Genetic and Environmental Determinants of Human NK Cell Diversity Revealed by Mass Cytometry

Abstract

Natural Killer (NK) cells play critical roles in immune defense and reproduction, yet remain the most poorly understood major lymphocyte population. Because their activation is controlled by a variety of combinatorially expressed activating and inhibitory receptors, NK cell diversity and function are closely linked. To provide an unprecedented understanding of NK cell repertoire diversity, we used mass cytometry to simultaneously analyze 35 parameters, including 28 NK cell receptors, on peripheral blood NK cells from five sets of monozygotic twins and twelve unrelated donors of defined HLA and killer cell immunoglobulin-like receptor (KIR) genotype. This analysis revealed a remarkable degree of NK cell diversity, with an estimated 6,000-30,000 phenotypic populations within an individual and >100,000 phenotypes in this population. Genetics largely determined inhibitory receptor expression, whereas activation receptor expression was heavily environmentally influenced. Therefore, NK cells may maintain self-tolerance through strictly regulated expression of inhibitory receptors, while using adaptable expression patterns of activating and costimulatory receptors to respond to pathogens and tumors. These findings further suggest the possibility that discrete NK cell subpopulations could be harnessed for immunotherapeutic strategies in the settings of infection, reproduction, and transplantation.

Laser Ablation–Inductively Coupled Plasma Mass Spectrometry: An Emerging Technology for Detecting Rare Cells in Tissue Sections

“…Unsurprisingly, there is now great interest in exploiting mass spectrometry as a specific and sensitive detection method in various biological applications, most notably in flow cytometry (30). A commercially available device known as the CyTOF is being adopted by many groups interested in clinical immune monitoring, with astonishing results (31,32) Sm-tagged anti-CD45 was successful. Unfortunately, when sections of spleen from mice that had received gold-labeled Mregs were counterstained with the 174 Yb-conjugated anti-HLA-DR Ab before being analyzed at low resolution by LA-ICP-MS, very high and spatially diverse background signals for 174 Yb were detected (Supplemental Fig.…”

Sweet Is the Memory of Past Troubles: NK Cells Remember

“…Activating and inhibitory receptors that regulate their responses have been discovered, specific ligands for many of these receptors have been identified, distinct subsets have been characterized, and self-renewal of mature NK cells has been documented. Recent studies by Blish and colleagues using multiparameter mass cytometry have estimated the existence of 6000-30,000 phenotypically distinct NK cell types in the blood of a healthy adult (Horowitz 2013). Although the capacity of NK cells to acquire memory has only been appreciated recently, hints for the existence of NK cell immunological memory originated in the 1960s, before NK cells were named or were proven to represent a distinct lineage of lymphocytes.…”

Computationally efficient multidimensional analysis of complex flow cytometry data using second order polynomial histograms

“…Data for [mt]100,000 cells were acquired on a CyTOF instrument (DVS Sciences) as previously described (40). Intact viable cells were identified by nucleic acid staining, cell length and exclusion of live/dead dye, as previously described (40).…”