Fibroblast stimulation in schistosomiasis. IV. Isolated egg granulomas elaborate a fibroblast chemoattractant in

To gain further understanding of the pathogenesis of hepaticfibrosis in schistosomiasis, the interaction between egg granulomas and fibroblasts was investigated in an in vitro model. Egggranulomas isolatedfrom livers of miceinfectedwithSchistosoma mansoni or Schistosoma japonicum and cultured in vitro released a nondialyzable substance which stimulated proliferation in resting dermal fibroblasts. The release of the fibroblast-stimulating substance remained relatively constant during the first 48 hr of incubation with granulomas, during which timegranulomasremainedmetabolically ac-tive in vitro. A dialyzable molecule(s) in granuloma supernatants interfered with fibroblast uptake of (3H]thymidine in vitro but did not inhibit cellular division. Granuloma supernatants also stimulated fibroblast secretion of prostaglandin E2 and caused an elevation in intracellular levels of cyclic adenosine monophosphate. Schistosomiasis is a helminthic disease affecting more than 200 million people in developing coun-tries [1]. Infection is initiated when the waterborne cercarial stage of the parasite penetrates the ski