ENHANCEMENT OF EOSINOPHIL-MEDIATED CYTOTOXICITY TO SCHISTOSOMULA OF SCHISTOSOMA-MANSONI BY AUTOLOGOUS MONONUCLEAR-CELLS FROM PATIENTS

Adherent mononuclear cells (monolayer), when co-cultured with autologo us peripheral blood eosinophils isolated from patients treated for Sch istosoma mansoni infections, enhanced the eosinophil-mediated killing of antibody coated schistosomula. The monolayer increased the activity of the eosinophils by 225%, and was observed in 80% of the patients s tudied. Heat labile factors other than complement, present in immune s erum,further enhanced the ability of eosinophils to kill schistosomula in the presence of the monolayer. On their own the adherent cells did not mediate obvious damage to the parasite. Eosinophils that had been pre-incubated with the monolayer (100 mins) and tested separately, ki lled equal numbers of schistosomula as in the co-culture assay; this e xcludes the possibility of concurrent schistosomula cytotoxicity by th e two cell populations. The ability of the monolayer to activate eosin ophils was not altered by inhibitors of protein synthesis. The monolay er was largely consistent of monocytes as demonstrated by an over 96% positive staining for non-specific esterases.