Deletion of self-reactive CCR7- thymocytes in the absence of MHC expression on thymic epithelial cells
The selection of alphabeta T cells in the thymus is punctuated by checkpoints at which thymocytes differentiate or undergo apoptosis. Wave 1 deletion is defined as apoptosis within nascent alphabeta T-cell antigen receptor (TCR)-signalled thymocytes that lack CCR7 expression. The antigen-presenting cell (APC) types that mediate wave 1 deletion are unclear. To measure wave 1 deletion, we compared the frequencies of TCRbeta + CD5 + Helios + CCR7- cells in nascent thymocyte cohorts in mice with normal or defective apoptosis. This thymocyte population is small in mice lacking major histocompatibility complex (MHC) expression. The scale of wave 1 deletion was increased by transgenic expression of the self-reactive Yae62 TCRbeta chain, was almost halved when haemopoietic APCs lacked MHC expression and, surprisingly, was unchanged when epithelial cells lacked MHC expression. These findings demonstrate efficiency, and some redundancy, in the APC types that mediate wave 1 deletion in the normal mouse thymus.
|ISBN||1476-5403 (Electronic) 1350-9047 (Linking)|
|Authors||Wirasinha, R. C.; Chan, A.; Yap, J. Y.; Hu, D. Y.; Teh, C. E.; Gray, D. H. D.; Goodnow, C. C.; Daley, S. R.|
|Responsible Garvan Author|
|Publisher Name||CELL DEATH AND DIFFERENTIATION|
|URL link to publisher's version||https://www.ncbi.nlm.nih.gov/pubmed/31019259|