CHARACTERIZATION OF HUMAN IMMUNE-RESPONSES TO THE CYTOSOLIC SUPEROXIDE-DISMUTASE AND GLUTATHIONE-S-TRANSFERASE FROM ONCHOCERCA-VOLVULUS

In onchocerciasis patients and in O. volvulus-exposed individuals with out signs of onchocerciasis, T-and B-cell responses to two recombinant ly expressed O. volvulus enzymes were analysed and compared to respons es to total protein extract of adult parasites, The cytosolic enzymes Cu/Zn superoxide dismutase 1 (OvSOD1) and glutathione S-transferase 2 (OvGST2) represent 2 detoxifying molecules which may play an important role in parasite defense against host-induced oxidative stress. The T -cell response to the two recombinant proteins was analysed bq investi gating the cytokine responses of peripheral blood mononuclear cells. I nduction of IL-S at the mRNA level and IL-5 and IL-Io at the protein l evel was demonstrated in patients with the generalized fc,rm of onchoc erciasis and endemic normals without clinical manifestations. IFN-gamm a was not found to be induced by either antigen. This pattern of lymph okine expression is indicative of a Th2-type response. Compared to pat ients with the generalized form, a higher level of cytokine induction was observed in the group of endemic normals. Low but significant IgG levels were observed against OvSOD1 in patients with onchocerciasis; h igher antibody levels were found against OvGST2 in patients and endemi c normals. The highest IgG levels were detected against the crude O. v olvulus extract. These results indicate that the two recombinant O. vo lvulus proteins induct: moderate T and B cell responses.