HIGH-LEVELS OF SPONTANEOUS AND PARASITE ANTIGEN-DRIVEN INTERLEUKIN-10PRODUCTION ARE ASSOCIATED WITH ANTIGEN-SPECIFIC HYPORESPONSIVENESS INHUMAN LYMPHATIC FILARIASIS

To determine whether counterregulation by interleukin (IL)-10 plays a role in the generation or maintenance of the antigen-specific hyporesp onsiveness seen in asymptomatic microfilaremic (MF) patients, parasite antigen (PAg)- and nonparasite antigen (NPAg)-driven IL-10 production by peripheral blood mononuclear cells (PBMC) was studied in 10 MF pat ients and in 11 patients with chronic lymphatic pathology (CP), PBMC f rom MF patients spontaneously secreted similar to 10-fold more IL-10 t han did PBMC from patients with CP, PAg also induced significantly mor e IL-10 production by PBMC from MF than from CP patients, There was a negative correlation between PAg-driven IL-10 production by PBMC and P Ag-specific T cell proliferation in the MF group. IL-10 secretion by p lastic adherent cells from MF persons was higher in response to PAg th an to NPAg, whereas IL-6 and tumor necrosis factor-alpha secretion wer e equivalent for PAg and NPAg, suggesting that PAg preferentially indu ces IL-10 secretion in these cells, Thus, PAg-induced IL-10 likely pla ys an important role in down-regulating antigen-specific proliferative responses in MF patients.