Reciprocal alterations of Th1/Th2 function in γδ T-cell subsets of human immunodeficiency virus-1-infected patients

Abstract

While T cells that express Vγ9 as a variable T-cell receptor chain dominate among peripheral blood γδ T cells in healthy adults, Vδ1 cells are the major subpopulation of γδ T cells in human immunodeficiency virus (HIV)-infected patients. We used intracellular cytokine staining and flow cytometry to analyse whether an imbalance of T helper 1 (Th1)/T helper 2 (Th2) cytokine patterns, as observed in αβ T cells, also occurs in γδ T cells. When compared with healthy HIV-negative subjects, HIV+ patients had a decreased number of interferon-γ (IFN-γ)+ γδ T cells, which showed a linear relation to the CD4+ cell count but not to the plasma viral load. Similar results were obtained when Vγ9 cells were analysed. In contrast, in the Vδ1 subpopulation, the number of IFN-γ+ cells was increased in HIV+ donors when compared with healthy subjects. Even though less impressive, the number of interleukin 4 (IL-4)- and IL-10-producing cells was uniformly inversely correlated with the number of tumour necrosis factor-α+ and IFN-γ+ cells. The increased IFN-γ-producing capacity of Vδ1 cells might represent a compensatory mechanism for the progressive loss of Vγ9 γδ T cells during the course of HIV infection.