6BIT

SIRPalpha antibody complex


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.19 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.210 
  • R-Value Observed: 0.212 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Anti-SIRP alpha antibody immunotherapy enhances neutrophil and macrophage antitumor activity.

Ring, N.G.Herndler-Brandstetter, D.Weiskopf, K.Shan, L.Volkmer, J.P.George, B.M.Lietzenmayer, M.McKenna, K.M.Naik, T.J.McCarty, A.Zheng, Y.Ring, A.M.Flavell, R.A.Weissman, I.L.

(2017) Proc Natl Acad Sci U S A 114: E10578-E10585

  • DOI: 10.1073/pnas.1710877114
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • Cancer immunotherapy has emerged as a promising therapeutic intervention. However, complete and durable responses are only seen in a fraction of patients who have cancer. A key factor that limits therapeutic success is the infiltration of tumors by c ...

    Cancer immunotherapy has emerged as a promising therapeutic intervention. However, complete and durable responses are only seen in a fraction of patients who have cancer. A key factor that limits therapeutic success is the infiltration of tumors by cells of the myeloid lineage. The inhibitory receptor signal regulatory protein-α (SIRPα) is a myeloid-specific immune checkpoint that engages the "don't eat me" signal CD47 expressed on tumors and normal tissues. We therefore developed the monoclonal antibody KWAR23, which binds human SIRPα with high affinity and disrupts its binding to CD47. Administered by itself, KWAR23 is inert, but given in combination with tumor-opsonizing monoclonal antibodies, KWAR23 greatly augments myeloid cell-dependent killing of a collection of hematopoietic and nonhematopoietic human tumor-derived cell lines. Following KWAR23 antibody treatment in a human SIRPA knockin mouse model, both neutrophils and macrophages infiltrate a human Burkitt's lymphoma xenograft and inhibit tumor growth, generating complete responses in the majority of treated animals. We further demonstrate that a bispecific anti-CD70/SIRPα antibody outperforms individually delivered antibodies in specific types of cancers. These studies demonstrate that SIRPα blockade induces potent antitumor activity by targeting multiple myeloid cell subsets that frequently infiltrate tumors. Thus, KWAR23 represents a promising candidate for combination therapy.


    Organizational Affiliation

    Institute for Stem Cell Biology and Regenerative Medicine, and Ludwig Center for Cancer Stem Cell Research, Stanford University School of Medicine, Stanford, CA 94305; richard.flavell@yale.edu irv@stanford.edu.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
KWAR23 Fab heavy chainI, J213Mus musculusMutation(s): 0 
Protein Feature View
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  • Reference Sequence

Find similar proteins by: Sequence  |  Structure

Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
KWAR23 Fab light chainK, L212Mus musculusMutation(s): 0 
Protein Feature View
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  • Reference Sequence

Find similar proteins by: Sequence  |  Structure

Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
Tyrosine-protein phosphatase non-receptor type substrate 1G, H117Homo sapiensMutation(s): 0 
Gene Names: SIRPABITMFRMYD1PTPNS1SHPS1SIRP
Find proteins for P78324 (Homo sapiens)
Explore P78324 
Go to UniProtKB:  P78324
NIH Common Fund Data Resources
PHAROS  P78324
Protein Feature View
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  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
PCA
Query on PCA
K,LL-PEPTIDE LINKINGC5 H7 N O3GLN
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.19 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.210 
  • R-Value Observed: 0.212 
  • Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 164.966α = 90
b = 164.966β = 90
c = 96.716γ = 120
Software Package:
Software NamePurpose
PHENIXrefinement
HKL-2000data reduction
SCALAdata scaling
PHASERphasing

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Bill & Melinda Gates FoundationUnited States--
Howard Hughes Medical Institute (HHMI)United States--
Ludwig Institute for Cancer ResearchUnited States--

Revision History 

  • Version 1.0: 2017-12-06
    Type: Initial release
  • Version 1.1: 2017-12-13
    Changes: Database references
  • Version 1.2: 2018-01-17
    Changes: Author supporting evidence
  • Version 1.3: 2019-11-20
    Changes: Author supporting evidence