CD4 but not CD8 is comodulated with the T-cell antigen receptor (TCR) after activation of a CD4+ CD8+ human leukemia line with staphylococcal enterotoxin.
Recent studies support the possibility of an interaction between CD4/8 and the TCR complex. To determine if there is specificity in this interaction, we have studied the comodulation of CD4/8 with the CD3/TCR complex on a CD4+ CD8+ human leukemic T-cell line stimulated with staphylococcal enterotoxin A (SEA) bound to Raji cells. FACS analysis revealed that CD3 and the TCR were modulated from the surface. CD4 and not CD8 was comodulated with the T-cell receptor complex, supporting the existence of a docking site on the TCR with selectivity for CD4 or CD8 but not both. Fewer than 45 SEA molecules per presenting cell led to detectable comodulation. The ratio of %CD4/%TCR modulation varied with both time and the amount of SEA used for stimulation. ConA or PHA induced modulation of CD3 but, unlike SEA, failed to induce IL-2 secretion, suggesting multiple pathways and states of T-cell activation. Our findings also suggest that some human T leukemic lines can respond to antigen.
Bodó
I
I
Department of Medicine, St. Luke's/Roosevelt Hospital Center, Columbia University, New York, NY 10032.
Vloka
J D
JD
Cleveland
W L
WL
D000911:Antibodies, Monoclonal / Q000276:immunology; D000954:Antigens, Surface / Q000276:immunology; D017252:CD3 Complex / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D004768:Enterotoxins / Q000276:immunology*; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000276:immunology*; D008934:Mitogens / Q000276:immunology; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D013778:Tetrazolium Salts; D013844:Thiazoles; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D017252:CD3 Complex; D004768:Enterotoxins; D007376:Interleukin-2; D008934:Mitogens; D016693:Receptors, Antigen, T-Cell, alpha-beta; D013778:Tetrazolium Salts; D013844:Thiazoles; C026066:enterotoxin A, Staphylococcal; C031818:enterotoxin B, staphylococcal; C022616:thiazolyl blue