The virulence for mice of strains of Escherichia coli related to the effects of K antigens on their resistance to phagocytosis and killing by complement.
The virulence for mice of strains of Escherichia coli related to the effects of K antigens on their resistance to phagocytosis and killing by complement.
复制标题
大肠杆菌菌株对小鼠的毒力与 K 抗原对其抵抗吞噬作用和补体杀伤作用的影响有关。
作者：
C. Howard;A. Glynn
当静脉注射到小鼠体内时，具有足够K抗原以抵抗补体杀伤的大肠杆菌菌株的吞噬作用很差。吞噬作用显着增加抗OK，但不抗O血清。相反，抗K血清对杀菌反应几乎没有影响。这并不是因为K抗原位点很少，而是因为它们的位置使得补体在距离其底物一定距离处被激活。用K抗原包被的红细胞被补体和抗K血清溶解不良，这表明K抗体不能非常有效地激活补体，尽管这些位点可能又太表面了。K抗原对吞噬作用和补体杀伤或溶解的影响都可以通过它们损害蛋白结合的能力来解释。
株大肠结果表明，富含K抗原的大肠杆菌对吞噬和补体杀伤有抵抗作用，对小鼠脑内注射有毒力。K抗原在动物和人类感染的意义进行了讨论。
Strains of Escherichia coli with sufficient K antigen to resist killing by complement were poorly phagocytosed when injected intravenously into mice. Phagocytosis was markedly increased by anti-OK but not by anti-O sera. In contrast anti-K sera had little or no effect on the bactericidal reaction. This was not because K antigenic sites were scarce but may have been because their position was such that complement was activated at a distance from its substrate. Red cells coated with K antigen were poorly lysed by complement and anti-K serum, suggesting that the K antibody did not activate complement very effectively although again the sites may have been too superficial. The effect of K antigens on phagocytosis and complement killing or lysis could all be explained by their ability to impair protein binding.
Strains of E. coli rich in K antigen were resistant to phagocytosis and complement killing and were virulent for mice on intracerebral injection. The significance of K antigens in animal and human infections is discussed.