First Author | Yamanouchi J | Year | 2003 |
Journal | J Immunol | Volume | 171 |
Issue | 12 | Pages | 6900-9 |
PubMed ID | 14662897 | Mgi Jnum | J:86928 |
Mgi Id | MGI:2682472 | Doi | 10.4049/jimmunol.171.12.6900 |
Citation | Yamanouchi J, et al. (2003) Cross-priming of diabetogenic T cells dissociated from CTL-induced shedding of beta cell autoantigens. J Immunol 171(12):6900-9 |
abstractText | Cross-presentation of self Ags by APCs is key to the initiation of organ-specific autoimmunity. As MHC class I molecules are essential for the initiation of diabetes in nonobese diabetic (NOD) mice, we sought to determine whether the initial insult that allows cross-presentation of beta cell autoantigens in diabetes is caused by cognate interactions between naive CD8(+) T cells and beta cells. Naive splenic CD8(+) T cells from transgenic NOD mice expressing a diabetogenic TCR killed peptide-pulsed targets in the absence of APCs. To ascertain the role of CD8(+) T cell-induced beta cell lysis in the initiation of diabetes, we expressed a rat insulin promoter (RIP)-driven adenovirus E19 transgene in NOD mice. RIP-E19 expression inhibited MHC class I transport exclusively in beta cells and rendered these cells resistant to lysis by CD8(+) (but not CD4(+)) T cells, both in vitro and in vivo. Surprisingly, RIP-E19 expression impaired the accumulation of CD8(+) T cells in islets and delayed the onset of islet inflammation, without affecting the timing or magnitude of T cell cross-priming in the pancreatic lymph nodes, which is the earliest known event in diabetogenesis. These results suggest that access of beta cell autoantigens to the cross-presentation pathway in diabetes is T cell independent, and reveal a previously unrecognized function of MHC class I molecules on target cells in autoimmunity: local retention of disease-initiating clonotypes. |