Identification of the predominant human NK cell effector subset mediating ADCC against HIV-infected targets coated with BNAbs or plasma from PLWH.

The potential of immunotherapy strategies utilizing BNAbs such as 3BNC117 and 10-1074 to limit viral replication while also facilitating clearance of HIV infected cells has heightened interest in identifying the predominant NK effector subset(s) capable of mediating Antibody Dependent Cellular Cytotoxicity (ADCC). Utilizing Advanced Poly-chromatic Flow Cytometry, we identified that CD57 positive NK cells from ART-suppressed PLWH expressed significantly higher levels of the CD16 FcγR Receptor, 2B4 ADCC co-receptor and HLA-DR activation marker while NKG2C positive NK cells expressed significantly higher levels of the CD2 ADCC co-receptor (p<0.001, n = 32). Functionally, CD57 positive NK cells from ART-suppressed PLWH with either high or low NKG2C expansion exhibited significantly enhanced degranulation and IFN-gamma production against heterologous gp120-coated ADCC targets coated with HIV reference plasma compared to CD57 negative NK cells (p = 0.002, n = 11). CD57 positive NK cells from control donors lacking NKG2C expansion also exhibited significantly more degranulation and IFN-gamma production at every timepoint tested against both heterologous ADCC targets (p = 0.019, n = 9) and HIV-1 infected autologous CD4+ primary T cells coated with BNAbs. Together, our data supports CD57 positive and NKG2C positive NK cells as the predominant ADCC effector subsets capable of targeting HIV-infected CD4+ cells in the presence of 3BNC117 and 10-1074 immunotherapy. This article is protected by copyright. All rights reserved.