Regulation of granulomatous inflammation in murine schistosomiasis. III. Recruitment of antigen-specific I-J+ T suppressor cells of the granulomatous response by I-J+ soluble suppressor factor.

Down-modulation of the schistosome egg-induced granulomatous response involves various interacting subsets of T suppressor (TS) lymphocytes. In the present study the inductive phase of the process of modulation was analyzed. A soluble, I-J+ granuloma TS cell recruiting factor (Gr-TSRF) derived from spleen cells of chronically infected mice is described. This factor eluted from immunoabsorbent columns coupled with anti-I-Jk alloantisera induced the recruitment and expansion of antigen-specific I-J+ TS cells from a TS precursor cell population in the spleens of acutely infected mice. The recruited TS cells suppressed the granulomatous response of normal recipients in a 2-day adoptive transfer model. The antigenic specificity of the recruited TS cells was demonstrated by their inability to suppress KLH-induced artificial granulomatous response. This mechanism of recruitment described in the current study and illustrated by adoptive transfer experiments is likely to be active in vivo in initiating the process of spontaneous modulation. The I-J+ Gr-TSRF and the I-J+ TS cell described in this paper, together with the previously described H-2 restricted I-C+ factor and the subsets of TS cells (THs, TSe, TSpr), indicate the existence of an intricate, regulatory pathway(s) that operates during the modulation of the granulomatous response.