Maturation InVivoofSchistosoma mansoniSchistosomula After Culture InVitro withGranulocytes andAntibody

serum. Samples were scored formicroscopically detectable damage, andtheremaining organisms were injected intravenously into normal mice. Thesemicewere perfused after 5.5to7weeks, andthe recoveryofadult worms was determined. Afterculture ofschistosomula in mediumalone, between 8.4and32.7%ofinjected organisms matured intoadult worms. There was no significant difference inthecapacity offreshly prepared and cultured schistosomula tomatureinvivo. Schistosomula cultured withantibody alone showed nosignificant damage invitro, andinonly oneofsevenexperiments was there a significant (35%)reduction compared withthemediumcontrols in their capacity tomatureinvivo. Schistosomula cultured withneutrophils alone or eosinophils alone showed no significant damageinvitro andno lossofviability in vivo.Schistosomula cultured withneutrophils andantibody showeda 28% reduction inrecoveryinoneexperiment butanincrease inrecovery(12and46%) intwoother experiments. Incontrast, schistosomula cultured witheosinophils andantibody showedevidence ofbothmarkeddamageinvitro (22to93%dead organisms) andlossofviability invivo(26to98%reduction inrecovery) inall sevenexperiments. Thesefindings justify theuseofthetoluidine bluemorphological assayasanestimate ofirreversible damage toschistosomula andconfirm that humaneosinophils andneutrophils differ markedly intheir capacity tomediate antibody-dependent