[Cellular responses elicited by challenged schistosomula of Schistosoma japonicum in the skin of naive and chronically infected mice].

ABSTRACT

Naive and chronically infected C57BL/6 mice were challenged percutaneously over the ear pinna with Schistosoma japonicum cercariae. After 15 hours, the number of EOS increased significantly in the skin of chronically infected mice. Inflammatory cells aggregated in the vicinity of schistosomula or entrapped intact and disintegrated schistosomula, forming granulocytic micro-abscesses in both groups. Ultrastructure studies revealed that flattened EOS tightly attached to the schistosomulum surface and degranulated. Local tegument damage occurred in the area of attachment. NEU adherence did not seem to be as intimate as EOS, and degranulation was not seen. The tegument of the attached schistosomulum remained normal. The result suggested that EOS appeared to be the efficient killer cell against skin phase schistosomula of S. japonicum.