Daëron M, Néauport-Sautès C, Blank U, Fridman W H
Eur J Immunol. 1986 Dec;16(12):1545-50. doi: 10.1002/eji.1830161213.
In order to determine whether T cell Fc gamma receptors (Fc gamma R) and IgG-binding factors (IgG-BF) are structurally related, we searched for common antigens on these molecules. We found that the anti-macrophage Fc gamma 1/gamma 2bR monoclonal antibody 2.4G2 binds to similar determinant(s) on the macrophage-like J774 cells and on the Fc gamma R+ hybridoma T cells T2D4. On the T cell membrane, these determinants are associated with Fc gamma 1/gamma 2bR. They are absent on Fc gamma R- hybridoma T cells or the FcR- BW5147 thymoma cells. 2.4G2-reactive molecules were also detected in soluble material either extracted or released in the supernatant of Fc gamma R+ hybridoma T cells. 2.4G2-reactive molecules released in the supernatant of T2D4 cells could be absorbed on Sepharose beads coupled to rabbit IgG and they were recovered by acid elution. Conversely, Sepharose beads coupled to 2.4G2 retained molecules which had affinity for rabbit IgG, which suppressed an in vitro antibody response and which had the same molecular weight as IgG-BF. These results indicate that T cell Fc gamma R and IgG-BF share common epitopes and that 2.4G2 can serve as an anti-IgG-BF antibody.
为了确定T细胞Fcγ受体（FcγR）和IgG结合因子（IgG-BF）在结构上是否相关，我们在这些分子上寻找共同抗原。我们发现抗巨噬细胞Fcγ1/γ2bR单克隆抗体2.4G2与巨噬细胞样J774细胞以及FcγR⁺杂交瘤T细胞T2D4上的相似决定簇结合。在T细胞膜上，这些决定簇与Fcγ1/γ2bR相关。它们在FcγR⁻杂交瘤T细胞或FcR⁻BW5147胸腺瘤细胞上不存在。在从FcγR⁺杂交瘤T细胞上清液中提取或释放的可溶性物质中也检测到了2.4G2反应性分子。T2D4细胞上清液中释放的2.4G2反应性分子可被偶联兔IgG的琼脂糖珠吸附，并通过酸洗脱回收。相反，偶联2.4G2的琼脂糖珠保留了对兔IgG有亲和力、抑制体外抗体反应且分子量与IgG-BF相同的分子。这些结果表明T细胞FcγR和IgG-BF共享共同表位，并且2.4G2可作为抗IgG-BF抗体。
