We are investigating host- and parasite factors which interact to produce schistosome lesions, through: purification of schistosome vitellaria granules, and study of their biochemical characteristics; study of enzymes and biochemical pathways instrumental in schistosome egg shell formation; artificial lung granuloma models using schistosome egg shell formation; artificial lung granuloma models using schistosome eggs or antigen adsorbed onto carrier particles for the study of pathogenesis and modulating factors affecting granulomas including immunopotentiators; comparison of schistosome pathogenicity in different trematode- and/or host species under controlled conditions; immunofluorescent studies of the localization of schistosome antigens in host or parasite tissues and their relationship to pathology; and the effect of drugs, and immunosuppressive measures on schistosome lesions. BIBLIOGRAPHIC REFERENCES: Sher, A., McIntyre, S. and von Lichtenberg, F. Schistosoma mansoni: Kinetics and class specificity of hypergammaglobulinemia induced during murine infection. Exptl. Parasitol., 1977. In press. von Lichtenberg, F., and Sher, A. and McIntyre, S. A lung model of Schistosome immunity in mice. Am. J. Pathol. (May, 1977). In press.