Low-molecular-weight protein ligands from Onchocerca volvulus preferentially stimulate the human γδ T cell Vδ1+ subset

Abstract

Onchocerciasis is a chronic infectious disease caused by the filarial nematode Onchocerca volvulus. A minor population of human γδ T cells expressing Vδ1 chains is preferentially stimulated by O. volvulus ligands in vitro. Therefore, the nature of the parasite ligand and the effector functions of Vδ1+ T cells stimulated by O. volvulus was investigated. A 5- to 30-kDa ligand from the adult parasite lysate that is sensitive to proteinase treatment was identified. Presentation for preferential stimulation of Vδ1+ T cells required processing. After in vitro stimulation with O. volvulus in the presence of interleukin-2. Vδ1+ T cells produced interferon-γ but not interleukin-4 and exhibited NK cytolytic activities. It is concluded that somatic 5- to 30-kDa protein ligands from O. volvulus stimulate Vδ1+ T cells and that Vδ1+ T cells play a role in immunity to O. volvulus.