Kodama H, Baba T, Ohishi I
Laboratory of Veterinary Immunology, College of Agriculture, University of Osaka Prefecture, Japan.
Dev Comp Immunol. 1994 Sep-Oct;18(5):389-95. doi: 10.1016/0145-305x(94)90004-3.
Botulinum C2 toxin (C2T) is composed of two nonlinked protein components, components I and II. The toxin reconstituted with component I and trypsinized component II inhibited phagocytosis of rainbow trout (Oncorhynchus mykiss) and mouse macrophages. Inhibition in both cell types was observed over a range of toxin concentrations that were not toxic to the cells. Because cytoplasmic action of rainbow trout macrophages is ADP-ribosylated by component I, the inhibition of phagocytosis in trout cells by C2T is probably due to inactivation of cytoplasmic actin. Moreover, phagocytosis by trout cells was also inhibited in a dose-dependent manner by trypsinized component II alone, and did not cause cell death. The present results show that the macrophages of aquatic vertebrates are susceptible to C2T, and that trypsinized component II elicits a novel biological activity by binding to the cell membrane of the macrophages.
肉毒杆菌C2毒素（C2T）由两个非连接的蛋白质成分，即成分I和成分II组成。用成分I和经胰蛋白酶处理的成分II重构的毒素抑制虹鳟鱼（Oncorhynchus mykiss）和小鼠巨噬细胞的吞噬作用。在对细胞无毒的一系列毒素浓度范围内，两种细胞类型均观察到抑制作用。由于虹鳟鱼巨噬细胞的细胞质作用被成分I进行了ADP核糖基化，C2T对鳟鱼细胞吞噬作用的抑制可能是由于细胞质肌动蛋白的失活。此外，单独的经胰蛋白酶处理的成分II也以剂量依赖的方式抑制鳟鱼细胞的吞噬作用，并且不会导致细胞死亡。目前的结果表明，水生脊椎动物的巨噬细胞对C2T敏感，并且经胰蛋白酶处理的成分II通过与巨噬细胞的细胞膜结合引发了一种新的生物学活性。
