Abstract: The invention features attracting polypeptides and nucleic acids encoding them. The attractin polypeptides are useful for enhancing immune responses.

Abstract: A soluble form of CD26 isolated from human serum is disclosed. The serum form shares similar enzymatic and antigenic properties with the membrane form. However, in several biochemical aspects there are distinct differences. In particular, the soluble serum form has a molecular weight of 175 kDa (in contrast to the 105 kDa molecular weight of the membrane form), and it does not bind Adenosine Deaminase Type-1. Nevertheless, the soluble form expresses functional dipeptidylpeptidase IV activity and retains the ability to costimulate the T lymphocyte response to recall antigen. Although 105 kDa membrane type CD26 may be found in the serum in small amounts, the majority of serum DPPIV activity is provided by a novel peptidase structurally distinct from membrane C26/DPPIV.

Abstract: A circulating, soluble form of DPPIV/CD26 isolated from human serum is disclosed. The serum form shares similar enzymatic and antigenic properties with the ubiquitous membrane form. However, in several biochemical aspects there are distinct differences. In particular, the circulating serum form has a molecular weight of 175 kDa (in contrast to the 105 kDa molecular weight of the membrane form), and it does not bind Adenosine Deaminase Type-1. Nevertheless, the circulating form expresses functional dipeptidylpeptidase IV activity and retains the ability to costimulate the T lymphocyte response to recall antigen. Circulating DPPIV has been determined to be the soluble form of a 175 kDa DPPIV CD26-related molecule rapidly expressed on the surface of activated T cells, prior to the expression of 105 kDa CD26. Although 105 kDa membrane type CD26 may be found in the serum in small amounts, the majority of serum DPPIV activity is provided by a novel peptidase structurally distinct from 105 kDa CD26/DPPIV.

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

Abstract: Methods for interfering with antigen presenting cell-mediated priming of resting peripheral blood T lymphocytes to undergo activation induced cell death ("apoptosis") by inhibiting an interaction between a membrane associated molecule ("an APC apoptotic ligand") present on stimulated antigen presenting cells ("APC") and a counter-receptor that is present on T lymphocytes are disclosed. The antigen presenting cells are preferably from the monocyte/macrophage cell line or are dendritic cells. Also disclosed are methods of screening for inhibitors of APC-mediated priming of T lymphocytes to undergo apoptosis and methods and agents for detecting, identifying and characterizing an APC apoptotic ligand.

Abstract: A purified preparation of a polypeptide that is immunologically reactive with the monoclonal antibody produced by the hybridoma designated ATCC # HB 10319.

Abstract: An isolated DNA that includes a sequence encoding a polypeptide with which the monoclonal antibody TIA-1 produced by the hybridoma designated ATCC#HB10319 is immunologically reactive; a vector or a cell containing such a DNA; and a method of using such a DNA to identify cytolytic lymphocytes.

Abstract: An isolated DNA that includes a sequence encoding a polypeptide with which the monoclonal antibody TIA-1 produced by the hybridoma designated ATCC#HB10319 is immunologically reactive; a vector or a cell containing such a DNA; and a method of using such a DNA to identify cytolytic lymphocytes.

Abstract: A hybrid cell line is developed which produces a monoclonal antibody which binds to a unique antigenic site expressed on the surface of phagocytic cells. The monoclonal antibody binds to and activates a specific domain of the CD11b glycoprotein so as to inhibit adhesion dependent functions of the phagocytic cell, but it does not affect other phagocytic functions. This monoclonal antibody can be used as a reactant in an in vitro diagnostic immunoassay for detecting the unique antigenic site on the surface of normal human neutrophils.

Abstract: A monoclonal antibody which binds preferentially to a subset of the human CD4+ lymphocyte population whereby to positively and precisely distinguish between helper-inducer and suppressor-inducer cells in the CD4+ cell population. The monoclonal antibody recognizes a novel antigen on the CD4+ lymphocytes by means of which it can bind CD4+ cells which express the antigen on the surface of CD4+ cells. The CD4+ subset cell population to which this antibody preferentially binds is the CD4+ helper-inducer population. This selectivity of the monoclonal antibody enables cell sorting, diagnostic and possible therapeutic applications thereof to be realized. The monoclonal antibody also reacts with CD8 cells, B cells and macrophages.

Abstract: A 15 kd protein antigen is associated with cytoplasmic granules in cytolytic T lymphocytes and natural killer cells. Monoclonal antibodies immunologically reactive with the 15 kd protein and nucleic acid probes encoding polypeptides that are immunologically cross-reactive with the 15 kd protein can be used, e.g., to identify cytolytic lymphocytes in a sample. Cloned cDNA encoding the antigen can be used to produce the antigen.

Abstract: A hybrid cell line is developed which produces a monoclonal antibody which binds to a unique antigenic site expressed on the surface of phagocytic cells. The monoclonal antibody binds to and activates a specific domain of the CD11b glycoprotein so as to inhibit adhesion dependent functions of the phagocytic cell, but it does not affect other phagocytic functions. This monoclonal antibody can be used as a reactant in an in vitro diagnostic immunoassay for detecting the unique antigenic site on the surface of normal human neutrophils.

Abstract: A monoclonal antibody which binds preferentially to a subset of the human CD8 lymphocyte population whereby to positively and precisely distinguish between cytotoxic effector and supressor effector cells in the CD8 cell population. The monoclonal antibody recognizes a novel epitope of LFA-1 antigen by means of which it can bind CD8 cells which express the eptope on a surface antigen thereof. The CD8 subset cell population to which this anitbody binds preferentially is the CD8 cytotoxic effector population. This selectivity of the monoclonal antibody enables cell sorting, diagnostic and positive therapeutic applications thereof to be utilized.

Abstract: A method of testing the effect of an agonist or an antagonist to B lymphocyte cell surface protein CD20 on B lymphocyte function which involves determining calcium ion flux across the B lymphocyte membrane, contacting the B lymphocyte with the agonist or antagonist, and determining the change in calcium ion flux across the membrane after exposure of the B lymphocyte to the agonist or antagonist, is described. In preferred embodiments of the method the agonist or antagonist is a ligand that binds CD20 or an antibody to CD20.In other preferred embodiments, calcium ion flux is more preferably determined in terms of transmembrane current flow and most preferrably determined in terms of the change in cytosloic CA.sup.2+ concentration.

Abstract: A method of reducing tissue injury in humans or other animal species using a monoclonal antibody to inhibit specific phagocyte functions. The monoclonal antibody is selected to bind to phagocytic leukocytes for the purpose of inhibiting migration to an inflammatory site in the body and to inhibit the adhesion and spreading of activated leukocytes reaching such an area and then, block release of toxic substances by these cells. The monoclonal antibody is administered in vivo prior or early in the course of an experience leading to an injurious inflammatory response such as can result from restoration of myocardial blood flow interrupted by an acute coronary thrombosis.

Abstract: Monoclonal antibody which lyses human natural killer (NK) cells in vitro in the presence of complement and which cells having a molecular weight of about 200-220 KD, as determined by SDS-PAGE electrophoresis on a 10% polyacrylamide gel.

Abstract: A method of distinguishing subsets within a plurality of human cells including producing a monoclonal antibody to a non-human primate cell, contacting the monoclonal antibody with the human cells, and distinguishing the subsets on the basis of different degrees of reactivity with the monoclonal antibody.

Abstract: A monoclonal antibody which specifically binds to the surface recognition structure of a predetermined mature human T cell clone, which recognition structure renders the clone capable of acting as causative agent in a predetermined autoimmune disease, the monoclonal antibody being capable of specifically binding to the recognition structure of the clone to inhibit the ability of the clone to act as a causative agent in the predetermined autoimmune disease.

Abstract: Monoclonal antibodies specific to a mature human T cell surface antigen of molecular weight of about 120,000 daltons as determined by electrophoresis, the antigen not being modulated by monoclonal antibodies specific to it and being restricted within the human lymphoid system to the surface of mature T cells, the monoclonal antibodies being capable of selectively binding mature human T cells and rendering them inactive in vivo and failing to induce the proliferation or activation of human lymphocytes.