Bindon C I, Hale G, Waldmann H
Department of Pathology, University of Cambridge, GB.
Eur J Immunol. 1990 Feb;20(2):277-81. doi: 10.1002/eji.1830200208.
A matched set of rat chimeric antibodies has been studied for their ability to activate various key stages of the complement cascade. Rat IgM and IgG2b were efficient at all stages from C1q binding to cell lysis. However, for other isotypes, a direct correlation between C1q binding and cell lysis did not apply. IgG2a, which was only modestly efficient at C1q binding, was relatively more so for binding and activation of while C1, and was by far the most effective isotype after IgG2b and IgM for C4 and C3 binding. IgG2c was relatively efficient at binding C1q and C1, but less so for the binding of C4 or for later stages. IgA was efficient at binding C1, but again, this was not reflected in activation of later stages. The results suggest that properties of different isotypes, as well as influencing binding of C1q, may regulate attachment of the C1r2C1s2 tetramer. In addition, distinct features of certain isotypes may favor C4 activation and binding, independent of their ability to activate C1.
一组匹配的大鼠嵌合抗体已被研究其激活补体级联反应各个关键阶段的能力。大鼠IgM和IgG2b在从C1q结合到细胞裂解的所有阶段都很有效。然而，对于其他同种型，C1q结合与细胞裂解之间不存在直接相关性。IgG2a在C1q结合方面效率一般，但在结合和激活C1方面相对更有效，并且在IgG2b和IgM之后，是C4和C3结合方面最有效的同种型。IgG2c在结合C1q和C1方面相对有效，但在C4结合或后期阶段则不然。IgA在结合C1方面有效，但同样，这并未反映在后期阶段的激活中。结果表明，不同同种型的特性，除了影响C1q的结合外，可能还调节C1r2C1s2四聚体的附着。此外，某些同种型的独特特征可能有利于C4的激活和结合，而与其激活C1的能力无关。
