title: Characterization of effector cells mediating IgG and IgM antibody-dependent cellular cytotoxicity.
abstract: Spleen effector cells for IgG- and IgM-induced antibody-dependent cellular cytotoxicity (ADCC) were characterized with respect to density and cell surface markers by using sheep erythrocytes (SRBC) coated with hybridoma-derived monoclonal anti-SRBC IgG or anti-SRBC IgM antibodies as targets. While basically the same effector cells are cytolytic for IgG and IgM antibody-coated SRBC, they differ with respect to their relative killing capacity for IgG- versus IgM-coated target cells. On the basis of physical and biochemical properties three populations with cytolytic capacity could be separated: (I) A light fraction of large cells had high cytolytic potential for both IgG- and IgM-coated SRBC. The cells were negative for the Fc receptor for IgG (Fc gamma-R-) and the C3-receptor (C3-R-), they carried the receptor for Helix pomatia A agglutinin (HP-A+), and reactivity was strongly reduced after treatment with anti-Thy-1 and complement (C). (II) High activity was also observed with a medium-dense fraction, preferably lysing IgG antibody-coated cells. The cells were Fc gamma-R+, partly C3-R+, mostly HP-A-, and only a minor portion of the cells were Thy-1+. (III) A dense fraction, displaying on a per cell basis low cytolytic potential, was more active in IgM than IgG ADCC. The cells were Fc gamma-R+, HP-A+ and Thy-1+. All three effector cell populations were non-adherent, non-phagocytic, and surface immunoglobulin-negative (s-Ig-).
mesh_terms: D000818:Animals; D000920:Antibody-Dependent Cell Cytotoxicity; D007074:Immunoglobulin G / Q000276:immunology*; D007075:Immunoglobulin M / Q000276:immunology*; D007694:Killer Cells, Natural / Q000276:immunology*; D008214:Lymphocytes / Q000145:classification; D008215:Lymphocytes, Null / Q000276:immunology; D051379:Mice; D008808:Mice, Inbred CBA / Q000276:immunology; D011971:Receptors, Immunologic / Q000032:analysis; D013154:Spleen / Q000166:cytology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
chemical_list: D007074:Immunoglobulin G; D007075:Immunoglobulin M; D011971:Receptors, Immunologic