Neoepitopes expressed by immune complexes

The impact of antibodies or other reagents selectively reacting with neoepitopes expressed by immune complexes (IC) upon the detection and isolation of IC is reviewed. Immunoglobulin, C1q and C3 are the three components which have been most utilised for the non-specific detection of IC. Particularly C3 of these three proteins is known to express neoepitopes which arise after enzymatic cleavage of the native C3 molecule. There are several monoclonal antibodies (MoAbs) which recognise these neoepitopes and their use renders IC assays and isolation both easier and less prone to spurious interactions and interference. Furthermore these MoAbs recognise neoepitopes arising at different stages of C3 degradation which may allow analysis of the human in vivo metabolism and processing of C3 bound to IC.