Ji Y H, Matsushita M, Okada H, Fujita T, Kawakami M
Department of Molecular Biology, School of Medicine, Kitasato University, Kanagawa-ken, Japan.
J Immunol. 1988 Dec 15;141(12):4271-5.
Ra-reactive factors (RaRF) are the name of a group of C-dependent bactericidal factors that bind specifically to Ra chemotype strains of Salmonella. These factors are present in the sera of a wide variety of vertebrates and have common characteristics. Here we investigate the C components required for the C activation induced by mouse RaRF, by using hemolysis of Ra LPS-coated E (ELPS) as a model system. It was found that C1-depleted and C1q-depleted sera were as effective as the undepleted serum in the lysis of ELPS sensitized with RaRF. Addition of the C1 component or C1q subcomponent to the depleted sera did not increase the effect. On the other hand, C4 and C2 components were found to be essential for the lysis of RaRF-sensitized ELPS. Activities of C4 and C2 remained on the sensitized cells even after washing the cells, suggesting that the classical C3 convertase, C4b2a, is generated on the RaRF-sensitized ELPS.
Ra反应因子（RaRF）是一组C依赖性杀菌因子的名称，它们特异性结合沙门氏菌的Ra化学型菌株。这些因子存在于多种脊椎动物的血清中，并具有共同特征。在此，我们以Ra LPS包被的E（ELPS）溶血作为模型系统，研究小鼠RaRF诱导C激活所需的C成分。发现C1缺陷血清和C1q缺陷血清在裂解经RaRF致敏的ELPS方面与未缺陷血清一样有效。向缺陷血清中添加C1成分或C1q亚成分并未增强效果。另一方面，发现C4和C2成分对于裂解经RaRF致敏的ELPS至关重要。即使在洗涤细胞后，C4和C2的活性仍保留在致敏细胞上，这表明经典C3转化酶C4b2a在经RaRF致敏的ELPS上产生。
