AbstractGamma-delta (γδ) T cells recognize antigens in an MHC-independent manner, with demonstrable cytotoxicity against cancer and virally infected cells. Human immunodeficiency virus (HIV) infection severely depletes the Vγ9Vδ2 (Vδ2) subset of these T cells in most infected individuals, with the exception of elite controllers. The capacity of Vδ2 cells to kill HIV-infected targets has been demonstrated in vitro, but this has not been verified in vivo. Here, we examined the immunotherapeutic potential of Vδ2 cells in controlling HIV replication in vivo and provide the first characterization of reconstituted γδ T cell subsets in the peripheral blood and lymphoid tissue in a humanized mouse model. We demonstrate the depletion of Vδ2 cells and increase in Vδ1 cells in the blood following HIV infection, similar to that observed in HIV-infected humans. The functionality of human Vδ2 cells isolated from humanized mice was confirmed via ex vivo expansion in response to zoledronate and IL-2 treatment. The adoptive transfer of activated Vδ2 cells failed to control HIV infection in vivo but instead exacerbated viremia by serving as early targets for HIV infection. Our findings suggest that Vδ2 cells play a critical and unappreciated role as early HIV targets of infection to promote viral dissemination.