It is possible that granzymes A and B show discordant expression in T regulatory cells [44]. The relative expression of perforin 1, the second element of perforin/granzyme

cytotoxic pathway, was not altered when compared to control group. Suppressors of cytokine signalling MG-132 clinical trial (SOCS) are involved in the balance of pro- and anti-inflammatory cytokine response. SOCS2 belongs to the FoxP3-dependent, Treg-specific molecules [45]. Our observations showed reduced mRNA expression of SOCS-2 and no change in SOCS-3 in Tregs separated from children with MS when compared to healthy subjects. There is some evidence that transcription factor FoxP3 can negatively regulate levels of SOCS-3 [46]. Interestingly, in contrast to our results, SOCS-2 expression was up-regulated in T cells separated

from peripheral blood of patients with rheumatoid arthritis and down-regulated in PBMC during anti-TNF-alpha treatment [47, 48]. The relation between master regulator of Tregs, FoxP3 and other transcription factors and cytokines at molecular level is complex and poorly understood. Some recent data demonstrated that STAT-1-activating cytokines IL-27 and IFN-γ influenced the FoxP3 expression induced by TGF-β [49]. The clinical significance of this finding is yet to be elucidated. Recently, it has been shown that IL-27 through the transcription factor c-Maf, IL-21 production and ICOS stimulation as an autocrine loop induce IL-10-producing T regulatory type 1 cells [50]. This co-operation seems Selumetinib datasheet to explain Doxorubicin datasheet some of the complex relations between pro-/anti-inflammatory cytokines and transcription factors. Laboratory conditions similar to ours were used by Torcia et al. [21] in an experiment conducted in Fulani, an ethnic group with low susceptibility to malaria. The gene expression

analysis of Tregs (in this case CD4+CD25+ cells) showed very interesting results, some of which are in accordance to our observations. The expression of TGF-β1, CTLA-4 and SOCS2 in Tregs was lower in Fulani when compared to Mossi and European donors, IL-10 expression was not altered. However, these authors noted also lower FoxP3 mRNA levels in Fulani in comparison with other assessed populations. This suggests an early block in the Treg differentiation process driven by TGF-β. Furthermore, Fulani had lower TGF-β1 and no changes in IL-10 serum levels. This functional deficit of Tregs suggests the higher immune reactivity in Fulani, resulting in higher resistance to Plasmodium falciparum infection. The pathophysiological association between adipose tissue-derived cytokines and the promotion of atherosclerosis is well established but the role of T regulatory cells, which should hamper the self-destructive inflammation, remains to be determined (discussed in [51]). An important outcome of our study is that T regulatory cells in children with MS have some disturbances in gene expression which can contribute to immune imbalance in this group of patients.