Down Regulation of Ia Antigen Expression on Inflammatory Macrophages by Factors Produced During Acute Infections with Rickettsia tsutsugamushi,
WALTER REED ARMY INST OF RESEARCH WASHINGTON DC
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Ascites produced during lethal infections with Rickettsia tsutsugamushi contained high levels of IFN-Y, corticosterone, and prostaglandins, which have been shown previously to modulate I-region associated Ia antigens on macrophages Mphi. To test whether these substances were modulating expression of Ia antigens on inflammatory Mphi responding to infection with this rickettsia the effect of ascites on lymphokine induction of Ia antigens on thioglycolate-induced Mphi of the Mphi-like cell line J774 was tested. It was found that ascites was not suppressive for Ia antigen induction and in fact contained sufficient IFN-gamma to induce Ia antigens on induced Mphi and J774 cells. The ascites, however, did suppress significantly the response of normal spleen cells to concanavalin A con A. Adherent cells isolated at various times from infected animals were potently suppressive as were culture supernatants recovered from these cells contained relatively high levels of prostaglandins and IFN-alphabeta. Reprints.
- Medicine and Medical Research