Weinberg J B, Ribi E, Wheat R W
Infect Immun. 1983 Oct;42(1):219-23. doi: 10.1128/iai.42.1.219-223.1983.
Various microbial products are known to influence the function of mouse peritoneal macrophages. Lipopolysaccharide (LPS) and certain lipid A-associated proteins are known to enhance the tumoricidal effects of macrophages. The purpose of this study was to determine whether porins (outer membrane proteins) of Salmonella typhimurium G30/C21 would influence the activity of macrophages from lipid A-responsive and -unresponsive mice. Porins, extracted by a combined sodium dodecyl sulfate-EDTA method from cell walls, were free of LPS as determined by Limulus amebocyte lysate assay and appeared as a band at approximately 36,000 molecular weight on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In tumor cell killing assays done under LPS-free conditions, the porins in doses of 1 to 10 ng/ml enhanced the tumoricidal effect of macrophages from bacillus Calmette-Guérin-infected C3H/HeN or C3H/HeJ mice. Protein-free LPS enhanced the tumoricidal activity of macrophages from bacillus Calmette-Guérin-infected C3H/HeN but not C3H/HeJ mice. The tumoricidal-enhancing activity of protein-free LPS was blocked by the lipid A-binding antibiotic polymyxin B sulfate, but the effects of porins were not altered by the polymyxin B sulfate. These results suggest that porins, proteins known to alter membrane function, may alter macrophage function by interaction with macrophage membranes.
已知多种微生物产物会影响小鼠腹腔巨噬细胞的功能。脂多糖（LPS）和某些与脂多糖A相关的蛋白质可增强巨噬细胞的杀肿瘤作用。本研究的目的是确定鼠伤寒沙门氏菌G30/C21的孔蛋白（外膜蛋白）是否会影响对脂多糖A有反应和无反应的小鼠巨噬细胞的活性。通过十二烷基硫酸钠-乙二胺四乙酸联合方法从细胞壁中提取的孔蛋白，经鲎试剂检测不含脂多糖，在十二烷基硫酸钠-聚丙烯酰胺凝胶电泳上呈现出一条分子量约为36000的条带。在无脂多糖条件下进行的肿瘤细胞杀伤试验中，1至10 ng/ml剂量的孔蛋白增强了来自卡介苗感染的C3H/HeN或C3H/HeJ小鼠巨噬细胞的杀肿瘤作用。无蛋白脂多糖增强了来自卡介苗感染的C3H/HeN小鼠巨噬细胞的杀肿瘤活性，但对C3H/HeJ小鼠巨噬细胞无效。无蛋白脂多糖的杀肿瘤增强活性被脂多糖A结合抗生素硫酸多粘菌素B阻断，但孔蛋白的作用未被硫酸多粘菌素B改变。这些结果表明，已知可改变膜功能的孔蛋白可能通过与巨噬细胞膜相互作用来改变巨噬细胞功能。
