Involvement of CD5 in Th1 and Th2 contact-mediated rescue of anti-mu and ionomycin induced growth inhibition in a B cell lymphoma.
Cross-linking of membrane Ig receptors by anti-mu antibodies (Ab) or treatment with ionomycin induced complete growth arrest and subsequent apoptotic cell death in an immature B cell lymphoma, BKS-2. The growth-inhibitory signals delivered by anti-mu and ionomycin were overcome by anti-CD3-activated Th2 clones D10.G4 and F1 and by Th1 cell clone S53. In this report the Th-mediated growth reversal in BKS-2 cells was shown to require contact-dependent interactions when the inhibition was caused by immobilized anti-mu or ionomycin. Th2 cells in transwells (lymphokines) failed to protect BKS-2 cells from the growth-inhibitory effect of immobilized anti-mu or ionomycin. Monoclonal antibodies to CD5 or CD40 ligands on activated Th cells partially inhibited the Th2 contact-dependent growth reversal of BKS-2 cells whereas simultaneous addition of both antibodies effectively prevented the delivery of contact-mediated growth signal. In contrast, anti-class I or class II Ab did not affect Th cell mediated growth reversal of BKS-2 cells. These data demonstrated that noncognate physical interaction with Th cells was essential for the recovery of BKS-2 cells when the latter were growth-arrested by strong inhibitory stimuli such as immobilized anti-mu and ionomycin. Further CD5 as well as CD40 ligands on Th cells are important for signal transduction in this type of T-B interaction.
Muthukkumar
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Department of Microbiology and Immunology, University of Kentucky, Lexington 40536-0230, USA.
Bondada
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D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D015703:Antigens, CD / Q000276:immunology*; D001402:B-Lymphocytes / Q000166:cytology* / Q000187:drug effects / Q000276:immunology; D023201:CD40 Ligand; D018956:CD5 Antigens; D002455:Cell Division / Q000187:drug effects / Q000276:immunology*; D002460:Cell Line; D007075:Immunoglobulin M / Q000276:immunology; D015759:Ionomycin / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000276:immunology; D016393:Lymphoma, B-Cell / Q000276:immunology; D008562:Membrane Glycoproteins / Q000276:immunology; D051379:Mice; D008808:Mice, Inbred CBA; D015398:Signal Transduction / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology*; D018418:Th2 Cells / Q000276:immunology*
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D018956:CD5 Antigens; D007075:Immunoglobulin M; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D023201:CD40 Ligand; D015759:Ionomycin