Blom Anna M, Österborg Anders, Mollnes Tom E, Okroj Marcin
Department of Laboratory Medicine Malmö, Section of Medical Protein Chemistry, Lund University, Inga Marie Nilssons Street 53, 20502 Malmö, Sweden.
Immune and Gene Therapy Laboratory, Department of Oncology-Pathology, Karolinska Institute, 17176 Stockholm, Sweden; Department of Hematology, Karolinska University Hospital Solna, 17176 Stockholm, Sweden.
Mol Immunol. 2015 Aug;66(2):164-70. doi: 10.1016/j.molimm.2015.02.029. Epub 2015 Mar 18.
An emerging number of diseases and therapeutic approaches with defined involvement of the complement system justify a need for specific markers reflecting activation of particular effector arms of the complement cascade. Measurement of such soluble markers in circulation is a challenge since the specificity of antibodies must be limited to activated complement fragments but not predominant and ubiquitous parental molecules. Existing assays for the measurement of soluble, activated complement proteins are based on the detection of conformational neoepitopes. We tested an alternative approach based on detection of short linear neoepitopes exposed at the cleavage sites after activation of the actual complement component. Obtained antibodies reactive to C4d and C5b fragments enabled us to set up highly specific sandwich ELISAs, which ensured trustful measurements without false positive readouts characteristic for some of the widely used assays.
越来越多的疾病以及明确涉及补体系统的治疗方法表明，需要有反映补体级联特定效应臂激活情况的特异性标志物。在循环中测量此类可溶性标志物是一项挑战，因为抗体的特异性必须仅限于活化的补体片段，而不是主要且普遍存在的亲本分子。现有的用于测量可溶性活化补体蛋白的检测方法是基于对构象新表位的检测。我们测试了一种基于检测实际补体成分激活后在裂解位点暴露的短线性新表位的替代方法。获得的对C4d和C5b片段有反应的抗体使我们能够建立高度特异性的夹心ELISA，确保了可靠的测量，而不会出现一些广泛使用的检测方法所特有的假阳性读数。
