Fc gamma-receptor-bearing, non-B lymphocytes in human peripheral blood: cytophilic immunoglobulin binds almost exclusively to large granular lymphocytes.
Cytophilic IgG (CYT-Ig) has previously been reported to bind to both the "TG" (E+, Fc gamma R+) and "L" (E-, Fc gamma R+) subsets of non-B lymphocytes in human peripheral blood. Present investigations show that IgG-binding cells, as detected by a sensitive antiglobulin rosetting reaction, are contained almost entirely within the large granular lymphocyte (LGL) subpopulation, and that fewer than 5% of other non-B lymphocytes acquire IgG from serum. Cell membrane-bound IgG sterically blocks the reaction of LGL with sheep red blood cells and therefore influences the proportions of these cells characterized as TG (E+) or L (E-) lymphocytes. Although the majority of TG lymphocytes are LGL, a further subpopulation of E+, Fc gamma R+ cells are detectable under particular test conditions. Unlike LGL, these lymphocytes do not react with rabbit IgG-coated ox RBC (EAG) in saline, but will form EAG rosettes when the reaction is enhanced in the presence of Ficoll. These Fc gamma R+ cells are mostly of typical small-lymphocyte morphology and do not bind detectable amounts of CYT-Ig, nor do they express the monoclonal antibody-defined VEP 13 determinant associated with Fc gamma R on LGL.
D000915:Antibody Affinity; D002450:Cell Communication; D003298:Coombs Test; D005362:Ficoll; D005455:Fluorescent Antibody Technique; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis / Q000378:metabolism*; D008214:Lymphocytes / Q000145:classification; D008215:Lymphocytes, Null / Q000276:immunology / Q000378:metabolism*; D011961:Receptors, Fc / Q000378:metabolism*; D012397:Rosette Formation
D007074:Immunoglobulin G; D011961:Receptors, Fc; D005362:Ficoll