Integrin αvβ8 binds with exquisite specificity to latent transforming growth factor-β (L-TGF-β). This binding is essential for activating L-TGF-β presented by a variety of cell types. Inhibiting αvβ8-mediated TGF-β activation blocks immunosuppressive regulatory T cell differentiation, which is a potential therapeutic strategy in cancer. Using cryo-electron microscopy, structure-guided mutagenesis, and cell-based assays, we reveal the binding interactions between the entire αvβ8 ectodomain and its intact natural ligand, L-TGF-β, as well as two different inhibitory antibody fragments to understand the structural underpinnings of αvβ8 binding specificity and TGF-β activation. Our studies reveal a mechanism of TGF-β activation where mature TGF-β signals within the confines of L-TGF-β and the release and diffusion of TGF-β are not required. The structural details of this mechanism provide a rational basis for therapeutic strategies to inhibit αvβ8-mediated L-TGF-β activation.
Cryo-EM Reveals Integrin-Mediated TGF-β Activation without Release from Latent TGF-β.
M. Campbell,A. Cormier,Saburo Ito,Robert I Seed,S. Nishimura
Published 2020 in Cell
ABSTRACT
PUBLICATION RECORD
- Publication year
2020
- Venue
Cell
- Publication date
2020-01-13
- Fields of study
Biology, Medicine
- Identifiers
- External record
- Source metadata
Semantic Scholar, PubMed
CITATION MAP
EXTRACTION MAP
CLAIMS
CONCEPTS
- cell-based assays
Cell experiments used to assess the functional consequences of αvβ8-ligand interactions.
- cryo-electron microscopy
A structural imaging method used to visualize the αvβ8 ectodomain and its ligand complexes.
Aliases: cryo-EM
- inhibitory antibody fragments
Antibody fragments tested for their ability to block αvβ8 interactions in the structural studies.
- integrin αvβ8
An integrin receptor ectodomain studied here as the binding partner that recognizes latent TGF-β.
Aliases: αvβ8
- latent tgf-β
The intact latent form of transforming growth factor-β that serves as the ligand in this study.
Aliases: L-TGF-β, latent transforming growth factor-β
- structure-guided mutagenesis
A protein-engineering approach that changes residues based on structural information to test interaction determinants.
- therapeutic strategies
Approaches intended to inhibit αvβ8-mediated latent TGF-β activation.
- αvβ8-mediated tgf-β activation
Activation of latent TGF-β triggered by the integrin αvβ8 receptor.
Aliases: integrin-mediated TGF-β activation
REFERENCES
Showing 1-88 of 88 references · Page 1 of 1