γδ+ T cells involvement in viral immune control of chronic human herpesvirus 8 infection

Little is known about what effector populations are associated with the control of human herpesvirus 8 (HHV-8) infection in vivo. We compared T lymphocyte subsets among HIV(-)HHV-8(+) and HIV(-)HHV-8(-) infected human individuals. alpha beta(+) T cells from HHV-8-infected individuals displayed a significantly higher percentage of differentiated effector cells among both CD4(+) and CD8(+) T cell subsets. HHV-8 infection was associated with significant expansion of gamma delta(+) V delta 1 T cells expressing a differentiated effector cell phenotype in peripheral blood. In vitro stimulation of PBMC from HHV-8-infected individuals with either infectious viral particles or different HHV-8 viral proteins resulted in gamma delta V delta 1 T cell activation. In addition, gamma delta V delta 1 T cells displayed a strong reactivity against HHV-8-infected cell lines and prevented the release of infectious viral particles following the induction of lyric replication. These data indicate that gamma delta T cells play a role in both innate and adaptive T cell responses against HHV-8 in immunocompetent individuals.