Method to Study Adaptive NK Cells Following MCMV Infections.

Immunological memory is a fundamental feature of the adaptive immune system that protects the host from recurrent infections from pathogens. Natural killer (NK) cells are a predominant member of the innate immune system that lack clonotypic receptors, which are essential for memory formation. However, evidence demonstrates that a unique subpopulation of NK cells develops adaptive-like features using germline-encoded receptors. Recent studies have shown that infection of cytomegalovirus (CMV) leads to clonal expansion of NKG2C and Ly49H NK cells, in humans and mouse, respectively. These activation receptors have the capability to recognize CMV-encoded proteins and facilitate a recall response upon reinfection. Although NK cells do not rearrange genes encoding their activating receptors as seen in B and T cells, they possess a selective process to generate memory features and a long-lived progeny. Here, we describe an established in vivo protocol for infecting mice with mouse cytomegalovirus (MCMV) to study an adaptive NK cell response.