The frequency and chemokine receptors expression profile of FoxP3-expressing CD4+CD25+ regulatory T cells in SF and peripheral blood (PB) from RA patients and PB from healthy controls were investigated by flow cytometry using three- or four-colour intracellular staining.
The present genetic and serologic data suggest that inherited altered genetic constitution at the IL2RA locus may predispose to a less destructive course of RA.
The present study provides the first evidence of increased CD25(-)FOXP3(+) cells in RA patients, which were associated with disease activity and with GC treatment in carriers of the high IL-10 genotype, suggesting that this population plays a role in the clinical response to prednisone in RA.
We observed an accumulation of rare nonsynonymous variants exclusive to RA cases in IL2RA and IL2RB (burden test: p = 0.007 and p = 0.018, respectively).
We observed an increased expression of full-length FoxP3 mRNA in RA patients when compared to healthy controls, as well as an increase in CD25 mRNA expression, but no corresponding increase in CTLA-4 mRNA expression.
Within the CD4 T lymphocytes subset we found that the CD45RO- (naive) cells selectively in RA displayed higher levels of CD25 protein and of interferon-gamma mRNA expression when compared with the respective subset of all other investigated groups.