Mold C, Gewurz H
J Immunol. 1981 Nov;127(5):2089-92.
C-reactive protein (CRP) is an acute phase serum protein found associated with damaged tissue at sites of inflammation. CRP bound to multivalent phosphocholine-containing or polycationic ligands activates C by the classical pathway. We have previously described liposomes of a particular lipid composition that are able both to activate the alternative pathway of C and to bind CRP. In addition many strains of Streptococcus pneumoniae activate the alternative pathway. We have shown CRP binding to these bacteria as well. Because antibody to an activating surface in many cases enhances alternative pathway activation, we tested CRP for a similar function in these systems. Our results indicate that, in contrast to antibody, CRP inhibits alternative pathway activation. This inhibition by CRP is apparently restricted to surfaces that bind CRP. Thus, CRP binding to membrane or bacterial surfaces can convert them from alternative pathway activation to classical pathway activation.
C反应蛋白（CRP）是一种急性期血清蛋白，在炎症部位与受损组织相关联。与含多价磷酸胆碱或聚阳离子配体结合的CRP通过经典途径激活补体C。我们之前描述过一种具有特定脂质组成的脂质体，它既能激活补体C的替代途径，又能结合CRP。此外，许多肺炎链球菌菌株可激活替代途径。我们也已证明CRP能与这些细菌结合。由于在许多情况下，针对激活表面的抗体可增强替代途径的激活，我们在这些系统中测试了CRP是否具有类似功能。我们的结果表明，与抗体不同，CRP会抑制替代途径的激活。CRP的这种抑制作用显然仅限于能结合CRP的表面。因此，CRP与膜或细菌表面的结合可将它们从替代途径激活转变为经典途径激活。
