Characterization of γδT cells in naive and HIV-infected chimpanzees and their responses to T-cell activators in vitro

Background gamma delta T cells are effector cells that eliminate cancer and virus-infected cells. Chimpanzees are an endangered species that can naturally and experimentally be infected with SIV and HIV, respectively, but no information about the functionality of gamma delta T cells during chronic lentiviral infection is currently available. Methods Healthy and HIV-infected chimpanzee gamma delta T cells were characterized by flow cytometry. gamma delta T subsets were studied after stimulation with T-cell activators, and the release of cytokines was analyzed by Luminex assay. Results gamma delta T-cell subsets, V delta 1 and V delta 2V gamma 9, showed different patterns in the expression of CD4, CD195, CD159a, and CD159c. Stimulation of gamma delta T cells resulted in increased levels of CD4 and HLA-DR, which is more pronounced in Vd1 T cells. Distinct cytokine patterns were found between healthy and HIV-infected chimpanzees. Conclusions Analyses of major chimpanzee gamma delta T subsets show similarities to human gamma delta T cells and suggest different functionality and roles in their immune response against HIV infection.