A signal transduction through a unique rat T cell specific antigen, 8H3.
A signal transduction was detected in various rat T cells by cross-linking of 8H3 antigen by 8H3 antibody. A rat T cell proliferative response induced by 8H3 antibody is dependent on the presence of adherent cells. When spleen cells were cultured in the presence of 8H3 antibody, only CD4-positive T cell proliferation was induced. These proliferative CD4-positive T cells express rat interleukin 2 receptor, alpha chain. Cross-linking of 8H3 antigen resulted in an increase in cytoplasmic free Ca2+ in T cells and phosphorylation of a 120 kDa component of the 8H3 antigen. It should be noted that cross-linking of 8H3 antigen together with CD4 antigen but not with CD8 antigen by suboptimal doses of 8H3 and corresponding antibodies initiated the mobilization of [Ca2+]i. Furthermore, physical association of 8H3 antigen with TCR was demonstrated by comodulation of these two molecular complexes in some T cells. Thus, 8H3 antigen is involved in rat T cell transmembrane signal transduction.
Torimoto
Y
Y
Department of Pathology, Sapporo Medical College, Japan.
Nagoya
S
S
Uede
T
T
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D016525:Antigenic Modulation; D015704:CD4 Antigens / Q000276:immunology; D016827:CD8 Antigens / Q000276:immunology*; D002118:Calcium / Q000378:metabolism; D005786:Gene Expression Regulation; D006825:Hybridomas; D008213:Lymphocyte Activation / Q000276:immunology*; D008297:Male; D010766:Phosphorylation; D051381:Rats; D011919:Rats, Inbred Strains; D015375:Receptors, Interleukin-2 / Q000276:immunology; D015398:Signal Transduction / Q000276:immunology*; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
D000911:Antibodies, Monoclonal; D015704:CD4 Antigens; D016827:CD8 Antigens; D015375:Receptors, Interleukin-2; D002118:Calcium