title: Response of T cells in vivo induced by repeated superantigen treatments at different time intervals.
abstract: We have investigated the response of T cells to staphylococcal enterotoxin A (SEA) injections in vivo. We found that a single injection of SEA with an optimal dose of 10 microg increased the expression of both CD4 and CD8 significantly. There was expansion of SEA-reactive T cells in vivo after SEA re-injection and the time interval between injections strongly influenced the responsiveness of CD4+ and CD8+ T cells. Anergy of T cells was observed after three SEA treatments. The time interval between injections mainly affected the unresponsiveness of CD4+ T cells, not CD8+ T cells. Marked deletion followed by anergy of CD4+ T cells was induced at short intervals, and anergy without obvious deletion of CD4+ T cells was induced at long intervals. We also found that the anergic state was reversible in vivo. Repeated SEA stimulation led to down-regulation of interleukin (IL)-2, and high levels of IL-10. This study showed that both CD4+ and CD8+ SEA-primed T cells were responsive to SEA rechallenge in vivo, and a third injection was needed to induce the anergy of T cells.
authors.affiliation: State Key Laboratory of Cancer Biology, Department of Pathology, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Huang
authors.forename: Yanfang
authors.initials: Y
authors.lastname: Sui
authors.forename: Xiumin
authors.initials: X
authors.lastname: Zhang
authors.forename: Shaoyan
authors.initials: S
authors.lastname: Si
authors.forename: Wei
authors.initials: W
authors.lastname: Ge
authors.forename: Peizhen
authors.initials: P
authors.lastname: Hu
authors.forename: Xia
authors.initials: X
authors.lastname: Li
authors.forename: Bin
authors.initials: B
authors.lastname: Ma
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D049109:Cell Proliferation; D002478:Cells, Cultured; D004768:Enterotoxins / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018089:Superantigens / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D013997:Time Factors
chemical_list: D004768:Enterotoxins; D018089:Superantigens; C026066:enterotoxin A, Staphylococcal