SIRPA (CD172a)

Target id: 2942

Nomenclature: SIRPA (CD172a)

Family: CD molecules, Signal regulatory proteins

Annotation status:  image of a grey circle Awaiting annotation/under development. Please contact us if you can help with annotation.  » Email us

   GtoImmuPdb view: OFF :     SIRPA (CD172a) has curated GtoImmuPdb data

Gene and Protein Information
Species TM AA Chromosomal Location Gene Symbol Gene Name Reference
Human 1 504 20p13 SIRPA signal regulatory protein alpha
Mouse 1 513 2 F1; 2 63.19 cM Sirpa signal-regulatory protein alpha
Rat 1 509 3q36 Sirpa signal-regulatory protein alpha
Gene and Protein Information Comments
Details are provided for the shorter protein isoform (isoform 1) encoded by the human gene. Isofom 2 is the longer protein at 508 amino acids (see NP_001317657). For the mouse, we show isoform 3 peptide details.
Database Links
Ensembl Gene
Entrez Gene
Human Protein Atlas
RefSeq Nucleotide
RefSeq Protein
Immunopharmacology Comments
SIRPα is an important inhibitory immune response regulator. It is expressed by a subset of intestinal dendritic cells (integrin CD103+ DCs) that are critical for maintaining intestinal (mucosal) immune system homeostasis. This subset of CD103+SIRPα+ DCs selectively activates Th17 cells and type 3 innate lymphoid cells (ILC3) [3-4]. Studies by Hansen et al. (2018) have shown that CD103+SIRPα+ DCs can be transformed in to pro-inflammatory cells via a process involving FcαRI co-stimulation-induced glycolytic reprogramming. This work shows how IgA-immune complexes in the human intestine can convert a tolerogenic milieu to a pro-inflammatory one, following exposure to environmental agents [2].

Pharmacological agents which block the SIRPα/CD47 antiphagocytic axis are being investigated as potential immuno-oncology therapeutics which would act to promote immunosurveillance and increase phagocytosis of cancer cells by tumour associated macrophages (TAMs). Specifically, the anti-SIPRα monoclonal antibody OSE-172 (Effi-DEM) is in early stage development (OSE IMMUNOTherapeutics), and proof of concept has been demonstrated in in vivo models. Preclinical testing suggests that the therapeutic effect of OSE-172 is observed in both monotherapy or when combined with other checkpoint inhibitors, or with immune system stimulators. Anti-CD47 antibodies are also in early stage development, as reported by Gholamin et al. (2017) [1].
Immuno Process Associations
Immuno Process:  Inflammation
GO Annotations:  Associated to 2 GO processes
GO:0043312 neutrophil degranulation TAS
GO:0050900 leukocyte migration TAS
Immuno Process:  Chemotaxis & migration
GO Annotations:  Associated to 1 GO processes
GO:0050900 leukocyte migration TAS
Immuno Process:  Cellular signalling
GO Annotations:  Associated to 1 GO processes
GO:0043312 neutrophil degranulation TAS
General Comments
The SIPRα protein binding interaction with CD47 produces an antiphagocytic signal, that is often termed a 'don't eat me' signal.


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1. Gholamin S, Mitra SS, Feroze AH, Liu J, Kahn SA, Zhang M, Esparza R, Richard C, Ramaswamy V, Remke M et al.. (2017) Disrupting the CD47-SIRPα anti-phagocytic axis by a humanized anti-CD47 antibody is an efficacious treatment for malignant pediatric brain tumors. Sci Transl Med, 9 (381). [PMID:28298418]

2. Hansen IS, Krabbendam L, Bernink JH, Loayza-Puch F, Hoepel W, van Burgsteden JA, Kuijper EC, Buskens CJ, Bemelman WA, Zaat SAJ et al.. (2018) FcαRI co-stimulation converts human intestinal CD103+dendritic cells into pro-inflammatory cells through glycolytic reprogramming. Nat Commun, 9 (1): 863. [PMID:29491406]

3. Joeris T, Müller-Luda K, Agace WW, Mowat AM. (2017) Diversity and functions of intestinal mononuclear phagocytes. Mucosal Immunol, 10 (4): 845-864. [PMID:28378807]

4. Watchmaker PB, Lahl K, Lee M, Baumjohann D, Morton J, Kim SJ, Zeng R, Dent A, Ansel KM, Diamond B et al.. (2014) Comparative transcriptional and functional profiling defines conserved programs of intestinal DC differentiation in humans and mice. Nat. Immunol., 15 (1): 98-108. [PMID:24292363]

How to cite this page

CD molecules: SIRPA (CD172a). Last modified on 06/03/2018. Accessed on 21/07/2018. IUPHAR/BPS Guide to PHARMACOLOGY,