Beharka A A, Armstrong J W, Iandolo J J, Chapes S K
Division of Biology, Kansas State University, Manhattan 66506-4901.
Infect Immun. 1994 Sep;62(9):3907-15. doi: 10.1128/iai.62.9.3907-3915.1994.
Macrophages from C2D transgenic mice deficient in the expression of major histocompatibility complex (MHC) class II proteins were used to identify binding sites for superantigens distinct from the MHC class II molecule. Iodinated staphylococcal enterotoxins A and B (SEA and SEB) and exfoliative toxins A and B (ETA and ETB) bound to C2D macrophages in a concentration-dependent and competitive manner. All four toxins increased F-actin concentration within 30 s of their addition to C2D macrophages, indicating that signal transduction occurred in response to toxin in the absence of class II MHC. Furthermore, ETA, ETB, SEA, and, to a lesser extent, SEB induced C2D macrophages to produce interleukin 6. Several molecular species on C2D macrophages with molecular masses of 140, 97, 61, 52, 43, and 37 kDa bound SEA in immunoprecipitation experiments. These data indicate the presence of novel, functionally active toxin binding sites on murine macrophages distinct from MHC class II molecules.
利用来自主要组织相容性复合体（MHC）II类蛋白表达缺陷的C2D转基因小鼠的巨噬细胞，来鉴定不同于MHC II类分子的超抗原结合位点。碘化葡萄球菌肠毒素A和B（SEA和SEB）以及剥脱毒素A和B（ETA和ETB）以浓度依赖性和竞争性方式与C2D巨噬细胞结合。所有这四种毒素在添加到C2D巨噬细胞后30秒内增加了F-肌动蛋白浓度，表明在没有II类MHC的情况下，毒素刺激引发了信号转导。此外，ETA、ETB、SEA以及程度较轻的SEB诱导C2D巨噬细胞产生白细胞介素6。在免疫沉淀实验中，C2D巨噬细胞上几种分子量为140、97、61、52、43和37 kDa的分子物种与SEA结合。这些数据表明，在小鼠巨噬细胞上存在不同于MHC II类分子的新型、具有功能活性的毒素结合位点。
