First Author | Murata S | Year | 2007 |
Journal | Science | Volume | 316 |
Issue | 5829 | Pages | 1349-53 |
PubMed ID | 17540904 | Mgi Jnum | J:121869 |
Mgi Id | MGI:3712579 | Doi | 10.1126/science.1141915 |
Citation | Murata S, et al. (2007) Regulation of CD8+ T cell development by thymus-specific proteasomes. Science 316(5829):1349-53 |
abstractText | Proteasomes are responsible for generating peptides presented by the class I major histocompatibility complex (MHC) molecules of the immune system. Here, we report the identification of a previously unrecognized catalytic subunit called beta5t. beta5t is expressed exclusively in cortical thymic epithelial cells, which are responsible for the positive selection of developing thymocytes. Although the chymotrypsin-like activity of proteasomes is considered to be important for the production of peptides with high affinities for MHC class I clefts, incorporation of beta5t into proteasomes in place of beta5 or beta5i selectively reduces this activity. We also found that beta5t-deficient mice displayed defective development of CD8(+) T cells in the thymus. Our results suggest a key role for beta5t in generating the MHC class I-restricted CD8(+) T cell repertoire during thymic selection. |