ALTERATION IN THE CYTOKINE SECRETION PATTERN IN T CELLS OF PATIENTS WITH CYSTIC FIBROSIS CAUSED BY DNA METHYLTRANSFERASE INHIBITOR 5-AZACITIDINE

Cystic fibrosis (CF) is the autosomal-recessive disorder caused by mutation in the cystic fibrosis transmembrane conductance regulator gene (CFTR). The Airway inflammation plays a central role in the progression of CF disease. Cystic fibrosis characterized by the overproduction of the pro-inflammatory cytokines and reduced expression of anti-inflammatory cytokines. Although the mechanisms of abnormal cytokine expression is still poorly understood, altered epigenetic regulations in T cells might contribute. In the present study we examined the expression of IFN-γ and IL-10 by CF T cells prior to and following 5-azaC treatment. In addition we investigated DNMTs levels in nuclear extracts of CD4+ T cells derived from CF and non-CF individuals. Seven CF patients (age: 5-12 years) were included in the study and compared to six age-matched healthy subjects (age: 6- 13 years). CD4+ T cells were isolated from PBMC using CD4 MicroBead kit (Miltenyi Biotec GmbH) and were cultured in RPMI 1640 medium at 37°C with 5% CO2, in presence or absence of 5-azacytidine. Concentrations of IL-10 and γ-INF in CD4+ T Cells were measured by ELISA (eBoiscience, san Diego, CA, USA). In our study we showed that 5 Azacytidine alters nuclear levels of DNMT 3a as well as modulates cytokine levels in CD4+ T cells derived from CF patients. After 5-azaC treatment secretion of IFN-γ was significantly decreased in CF T cells, while amount of IL-10 was elevated by ~2.5 times compared to untreated controls (P<0.05). In summary, data presented in this report demonstrates that epigenetic mechanisms such as DNA methylation may be considered as a one of the potential therapeutic target in a treatment of Cystic Fibrosis.

N-methyl-D-aspartate and sigma-ligands change the production of interleukins 8 and 10 in lymphocytes through modulation of the NMDA glutamate receptor

Human T lymphocytes express both ionotropic and metabotropic glutamate receptors that control immune responses, cell activation, maturation and death. In this study, we examined the effect of N-methyl-D-aspartate (NMDA) and sigma1-receptor ligands on the secretion of the proinflammatory chemokine interleukin 8 (IL-8) and the anti-inflammatory cytokine interleukin 10 (IL-10) in human leukemia Jurkat cells and peripheral blood lymphocytes (PBLs). We have shown that NMDA increased IL-8 and decreased IL-10 secretion and that sigma-ligands modulated the action of NMDA. Moreover, the effects of NMDA and sigma-ligands were interrelated with the nitric oxide (NO) content, suggesting that the intracellular concentration of NO could play a major role in the synthesis of cytokines. Western blots against the NR2A and NR2B subunits of the NMDA glutamate receptor revealed that long-term (48 h) treatment of PBLs with glutamate at concentrations within normal plasma levels (1 x 10(-5)M), in contrast to low concentrations (0.3 x 10(-6)M), downregulates the NR2A subunit, probably by internalization. Furthermore, we found that PBLs with noninternalized NR2A secreted less IL-10 than lymphocytes with downregulated NR2A; under these conditions, the transcriptional activity of NF-kappaB was increased whereas the transcriptional activity of c-Fos was decreased. These findings implicate that the activities of NF-kappaB and c-Fos control the expression of the IL8 and IL10 genes, depending on the subunit composition of the NMDA receptor. In conclusion, we suggest that lymphocytes express an active NMDA receptor only in a low-glutamate milieu.

Glutamate decreases the secretion of IL-10 by peripheral blood lymphocytes in persons with autoimmune thyroiditis

Human T lymphocytes expose ionotropic and metabotropic glutamate receptors, which control immune responses, cell activation, maturation, and death. Several cytokines release during inflammation which identification may have important physiological and clinical implications. Main biological function of IL-10 is limitation and termination of inflammatory responses and the regulation of differentiation and proliferation of several immune cells. Various inflammatory molecules regulated the secretion of IL-8 and IL-10, but the action of glutamate on the biosynthesis of cytokines is unknown. We have found that in peripheral blood lymphocytes glutamate at the concentrations within normal plasma levels (1 x 10(-5) M), as well as at lower concentration (0.3 x 10(-6) M) changes the secretion of immunosuppressive cytokine IL-10, whereas synthesis of proinflammatory chemokine, IL-8 did not changed significantly. Moreover, our results have shown that peripheral blood lymphocytes from patients with autoimmune thyroiditis release less IL-10 at both concentration of glutamate than peripheral blood lymphocytes from healthy persons. These data suggest that glutamate decrease the secretion of IL-10 by peripheral blood lymphocytes, especially in patients with autoimmune thyroiditis that may be responsible for prolongation of inflammation.