Anti-SIRPB1 antibody [B4B6]

Supplementary information

This supplementary information is collated from multiple sources and compiled automatically.

Signal regulatory protein beta-1 (SIRPB1) also known as CD172b is a transmembrane glycoprotein that functions as an inhibitory receptor. It weighs about 55 kDa. SIRPB1 is mainly expressed on myeloid cells including monocytes macrophages and granulocytes. It contains an immunoreceptor tyrosine-based inhibitory motif (ITIM) which recruits phosphatases such as Src homology region 2 domain-containing phosphatase-1 (SHP-1) upon phosphorylation. This motif plays an important role in mediating inhibitory signals inside the cell.

Biological function summary

Within the immune system context SIRPB1 acts to regulate functions related to myeloid cells. It does not form part of a larger receptor complex but significantly influences cell communication. It modulates responses like phagocytosis and cellular activation maintaining balanced immune reactions. The interaction with its ligands like CD47 or DAP12 provides insights into its ability to send inhibitory signals contributing to the overall control of immune responses.

Pathways

SIRPB1 gets involved in immune regulation and signal transduction. It plays a significant role in the CD47-SIRP signaling pathway which affects processes like cell migration and phagocytosis. The interaction with SHP-1 and SHP-2 phosphatases signifies its integration within signaling networks governing negative regulation of cellular activation. Through these pathways SIRPB1 interacts with related proteins like SIRPA and SIRPG which have similar functions yet distinct roles within the immune system.

SIRPB1 has associations with inflammatory conditions and cancer. In inflammatory disorders like rheumatoid arthritis altered expression of SIRPB1 can contribute to pathogenesis by modifying immune cell activation further linking it with SIRPA in the modulation of immune responses. In cancer SIRPB1's role extends to tumor immune evasion where upregulated CD47 affects SIRPB1 pathways to inhibit phagocytosis by macrophages influencing tumor progression. Understanding SIRPB1's connections with these proteins and pathways opens avenues for therapeutic interventions in these diseases.