The presence of a receptor for complement on T lymphocytes. Restriction of the complement receptor to Fc-receptor-bearing T lymphocytes.
Using rhodaminated guinea pig anti-ovalbumin:ovalbumin:complement complexes, a fluoresceinated monoclonal anti-Thy 1 antibody and a FACS-II equipped with dual fluorescence detection channels, we find that 25-30% of Thy 1+ splenocytes express a receptor for complement. That a receptor for complement is involved in binding the guinea-pig AgAb:C' complexes is supported by the observations that: a) guinea-pig complexes, which were not treated with a serum source of complement or which were treated with either fresh serum in the presence of EDTA or with heat-inactivated serum, do not bind to the T lymphocytes, and b) heat-aggregated human gamma globulin, which effectively inhibits binding of mouse AgAb complexes to the aFcR gamma, has no effect on the binding of guinea-pig AgAb:C' complexes to the T lymphocytes. By analyzing cell subpopulations isolated by cell sorting, it is demonstrated that the C'R-positive T lymphocyte clearly delineates a major subpopulation of aFcR gamma-positive T lymphocytes, whereas no cells are found bearing a C'R, while lacking the aFcR gamma. The implications of the presence of a C'R in immunoregulation are discussed.
D000818:Animals; D004492:Edetic Acid / Q000494:pharmacology; D005455:Fluorescent Antibody Technique; D006168:Guinea Pigs; D066298:In Vitro Techniques; D011951:Receptors, Complement / Q000276:immunology*; D011961:Receptors, Fc / Q000276:immunology*; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology*
D011951:Receptors, Complement; D011961:Receptors, Fc; D004492:Edetic Acid