Practical NK cell phenotyping and variability in healthy adults

Abstract

Human natural killer (NK) cells display a wide array of surface and intracellular markers that indicate various states of differentiation and/or levels of effector function. These NK cell subsets exist simultaneously in peripheral blood, and may vary amongst individuals. We examined variety amongst selected NK cell receptors expressed by NK cells from normal donors, as well as the distribution of select NK cell subsets and NK cell receptor expression over time in several individual donors. Peripheral blood mononuclear cells (PBMCs) were evaluated using flow cytometry via fluorochrome-conjugated antibodies against a number of NK cell receptors. Results were analyzed for both mean fluorescence intensity (MFI) and the percent positive cells for each receptor. CD56bright and CD56dim NK cell subsets were also considered separately, as was variation of receptor expression in NK cell subsets over time in selected individuals. Through this effort we provide ranges of NK cell surface receptor expression for a local adult population as well as provide insight into intra-individual variation.

Biallelic mutations in IRF8 impair human NK cell maturation and function

“…From our initial evaluation in 2004 and at all subsequent times evaluated, patient 1's CD56 bright subset was between 30% and 40% (27.9%-40.3%) of the NK cell population, in contrast to controls, which fell within the previously described range (4.1%-8.4%) (Figure 3, A-C, and ref. 25). Evaluation of hetero- (Figure 3, B-D).…”

Human CD56bright NK Cells: An Update

“…Angelo et al (20) analyzed a panel of 40 adult healthy donors with respect to NK cell subset distribution with the aim to establish normative ranges. They found that CD56 bright NK cells represent 8.56 6 6.90% (range, 0.63-38.32%) of peripheral blood NK cells, which is in accordance with older literature, but which also means that a percentage .10% (usually considered the upper limit) is observed quite frequently.…”

Genetic Causes of Human NK Cell Deficiency and Their Effect on NK Cell Subsets

“…Human NK cells in peripheral blood are broadly classified as being CD56 + CD3 − and generally comprise 1–17% of mononuclear cells within peripheral blood of healthy adults (5). They are found primarily in two broadly defined phenotypic subsets, namely the CD56 bright and CD56 dim subsets, with the CD56 dim subset being the predominant one in peripheral blood.…”

“…In some cases, namely GATA2 deficiency, a single gene defect may account for a widely variable clinical phenotype with regards to NK cell number. This likely is related to the effect of specific mutations but may also be reflective of innate plasticity of NK cell numbers and subsets over time, in even healthy individuals, and the infectious history of the patient (5, 23, 24). …”

“…While originally classified as classical or functional, the lines between the types of NK cell deficiencies has been blurred by increased resolution of NK cell subsets as well as the normative ranges and diversity of human NK cells (5, 23, 24). This is exemplified by the example of GATA2 mutation, which was initially reported as leading to absence of circulating NK cells but which, upon careful analysis was shown to lead to decreased NK cell number, specifically loss of the CD56 bright NK cell subset, accompanied by decreased function (33).…”