Constitutive expression of high affinity interleukin 2 receptors on human CD16-natural killer cells in vivo.
The majority of human NK cells express low affinity IgG Fc receptors (CD16+), whereas a minor subset of NK cells lack Fc receptor expression (CD16-). In contrast to CD16+ NK cells that express only p75 IL-2 receptors, CD16- NK cells constitutively co-express both p75 and p55 IL-2 receptors in vivo and preferentially respond to low concentrations of IL-2 with increased cytolytic activation and proliferation. Scatchard analysis demonstrated the presence of approximately 1,200 high affinity (approximately 25 pM kD) and approximately 9,600 intermediate affinity (approximately 2 nM kD) IL-2 receptors on CD16- NK cells. CD16+ NK cells expressed only a single intermediate affinity IL-2 receptor of approximately 1.9 nM kD (approximately 9,000 sites per cell). The IL-2 binding data thus substantiated the phenotypic and functional studies and definitively show that the differential responsiveness of CD16- and CD16+ NK cells to IL-2 is manifested through different affinity IL-2 receptors.
Nagler
A
A
Becton Dickinson Monoclonal Center, Inc., San Jose, California 95131.
Lanier
L L
LL
Phillips
J H
JH
D015703:Antigens, CD / Q000032:analysis*; D000943:Antigens, Differentiation / Q000032:analysis*; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006801:Humans; D007074:Immunoglobulin G; D007376:Interleukin-2 / Q000378:metabolism; D007694:Killer Cells, Natural / Q000276:immunology*; D007700:Kinetics; D011961:Receptors, Fc / Q000032:analysis*; D017452:Receptors, IgG; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis* / Q000378:metabolism
D015703:Antigens, CD; D000943:Antigens, Differentiation; D007074:Immunoglobulin G; D007376:Interleukin-2; D011961:Receptors, Fc; D017452:Receptors, IgG; D015375:Receptors, Interleukin-2