Interaction between the CD45 antigen and phytohemagglutinin. Inhibitory effect on the lectin-induced T cell proliferation by anti-CD45 monoclonal antibody.
Immunoprecipitation studies from 125I-labeled T cells, previously activated with the lectin phytohemagglutinin (PHA) from Phaseolus vulgaris, showed a preferential association between the CD45 glycoprotein family containing members of 220, 205, 190 and 180 kDa, and a protein of 33 kDa. This 33-kDa protein, with an identical molecular mass as PHA, was not associated with other highly expressed molecules such as class I histocompatibility antigens (HLA-A,B,C), transferrin receptor, CDw44 and CD11a. Further immunoprecipitation analysis from peripheral blood lymphocytes incubated with 125I-labeled PHA confirmed the identification of the CD45-associated 33-kDa protein as the lectin PHA. These results prompted us to analyze the possible involvement of the CD45 molecules in the T cell activation process induced by PHA. Thus, two monoclonal antibodies specific for CD45 antigens were able to inhibit the T cell proliferation induced by the lectin. This inhibitory ability was exerted by affecting both the interleukin 2 production and the interleukin 2 receptor expression.
D000911:Antibodies, Monoclonal / Q000276:immunology*; D006649:Histocompatibility Antigens / Q000276:immunology*; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis; D017493:Leukocyte Common Antigens; D008213:Lymphocyte Activation; D010835:Phytohemagglutinins / Q000494:pharmacology*; D011971:Receptors, Immunologic / Q000096:biosynthesis; D015375:Receptors, Interleukin-2; D013601:T-Lymphocytes / Q000276:immunology*
D000911:Antibodies, Monoclonal; D006649:Histocompatibility Antigens; D007376:Interleukin-2; D010835:Phytohemagglutinins; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D017493:Leukocyte Common Antigens