Spontaneous and egg antigen-induced syntheses of immunoglobulin and antibody by spleen cells and hepatic granulomas of mice infected with Schistosoma japonicum.

In the absence of egg antigen (SEA), spleen cells from C57BL/6 mice infected for 22 weeks with Schistosoma japonicum were spontaneously induced in vitro to synthesize total immunoglobulin and antibody to SEA. Hepatic granulomas from mice infected for 12 weeks, but not for 22 weeks, also showed spontaneous syntheses of total immunoglobulin and antibody to SEA, but these syntheses were not enhanced upon the addition of SEA. Total immunoglobulin production was enhanced when SEA was added to spleen cells from mice infected for 4 to 7 weeks but not at any other time point.