Critical Role of CD2 Co-stimulation in Adaptive Natural Killer Cell Responses Revealed in NKG2C-Deficient Humans.
Cell Rep 2016;
15:1088-1099. [PMID:
27117418 PMCID:
PMC4858565 DOI:
10.1016/j.celrep.2016.04.005]
[Citation(s) in RCA: 161] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 03/09/2016] [Accepted: 04/01/2016] [Indexed: 12/01/2022] Open
Abstract
Infection by human cytomegalovirus (HCMV) leads to NKG2C-driven expansion of adaptive natural killer (NK) cells, contributing to host defense. However, approximately 4% of all humans carry a homozygous deletion of the gene that encodes NKG2C (NKG2C−/−). Assessment of NK cell repertoires in 60 NKG2C−/− donors revealed a broad range of NK cell populations displaying characteristic footprints of adaptive NK cells, including a terminally differentiated phenotype, functional reprogramming, and epigenetic remodeling of the interferon (IFN)-γ promoter. We found that both NKG2C− and NKG2C+ adaptive NK cells expressed high levels of CD2, which synergistically enhanced ERK and S6RP phosphorylation following CD16 ligation. Notably, CD2 co-stimulation was critical for the ability of adaptive NK cells to respond to antibody-coated target cells. These results reveal an unexpected redundancy in the human NK cell response to HCMV and suggest that CD2 provides “signal 2” in antibody-driven adaptive NK cell responses.
NKG2C−/− donors have normal T cell immunity to cytomegalovirus
NKG2C−/− donors have normal frequencies of adaptive NK cells
CD2 is critical for antibody-triggered responses by adaptive NK cells
CD2 synergizes with NKG2C in classical adaptive NK cells
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