Modulation of murine schistosomiasis by exogenously administered prostaglandins

The effect of parenteral administration of prostaglandins, 15-(s)-15-methyl PGE1 (M-PGE) and PGF2 alpha (PGF) on the pathophysiologic manifestations of active murine Schistosoma mansoni infection was examined. Both M-PGE and PGF resulted in a nearly 50% suppression of granuloma size following a 7-day course of treatment. M-PGE and PGF appeared to act by different mechanisms. The former caused a broad-spectrum immunosuppression manifested as reduced splenomegaly, B-cell proliferation, and antigen-specific interleukin-2 (IL-2) production as well as decreased granuloma macrophage Ia antigen expression, superoxide anion (O2-) production, and interleukin-1 (IL-1) production. In contrast, PGF did not ameliorate splenomegaly, but caused increases in splenic asialo-GM1 (natural killer cells) and L3T4 (helper) positive T cells. Prostaglandin F also reduced IL-2 production, but to a lesser extent that M-PGE. Although PGF caused reduced granuloma macrophage Ia expression and O2- production, it did not suppress IL-1 production. Overall, these data show that PGs can significantly modulate immunopathologic events in chronic granulomatous disease states.