Pure E, Durie C J, Summerill C K, Unkeless J C
J Exp Med. 1984 Dec 1;160(6):1836-49. doi: 10.1084/jem.160.6.1836.
We have evaluated the expression of surface Fc gamma 2b/gamma 1R by lipopolysaccharide (LPS)-activated murine spleen cells, the release of soluble Fc gamma 2b/gamma 1R by activated spleen cells, and the presence of circulating Fc gamma 2b/gamma 1R in mouse serum. LPS activation of murine spleen cells and a cloned B cell line, BCL-1 CW 13.20-3B3, resulted in a 5-10-fold increase in surface Fc gamma 2b/gamma 1R and the concominant appearance in the culture medium of a soluble molecule that is antigenically related to the Fc gamma 2b/gamma 1R. The increase in cell-associated and soluble Fc gamma 2b/gamma 1R after LPS activation is attributable primarily to B cells. Circulating Fc gamma 2b/gamma 1R was also detected in normal mouse serum at a concentration of 10(-9) to 10(-8) M. Levels of circulating Fc gamma 2b/gamma 1R increase with the age of the animals, and were low in adult germ-free mice and elevated in young mice with certain autoimmune diseases. The circulating Fc gamma 2b/gamma 1R bound to IgG-Sepharose, and was partially purified by affinity chromatography on 2.4G2 Fab-Sepharose. After radiolabeling and immunoprecipitation with rabbit anti-Fc gamma 2b/gamma 1R serum, one component of Mr 48,000, was detected.
我们评估了脂多糖(LPS)激活的小鼠脾细胞表面Fcγ2b/γ1R的表达、激活的脾细胞释放可溶性Fcγ2b/γ1R的情况以及小鼠血清中循环Fcγ2b/γ1R的存在。LPS激活小鼠脾细胞和克隆的B细胞系BCL-1 CW 13.20-3B3,导致表面Fcγ2b/γ1R增加5至10倍,并在培养基中同时出现一种与Fcγ2b/γ1R抗原相关的可溶性分子。LPS激活后细胞相关和可溶性Fcγ2b/γ1R的增加主要归因于B细胞。在正常小鼠血清中也检测到循环Fcγ2b/γ1R,浓度为10^(-9)至10^(-8) M。循环Fcγ2b/γ1R的水平随动物年龄增加而升高,在成年无菌小鼠中较低,在患有某些自身免疫性疾病的幼鼠中升高。循环Fcγ2b/γ1R与IgG-Sepharose结合,并通过2.4G2 Fab-Sepharose亲和层析进行部分纯化。经放射性标记并用兔抗Fcγ2b/γ1R血清进行免疫沉淀后,检测到一个分子量为48,000的组分。