EXPRESSION AND FUNCTION OF I REGION DETERMINANTS ON IMMUNOCOMPETENT CELLS .1. SELECTIVE EXPRESSION OF I-C REGION DETERMINANTS ON IMMUNE CELLS

  • 1 January 1977
    • journal article
    • research article
    • Vol. 119  (2) , 737-743
Abstract
The cytotoxic activity of anti-Iak serum and complement on various immune functions of BALB/c [mouse] (H-2d) cells was examined. Since the cytotoxic action of this antiserum on H-2d cells defines specificity Ia.7 [immune response-associated antigen 7], an I-C region product, the selective expression of this antigen was studied. The in vitro anti-Lac [p-azophenyl .beta.-D lactoside] response was used to study the cells involved in the induction and regulation of antibody. Ia.7 is apparently present on Ig[immunoglobulin]M and IgG precursor B [bone marrow-derived] cells and in lesser amounts on plaque-forming cells. The antiserum recognizes, with less efficiency, a product on specific T [thymus-derived] suppressor cells, which is possibly coded for by the adjacent I-J subregion. Fluorescence and functional tests indicate the absence of Ia.7 on macrophages. It is also lacking on T helper cells. When the antiserum was tested on the in vitro cytotoxic responses to alloantigens, neither T effector cells nor their precursors were apparently affected.