The location of antigenic sites on the surface of the nematode parasite Strongyloides ratti reactive to antibody-directed cellular cytotoxicity from both macrophages and eosinophils from the natural host.

Heat-treated and untreated sera from rats immune to Strongyloides ratti are capable of arming both immune and non-immune macrophages and eosinophils in vitro. These cells are capable of killing larvae of the parasite. Electron microscopy has indicated multi-point attachment of the cells to the epicuticular transverse grooves of the larvae within 4 and 24 h of incubation at 37 degrees.