CD47, also known as Integrin-Associated Protein (IAP), is a transmembrane protein encoded by the CD47 gene. It belongs to the immunoglobulin superfamily and can interact with various proteins such as integrins, Thrombospondin-1 (TSP-1), and Signal Regulatory Protein alpha (Sirpα). The structure of CD47 protein includes an extracellular N-terminal IgV domain, 5 transmembrane domains, and an intracellular C-terminal cytoplasmic tail, and it is widely expressed on the surface of almost all normal cells.Sirpα is a membrane glycoprotein that belongs to the SIRP family, primarily expressed on the surface of macrophages, dendritic cells, and neuronal cells. As an inhibitory receptor, Sirpα interacts with CD47 to release a “don’t eat me” signal, thereby inhibiting the phagocytic activity of macrophages. Some tumor cells also overexpress CD47 to facilitate immune evasion. The cytoplasmic region of SIRPα is highly conserved in humans, rats, and mice, containing multiple tyrosine residues in the immunoreceptor tyrosine-based inhibitory motif (ITIM). When bound to CD47, SIRPα undergoes phosphorylation, recruits SHP1 and SHP2, and transmits intracellular signals.The SIRPα Reporter Jurkat Cell Line is a luciferase reporter cell line constructed based on the CD47-SIRPα signaling pathway. When SIRPα Reporter Jurkat cells are co-cultured with CD47 aAPC CHO-K1, CD47 binds to SIRPα, recruits SHP1/2, inhibits TCR signaling, and suppresses the expression of luciferase. By adding Anti-CD47 or Anti-SIRPα antibodies to block the binding of CD47 and SIRPα, TCR signaling is restored, and luciferase expression returns to normal. The luciferase readings represent the activation and blocking effects of the signaling pathway, making it suitable for evaluating the in vitro effects of CD47 and SIRPα-related antibody drugs.
