Increase in Vδ1+γδ T cells in the peripheral blood and bone marrow as a selective feature of HIV-1 but not other virus infections

Dysregulation of T-cell receptor (TCR) αβ bearing lymphocytes and an increase in Vδ1⁺γδ T cells are typical features of HIV-1 infection. However, the role of γδ T cells remains unclear. Therefore, peripheral blood mononuclear cells (PBMC) of 103 HIV-1-infected patients were investigated with respect to expression of Vδ1. These results were compared to the Vδ1 expression of bone marrow mononuclear cells (BMMC). In contrast to healthy controls, Vδ1⁺ cells dominated among both PBMC and BMMC in HIV-1-infected patients. Analysis of the coexpression of CD25, CD8, HLA-DR and CD45RO revealed a high prevalence of Vδ1/CD45RO and Vδ1/HLA-DR double-positive PBMC only in HIV-1-infected patients but not in healthy donors. Furthermore, analysis of the γδ TCR repertoire in patients infected with hepatitis B virus, hepatitis C virus, herpes simplex virus (HSV)-1 and HSV-2 showed that the selective enhancement of Vδ1⁺ cells was restricted to HIV infection and not observed in other virus diseases. Our data provide further support for the involvement of γδ T cells in immunosuppression and progression of HIV infection.