FHR-3, Human, mAb clone 3.11

Anti-FHR-3; clone 3.11 is a mouse monoclonal antibody recognizing human full length Complement Factor H-related protein 3 (FHR-3), a glycoprotein that belongs to the complement regulatory protein family. FHR-3 is synthesized and secreted primarily by the liver but also by immune cells such as monocytes, macrophages, and dendritic cells. It is present in plasma in various glycosylated forms ranging from 35 to 56 kDa. Structurally, FHR-3 shares homology with Complement Factor H (CFH), a pivotal regulator within the complement system. Also FHR-3 operates as part of the complement regulatory network, contributing to control of the complement cascade but its precise function is poorly characterized. FHR-3 predominantly exerts its regulatory influence within the alternative pathway (AP) of the complement system. Weak cofactor activity and an enhancement of the FH cofactor activity were reported, and also a marginal inhibitory effect was observed in hemolytic assays using FH depleted serum. However, these results need to be confirmed in independent studies. Disruptions in FHR-3 expression or function have been linked to specific diseases. For instance, imbalances in FHR-3 levels or activities have been associated with conditions like atypical hemolytic uremic syndrome (aHUS), age-related macular degeneration (AMD) and systemic lupus erythematosus (SLE). In these disorders, aberrant complement activation and deposition on self-tissues can contribute to pathological processes. FHR-3’s involvement in the alternative pathway positions it as a potential therapeutic target for interventions aimed at modulating complement-driven diseases. The participation of FHR-3 in the AP suggests its potential as a therapeutic target for interventions aimed at controlling diseases driven by complement dysregulation.