PARASITE AND EGG BURDEN, HEPATIC COLLAGEN AND HISTOLOGIC PATTERN OF LIVER GRANULOMAS IN SELECTION-III HIGH AND LOW ANTIBODY RESPONDER MICE INFECTED WITH SCHISTOSOMA-MANSONI

Selection III mice have particular immunological characteristics: they are high (H III) or low (L III) antibody producer animals, yet both l ines display similar T cell responses and macrophage activities. We su bmitted these mice to infection with Schistosoma mansoni to assess in vivo parasite and egg burden, hepatic collagen and cellular compositio n of granulomas in both lines. Titration of anti-Schistosoma IgG by EL ISA showed remarkably higher values in H III line, at both studied per iods (8th and 12th weeks post-infection). Nevertheless, the number of adult worms recover ed from the portal system was similar in both line s, being not associated with anti-Schistosoma antibody levels. There i s an increase in hepatic collagen front the 8th to the 12th weeks post infection, which is paralleled by an increase in the number of eggs in the liver. This association apparently occurs at the same ratio in H III and L III animals. The most important difference found between the two lines was the outstanding contrast in terms of volume and eosinop hil counts in the granulomas, with lesions from H III mice clearly bei ng larger and containing more of these cells than LIII lesions.