TIM3/CEACAM1 pathway involves in myeloid-derived suppressor cells induced CD8+ T cells exhaustion and bone marrow inflammatory microenvironment in myelodysplastic syndrome.

Myeloid-derived suppressor cells (MDSC) induced cellular immune deficiency and bone marrow inflammatory microenvironment play an important role in the pathogenesis and progression of myelodysplastic syndrome (MDS), but the underlying mechanism remains unclear. Here, we revealed that immune checkpoint protein TIM3 and CEACAM1 were highly demonstrated on MDSC and CD8+ T cells in MDS patients. CD8+ T cells were reduced in number and function and presented a exhaustion state. The levels of pro-inflammatory cytokines (IL-1ß, IL-18) and CEACAM1 were raised in bone marrow supernatants and MDSC culture supernatants. Blocking or neutralizing TIM3/CEACAM1 and IL-1ß/IL-18 partially reversed exhaustion of CD8+ T cells. Moreover, TIM3 correlated with NF-κB /NLRP3 inflammatory pathway. The levels of NF-κB/NLRP3/Caspase-1/IL-1ß and IL-18 were all increased in MDSC of MDS. Co-culturing MDSC from MDS patients with rhCEACAM1 enhanced NF-κB/NLRP3/Caspase-1/IL-1ß and IL-18 levels, whereas blocking TIM3 could partially reverse the above manifestations. These results indicated that TIM3/CEACAM1 pathway involved in CD8+ T cells exhaustion and might activate the NF-κB/NLRP3/Caspase-1 pathway in MDSC, increasing pro-inflammatory cytokines secretion in MDS bone marrow microenvironment. This study provided a basis for applying immune checkpoint inhibitors that could simultaneously modulate pro-inflammatory cytokine secretion and enhance anti-tumour immune function in the treatment of MDS.

1-deoxysphingolipids bind to COUP-TF to modulate lymphatic and cardiac cell development.

Identification of physiological modulators of nuclear hormone receptor (NHR) activity is paramount for understanding the link between metabolism and transcriptional networks that orchestrate development and cellular physiology. Using libraries of metabolic enzymes alongside their substrates and products, we identify 1-deoxysphingosines as modulators of the activity of NR2F1 and 2 (COUP-TFs), which are orphan NHRs that are critical for development of the nervous system, heart, veins, and lymphatic vessels. We show that these non-canonical alanine-based sphingolipids bind to the NR2F1/2 ligand-binding domains (LBDs) and modulate their transcriptional activity in cell-based assays at physiological concentrations. Furthermore, inhibition of sphingolipid biosynthesis phenocopies NR2F1/2 deficiency in endothelium and cardiomyocytes, and increases in 1-deoxysphingosine levels activate NR2F1/2-dependent differentiation programs. Our findings suggest that 1-deoxysphingosines are physiological regulators of NR2F1/2-mediated transcription.

Upregulated expression of leukocyte immunoglobulin-like receptor A3 in patients with severe aplastic anemia.

Severe aplastic anemia (SAA) is a rare and potentially life-threatening disease characterized by pancytopenia and bone marrow (BM) hypoplasia. In a previous study by our group, increased expression of leukocyte immunoglobulin-like receptors A (LILRA), LILRA3 in myeloid dendritic cells (mDCs) and LILRA5 in CD34+ cells in SAA was detected using proteomics techniques, highlighting their potential role in disease pathogenesis. In the present study, the expression of LILRA1-6 mRNA was assessed in the BM mononuclear cells of patients with SAA using reverse transcription-quantitative (RT-q)PCR. The expression of homogenic LILRA3 and LILRA5 isoform on mDCs, as well as CD34+, CD3+CD8+, CD19+ and CD14+ cells, was detected using flow cytometry. mDCs were then induced, cultured and sorted. The expression of LILRA3 was confirmed using RT-qPCR and western blot analyses. The serum levels of soluble LILRA3 were measured using ELISA. Furthermore, the relationship between LILRA3 expression and disease severity was assessed. The results indicated increased LILRA3 mRNA expression in patients with SAA. The percentage of LILRA3+ in BM mDCs and CD34+ cells was increased. Compared with controls, the relative LILRA3 mRNA expression and the relative protein intensity were highly increased in SAA mDCs. The serum LILRA3 levels in patients with SAA were also increased. The proportion of LILRA3+CD11C+ human leukocyte antigen (HLA)-DR+/CD11C+HLA-DR+ cells was positively correlated with the ratio of LILRA3+CD34+/CD34+ cells and the expression of LILRA3 mRNA. Taken together, the expression of LILRA3 on mDCs of patients with SAA was increased, which may affect the function of mDCs. LILRA3 may have a significant role in the immune pathogenesis of SAA.

[Expression and Significance of IL-9 and IL-6 in Patients with BCR-ABL- MPN].

OBJECTIVE: To investigate the expression of IL-9 and IL-6 in patients with BCR-ABL- bone marrow proli- ferative tumor (MPN), and to explore its role in the occurrence and development of MPN. METHODS: A total of 71 newly diagnosis MPN patients treated in Tianjin Medical University General Hospital from 2018 to 2019 were selected, including 32 patients with polycythemia vera (PV) and 22 patients with primary thrombocytosis (ET), and 17 patients with primary myelofibrosis (PMF). Then 58 patients who retestine after treatment were selected as therapy group，and 20 healthy volunteers were recruited as control group. ELISA was used to detect the expression level of IL-6 and IL-9 in bone marrow supernatant, and the relative expression level of IL-6 and IL-9 mRNA in BMMNC was detected by real-time PCR. The proportion of Th9 cells in peripheral blood were detected by flow cytometry (FCM). The expression level of IL-6 mRNA and IL-9 mRNA of BMMNC and clinical indicators were analyzed, and the correlation between JAK2 gene mutation load and IL-9 level was further analyzed. RESULT: The level of IL-6 in bone marrow supernatant and the expression of IL-6 mRNA in BMMNC were higher in the newly diagnosed group as compared with those in the treated group and the control group (P<0.001). The expression level of IL-9 in bone marrow supernatant and the expression of IL-9 mRNA in BMMNC were lower in the newly diagnosed group as compared with those in the treated group and the control group (P<0.05). The proportion of Th9 cells in peripheral blood was lower in the newly diagnosed group as compared with that in the treated group and the control group (P<0.001). The level of IL-6 in bone marrow supernatant and the expression of IL-6 mRNA in BMMNC in JAK2+ group were higher than those in JAK2- group (P<0.05). The expression level of IL-9 in bone marrow supernatant and the expression of IL-9 mRNA in BMMNC were lower in JAK2+ group as compared with those in JAK2- group (P<0.05). The expression of IL-6 and IL-9 in the patient group showed correlation with the number of lymphocytes (IL-6: r=-0.49, P<0.01; IL-9: r=0.53, P<0.001), and also related with Hb in PV patients (IL-6: r= 0.87, P<0.001; IL-9: r=-0.54, P<0.01), and platelets in ET patients (IL-6: r=0.64, P<0.05; IL-9: r=-0.46, P<0.05). CONCLUSION: The increased expression of IL-6 in MPN and hyperfunction may promote the progression of BCR-ABL- MPN disease. The expression of IL-9 in MPN decreases, and it negatively correlates with the mutation load of JAK2 gene, which may be related with the decrease of tumor environmental antitumor immune effect.

Myeloid-derived suppressor cell cytokine secretion as prognostic factor in myelodysplastic syndromes.

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature myeloid cells that play a critical immunosuppressive role in the tumour micro-environment. Although biological research on MDSCs has made progress, the relationship between the secretion of cytokines by MDSCs and poor prognosis is not clear, and there are no criteria to measure the functional status of MDSCs. Here, we detected the mRNA expression of IL-10, IL-12, TGF-ß and TNF-α in MDSCs and the levels of these cytokines in MDSC culture supernatants of patients with myelodysplastic syndromes, and quantified the functional status of MDSCs by IL-10/IL-12 ratio and TGF-ß/TNF-α ratio. We found that the ratio of IL-10/IL-12 and TGF-ß/TNF-α was significantly higher in higher-risk MDS than in lower-risk MDS and normal control groups. The TGF-ß/TNF-α ratio in MDSCs was positively correlated with the percentage of blast cells and was negatively correlated with the percentage of CD3+CD8+ T lymphocytes. Meanwhile, the TGF-ß/TNF-α ratio was higher in patients with a lower absolute neutrophil count. It suggested that MDSCs in higher-risk MDS have a stronger immunosuppressive effect and might be related to poor prognosis. Quantifying the functional status of MDSCs with IL-10/IL-12 and TGF-ß/TNF-α ratio might help to evaluate the balance of cellular immunity of MDSCs in MDS.

CD8+ T cells exhaustion induced by myeloid-derived suppressor cells in myelodysplastic syndromes patients might be through TIM3/Gal-9 pathway.

CD8+ T cells play a central role in antitumour immunity, which often exhibit 'exhaustion' in the setting of malignancy and chronic viral infection due to T cell immunoglobulin and mucin domain 3 (TIM3) and myeloid-derived suppressor cells (MDSCs). Our team previously found that overactive MDSCs and exhausted TIM3+ CD8+ T cells were observed in myelodysplastic syndromes (MDS) patients. However, it is not obvious whether MDSCs suppress CD8+ T cells through TIM3/Gal-9 pathway. Here, Gal-9, as the ligand of TIM3, was overexpressed in MDSCs. The levels of Gal-9 in bone marrow supernatants, serum and culture supernatants of MDSCs from MDS patients were elevated. CD8+ T cells from MDS or normal controls produced less perforin and granzyme B and exhibited increased early apoptosis after co-culture with MDSCs from MDS. Meanwhile, the cytokines produced by CD8+ T cells could be partially restored by TIM3/Gal-9 pathway inhibitors. Furthermore, CD8+ T cells produced less perforin and granzyme B after co-culture with excess exogenous Gal-9, and the function of CD8+ T cells was similarly restored by TIM3/Gal-9 pathway inhibitors. Expression of Notch1, EOMES (associated with perforin and granzyme B secretion), p-mTOR and p-AKT (associated with cell proliferation) was decreased in CD8+ T cells from MDS after co-culture with excess exogenous Gal-9. These suggested that MDSCs might be the donor of Gal-9, and TIM3/Gal-9 pathway might be involved in CD8+ T cells exhaustion in MDS, and that TIM3/Gal-9 pathway inhibitor might be the promising candidate for target therapy of MDS in the future.

Elevated TIM3 expression of T helper cells affects immune system in patients with myelodysplastic syndrome.

T cell immunoglobulin and mucin domain 3 (TIM3) expression is associated with immunosuppression and clinical outcomes in many diseases. However, the specific mechanism of TIM3 in immune system has not been clarified. In order to illustrate the mechanism of TIM3 in immune system, we analyzed the expression, function and regulation of TIM3 in T helper (Th)1 cells, Th2 cells, Th17 cells and regulatory T cells (Treg) through flow cytometry in patients with myelodysplastic syndrom (MDS). Our data showed elevated proportion of Th2 and Treg cells, while the proportion of Th1 and Th17 cells decreased in patients with MDS (p<0.05) and the expression of TIM3 increased in Th1, Th17 and Treg cells in patients with MDS when compared with expression in control patients (p<0.05). The secretion of transforming growth factor-ß in TIM3+Treg cells decreased in patients with MDS. These findings suggested that TIM3 might affect immune helper systems by regulating Treg cells and related immune cells. Therefore, studying the role of the TIM3 pathway in MDS is necessary and may help to provide a new way to explore the pathogenesis and treatments of MDS.

[Relationship of Peripheral Blood IL-37 Expression with T Lymphocytes Subsets and NK Cells in Patients with Primary Immune Thrombocytopenia].

OBJECTIVE: To study the correlation of IL-37 with T lymphocytes subsets and NK cells in ITP patients, and to explore its possible mechanisms involved in the pathogenesis of ITP. METHODS: Forty-five patients with newly diagnosed ITP(newly diagnosed group), 32 patients of complete remission (remission group) and 22 healthy persons(control group) were selected. The serum level of IL-37 in 3 groups was determined by enzyme linked immunosorbent assay (ELISA). The mRNA expression of IL-37, IL-17 and IL-18 in peripheral blood mononuclear cells（PBMNC） in 3 groups was measured by real-time fluorescence quantitative polymerase chain reaction (PCR). The number of IL-18Rα+CD4+ T cells and Tim-3+NK cells in the peripheral blood in 3 groups was detected by flow cytometry (FCM). RESULTS: The serum level of IL-37 in the peripheral blood of ITP patients in the newly diagnosed group was significantly higher than that in the control group and the remission group(P＜0.01) . The expression level of IL-37 in PBMNC of the ITP patients in newly diagnosed group was higher than that in the control group and the remission group(P＜0. 05). The expression level of IL-17 and IL-18 in PBMNC of the ITP patients in newly diagnosed group was higher than that in the control group and the remission group(P＜0. 01); the expression of IL-18Rα in CD4+ T cells in newly diagnosed group was significantly higher than that in both the control and the remission group(P＜0.01).The expression of Tim-3 in NK cells in ITP patients was significantly lower than that in the control group (P＜0. 01). In ITP patients, the serum IL-37 level and IL-18Rα+CD4+T cells ratio both negatively correlated with Plt count (r=-0.58, r=-0.48) moreo-ver the serum IL-37 level also negatively correlated with amount of CD4+ T cells and NK cells (r=-0.29, r=-0.28), but positively correlated with amount of CD8+ T cells (r=0.329). CONCLUSION: The IL-37 and its receptors may play an immunoregulatory role in CD4+ T cells and NK cells, the IL-37 may be a therapeutic target for ITP patients.

Abnormal changes in the quantity and function of osteoblasts cultured in vitro in patients with myelodysplastic syndrome.

Changes in bone marrow niches can lead to the occurrence of myelodysplastic syndrome (MDS). As an important part of the bone marrow niche, osteoblasts serve a key role in the progression of MDS. The present study investigated the quantity and function of osteoblasts and, through in vitro assays, detected changes in signaling pathways and the association with progression in MDS patients. The ratios of osteoprogenitors (CD34+OCN+) and OCN+CD34-Lin- osteoblasts in MDS patients were significantly less than those of normal controls. The results of this study demonstrated that the quantity and activity of osteoblasts in MDS patients were lower than those in normal controls. Furthermore the activity of osteoblasts in patients correlated with the severity of MDS. The quantity of osteoblasts cultured in vitro from high-risk and very high-risk MDS patients (WHO Classification-Based Prognostic Scoring System score 3-6) was decreased. The levels of T-cell immunoglobulin and mucin domain-containing 3 (TIM3) and Jagged 1 were also increased in the osteoblasts in vitro. These results indicated that osteoblasts are abnormally altered in MDS patients, and that there are associations between abnormal changes of osteoblasts and the severity of MDS.

[Number and Function of Myeloid-Derived Suppressor Cells in Patients with Adult Primary Immune Thrombocytopenia].

OBJECTIVE: To analyze the number of myeloid-derived suppressor cells(MDSC) and the level of prostaglandin E2(PGE2) in the bone marrow of adult ITP patients, and to explore their possible mechanisms involved in the pathogenesis of this disease. METHODS: Twenty-five patients of newly diagnosed ITP, 25 patients of complete remission group and 15 patients of control group were selected. The number of MDSC in the bone marrow between 3 groups was detect by flow cytometry (FCM). The serum level of prostaglandin E2 (PGE2) in 3 groups was determined by enzyme linked immunosorbent assay (ELISA). The relative expression of IFN-γ mRNA in bone marrow mononuclear cells was measured by real time fluorescence quantitative polymerase chain reaction (RT-qPCR) in each groups. RESULTS: The number of MDSC in the complete remission group was significantly higher than that in the control group (P<0.05); the number of MDSC in the newly diagnosed group was higher than that in the control group; the number of MDSC in the complete remission group was higher than that in the newly diagnosed group. The serum level of PGE2 in bone marrow of ITP patients in the newly diagnosed group was higher than that of the control group（P<0.05）. The serum level of PGE2 in the bone marrow of ITP patients of the complete remission group was higher than that of the control group (P<0.05）. The level of PGE2 in bone marrow serum of ITP patients of the newly diagnosed group was lower than that in the complete remission group(P<0.05）. The relative expression level of IFN-gamma in bone marrow mononuclear cells of the ITP patients in newly diagnosed group was higher than that in the control group and the complete remission group（P<0.001）. The relative quantification (RQ) of IFN-γ in bone marrow mononuclear cells was 2.60 between the newly diagnosed group and the complete remission group. CONCLUSION: When adult ITP disease is remitted, the number of MDSC rises and correlates with the therapeutic response and PGE2 level in the bone marrow.

Abnormal CD25 expression on hematopoietic cells in myelodysplastic syndromes.

OBJECTIVE: To investigate the frequencies and biological characteristics of CD25 positive hematopoietic stem cells (HSC) in myelodysplastic syndromes. METHODS: The expression of CD25 on HSC in bone marrow derived from patients with untreated MDS patients, untreated AML patients and normal controls were accessed by flow cytometry (FCM). The correlation analysis was done between CD25+ HSC and clinical parameters in MDS patients. RESULTS: The expression of CD25 on HSC (CD34+CD38- cells) in MDS patients (28.81%) was significantly higher than that in normal controls (9.41%, P = 0.020), which similar to that in AML patients (32.54%, P = 0.410). The CD25 expression on HSC was positively correlated with the CD123 expression on HSC (r = 0.602, P = 0.008). The expression of CD25 on HSC in high-risk MDS group (53.27%) based on IPSS score was significantly higher than that in low-risk MDS group (18.66%, P = 0.003). In MDS patients, CD25+ HSC were negatively correlated with the counts of neutrophils (r = -0.684, P = 0.002) and platelets (r = -0.561, P = 0.015), while positively correlated with the percentage of blasts in bone marrow (r = 0.596, P = 0.009). The CD25 expression on erythroblasts had a significant positive correlation with red blood cell counts in MDS patients (r = 0.536, P = 0.012). CONCLUSIONS: CD25 was over-expressed on HSC in MDS patients, especially in high-risk MDS patients. Increased CD25+ HSC was correlated with progression of MDS. Low-expression of CD25 on erythroblasts might correlate with anemia in MDS patients. CD25 could be a specific marker of LSC in MDS, and could involve in the mechanisms of development and progression of MDS.

Increased TIM3+CD8+T cells in Myelodysplastic Syndrome patients displayed less perforin and granzyme B secretion and higher CD95 expression.

T cell immunoglobulin and mucin domain 3(TIM3) is a negative regulator of cellular immunity and it is highly expressed on CD8+T cells in persistent viral infection and cancer setting as report. However, how TIM3 expressed on CD8+T cells in myelodysplastic syndrome (MDS), that is a malignant disorder, has not been clarified. Here, decreased CD8+T cells, less IFN-γ secretion in CD8+T cells and increased TIM3 on CD8+T cells had been seen. Increased TIM3+CD8+T cells with lower perforin and granzyme B expression and higher CD95 expression in MDS patients had been observed. These findings suggested that TIM3 might be related to CD8+T cells defect. Therefore, further explorations about mechanism of TIM3+CD8+T cells defect are needed, which might be helpful for adoptive T-cell therapy in MDS.

Th17 Cells Exhibit Antitumor Effects in MDS Possibly through Augmenting Functions of CD8+ T Cells.

Th17 cells are a newly found subset of distinct CD4+ Th effector cells' family and are found to play an important role in cancers. Myelodysplastic syndromes (MDS) are a common malignant hematological disease. Here, we showed that both the percentage and the function of Th17 cells were elevated in low-risk MDS while being decreased in high-risk MDS. Levels of upstream molecules of Th17 cells, IL-6 and IL-23, were higher in low-risk MDS but lower in high-risk MDS patients. The abnormal percentage of Th17 cells was closely related to clinical parameters including karyotype, morphologic blast percentage of bone marrow, peripheral absolute neutrophil count, and hemoglobin concentration. Furthermore, expression rates of perforin and granzyme B in BM CD3+CD8+ cells (cytotoxic T lymphocyte, CTL) positively correlated with levels of IL-17 but negatively correlated with BM blast percentage and could be significantly increased after stimulation with human recombinant IL-17 (rhIL-17). Our results suggested that Th17 cells might play an antitumor effect in the pathogenesis of MDS through IL-17/CTL pathway.

[Expression and Significance of HOXA9 in Patients with Myelodysplastic Syndromes].

OBJECTIVE: To investigate the expression pattern of HOXA9 in myelodysplastic syndrome (MDS) patients and its relation with clinical characteristics and treatment response. METHODS: The mRNA and protein expression levels of HOXA9 in bone marrow cells from 33 cases of MDS, 12 cases of AML, 20 cases of ITP and 18 normal controls were detected by real-time guautitative PCR(RT-PCR) and flow cytometry, respectively. RESULTS: The percentage of HOXA9(+)/CD34(+) and HOXA9(+)/CD34(+)CD38(-) in MDS patients were significantly higher than that in control group (P<0.05), and the mRNA and protein expression of HOXA9 in MDS patients had a similar trend. The percentages of HOXA9(+)/CD34(+) and HOXA9(+)/CD34(+)CD38(-) before decitabine treatment were (50.64±27.59)% and (55.67±28.57)% respectively, which were both higher than those in control group (P<0.05). After decitabine treatment, expression of HOXA9 significantly decreased (P<0.05). CONCLUSION: HOXA9 is overexpressed in MDS patients and associated with several clinical characteristics. The detection of HOXA9 expression may have guide roles for diagnosis and treatment of MDS patients.

[Hypomethylation and overexpression of CD70 in CD4+ T cells of the patients with immuno-related pancytopenia].

OBJECTIVE: To study the expression of CD70 and the methylation level of CD70 promoter in immuno-related pancytopenia（IRP）patients, and explore the role of CD70 in the pathogenesis of IRP. METHODS: Thirty- five IRP patients and fifteen healthy donors were enrolled in this study. Peripheral blood mononuclear cells were isolated from venous blood by density gradient centrifugation, and CD4(+) T cells were isolated by immunomagnetic beads. The mRNA level and the percentage of CD70 of CD4(+) T cells were measured by real- time quantitative polymerase chain reaction（RT- PCR）and flow cytometry respectively. Methylation- Specific PCR（MSP）was performed to determine the methylation level of CD70 promoter. RESULTS: The percentage of CD70 expression on CD4(+) T cells of untreated IRP patients［（7.46±1.51）%ï¼½was significantly higher than that of recovered ones［（5.95±1.34）%ï¼½and normal controls［（1.83 ± 0.60）%ï¼½, and that of recovered IRP patients was significantly higher than of normal controls（P<0.05）. The relative expressions of CD70 mRNA in CD4(+) T cells were 2.314（0.200-6.084）, 1.021（0.135-3.434）, 0.353（0.008-2.258）in three groups respectively. The differences among untreated IRP patients, recovered IRP patients and normal controls were significant（P<0.05）. The CD70 promoter methylation level in CD4(+) T cells of all IRP patients was significantly lower than that of normal controls （P<0.05）. The expression of CD70 positively correlated to the ratio of CD5(+) B cells（r=0.533, P<0.01）. CONCLUSION: The overexpression of CD70 may lead to immunologic disarrangement of patients, which may play important role in the pathogenesis of IRP.

[Abnormal DNA methylation in CD4⁺ T cells from patients with immune related pancytopenia: a preliminary study].

OBJECTIVE: To explore the global DNA methylation and the expression of regulatory genes for methylation in CD4⁺ T cells of the patients with immune related pancytopenia (IRP) and explore the role of methylation in the pathogenesis of IRP. METHODS: Thirty IRP patients (untreated, n = 15; remission, n = 15) and 15 healthy donors as controls were enrolled from December 2012 to December 2013. CD4⁺ T cells were sorted by immunomagnetic separation. The global DNA methylation was tested with enzyme-linked immunosorbent assay (ELISA). The mRNA levels of DNA methylation-related regulating genes, DNA methyltransferases (DNMTs) and methylated CpG binding proteins (MBDs), were measured by real-time quantitative-polymerase chain reaction (RT-PCR). RESULTS: The level of global DNA methylation in peripheral blood CD4⁺ T cells of untreated IRP patients (3.525% ± 2.046%) and remission patients (4.790% ± 1.471%) were significantly lower than that of normal controls (10.101% ± 3.449%) respectively (both P < 0.05). DNMT3b mRNA level of untreated IRP patients (1.332 ± 0.785) was significantly lower than that of normal controls (2.077 ± 1.059) in CD4⁺ T cells (P < 0.05). The mRNA expression of MBD2 was significantly higher in CD4⁺ T cells from untreated and remission IRP patients (2.999 ± 1.601, 2.055 ± 1.576) than that in controls (0.581 ± 0.247) (both P < 0.05). The MBD4 mRNA level was significantly higher in CD4⁺ T cells from untreated IRP patients (2.736 ± 2.719) compared to that in normal controls (1.167 ± 1.006) (P < 0.05). DNMT3b mRNA expression and CD4⁺ T cell DNA methylation to be positive correlated within IRP patients (r = 0.569, P < 0.01). The MBD2 mRNA expression was negatively correlated with CD4⁺ T cell DNA methylation and the ratio of Th1/Th2 (r = -0.763, P < 0.01; r = -0.652, P < 0.05) . The global methylation of CD4⁺ T cells negatively related to the ratio of CD5⁺ B cells (r = -0.439, P < 0.05). CONCLUSION: The globe DNA hypomethylation and abnormal expression of DNA methylation-related enzymes in peripheral blood CD4⁺ T cells may be related with the pathogenesis of IRP.

[Association between serum interleukin-17 level and abnormal cellular immunological status in patients with severe aplastic anemia].

OBJECTIVE: To explore the role of interleukin-17 (IL-17) in the pathogenesis of severe aplastic anemia (SAA). METHODS: Peripheral blood samples were obtained from 40 SAA patients (25 untreated, 15 recovery) and 10 normal controls from October 2012 to October 2013. The level of IL-17 in peripheral blood was measured with cytometric bead array (CBA). The correlations between IL-17 and T cells subset (CD4(+)/CD8(+)), dendritic cells (DC) subset (mDC/pDC), regulatory T cells (Treg) and hemogram were analyzed. RESULTS: The serum level of IL-17 in untreated patients was higher than that in recovery patients and normal controls ((17.07 ± 15.18) vs (7.09 ± 3.84) and (3.53 ± 2.08) ng/L, both P < 0.01). Also significant differences existed between the latter two groups (P < 0.05). The ratio of CD4(+)/CD8(+) was (0.32 ± 0.08) in untreated patients and it was lower than that in recovery patients (1.11 ± 0.31, P < 0.01) and normal controls (1.07 ± 0.26, P < 0.01). The ratio of mDC/pDC was (3.16 ± 0.55) in untreated patients was higher than that in recovery patients (1.60 ± 0.43, P < 0.01)and normal controls (1.43 ± 0.38, P < 0.01). The percentage of Tregs in peripheral blood lymphocyte (CD4(+)CD25(+)CD127(dim)/PBL) was 0.80% ± 0.31% in untreated patients and it was lower than that in recovery patients (1.78% ± 0.69%, P < 0.01) and normal controls (2.23% ± 0.66%, P < 0.01). The serum level of IL-17 in untreated SAA patients was related positively with mDC/pDC ratio (r = 0.414, P < 0.05) and negatively with CD4(+)/CD8(+) ratio (r = -0.421, P < 0.05) and CD4(+)CD25(+)CD127(dim)/PBL(r = -0.650, P < 0.01). And significant negative correlations existed between serum IL-17 and white blood cells in untreated patients (r = -0.689, P < 0.01) and recovery patients (r = -0.640, P < 0.05). CONCLUSION: The elevated serum level of IL-17 in SAA is related with the immunological status and disease severity.

[Abnormal quantity of regulatory T cells in peripheral blood of patients with severe aplastic anemia and its clinical significance].

This study was purposed to investigate the role of regulatory T cells (Treg) in the immune unbalance for patients with acquired severe aplastic anemia (SAA). The flow cytometry was used to detect the quantity of CD4(+) CD25(+) CD127(dim) Tregs, T cell subset (CD4(+)/CD8(+) ratio), dendritic cell(DC) subset(mDC/pDC ratio) in 44 SAA patients(25 untreated patients and 19 recovery patients) and 23 normal controls. The correlation between Tregs and T cell subset, DC subset and hemogram were analyzed. The results showed that the percentage of CD4(+) CD25(+) CD127(dim) Tregs in peripheral blood lymphocyte(PBL) of untreated patients was (0.83 ± 0.44) %, which was obviously lower than that in recovery patients (2.91 ± 1.24)% and normal controls (2.18 ± 0.55)% (P < 0.05), but the difference was not statistically significant between latter two groups. The ratio of CD4(+)/CD8(+) was (0.5 ± 0.3) in untreated patients, which was obviously lower than that in recovery patients (1.2 ± 0.4) and normal controls (1.11 ± 0.24) (P < 0.05). The ratio of mDC/pDC was (3.08 ± 0.72) in untreated patients, which was significantly higher than that in recovery patients(1.61 ± 0.49) and normal controls (1.39 ± 0.36) (P < 0.05). The percentage of CD4(+) CD25(+)CD127(dim) Tregs in PBL positively correlated with CD4(+)/CD8(+) ratio (r = 0.695, P < 0.01), and that negatively correlated with mDC/pDC ratio (r = -0.796, P < 0.01). There were significant positive correlations between CD4(+)CD25(+)CD127(dim) Tregs/PBL and WBC, Ret% (r = 0.761, 0.749 respectively, P < 0.01). It is concluded that the decrease of CD4(+)CD25(+)CD127(dim) Tregs quantity in SAA may be one of mechanisms underlying bone marrow failure resulting from the deterioration of immune tolerance and hyperfunction of T-cells.

Elevated TIM3+ hematopoietic stem cells in untreated myelodysplastic syndrome displayed aberrant differentiation, overproliferation and decreased apoptosis.

TIM3, as a negative regulator of anti-tumor immunity, is highly expressed on LSCs, but not on normal HSCs. TIM3 on HSCs in MDS patients has not been clarified. Here, both the percentage of TIM3 on HSCs and the MFI of TIM3+ HSCs were higher in untreated MDS than control and were closed to AML, and excessive TIM3+ HSCs was closely related to clinical parameters: WPSS score, karyotype analysis, morphologic blasts, the number of cytopenia involving hematopoietic lineages, anemia and granulocytopenia. TIM3+ HSCs expressed lower CD11b, TpoR, EpoR, G-CSFR and Annexin V, and higher CD71 and GATA2. TIM3+ HSCs displayed aberrant differentiation, overproliferation and decreased apoptosis. TIM3 might be a promising marker for identifying malignant clone cells in MDS and a candidate for targeted therapy.