Distinct gene signature revealed in white blood cells, CD4 and CD8 T cells in (NZBx NZW) F1 lupus mice after tolerization with anti-DNA Ig peptide

Abstract

Tolerizing mice polygenically predisposed to lupus-like disease (NZB/NZW F1 females) with a peptide mimicking anti-DNA IgG sequences containing MHC class I and class II T cell determinants (pConsensus, pCons) results in protection from full-blown disease attributable in part to the induction of CD4+ CD25+ Foxp3+ and CD8+ Foxp3+ regulatory T cells. We compared 45 000 murine genes in total white blood cells (WBC), CD4+ T cells, and CD8+ T cells from splenocytes of (NZBxNZW) F1 lupus-prone mice tolerized with pCons vs untreated nave mice and found two-fold or greater differential expression for 448 WBC, 174 CD4, and 60 CD8 genes. We identified differentially expressed genes that played roles in the immune response and apoptosis. Using real-time PCR, we validated differential expression of selected genes (IFI202B, Bcl2, Foxp3, Trp-53, CCR7 and IFNar1) in the CD8+ T cell microarray and determined expression of selected highly upregulated genes in different immune cell subsets. We also determined Smads expression in different immune cell subsets, including CD4+ T cells and CD8+ T cells, to detect the effects of TGF-Β, known to be the major cytokine that accounts for the suppressive capacity of CD8 + Treg in this system. Silencing of anti-apoptotic gene Bcl2 or interferon genes (IFI202b and IFNar1 in combination) in CD8 T cells from tolerized mice did not affect the expression of the other selected genes. However, silencing of Foxp3 reduced expression of Foxp3, Ifi202b and PD1all of which are involved in the suppressive capacity of CD8+ Treg in this model. © 2010 Macmillan Publishers Limited All rights reserved.