ONCHOCERCA-VOLVULUS PROVIDES LIGANDS FOR THE STIMULATION OF HUMAN-GAMMA DELTA T-LYMPHOCYTES EXPRESSING V-DELTA-1 CHAINS/

Peripheral blood mononuclear cells (PBMC) from 8 onchocerciasis patien ts, treated or not with ivermectin, were analyzed for phenotypic cell surface markers. A significant increase (P < .05) in gamma/delta T cel ls expressing the Vdelta1 chain compared with normal and endemic contr ols was detected in all patients. PBMC populations from onchocerciasis patients were not expanded after restimulation with Onchocerca volvul us antigens in vitro, but both Vdelta1 and Vdelta2 T cells from normal donors were increased significantly in response to O. volvulus and My cobacterium tuberculosis (P < .05), respectively. Frozen sections of a ll 5 onchocerca nodules tested demonstrated an increased number of CD3 + cells in the vicinity of the adult worm, in all cases expressing the alpha/beta T cell receptor and in 2 patients also expressing the gamm a/delta T cell receptor; 60% of T cells expressed the activation marke r Ki67. These data suggest that O. volvulus provides ligands to Vdelta 1 T cells.