title: Expression of Fc gamma receptors on a subpopulation of nonlymphoid tumor cells and its enrichment.
abstract: Nonadherent Fc gamma receptors (Fc gamma R) expressing cells from SEYF-a tumors that form rosettes with sheep erythrocytes coated with IgG antibodies (EA) were isolated by Percoll density gradients. The EA-IgG rosette-forming cells were characterized by the parameters of 1) binding of IgG immune complexes; 2) binding of purified monoclonal antibodies against mouse FcR; 3) sensitivity to complement-dependent lysis mediated by syngeneic anti-SEYF-a antibodies; 4) expression of parental H-2 antigen when grown in F1 hybrids; 5) incorporation of [125I]5-iodo-2'-deoxyuridine; and 6) growth in syngeneic mice. The nonadherent EA-IgG rosette-forming cell population was found to be composed of both host lymphocytes as well as of tumor cells. Tumor-seeking lymphocytes then were removed from SEYF-a tumors by velocity sedimentation on Percoll. The remaining cell population was tumorigenic and expressed FcR, as well as tumor antigens. These tumor EA-IgG rosette-forming cells exhibited a very low rate of DNA synthesis compared with that of non-rosetting tumor cells.
mesh_terms: D000818:Animals; D000936:Antigen-Antibody Complex; D002460:Cell Line; D007074:Immunoglobulin G / Q000302:isolation & purification*; D008214:Lymphocytes / Q000276:immunology; D008264:Macrophages / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009374:Neoplasms, Experimental / Q000276:immunology*; D011961:Receptors, Fc / Q000302:isolation & purification*; D017452:Receptors, IgG; D012397:Rosette Formation; D014412:Tumor Virus Infections / Q000276:immunology
chemical_list: D000936:Antigen-Antibody Complex; D007074:Immunoglobulin G; D011961:Receptors, Fc; D017452:Receptors, IgG