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

Abstract

Selection III mice have particular immunological characteristics: they are high (H III) or low (L III) antibody producer animals, yet both lines display similar T cell responses and macrophage activities. We submitted these mice to infection with Schistosoma mansoni to assess in vivo parasite and egg burden, hepatic collagen and cellular composition of granulomas in both lines. Titration of anti-Schistosoma IgG by ELISA showed remarkably higher values in H III line, at both studied periods (8th and 12th weeks post-infection). Nevertheless, the number of adult worms recovered from the portal system was similar in both lines, being not associated with anti-Schistosoma antibody levels. There is an increase in hepatic collagen from 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 eosinophil counts in the granulomas, with lesions from H III mice clearly being larger and containing more of these cells than LIII lesions.

Experimental models of Schistosoma mansoni infection

“…1a : Viera & Moraes-Santos (1987); 2: Cheever et al (1987); 2a: Biozzi high (HIII) and low (LIII) responder mice (Blum & Cioli 1978, Catapani et al 1994; 3a: nude athymic mice lacking T cells ; 3b: mice with severe combined immunodeficiency lacking T & B cells (Amiri et al 1992; 3c: mast cell deficient mice (Cheever et al 1987); 3d: Cheever et al (1987); 3e: Gaubert et al (1999); 5a: Yap et al (1977); 5b: β-2 microglobulin deficient mice , Hernandez et al1997b; 5c: mice unable to process class 1 antigens (Yap et al 1977); 5d: receptor for macrophage Inflammatory Protein-1α [CCR-III] (Gao et al 1997); 5e: mice lacking both TNF-α receptors (Yap et al unpublished); 5f: µ-MT mice , Ferru et al 1998) JHD B-less mice had normal granulomas at 8 wk (Hernandez et al 1997a); 5g: Jankovic et al (1997); 5h: Jankovic et al (1998); 5i: IL-4 ko mice from cross of 129J and C57BL/6 mice ; 5j: IL-4 ko mice bred back to the C57BL/6 background (Rosa Brunet et al 1997); 5k: IL-4 ko mice formed using C57BL/6 germline only (Metwali et al 1996);5l: Rosa Brunet et al (1999a); 5m: Wynn et al (1998);5n: Wynn et al (1998);5o: Amiri et al (1994, Yap et al unpublished);5p: (Akihani et al 1996, Rezende et al 1997a, Oliveira et al 2000; 5q: ; 5r: 5 lipoxegenase, 12-lipoxygenase (Secor et al 1998 ↓ / ↓ ? ↑, ↓: increase, decrease or no change; ?…”