The level of CD8 expression can determine the outcome of thymic selection.

@article{Robey1992TheLO,
  title={The level of CD8 expression can determine the outcome of thymic selection.},
  author={Ellen A. Robey and Fred Ramsdell and Dimitris Kioussis and Weihong Sha and Dennis Y. Loh and Richard Axel and B. J. Fowlkes},
  journal={Cell},
  year={1992},
  volume={69 7},
  pages={1089-96}
}
During thymic development, thymocytes that can recognize major histocompatability complex (MHC) molecules on thymic epithelial cells are selected to survive and mature (positive selection), whereas thymocytes that recognize MHC on hematopoietic cells are destroyed (negative selection). It is not known how MHC recognition can mediate both death and survival. One model to explain this paradox proposes that thymocytes whose T cell antigen receptors (TCRs) recognize MHC with high affinity are… CONTINUE READING