Cell-Mediated and Monoclonal Antibody-Dependent Killing of Onchocerca volvulus Microfilariae*

To identify the target antigens implicated in the adherence and killing of microfilariae (mf) by leucocytes, we incubated nodular mf and leucocytes in the presence of anti-cuticular monoclonal antibodies (MOVs)and fresh scrum. Leucocyte donors were patients with a mean age of 37 years (with 0-1 mf snip), who had lived in the endemic village studied rural least 10 yean After 16-20h of incubation, up to 74% of the mf could be seen with 10 or more cell adhering, to them. By 36-40 h up to 54% of the mf had been killed by the leucocytes in the presence of cocktail of monoclonal antibodies termed MOV GI V. The degree of killing in control experiments with the monoclonal antibody MOV I remained lower (P 0.05), ranging from 0.0 to 4.5% of mf with initial viability of 90-95%. Western blotting revealed MOV GIV prominent target antigens of 10.5, 18.0. 23.5 and 27;kDa in crude surface of female O. volvulus. The detected antigens may play a role m host protection.