Sirpa Mouse Models

Why Model Sirpa

Sirpa is the mouse ortholog of human SIRPA and encodes SIRPα (CD172a), an inhibitory receptor expressed on myeloid cells including macrophages. SIRPα binds CD47 and has been associated with a signal that limits macrophage phagocytosis.

The CD47-SIRPα axis is a target of cancer immunotherapy aimed at promoting macrophage-mediated clearance of tumor cells; reported clinical results have varied. Species differences in SIRPα-CD47 binding affect engraftment of human cells, which is relevant to humanized mouse models.

Model Applications

Humanized SIRPA models, often combined with CD47 humanization and immunodeficiency alleles, have been used to support engraftment of human cells and to evaluate CD47-SIRPα-targeted therapeutics in defined experimental settings.

Sirpa variants have been shown to influence human hematopoietic cell engraftment in immunodeficient hosts.

Custom Sirpa Model Options

Engineered to your specifications, with molecular validation of the targeted allele and germline transmission guaranteed.

• Conventional knockout
• Conditional knockout
• Point mutation / knockin
• Reporter knockin
• Humanized
• Targeted transgenic

Sources

• Targeting phagocytosis checkpoints for cancer immunotherapy. Nat Rev Cancer. 2025. doi:10.1038/s41568-025-00893-w
• Oldenborg PA et al. Role of CD47 as a marker of self on red blood cells. Science. 2000. doi:10.1126/science.288.5473.2051
• Kharitonenkov A et al. A family of proteins that inhibit signalling through tyrosine kinase receptors. Nature. 1997. doi:10.1038/386181a0

Last reviewed: October 22, 2026 · Reviewed by: Paul Sheiffele

Related gene targets: Cd47 · Sirpb1 · Sirpg · Pdcd1