Briles D E, Forman C, Horowitz J C, Volanakis J E, Benjamin W H, McDaniel L S, Eldridge J, Brooks J
Department of Microbiology, University of Alabama, Birmingham 35294.
Infect Immun. 1989 May;57(5):1457-64. doi: 10.1128/iai.57.5.1457-1464.1989.
Antibodies to pneumococcal capsular polysaccharides are well known for their ability to protect against pneumococcal infection. Recent studies indicate that antibodies to cell wall antigens, including pneumococcal surface protein A and the phosphocholine (PC) determinant of teichoic acids as well as human C-reactive protein (which also binds to PC), can protect mice against pneumococcal infection. In the present study we compared the protective effects of these agents as measured by mouse protection, the blood bactericidal assay, and clearance of pneumococci from the blood and peritoneal cavity. Our findings extend previous results indicating that human C-reactive protein and antibodies to noncapsular antigens are generally less protective than anticapsular antibodies. The new results obtained indicate the following: (i) mouse protection studies with intraperitoneal and intravenous infections provide very similar results; (ii) monoclonal immunoglobulin G2a (IgG2a) antibodies to PC, like IgG1, IgG2b, and IgG3 antibodies to PC, are highly protective against pneumococcal infection in mice; (iii) human antibody to PC is able to protect against pneumococcal infection in mice; (iv) antibodies to PspA are effective at mediating blood and peritoneal clearance of pneumococci; (v) complement is required for the in vivo protective effects of both IgG and IgM antibodies to PC; (vi) IgG1, IgG2b, and IgG3 anti-PC antibodies all mediate complement-dependent lysis of PC-conjugated erythrocytes; and (vii) antibodies and human C-reactive proteins that are reactive with capsular antigens but not cell wall antigens are able to mediate significant antibacterial activity in the blood bactericidal assay.
抗肺炎球菌荚膜多糖抗体因其预防肺炎球菌感染的能力而广为人知。最近的研究表明，针对细胞壁抗原的抗体，包括肺炎球菌表面蛋白A、磷壁酸的磷胆碱（PC）决定簇以及人C反应蛋白（其也与PC结合），可保护小鼠免受肺炎球菌感染。在本研究中，我们通过小鼠保护实验、血液杀菌试验以及血液和腹腔中肺炎球菌的清除情况，比较了这些制剂的保护效果。我们的研究结果扩展了先前的结果，表明人C反应蛋白和针对非荚膜抗原的抗体通常比抗荚膜抗体的保护作用弱。获得的新结果表明：（i）腹腔内和静脉内感染的小鼠保护实验提供了非常相似的结果；（ii）针对PC的单克隆免疫球蛋白G2a（IgG2a）抗体，与针对PC的IgG1、IgG2b和IgG3抗体一样，对小鼠肺炎球菌感染具有高度保护作用；（iii）人抗PC抗体能够保护小鼠免受肺炎球菌感染；（iv）抗PspA抗体在介导肺炎球菌的血液和腹腔清除方面有效；（v）补体是IgG和IgM抗PC抗体体内保护作用所必需的；（vi）IgG1、IgG2b和IgG3抗PC抗体均介导PC结合红细胞的补体依赖性裂解；（vii）与荚膜抗原而非细胞壁抗原反应的抗体和人C反应蛋白能够在血液杀菌试验中介导显著的抗菌活性。
