Murine Schistosoma bovis infection: analysis of parasitic and immune parameters

Humoral and cellular responses to Schistosoma bovis antigens have been eval uated over a period of II weeks in mice exposed to S. bovis cercariae and d ata analysed in the context of the parasitic parameters (worm and egg loads ) recorded at days 30, 60 and 80 of the ongoing infection. Results revealed a decrease of worm burden, particularly marked for female worms, between d ay 60 and day 80 of infection suggesting a higher susceptibility of female schistosomes to attrition mechanisms. The B-cell response, studied by measu ring the production of different isotypes, was directed against different s tage specific antigens, with a predominance of IgG1 antibodies associated w ith a significant increase of IgA and IgE antibodies after egg deposition. The T-cell response, assessed after in vitro stimulation of splenocytes, sh owed a predominant production of Th-2 cytokines (IL-4, IL-5 and IL-10) occu rring after egg laying. Interestingly in contrast to S. mansoni infection t he Th-2 polarization did not seem to be exclusively triggered by egg-associ ated antigens since significant amounts of IL-10 were produced after stimul ation with adult worm antigen preparation (SWAP) before the beginning of eg g deposition.