Regulation of antigen-induced blastogenesis and interleukin-2 expression by adherent mononuclear cells in humans infected with Schistosoma mansoni.

Abstract

The immune response and its regulation by adherent mononuclear cells were investigated in 39 Egyptians aged 13-30 (mean +/- SD, 16.2 +/- 3.6) with chronic Schistosoma mansoni infection (fecal egg excretion, 40-2480 eggs/g; mean, 709 +/- 612). Blastogenesis and production of interleukin-2 (IL-2) by peripheral blood mononuclear cells showed a significant correlation when streptolysin O but not when soluble worm antigenic preparation (SWAP) was used as stimulus. This suggested independent regulation of these responses to SWAP. Thirteen subjects showed SWAP-restricted suppression of blastogenesis but not IL-2 production by adherent cells. Compared with 24 other S. mansoni-infected subjects, they had depressed blastogenic responses to SWAP but comparable SWAP-induced IL-2 production and responsiveness to exogenous IL-2. This study indicates that IL-2 production is not the site of action of parasite antigen-restricted suppressor adherent cells in chronic S. mansoni infection.