Characterization of the Adaptive Nkg2c+ Nk Cell in Human Cytomegalovirus Infected Individuals: A Systematic Review

Abstract

The significance of adaptive natural killer (NK) cells in the subject pertaining to human cytomegalovirus (HCMV) infection is emphasized by the preferential expansion of a specific subset, termed NKG2C+ which can recognize an array of HCMV-encoded proteins. Until today, the subject of adaptive or ‘memory-like’ NK cells remains controversial, but more emerging evidence shows the cells' ability to ‘remember’. The purpose of this systematic review was to appraise recent literature that centered on the expansion of adaptive NKG2C+ NK cells driven by HCMV infection, specific to ‘human’. Databases including PubMed, Scopus, and JURN were systematically searched to source relevant journal articles published between 2011 and 2021, in a period of 10 years. Full-text terms such as ‘NKG2C+ adaptive NK cells’ AND ‘human cytomegalovirus’ were applied to retrieve related articles. This systematic review is comprised of continuous data on the expansion of NKG2C+ NK cells driven by HCMV and other HCMV-affiliated receptors, immune cells, and diseases with appropriate implementation of distinct inclusion and exclusion criteria. The authors evaluated the risk of bias and quality evidence of the data independently. The study is beneficial by gathering the evidence to conclude the occurrence of adaptive or ‘memory-like’ properties in human NK cells.