title: Further evidence for heterogeneity of Fc gamma-receptors on guinea pig splenic B and T lymphocytes: analysis using monoclonal antibodies to two distinct types of Fc gamma-receptor.
abstract: In our previous paper, we reported that guinea pig splenic lymphocytes expressed two distinct Fc-receptors for homologous IgG (Fc gamma Rs), one monospecific for IgG2 (Fc gamma 2R) and the other bispecific for IgG1 and IgG2 (Fc gamma 1/gamma 2R), when analyzed by EA-rosette assay. These Fc gamma Rs on the cells were further studied by using two monoclonal antibodies toward the Fc gamma Rs on guinea pig peritoneal macrophages (anti-Fc gamma 1/gamma 2R and anti-Fc gamma 2R antibody). The anti-Fc gamma 1/gamma 2R antibody completely inhibited the rosette formation of splenic lymphocytes with IgG1-sensitized sheep erythrocytes [EA(IgG1)]. On the other hand, EA(IgG2)-rosette formation was inhibited partially by anti-Fc gamma 2R but not by anti-Fc gamma 1/gamma 2R antibody. Complete inhibition of the EA (IgG2)-rosette formation was achieved by simultaneous additions of both anti-Fc gamma 2R and anti-Fc gamma 1/gamma 2R antibodies. The binding of IgG2 antibody complexed with ovalbumin to the cells was partially inhibited by either anti-Fc gamma R antibody, and complete inhibition occurred in the presence of both the antibodies, indicating that two types of Fc gamma R, Fc gamma 1/gamma 2R, and Fc gamma 2R, are expressed on the cells. The determination of these Fc gamma Rs on B and T lymphocytes by two-color flow cytometry showed that about 52% of B lymphocytes expressed Fc gamma 1/gamma 2R alone and 32% of the cells expressed both the Fc gamma Rs. On the other hand, about 12% of T lymphocytes was found to express Fc gamma 2R alone and the cells expressing Fc gamma 1/gamma 2R were in the minority (3.8%). T lymphocytes expressing both the Fc gamma Rs were not detected. These results show that guinea pig B lymphocytes bear two types of Fc gamma Rs and are heterogeneous with regard to their Fc gamma Rs and that T lymphocytes express Fc gamma 2R mainly.
authors.affiliation: Department of Hygienic Chemistry, Faculty of Pharmaceutical Sciences, Hokkaido University.
authors.forename: T
authors.initials: T
authors.lastname: Yamashita
authors.forename: J
authors.initials: J
authors.lastname: Koyama
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000936:Antigen-Antibody Complex / Q000378:metabolism; D001402:B-Lymphocytes / Q000276:immunology*; D005434:Flow Cytometry; D006168:Guinea Pigs; D007074:Immunoglobulin G / Q000378:metabolism; D066298:In Vitro Techniques; D011961:Receptors, Fc / Q000276:immunology*; D017452:Receptors, IgG; D012397:Rosette Formation; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D007074:Immunoglobulin G; D011961:Receptors, Fc; D017452:Receptors, IgG