Class I-specific antibodies inhibit proliferation in primary but not secondary mouse T cell responses.
Murine T and B splenocytes were incubated with antibodies that recognize CD3 or surface IgM. These antibodies induced proliferation of their respective target cells. Once stimulated via their receptors, the proliferation of both CD4+ and CD8+ T but not B lymphocytes was inhibited by class I-specific antibodies or their monovalent Fab' fragments. The inhibition of proliferation was dependent on the site on class I molecules recognized by the antibodies used, with the alpha 1/alpha 2 domains of H-2K molecules representing the major site for inhibition. Only soluble antibody-mediated proliferation could be inhibited by class I-directed antibodies; proliferation induced by CD3-specific antibody immobilized on plastic was not inhibited. Primary allogeneic MLR was also inhibited by class I-specific antibodies. In contrast, neither secondary allogeneic MLR, secondary Ag-specific responses, nor proliferation of CTL clones or tumor cell lines were inhibited by class I-specific antibodies. These results suggest a role for class I molecules in regulation of TCR/CD3- but not surface IgM-mediated cell signaling, which depends on the form of stimulation and the stage of differentiation of T cells.
Centre d'Immunologie INSERM-CNRS de Marseille-Luminy, France.
N
N
Amirayan
C
C
Vernet
P
P
Machy
D000818:Animals; D000906:Antibodies / Q000276:immunology*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology; D017252:CD3 Complex; D006224:Cricetinae; D000939:Epitopes; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D051379:Mice; D008815:Mice, Inbred Strains; D051381:Rats; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
D000906:Antibodies; D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D000939:Epitopes; D015395:Histocompatibility Antigens Class I; D011948:Receptors, Antigen, T-Cell