Vδ1 T lymphocytes producing IFN-γ and IL-17 are expanded in HIV-1-infected patients and respond to Candida albicans

In early HIV-1 infection, Vδ1 T lymphocytes are increased in peripheral blood and this is related to chemokine receptor expression, chemokine response, and recirculation. Herein we show that, at variance with healthy donors, in HIV-1-infected patients ex vivo-isolated Vδ1 T cells display cytoplasmic interferon-γ (IFN-γ). Interestingly, these cells coexpress cytoplasmic interleukin-17 (IL-17), and bear the CD27 surface marker of the memory T-cell subset. Vδ1 T cells, isolated from either patients or healthy donors, can proliferate and produce IFN-γ and IL-17 in response to Candida albicans in vitro, whereas Vδ2 T cells respond with proliferation and IFN-γ/IL-17 production to mycobacterial or phosphate antigens. These IFN-γ/IL-17 double-producer γδ T cells express the Th17 RORC and the Th1 TXB21 transcription factors and bear the CCR7 homing receptor and the CD161 molecule that are involved in γδ T-cell transendothelial migration. Moreover, Vδ1 T cells responding to C albicans express the chemokine receptors CCR4 and CCR6. This specifically equipped circulating memory γδ T-cell population might play an important role in the control of HIV-1 spreading and in the defense against opportunistic infections, possibly contributing to compensate for the impairment of CD4 ⁺ T cells.