Abstract: The level of CD8+ T cell cytotoxicity directed toward activated CD4+ T cells expressing a specific T cell receptor V&bgr; chain and a major histocompatibility complex class Ib molecule is assayed by contacting a sample containing CD8+ T cells with the activated CD4+ T cells for a determined period of time and determining the amount of activated CD4+ T cell death during the time period. The level of CD8+ T cell activity stimulated by the activated CD4+ T cells is assayed by measuring lymphokine release from stimulated CD8+ T cells or by determining the amount of cell surface molecules specifically expressed on stimulated CD8+ T cells. An agent capable of stimulating or inhibiting CD8+ T cells cytotoxicity toward the activated CD4+ T cells will suppress or inhibit the suppression of an immune response mediated by the activated CD4+ T cells, respectively.

Abstract: Activation of cells bearing CD40 on their cell surface by CD40 ligand is inhibited by contacting the cells with an agent capable of inhibiting interaction between CD40 ligand and the cells, in an amount effective to inhibit activation of the cells. Activation of cells bearing CD40 on their surface by CD40 ligand in a subject is inhibited by administering to the subject an agent capable of inhibiting interaction between CD40 ligand and the cells, in an amount effective to inhibit activation of the cells. Conditions dependent on CD40 ligand-induced activation of CD40-bearing cells are treated.

Abstract: A single-stranded nucleic acid molecule which encodes an amino acid sequence comprising at least a portion of a T4 glycoprotein is provided. Additionally, amino acid sequences which comprise at least a portion of a T4 glycoprotein and are useful as a prophylaxis for treating a subject with acquired immune deficiency syndrome are provided. These amino acid sequences, which are capable of specifically forming a complex with a human immunodeficiency virus envelope glycoprotein and which are soluble in an aqueous solution may be administered to a subject infected with a human immunodeficiency virus so as to block the human immunodeficiency virus from binding to T4+ cells. Monoclonal antibodies directed to the water-soluble amino acid sequences of the present invention may be used as vaccines for immunizing a subject against acquired immune deficiency syndrome.

Abstract: This invention provides a monoclonal antibody which specifically recognizes and forms a complex with a protein located on the surface of activated T cells and thereby inhibits T cell activation of B cells. This invention also provides the monoclonal antibody 5c8 (ATCC Accession No. ______).

Abstract: This invention provides for an isolated protein specifically recognized by monoclonal antibody 5c8 produced by the hybridoma having ATCC Accession No. HB 10916. This invention also provides for an isolated protein having substantially the same biological activity as the aforementioned isolated protein. In addition, this invention provides for a pharmaceutical composition comprising the isolated protein and a pharmaceutically acceptable carrier.

Abstract: This invention provides a method of inhibiting an allergic response in a subject by inhibiting T cell activation of B cells, wherein said method comprises administering to the subject an antibody capable of binding to a protein which is specifically recognized by monoclonal antibody 5C8 produced by the hybridoma having ATCC Accession No. HB 10916.

Abstract: This invention provides for a method for inhibiting rejection of a transplant organ in a subject which comprises administering to the subject an antibody capable of binding to a protein which is specifically recognized by monoclonal antibody 5c8 produced by the hybridoma having ATCC Accession No. HB 10916. The present invention further provides for a method for inhibiting rejection of a transplant organ in a subject, which comprises administering to the subject a pharmaceutical composition comprising a monoclonal antibody capable of binding to a protein which is specifically recognized by monoclonal antibody 5c8 produced by the hybridoma having ATCC Accession No. HB 10916. In one embodiment of the invention, the transplant organ is a heart, a kidney or a liver. In another embodiment, the monoclonal antibody is 5c8 produced by the hybridoma having ATCC Accession No. HB 10916.

Abstract: Activation of cells bearing CD40 on their cell surface by CD40 ligand is inhibited by contacting the cells with an agent capable of inhibiting interaction between CD40 ligand and the cells, in an amount effective to inhibit activation of the cells. Activation of cells bearing CD40 on their surface by CD40 ligand in a subject is inhibited by administering to the subject an agent capable of inhibiting interaction between CD40 ligand and the cells, in an amount effective to inhibit activation of the cells. Reperfusion injury, in an non-transplant recipient, is a condition associated with CD40 ligand-induced activation of CD40-bearing cells. Therefore, reperfusion injury can be treated by the administration of anti-human CD40L monoclonal antibodies, such as those described herein (e.g. 5c8 mAb).

Abstract: This invention provides for a human T cell leukemia cell line designated D1.1 having ATCC Accession No. CRL 10915. The cell line is capable of constitutively providing contact-dependent helper function to B cells.

Abstract: The present invention provides for an isolated nucleic acid molecule encoding a light chain protein of an antibody, wherein the antibody binds specifically to a protein specifically recognized by monoclonal antibody 5c8 produced by the hybridoma having ATCC Accession Number HB 10916. The invention also provides for an isolated nucleic acid molecule encoding a heavy chain protein of an antibody, wherein the antibody binds specifically to a protein specifically recognized by monoclonal antibody 5c8 produced by the hybridoma having ATCC Accession Number HB 10916. The present invention also provides for a gene transfer vector comprising a nucleic acid molecule, a host vector system comprising the gene transfer vector, and a composition comprising a nucleic acid molecule.

Abstract: This invention provides an isolated single-stranded nucleic acid which encodes an aqueous-soluble polypeptide comprising at least a portion of a human T4 glycoprotein, which portion specifically forms a complex with a human immunodeficiency virus envelope glycoprotein.

Abstract: This invention provides an isolated nucleic acid molecule encoding a protein from the surface of activated T cells, wherein the protein is necessary for T cell activation of B cells. The nucleic acid molecule may include a DNA molecule or a cDNA molecule. This invention further provides a gene transfer vector including the nucleic acid molecule operably linked to a promoter of RNA transcription. The vector may be a plasmid or a viral vector. This invention further provides a host vector system including the gene transfer vector in a suitable host cell. The transformed yeast or a stably transformed mammalian cell. This invention further provides a method of producing a T cell surface protein necessary for T cell activation of B cells which includes growing the host vector system under conditions permitting production of the protein, followed by recovering the protein so produced.

Abstract: A single-stranded nucleic acid molecule which encodes an amino acid sequence comprising at least a portion of a T4 glycoprotein is provided. Additionally, amino acid sequences which comprise at least a portion of a T4 glycoprotein and are useful as a prophylaxis for treating a subject with acquired immune deficiency syndrome are provided. These amino acid sequences, which are capable of specifically forming a complex with a human immunodeficiency virus envelope glycoprotein and which are soluble in an aqueous solution may be administered to a subject infected with a human immunodeficiency virus so as to block the human immunodeficiency virus from binding to T4.sup.+ cells.Monoclonal antibodies directed to the water-soluble amino acid sequences of the present invention may be used as vaccines for immunizing a subject against acquired immune deficiency syndrome.

Abstract: A single-stranded nucleic acid molecule which encodes the amino acid sequence comprising at least a portion of a T4 glycoprotein is provided. Additionally, amino acid sequences which comprise at least a portion of a T4 glycoprotein and are useful as a prophylaxis for treating a subject with acquired immune deficiency syndrome are provided. These amino acid sequences, which are capable of specifically forming a complex with a human immunodeficiency virus glycoprotein and which are soluble in an aqueous solution may be administered to a subject infected with a human immunodeficiency virus so as to block the human immunodeficiency virus from binding to T4 cells. Monoclonal antibodies directed to the water-soluble amino acid sequences of the present invention may be used as vaccines for immunizing a subject against acquired immune deficiency syndrome.

Abstract: The present invention provides methods of treating a subject suffering from a disorder associated with elevated levels of VLA-1 which comprises administering to the subject a therapeutically effective amount of an antibody which specifically forms a complex with VLA-1, inhibits collagen binding to VLA-1, and is directed to the epitope to which antibody 1B3.1 (ATCC No. HB10536) is directed and a pharmaceutically acceptable carrier.

Abstract: This invention provides a monoclonal antibody which specifically recognizes and forms a complex with a protein located on the surface of activated T cells and thereby inhibits T cell activation of B cells. This invention also provides the monoclonal antibody 5c8 (ATCC Accession No. HB 10916).This invention provides a human CD4.sup.- T cell leukemia cell line designated D1.1 (ATCC Accession No. CRL 10915) capable of constitutively providing contact-dependent helper function to B cells. This invention also provides an isolated protein from the surface of activated T cells, wherein the protein is necessary for T cell activation of B cells. This invention further provides an isolated, soluble protein from the surface of activated T cells, wherein the protein is necessary for T cell activation of B cells.

Abstract: The present invention provides an antibody which specifically forms a complex with and inhibits collagen binding to VLA-1 and methods of using same.

Abstract: A single-stranded nucleic acid molecule which encodes an amino acid sequence comprising at least a portion of a T4 glycoprotein is provided. Additionally, amino acid sequences which comprise at least a portion of a T4 glycoprotein and are useful as a prophylaxis for treating a subject with acquired immune deficiency syndrome are provided. These amino acid sequences, are capable of specifically forming a complex with a human immunodeficiency virus envelope glycoprotein and which are soluble in an aqueous solution. Monoclonal antibodies directed to the water-soluble amino acid sequences of the present invention may be used as vaccines for immunizing a subject against acquired immune deficiency syndrome.