Experimental schistosomiasis mansoni: characterization of connective tissue cells in hepatic periovular granulomas.

Connective tissue cells present in periovular granulomas, induced in mice livers by schistosomal infection, were studied in situ and in an in vitro culture after cell migration from explanted granulomas. They were compared to cells of the adjacent hepatic tissue. Connective tissue cells in granulomas and granuloma-derived primary cell lines were characterized as myofibroblasts. The presence of lipid droplets in cells of early granulomas, and comparison with adjacent perisinusoidal cells, indicated their origin through activation and mobilization of lipocytes from the adjacent hepatic tissue. This origin was confirmed in long-standing cultures of granuloma-derived cells, in the stationary phase of growth, in which myofibroblasts could return spontaneously into the fat-storing phenotype.