, fusion proteins, antigenic peptides and anti-B7-4 antibodies. Diagnostic, screening, and therapeutic methods utilizing compositions of the invention are also provided.

Abstract: Tumor cells modified to express one or more T cell costimulatory molecules are disclosed. Preferred costimulatory molecules are B7-2 and B7-3. The tumor cells of the invention can be modified by transfection with nucleic acid encoding B7-2 and/or B7-3, by using an agent which induces or increases expression of B7-2 and/or B7-3 on the tumor cell or by coupling B7-2 and/or B7-3 to the tumor cell. Tumor cells modified to express B7-2 and/or B7-3 can be further modified to express B7. Tumor cells further modified to express MHC class I and/or class II molecules or in which expression of an MHC associated protein, the invariant chain, is inhibited are also disclosed. The modified tumor cells of the invention can be used in methods for treating a patient with a tumor, preventing or inhibiting metastatic spread of a tumor or preventing or inhibiting recurrence of a tumor.

Abstract: A genetic locus and corresponding family of proteins associated with regulation of immune development, function, and cell survival are provided. The locus comprising the TIM family is genetically associated with immune dysfunction, including atopy, autoimmunity, inflammatory bowel disease, dysplasia, and susceptibility to blood-bourne infectious diseases. Polymorphisms in the human TIM-1 gene and exposure to Hepatitis A Virus (HAV) are shown to be associated with protection from the development of atopy.

Abstract: The invention provides isolated nucleic acids molecules, designated PD-L2 nucleic acid molecules, which encode novel B7-related molecules which are ligands for PD-1. The invention also provides antisense nucleic acid molecules, recombinant expression vectors containing PD-L2 nucleic acid molecules, host cells into which the expression vectors have been introduced, and nonhuman transgenic animals in which a PD-L2 gene has been introduced or disrupted. The invention further provides isolated PD-L2 polypeptides, fusion proteins, antigenic peptides and anti-PD-L2 antibodies. The invention still further provides methods for promoting or inhibiting the interaction between PD-L2 and PD-1. Diagnostic and treatment methods utilizing compositions of the invention are also provided.

Abstract: The invention provides isolated nucleic acids molecules, designated PD-L2 nucleic acid molecules, which encode novel B7-related molecules which are ligands for PD-1. The invention also provides antisense nucleic acid molecules, recombinant expression vectors containing PD-L2 nucleic acid molecules, host cells into which the expression vectors have been introduced, and nonhuman transgenic animals in which a PD-L2 gene has been introduced or disrupted. The invention further provides isolated PD-L2 polypeptides, fusion proteins, antigenic peptides and anti-PD-L2 antibodies. The invention still further provides methods for promoting or inhibiting the interaction between PD-L2 and PD-1. Diagnostic and treatment methods utilizing compositions of the invention are also provided.

Abstract: The invention provides isolated nucleic acids molecules, designated B7-4 nucleic acid molecules, which encode novel B7-4 polypeptides. The invention also provides antisense nucleic acid molecules, recombinant expression vectors containing B7-4 nucleic acid molecules, host cells into which the expression vectors have been introduced, and nonhuman transgenic animals in which a B7-4 gene has been introduced or disrupted. The invention still further provides isolated B7-4 proteins, fusion proteins, antigenic peptides and anti-B7-4 antibodies. Diagnostic, screening, and therapeutic methods utilizing compositions of the invention are also provided.

Abstract: The present invention relates to genes and their encoded proteins which induce immunological effector cell activation and chemattraction. The proteins of the invention attract subsets of immunological effector cells and stimulate them to express their specialized effector cell functions. Such proteins, termed Ap-1 proteins, are expressed by lymphoid cells, and bind to effector cells such as macrophages and mast cells. In particular, the ApPursuant to the provisions of 35 U.S.C. .sctn.202(c), it is hereby acknoledged that the Governament has certain rights in this invention, which was made in part with funds from the National Institutes of Health.