title: Antigen-specific T cell unresponsiveness in cloned helper T cells mediated via the CD2 or CD3/Ti receptor pathways.
abstract: We have investigated the role of the CD2 protein in the negative regulation of immune function and report that similar to antigen and anti-CD3, the monoclonal anti-CD2 antibodies (T112 and T113) can induce specific unresponsiveness. Antigen and anti-CD2 tolerogenic signals both down-regulated the phenotypic expression of CD3-Ti. In contrast CD2 surface expression was up-regulated after exposure to peptide and down-regulated after anti-T112 and T113 preincubation. However, in both instances interleukin 2 receptor surface levels were increased. These phenotypic changes could only be partly explained by variations in the levels of the transcripts encoding the CD3-Ti and CD2 molecules.
mesh_terms: D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology*; D017252:CD3 Complex; D002999:Clone Cells / Q000276:immunology; D005786:Gene Expression Regulation; D006801:Humans; D007108:Immune Tolerance; D008213:Lymphocyte Activation; D010641:Phenotype; D011971:Receptors, Immunologic / Q000032:analysis; D015375:Receptors, Interleukin-2; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2