| First Author | Palmowski MJ | Year | 2006 |
| Journal | J Immunol | Volume | 177 |
| Issue | 2 | Pages | 983-90 |
| PubMed ID | 16818754 | Mgi Jnum | J:134948 |
| Mgi Id | MGI:3790141 | Doi | 10.4049/jimmunol.177.2.983 |
| Citation | Palmowski MJ, et al. (2006) Role of immunoproteasomes in cross-presentation. J Immunol 177(2):983-90 |
| abstractText | The evidence that proteasomes are involved in the processing of cross-presented proteins is indirect and based on the in vitro use of proteasome inhibitors. It remains, therefore, unclear whether cross-presentation of MHC class I peptide epitopes can occur entirely within phagolysosomes or whether it requires proteasome degradation. To address this question, we studied in vivo cross-presentation of an immunoproteasome-dependent epitope. First, we demonstrated that generation of the immunodominant HY Uty(246-254) epitope is LMP7 dependent, resulting in the lack of rejection of male LMP7-deficient (LMP7(-/-)) skin grafts by female LMP7(-/-) mice. Second, we ruled out an altered Uty(246-254)-specific T cell repertoire in LMP7(-/-) female mice and demonstrated efficient Uty(246-254) presentation by re-expressing LMP7 in male LMP7(-/-) cells. Finally, we observed that LMP7 expression significantly enhanced cross-priming of Uty(246-254)-specific T cells in vivo. The observations that male skin grafts are not rejected by LMP7(-/-) female mice and that presentation of a proteasome-dependent peptide is not efficiently rescued by alternative cross-presentation pathways provide strong evidence that proteasomes play an important role in cross-priming events. |
