The goal of this project is to explore the suppression of autoimmunity in tolerized lupus mice by studying targeted genes differentially expressed by CD8+ inhibitory T cells (Ti) from tolerized mice compared to na?ve littermates. Those CD8+ Ti suppress SLE upon adoptive transfer to young BWF1 mice and they secrete IFNg and TGFb but not IL-10. We have identified a subset of differentially expressed genes in tolerized vs naive splenic T cells using 45,000 murine genes/ESTs of the Affymetrix Gene Chip array 430, 2.0. Gene expression has been studied in whole blood cells, CD4 and CDS cells from the splenocytes of naive and lupus prone BWF1 mice tolerized i.v. with a high dose of synthetic peptide (pConsensus, pCons). Significant increased expression pattern (with real- time RT-PCR validation) of 10 genes in CD8+ T cells from tolerized mice was found and allows us to target selected genes to establish their role in active immune suppression by those cells. In this proposal, we are focusing on three selected genes to study molecular analyses and biological significance. The genes are IFI 202b, bc!2 and FoxpS - all consistently upregulated in CD8+ Ti from tolerized mice. Each gene is known to play a role in cell apoptosis, and each gene influences or is influenced by IFN and/or TGF b. Our strategy is to silence each of the 3 genes both in vitro and in vivo,alone or in combination, in CD8+ Ti, using siRNA, then measure the effect of that silencing on apoptosis and on cytokine production in the CD8+TJ cell itself and in its CD4+ helper T cell target. The overall purpose is to ? understand the molecular mechanisms by which these CD8+ inhibitory T cells suppress autoimmunity; ? results may identify new targets for therapies in SLE patients. ? ? ?
