Y excessive apoptotic activity with autoimmune assault in the bone marrow whereas the latter involves decreased apoptotic indices and dramatic suppression of host anti-tumor responses, giving dysplastic cells the growth potential to progress into acute myeloid leukemia [22,23]. In our present study, increased Th17 cells have been advocated in E-MDS in a pattern reminiscent of autoimmunity, backed up by an analogous result from Mufti’s group [7]. Different from previous report [20], we found elevated RORC mRNA expression level in peripheral blood of E-MDS patients compared with normal CASIN controls and L-MDS patients, suggesting that the differentiation of Th17 cells takes part in E-MDS pathophysiology specifically. 23727046 In our present study, no significant difference of IL-17 concentration whether in the BM or PB among E-MDS patients, L-MDS patients, or healthy controls was found.Th22 and Th17 Cells in Different Stages of MDSFigure 4. The ratio of RORC, IL-6, TNF-a, IL-23 mRNA in healthy controls and MDS patients. (A) The ratio of RORC mRNA in E-MDS patients compared with that of healthy controls or L-MDS was 4.7 (*P = 0.0007) or 3.3 (*P = 0.002), respectively. (B) The ratio of IL-6 mRNA in L-MDS patients compared with that of healthy controls or E-MDS was 5.3 (*P = 0.0001) or 2.4 (*P = 0.037), respectively. (C) The ratio of TNF-a mRNA in L-MDS patients compared with that of healthy controls or E-MDS was 10.6 (*P = 0.002) or 3.5 (*P = 0.049), respectively. (D) IL-23p19 mRNA expression level among EMDS, L-MDS and healthy controls was comparable (P.0.05). Bars represent SD. doi:10.1371/journal.pone.0051339.gAlthough IL-23 signaling is dispensable for Th17 commitment, it induces IL-17 production as one of the essential cofactors [24]. Our present study regarding IL-23 mRNA expression level did not show the difference between E-MDS, L-MDS and controls. Along with previous studies regarding the serum level of IL-23 [7], we speculate that the unaltered IL-17 level vs. elevated Th17 cells in E-MDS attributes to IL-23 insufficiency. In our study, there existed a positive correlation between peripheral Th22 and Th17 subset in E-MDS patients, implying that differentiation of Th22 and Th17 cells may be induced in an influential manner in E-MDS. Co-existence of Th22 and Th17 cells along with 1317923 pro-inflammatory cytokines leads to a dramatic increase in the overexuberant inflammatory immune reaction [8]. Such functional synergism may happen in the persistent low-level inflammatory state of E-MDS in which elevated levels of proapoptotic cytokines, low regulatory T-cells (Tregs) MedChemExpress ML-281 number and increased natural killer (NK) cytotoxicity against hematopoiesis arewidely recognized features [25,26,27]. On the other hand, LMDS, a disease stage progressing towards AML with additional genetic lesions, is characterized by increased numbers of Tregs [28], dysfunctional NK cells [29] and higher immunoinhibitory molecule B7-H1 expression on MDS blasts [22], resulting in immune evasion of the malignant clone. Stimulation of IL-6 plus TNF-a could promote Th22-cell differentiation from CD4+ T cells [30]. Both TNF-a and IL-6 have been detected excessively expressed in the sera of patients with high risk MDS [31]. Our data demonstrated that L-MDS patients had increased IL-6 and TNF-a mRNA expression compared with E-MDS patients or normal controls. Thus, it can be concluded that a cell-cytokine milieu within the tumor microenvironment of L-MDS may be suitable for the polarization of T.Y excessive apoptotic activity with autoimmune assault in the bone marrow whereas the latter involves decreased apoptotic indices and dramatic suppression of host anti-tumor responses, giving dysplastic cells the growth potential to progress into acute myeloid leukemia [22,23]. In our present study, increased Th17 cells have been advocated in E-MDS in a pattern reminiscent of autoimmunity, backed up by an analogous result from Mufti’s group [7]. Different from previous report [20], we found elevated RORC mRNA expression level in peripheral blood of E-MDS patients compared with normal controls and L-MDS patients, suggesting that the differentiation of Th17 cells takes part in E-MDS pathophysiology specifically. 23727046 In our present study, no significant difference of IL-17 concentration whether in the BM or PB among E-MDS patients, L-MDS patients, or healthy controls was found.Th22 and Th17 Cells in Different Stages of MDSFigure 4. The ratio of RORC, IL-6, TNF-a, IL-23 mRNA in healthy controls and MDS patients. (A) The ratio of RORC mRNA in E-MDS patients compared with that of healthy controls or L-MDS was 4.7 (*P = 0.0007) or 3.3 (*P = 0.002), respectively. (B) The ratio of IL-6 mRNA in L-MDS patients compared with that of healthy controls or E-MDS was 5.3 (*P = 0.0001) or 2.4 (*P = 0.037), respectively. (C) The ratio of TNF-a mRNA in L-MDS patients compared with that of healthy controls or E-MDS was 10.6 (*P = 0.002) or 3.5 (*P = 0.049), respectively. (D) IL-23p19 mRNA expression level among EMDS, L-MDS and healthy controls was comparable (P.0.05). Bars represent SD. doi:10.1371/journal.pone.0051339.gAlthough IL-23 signaling is dispensable for Th17 commitment, it induces IL-17 production as one of the essential cofactors [24]. Our present study regarding IL-23 mRNA expression level did not show the difference between E-MDS, L-MDS and controls. Along with previous studies regarding the serum level of IL-23 [7], we speculate that the unaltered IL-17 level vs. elevated Th17 cells in E-MDS attributes to IL-23 insufficiency. In our study, there existed a positive correlation between peripheral Th22 and Th17 subset in E-MDS patients, implying that differentiation of Th22 and Th17 cells may be induced in an influential manner in E-MDS. Co-existence of Th22 and Th17 cells along with 1317923 pro-inflammatory cytokines leads to a dramatic increase in the overexuberant inflammatory immune reaction [8]. Such functional synergism may happen in the persistent low-level inflammatory state of E-MDS in which elevated levels of proapoptotic cytokines, low regulatory T-cells (Tregs) number and increased natural killer (NK) cytotoxicity against hematopoiesis arewidely recognized features [25,26,27]. On the other hand, LMDS, a disease stage progressing towards AML with additional genetic lesions, is characterized by increased numbers of Tregs [28], dysfunctional NK cells [29] and higher immunoinhibitory molecule B7-H1 expression on MDS blasts [22], resulting in immune evasion of the malignant clone. Stimulation of IL-6 plus TNF-a could promote Th22-cell differentiation from CD4+ T cells [30]. Both TNF-a and IL-6 have been detected excessively expressed in the sera of patients with high risk MDS [31]. Our data demonstrated that L-MDS patients had increased IL-6 and TNF-a mRNA expression compared with E-MDS patients or normal controls. Thus, it can be concluded that a cell-cytokine milieu within the tumor microenvironment of L-MDS may be suitable for the polarization of T.
