Staphylococcal enterotoxin B and tumor-necrosis factor-alpha-induced relapses of experimental allergic encephalomyelitis: protection by transforming growth factor-beta and interleukin-10.
A study was made of the ability of the superantigen staphylococcal enterotoxin B (SEB) to induce relapses of experimental allergic encephalomyelitis (EAE) in SJL mice that had partially or completely recovered from acute EAE. We find that a single injection of 0.05 mg SEB i.v. induces mild relapses in 50% of such mice. In addition, tumor necrosis factor (TNF)-alpha (0.2 micrograms, i.p.) also induces EAE relapses in 43% of SJL mice when injected 1-2 months after recovery. SEB does not induce a second relapse if reinjected when V beta 17a+T cells are still partially deleted. In these mice, however, TNF-alpha is equally effective in inducing relapses as in mice that did not receive SEB previously. We showed earlier that transforming growth factor (TGF)-beta and TNF-alpha have antagonistic effects on experimental autoimmune diseases; e.g., in spontaneously relapsing EAE, TGF-beta and anti-TNF were protective, while anti-TGF-beta caused disease exacerbation. Interleukin (IL)-10 is also known to counteract certain TNF effects. We now find that both human IL-10 and TGF-beta 2 lower the incidence of EAE relapses when given simultaneously with SEB or TNF-alpha. The protective effect of TGF-beta is significant only against relapses induced by SEB (reduced to 9%), and that of IL-10 only against relapses induced by TNF (reduced to 0%) with the treatment regimens employed. Neutralizing anti-TGF-beta does not increase the incidence of SEB-induced EAE relapses. In contrast, anti-IL-10 increases both the incidence and the severity of such relapses. We conclude that TNF production is probably important in causing EAE relapses, but that other aspects of the SEB-induced reactivation of myelin-specific T cells also contribute. Furthermore, endogenous IL-10 rather than TGF-beta production appears to limit the susceptibility to induction of EAE relapses in this model.
D000818:Animals; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control*; D004768:Enterotoxins / Q000633:toxicity*; D005260:Female; D005620:Freund's Adjuvant / Q000633:toxicity; D016753:Interleukin-10 / Q000627:therapeutic use*; D008297:Male; D051379:Mice; D008806:Mice, Inbred AKR; D008807:Mice, Inbred BALB C; D008815:Mice, Inbred Strains; D012008:Recurrence; D018089:Superantigens / Q000633:toxicity; D016212:Transforming Growth Factor beta / Q000627:therapeutic use*; D014409:Tumor Necrosis Factor-alpha / Q000633:toxicity*
D004768:Enterotoxins; D018089:Superantigens; D016212:Transforming Growth Factor beta; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; C031818:enterotoxin B, staphylococcal; D005620:Freund's Adjuvant