Modulation of superantigen-induced T-cell deletion by antibody anti-Pgp-1 (CD44).
We examined the effects of anti-Pgp-1 (CD44) antibody on the in vitro deletion of murine CD4 and CD8 single positive T cells induced by Staphylococcal enterotoxin B (SEB). Soluble anti-Pgp-1 antibody enhanced the apoptosis and decreased the proliferation of SEB-responding T cells. In contrast, cross-linked anti-Pgp-1 antibody provided costimulatory signals for the T-cell activation induced by anti-CD3 antibody. Hyaluronic acid (HA), a ligand of Pgp-1, did not affect proliferation and deletion induced by SEB, whereas it mimicked the effects of the cross-linked antibody in anti-CD3-driven proliferation. T-cell Pgp-1 surface expression after 48 hr incubation with SEB was unchanged as compared to unstimulated cells. However, when the memory T cells were established, some V beta 8+ (SEB-specific) T cells Pgp-1low became Pgp-1high, displaying a bimodal character. Moreover, the Pgp-1 increased expression correlated with an increase of Pgp-1 soluble form in the supernatant. These findings suggested that signals following the triggering of the Pgp-1 molecule are important in controlling T-cell survival.
Ayroldi
E
E
Department of Clinical Medicine, Pathology and Pharmacology, Perugia University Medical School, Italy.
Cannarile
L
L
Ricardi
C
C
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D017209:Apoptosis / Q000276:immunology*; D018801:CD2 Antigens / Q000276:immunology; D017252:CD3 Complex / Q000276:immunology; D018929:Cell Culture Techniques; D004768:Enterotoxins / Q000276:immunology*; D005434:Flow Cytometry; D018960:Hyaluronan Receptors / Q000276:immunology*; D008213:Lymphocyte Activation; D051379:Mice; D008809:Mice, Inbred C3H; D011233:Precipitin Tests; D012995:Solubility; D018089:Superantigens / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000502:physiology
D000911:Antibodies, Monoclonal; D018801:CD2 Antigens; D017252:CD3 Complex; D004768:Enterotoxins; D018960:Hyaluronan Receptors; D018089:Superantigens; C031818:enterotoxin B, staphylococcal