Abstract
Human terminal C complexes C5b-6, C5b-7, C5b-8, and C5b-9 express neoantigenic determinants (neoAg; Kolb, W. P. and Müller-Eberhard, H. J., Proc. Nat. Acad. Sci. 72, 1687, 1975). Complex-specific antiserum (anti-neoAg) detected neoAg on 27 ± 11% of viable human peripheral blood leukocytes (PBL) when prepared from defibrinated blood by Ficoll-Hypaque sedimentation. Specificity of anti-neoAg was established by immunodiffusion, by agglutination of EAC1-7, but not EA, E, or EAC4,2,3b, and by inhibition of EAC1-7 agglutination by C5b-9 complex. Specificity of the fluorescent staining reaction was established by inhibition of staining with C5b-9, but not with fresh serum, and by fluorescent staining of EAC1-7, but not EAC4,2,3b, EA, or E. In addition to neoAg, the individual components, C5, C6, C7, C8, and C9 were detected on PBL and the coincidence of C5 and neoAg on the same cells was 83%, and of C8 and neoAg 79%.
