A TCR mechanotransduction signaling loop induces negative selection in the thymus

Autor: Kaitao Li, Ke Bai, Baoyu Liu, Khalid Salaita, Paul E. Love, Prithiviraj Jothikumar, Zhou Yuan, William Rittase, Chenghao Ge, Alfred Singer, Xinhua Yu, Jinsung Hong, Yun Zhang, Miho Shinzawa, Cheng Zhu, Brian D. Evavold, Amy Palin
Rok vydání: 2018
Předmět:
Zdroj: Nature Immunology. 19:1379-1390
ISSN: 1529-2916
1529-2908
Popis: The T cell antigen receptor (TCR) expressed on thymocytes interacts with self-peptide major histocompatibility complex (pMHC) ligands to signal apoptosis or survival. Here, we found that negative-selection ligands induced thymocytes to exert forces on the TCR and the co-receptor CD8 and formed cooperative TCR-pMHC-CD8 trimolecular 'catch bonds', whereas positive-selection ligands induced less sustained thymocyte forces on TCR and CD8 and formed shorter-lived, independent TCR-pMHC and pMHC-CD8 bimolecular 'slip bonds'. Catch bonds were not intrinsic to either the TCR-pMHC or the pMHC-CD8 arm of the trans (cross-junctional) heterodimer but resulted from coupling of the extracellular pMHC-CD8 interaction to the intracellular interaction of CD8 with TCR-CD3 via associated kinases to form a cis (lateral) heterodimer capable of inside-out signaling. We suggest that the coupled trans-cis heterodimeric interactions form a mechanotransduction loop that reinforces negative-selection signaling that is distinct from positive-selection signaling in the thymus.
Databáze: OpenAIRE