NK Cells Acquire CCR5 and CXCR4 by Trogocytosis in People Living with HIV-1.

NK cells play a major role in the antiviral immune response, including against HIV-1. HIV-1 patients have impaired NK cell activity with a decrease in CD56 NK cells and an increase in the CD56CD16 subset, and recently it has been proposed that a population of CD56NKG2CKIRCD57 cells represents antiviral memory NK cells. Antiretroviral therapy (ART) partly restores the functional activity of this lymphocyte lineage. NK cells when interacting with their targets can gain antigens from them by the process of trogocytosis. Here we show that NK cells can obtain CCR5 and CXCR4, but barely CD4, from T cell lines by trogocytosis in vitro. By UMAP (Uniform Manifold Approximation and Projection), we show that aviremic HIV-1 patients have unique NK cell clusters that include cells expressing CCR5, NKG2C and KIRs, but lack CD57 expression. Viremic patients have a larger proportion of CXCR4 and CCR5 NK cells than healthy donors (HD) and this is largely increased in CD107 cells, suggesting a link between degranulation and trogocytosis. In agreement, UMAP identified a specific NK cell cluster in viremic HIV-1 patients, which contains most of the CD107a, CCR5 and CXCR4 cells. However, this cluster lacks NKG2C expression. Therefore, NK cells can gain CCR5 and CXCR4 by trogocytosis, which depends on degranulation.