Cell Cycle Dynamics Drive T Cell Exhaustion and Fate Decisions, Study Shows
Researchers using single-cell mass cytometry have found that T cell exhaustion — a dysfunctional state that limits immune responses — is associated with abnormal arrest in the S-G2 phases of the cell cycle, downstream of tonic CAR signaling. The study used pharmacological inhibitors and chimeric antigen receptor (CAR) T cell models to disentangle how cell cycle progression, receptor signaling, and T cell differentiation interact. These findings suggest that cell cycle dysregulation may be a mechanistic driver of CD8 T cell dysfunction in human cancers, with potential implications for improving CAR T cell therapies.
A preprint study posted to bioRxiv reports that T cell exhaustion programs are mechanistically linked to aberrant cell cycle (CC) arrest in the S and G2 phases, particularly in the context of tonic CAR signaling — the low-level, antigen-independent signaling that can drive T cells into a dysfunctional state. Using high-throughput single-cell mass cytometry, the researchers simultaneously measured cell cycle status, receptor signaling, division history, and differentiation state across human T cells. By applying cell cycle inhibitors and receptor signaling modulators, they found that early G1/S cell cycle programs interact with receptor signaling to govern T cell fate decisions. Exhaustion programs were found to be downstream of the aberrant S-G2 arrest signatures induced by tonic CAR signaling, a relationship validated in vitro, in cell culture models, and in vivo across human cancer datasets. The findings associate this S-G2 arrest pattern with CD8 T lymphocyte dysfunction broadly observed in human tumors, suggesting that cell cycle sensing is a key node in the transition from functional to exhausted T cell states.
What's missing
As a preprint, this work has not yet undergone formal peer review. The study does not address whether pharmacologically reversing S-G2 arrest can rescue T cell function in vivo.
What different sources said
- bioRxivCenter
Cell Cycle Sensing Shapes Human T Cell Fate and Exhaustion Programs
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