IgD-receptor (IgD-R) cross-linking partially protects murine T cells from dexamethasone-induced apoptosis.
Based on our previous findings that immunoglobulin D (IgD) receptor (IgD-R) cross-linking with oligomeric IgD (IgD-R-xL) led to T cell activation, we examined the effect of IgD-R-xL on the expression of Fas antigen and apoptosis induction. In splenic T cells, IgD-R-xL followed by dexamethasone (dex) treatment resulted in a decreased percentage of Fas-positive cells as well as a decreased mean fluorescence intensity (P<0.05) when compared with cells treated with dex alone. There are significant differences in annexin-fluorescein isothiocyanate (FITC) and phosphatidylinositol (PI) staining between samples treated with dex alone and IgD-R-xL followed by dex-treated samples (P<0.05), suggesting a protective role for IgD-R-xL. No significant differences are seen in Fas antigen expression, annexin-FITC staining, and/or PI staining in murine T hybridoma (7C5) cells cultured under similar conditions (P<0.07). We hypothesize that ligation of IgD-R may predispose antigen-specific T lymphocytes for survival during primary immune responses when IgD-positive B cells serve as antigen-presenting cells.
Tamma
Seetha M Lakshmi
SM
Department of Microbiology and Immunology, CUNY Medical School, New York, New York 10031, USA.
Coico
Richard F
RF
D000818:Animals; D017302:Annexins / Q000032:analysis; D017209:Apoptosis; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000276:immunology*; D002478:Cells, Cultured; D003907:Dexamethasone / Q000494:pharmacology*; D005260:Female; D006825:Hybridomas; D007072:Immunoglobulin D / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D011961:Receptors, Fc / Q000378:metabolism*; D013154:Spleen / Q000166:cytology / Q000276:immunology; D019014:fas Receptor / Q000378:metabolism
D017302:Annexins; D007072:Immunoglobulin D; D011961:Receptors, Fc; D019014:fas Receptor; C050855:immunoglobulin D receptor; D003907:Dexamethasone