Download MendeleyCholesterol inhibits TCR signaling by directly restricting TCR-CD3 core tunnel motility.
Chen, Y., Zhu, Y., Li, X., Gao, W., Zhen, Z., Huang, B., Ma, Z., Zhang, A., Song, X., Ma, Y., Guo, C., Zhang, F., Huang, Z.(2022) Mol Cell 82: 1278-1287.e5
- PubMed: 35271814
- DOI: https://doi.org/10.1016/j.molcel.2022.02.017
- Primary Citation of Related Structures:
7FJD, 7FJE, 7FJF - PubMed Abstract:
Cholesterol molecules specifically bind to the resting αβTCR to inhibit cytoplasmic CD3ζ ITAM phosphorylation through sequestering the TCR-CD3 complex in an inactive conformation. The mechanisms of cholesterol-mediated inhibition of TCR-CD3 and its activation remain unclear. Here, we present cryoelectron microscopy structures of cholesterol- and cholesterol sulfate (CS)-inhibited TCR-CD3 complexes and an auto-active TCR-CD3 variant. The structures reveal that cholesterol molecules act like a latch to lock CD3ζ into an inactive conformation in the membrane. Mutations impairing binding of cholesterol molecules to the tunnel result in the movement of the proximal C terminus of the CD3ζ transmembrane helix, thereby activating the TCR-CD3 complex in human cells. Together, our data reveal the structural basis of TCR inhibition by cholesterol, illustrate how the cholesterol-binding tunnel is allosterically coupled to TCR triggering, and lay a foundation for the development of immunotherapies through directly targeting the TCR-CD3 complex.
Organizational Affiliation:
HIT Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin 150080, China.
