Griffiss J M, Jarvis G A, O'Brien J P, Eads M M, Schneider H
Center for Immunochemistry, University of California, San Francisco.
J Immunol. 1991 Jul 1;147(1):298-305.
We studied the specificity of naturally acquired IgM bactericidal for strains of Neisseria gonorrhoeae that varied in sensitivity to the lytic action of normal human serum (NHS) and the relative ability of these strains to deplete the classical (CP) and alternative (ACP) C pathways. Lysis of both highly sensitive and relatively insensitive strains was inhibited by the same gonococcal lipooligosaccharides (LOS), as well as by Salmonella minnesota Re LOS and three hexosamine-containing glycose polymers. A polymer of N-acetylgalactosamine phosphate was the most inhibitory; a polymer of N-acetylglucosamine phosphate only partially inhibited. Neither 3-deoxy-D-manno-octulosonic acid (dOc1A) nor a polymer that contained dOc1A but not hexosamine inhibited NHS lysis. A co-polymer of N-acetylgalactosamine-dOc1A inhibited both bactericidal activity and the binding of IgM to the LOS of a highly serum-sensitive (sers) gonococcal strain. Carboxyl reduction of the dOc1A in this polymer did not affect its inhibitory capacity for gonococcal antibody, but abolished its binding to homologous antibody induced by vaccination. CP activity was not affected by vaccination. CP activity was not affected by absorption of NHS with gonococcal strains, whereas ablation of CP activity markedly but variously diminished lytic activity for highly sers strains. ACP activity was variously depleted by gonococcal strains, and the proportion of bacteria that could be lysed through the ACP varied among strains and among different populations of a given strain. The titer at which a strain was sensitive to NHS lysis was a function of its ACP consumption (p = 0.006), which accounted for 70% of the differences in titer among strains. Analyses of the absorbed sera revealed that the gonococci had variously depleted properdin from NHS as assessed by using an Ag-capture solid-phase RIA. Addition of purified properdin to absorbed sera restored ACP activity to normal levels. Western immunoblots of gonococcal lysates showed that purified properdin bound directly to a 39-kDa outer membrane protein. We conclude that both CP activation by IgM binding to LOS epitopes, one of which contains hexosamine, and ACP activation, which is a function of strain-specific direct binding of properdin, can initiate lysis of sers strains and that ACP activation, also enhances lysis and accounts for variations in sensitivity of sers strains.
我们研究了自然获得的IgM对淋病奈瑟菌菌株的杀菌特异性，这些菌株对正常人血清（NHS）的溶解作用敏感性不同，以及这些菌株消耗经典（CP）和替代（ACP）补体途径的相对能力。高敏感菌株和相对不敏感菌株的溶解均受到相同的淋球菌脂寡糖（LOS）以及明尼苏达沙门氏菌Re LOS和三种含己糖胺的糖聚合物的抑制。N-乙酰半乳糖胺磷酸聚合物的抑制作用最强；N-乙酰葡糖胺磷酸聚合物仅部分抑制。3-脱氧-D-甘露糖-辛酮糖酸（dOc1A）以及含有dOc1A但不含己糖胺的聚合物均不抑制NHS溶解。N-乙酰半乳糖胺-dOc1A共聚物抑制了高血清敏感（sers）淋球菌菌株的杀菌活性以及IgM与LOS的结合。该聚合物中dOc1A的羧基还原不影响其对淋球菌抗体的抑制能力，但消除了其与疫苗诱导的同源抗体的结合。CP活性不受疫苗接种的影响。CP活性不受淋球菌菌株对NHS吸收的影响，而CP活性的消除则显著但不同程度地降低了对高sers菌株的溶解活性。ACP活性因淋球菌菌株而异，并且通过ACP能够溶解的细菌比例在不同菌株以及同一菌株的不同群体之间有所不同。菌株对NHS溶解敏感的滴度是其ACP消耗的函数（p = 0.006），这占菌株之间滴度差异的70%。对吸收血清的分析表明，通过使用抗原捕获固相RIA评估，淋球菌从NHS中不同程度地消耗了备解素。向吸收血清中添加纯化的备解素可使ACP活性恢复到正常水平。淋球菌裂解物的Western免疫印迹显示，纯化的备解素直接与一种39 kDa的外膜蛋白结合。我们得出结论，IgM与LOS表位结合（其中一个表位含有己糖胺）激活CP以及备解素的菌株特异性直接结合激活ACP，均可启动sers菌株的溶解，并且ACP激活还增强了溶解作用，并解释了sers菌株敏感性的差异。
