Adaptive reprogramming of NK cells during recovery from severe COVID-19

Natural killer (NK) cells are a critical component of innate immune effectors and a prominent contributor to acquired immunity, playing a pivotal role in protective immunity against viral infections. Recent studies have unveiled diversity within NK cells, highlighting their capacity to differentiate into a memory-like, adaptive NK subset. Adaptive NK cells represent the versatile nature of NK cells in innate and acquired immunity, exhibiting clonal-like proliferation in response to pathogens and the potential to form immunological memory. Further, a subset of adaptive NK cells functions as antigen-presenting cells via HLA Class II. However, the developmental process of human adaptive NK cells has remained unclear. This is largely due to a lack of a suitable model to assess the adaptive NK cell development in humans.The aim of this study was to explore the diversification process of human NK cells. To this end, we conducted a comparative characterization of NK cell populations through scRNA-seq analysis on peripheral blood mononuclear cells (PBMCs) of COVID-19patients and healthy individuals vaccinated with the SARS-CoV-2 mRNA vaccine.PBMC Samples of 7 vaccinated healthy individuals and SARS-CoV-2 patients were subjected to scRNA-seq, scBCR-seq and scTCR-seq with 10x Genomics.