Immunopathology of experimental schistosome (S. Mansoni) egg granulomas in mice--possible defence mechanisms mediated...

A ten month experimental S. Mansoni infection was followed in mice by studying schistosome egg granulomatous inflammation, antigen and immunoglobulins deposits in the granulomata and the circulating antibodies. During the experimental infection it was demonstrated that while the granulomatous reaction matures there is a progressive restriction of the antigens to the miracidia. Furthermore, immunoglobulins, particularly IgG and C3 deposits were demonstrated in the granulomata. Our data support the concept that schistosome egg granuloma is a hypersensitivity high turnover granuloma that is particularly efficient in walling off the antigen. Whereas the granuloma is built up largely by a cell mediated immune reaction, antibody deposits are also found, probably functioning as a local humoral antibody barrier which allows a slow and progressive neutralisation of the antigens. Viewed as a whole, experimental schistosome egg granuloma might be considered as a mixed, chiefly cell but also humoral antibody mediated immune reaction.