title: Potential confusion of contaminating CD16+ myeloid DCs with anergic CD16+ NK cells in chimpanzees.
abstract: Precise identification of NK-cell populations in humans and nonhuman primates has been confounded by imprecise phenotypic definitions. A common definition used in nonhuman primates, including chimpanzees, is CD3(-) CD8α(+) CD16(+) , and this is the dominant NK-cell phenotype in peripheral blood. However, recent data suggest that in chimpanzees a rare CD8α(-) CD16(+) population also exists. Herein, we present evidence validating the existence of this rare subset in chimpanzee peripheral blood, but also demonstrating that gating on CD3(-) CD8α(-) CD16(+) cells can inadvertently include a large number of CD16(+) myeloid DCs (mDCs). We confirmed the inclusion of mDCs in CD3(-) CD8α(-) CD16(+) gated cells by demonstrating high expression of CD11c, BDCA-1 and HLA-DR, and by the lack of expression of NKp46 and intracellular perforin. We also functionally validated the CD8α(-) NK-cell and mDC populations by mutually exclusive responsiveness to a classical NK-cell stimulus, MHC class I-deficient cells, and a prototypic mDC stimulus, poly I:C, respectively. Overall, these data demonstrate common problems with gating of NK cells that can lead to erroneous conclusions and highlight a critical need for consensus protocols for NK-cell phenotyping.
authors.affiliation: Division of Immunology, New England Primate Research Center, Harvard Medical School, Southborough, MA 01772-9102, USA.
authors.forename: R Keith
authors.initials: RK
authors.lastname: Reeves
authors.forename: Tristan I
authors.initials: TI
authors.lastname: Evans
authors.forename: Patricia N
authors.initials: PN
authors.lastname: Fultz
authors.forename: R Paul
authors.initials: RP
authors.lastname: Johnson
mesh_terms: D000818:Animals; D017252:CD3 Complex / Q000276:immunology; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000276:immunology*; D007694:Killer Cells, Natural / Q000276:immunology*; D002679:Pan troglodytes / Q000276:immunology*; D017452:Receptors, IgG / Q000276:immunology*
chemical_list: D017252:CD3 Complex; D017452:Receptors, IgG