Engagement of Fc gamma receptors in phagocytosis of immune complexes containing sntibodies to mutant and native molecule of human chorionic gonadotropin

Author: Nino Gachechiladze
Co-authors: Gachechiladze N., Chikadze N.,Mitskevichi N., Lund T., Delves PJ., Roit A., Porakishvili N.
Keywords: immune complexes, hCG, phagocytosis, Fc receptor
Annotation:

It was recently demonstrated that the prototype version of anti-hCG vaccine based upon the hCGβ-chain recombinant molecule containing a single point mutation of an arginine to glutamic acid at a position 68 [hCGβ(R68E)] generates antibodies that bind to the C-terminal peptide on the native molecule and form immune complexes which are readily phagocytosed in vitro by monocytes and neutrophils. The aim of this study was to investigate the role of FcγRs in vitro, in phagocytosis of hormone-antibody complexes formed after immunization with the mutant hCGβ(R68E). We report here that the phagocytosis of immune complexes containing anti-hCGβ(R68E) sera of rabbits and native hCG molecules by monocytes and neutrophils is mediated by FcγRI(CD64) and FcγRIII(CD16) respectively in cooperation with the complement receptor 3 (CR3).