Antigen-specific cell conjugate formation and long-lasting calcium responses in recognition of Mls cellular superantigen by cloned murine T lymphocytes.
T lymphocyte recognition of cell-associated minor lymphocyte stimulation (Mls) superantigen was studied by simultaneous flow cytometric measurement of T cell free ionized intracellular calcium ([Ca2+]i) with the fluorescent probe indo-1 and T cell binding to antigen-presenting cells stained with a long-chained, membrane-fixed cyanine dye. Cloned T cell-B lymphocyte antigen-presenting cell conjugate formation and increased T cell [Ca2+]i were antigen specific and tightly linked in four Mls-reactive T cell clones. The T cell-antigen-presenting cell conjugates were extremely stable and, like T cell [Ca2+]i elevation, were maintained for more than 2 hr. Three ligand-receptor pairs, (i) T cell receptor/antigen+class II, (ii) CD4/class II, and (iii) LFA-1/ICAM-1, were obligatory participants in T cell recognition of cell-bound superantigen since monoclonal antibodies to any of them blocked formation of cell conjugates. Despite previous reports, Mls recognition occurred by the conventional T cell recognition pathway with easily detected phosphoinositide hydrolysis. B cell activation greatly enhances their recognition by Mls-specific T cells.
Ishida
Y
Y
Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, Rockville, Maryland 20852.
Chused
T M
TM
Murakami
S
S
Abe
R
R
D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D015704:CD4 Antigens / Q000276:immunology; D002118:Calcium / Q000378:metabolism*; D015815:Cell Adhesion Molecules / Q000276:immunology; D002999:Clone Cells; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D018799:Intercellular Adhesion Molecule-1; D008213:Lymphocyte Activation; D016169:Lymphocyte Function-Associated Antigen-1 / Q000276:immunology; D051379:Mice; D008815:Mice, Inbred Strains; D016747:Minor Lymphocyte Stimulatory Antigens / Q000276:immunology*; D010716:Phosphatidylinositols / Q000378:metabolism; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology*
D015704:CD4 Antigens; D015815:Cell Adhesion Molecules; D000949:Histocompatibility Antigens Class II; D016169:Lymphocyte Function-Associated Antigen-1; D016747:Minor Lymphocyte Stimulatory Antigens; D010716:Phosphatidylinositols; D018799:Intercellular Adhesion Molecule-1; D002118:Calcium