[Functional roles of LFA-1 involved in signal transduction for thymocyte activation].
The biological significance of the signals triggered by the interaction of cell surface expressed LFA-1 and ICAM-1 has been investigated in Con A and immobilized anti-CD3 mAb stimulated cultures. When added at the beginning of activation in the presence of Con A, soluble anti-LFA-1 and anti-ICAM-1 mAbs could strongly inhibit cell proliferation. Such inhibitory effect was also exhibited in the proliferative response of thymocytes to immobilized anti-CD 3 mAb activation. However, the soluble anti-LFA-1 mAb was unable to inhibit the proliferation of primed thymocytes preactivated with Con A for 24 h or of IL-1 + IL-2 activated fresh thymocytes. Anti-LFA-1 mAb could profoundly inhibit Con A-induced thymocytes to produce IL-2 and IL-6 and to reduce IL-2 receptor expression. By contrast, anti-LFA-immobilized on plastic plates together with immobilized anti-CD 3 mAbs or CD 3 cross-linking with LFA-1 by secondary antibodies resulted in an enhanced activation signals for thymocytes to proliferate compared with that activated by anti-CD 3 alone. Thus, mAb to LFA-1 is a functional molecule for thymocyte activation, mediating signals contributed to very early phases of signal transduction through TCR/CD 3 pathway, and that LFA-1 might provide a costimulatory signal for expression of IL-2 R and IL-2 production.
Lu
L S
LS
Department of Immunology, Beijing Medical University.
Chen
W F
WF
D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D017252:CD3 Complex / Q000276:immunology; D015815:Cell Adhesion Molecules / Q000276:immunology*; D002455:Cell Division; D002478:Cells, Cultured; D005260:Female; D007376:Interleukin-2 / Q000096:biosynthesis; D015850:Interleukin-6 / Q000096:biosynthesis; D016169:Lymphocyte Function-Associated Antigen-1 / Q000276:immunology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis; D015398:Signal Transduction / Q000187:drug effects*; D013601:T-Lymphocytes / Q000378:metabolism*; D013950:Thymus Gland / Q000166:cytology / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D017252:CD3 Complex; D015815:Cell Adhesion Molecules; D007376:Interleukin-2; D015850:Interleukin-6; D016169:Lymphocyte Function-Associated Antigen-1; D015375:Receptors, Interleukin-2