CD8 thymocyte differentiation: T cell two-step

A new study demonstrates that commitment to the CD8 lineage in the thymus requires sequential T cell antigen receptor (TCR) and interleukin 7 (IL-7) signaling.

The TCR signal first induces IL-7 responsiveness, then recognition of IL-7 induces the nuclear factor Runx3, which specifies the CD8 lineage.

Runt-related transcription factor 3 (Runx3) encodes a member of the runt domain-containing family of transcription factors. It functions as a tumor suppressor, and the gene is frequently deleted or transcriptionally silenced in cancer.

This video describes the cellular signaling that takes place with the T cell receptor. This video is from: Janeway's Immunobiology, 7th Edition Murphy, Travers, & Walport. Source: Garland Science.

References:

CD8+ thymocyte differentiation: T cell two-step. Nature, 2010.
http://www.nature.com/ni/journal/v11/n3/abs/ni0310-189.html
Genomics and the Multifactorial Nature of Human Autoimmune Disease. NEJM, 2011.