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Background: Myelodysplastic syndrome (MDS) is a complicated hematopoietic malignancy characterized by bone marrow (BM) dysplasia with symptoms like anemia, neutropenia, or thrombocytopenia. MDS exhibits considerable heterogeneity in prognosis, with approximately 30% of patients progressing to acute myeloid leukemia (AML). Single cell RNA-sequencing (scRNA-seq) is a new and powerful technique to profile disease landscapes. However, the current available scRNA-seq datasets for MDS are only focused on CD34 + hematopoietic progenitor cells. We argue that using entire BM cell for MDS studies probably will be more informative for understanding the pathophysiology of MDS., Methods: Five MDS patients and four healthy donors were enrolled in the study. Unsorted cells from BM aspiration were collected for scRNA-seq analysis to profile overall alteration in hematopoiesis., Results: Standard scRNA-seq analysis of unsorted BM cells successfully profiles deficient hematopoiesis in all five MDS patients, with three classified as high-risk and two as low-risk. While no significant increase in mutation burden was observed, high-risk MDS patients exhibited T-cell activation and abnormal myelogenesis at the stages between hematopoietic stem and progenitor cells (HSPC) and granulocyte-macrophage progenitors (GMP). Transcriptional factor analysis on the aberrant myelogenesis suggests that the epigenetic regulator chromatin structural protein-encoding gene HMGA1 is highly activated in the high-risk MDS group and moderately activated in the low-risk MDS group. Perturbation of HMGA1 by CellOracle simulated deficient hematopoiesis in mouse Lineage-negative (Lin - ) BM cells. Projecting MDS and AML cells on a BM cell reference by our newly developed MarcoPolo pipeline intuitively visualizes a connection for myeloid leukemia development and abnormalities of hematopoietic hierarchy, indicating that it is technically feasible to integrate all diseased bone marrow cells on a common reference map even when the size of the cohort reaches to 1,000 patients or more., Conclusion: Through scRNA-seq analysis on unsorted cells from BM aspiration samples of MDS patients, this study systematically profiled the development abnormalities in hematopoiesis, heterogeneity of risk, and T-cell microenvironment at the single cell level., (© 2024. The Author(s).)

Background: Genetic mutations play a crucial role in the development and progression of myelodysplastic syndromes (MDS), impacting the immune microenvironment and influencing the choice of treatment regimen, as well as the efficacy and prognosis of patients. The objective of this study was to examine variations in hematological and immunological characteristics associated with common gene mutations in MDS patients and establish a foundation for the precise treatment of MDS., Methods: The hematological, immunological, and other clinical features of 71 recently diagnosed MDS patients from January 1, 2019, to July 31, 2023, were retrospectively analyzed. These patients were categorized based on their gene mutations, and the variances in hematological and immunological characteristics among distinct groups were compared., Results: Hematological variances were observed among different gene mutation groups. Specifically, platelet counts in the splicing factor 3B subunit 1 ( SF3B1 ) mutation group were notably higher compared to the wild-type group ( p = 0.009). Conversely, in the additional sex combs like 1 ( ASXL1 ) mutation groups, monocyte ratios were significantly elevated in comparison to the wild-type group ( p = 0.046), and in the ten-eleven translocation 2 ( TET2 ) mutation group, lymphocyte ratios were significantly lower ( p = 0.022). Additionally, the leukocyte ( p = 0.005), neutrophil ratio ( p = 0.002), and lymphocyte ratio ( p = 0.001) were significantly higher in the Runt-related transcription factor 1 ( RUNX1 ) mutation group. Regarding immunological distinctions, the Natural Killer (NK) cell ratio demonstrated a significant increase in the SF3B1 mutation group ( p = 0.005). Moreover, the TET2 mutation group exhibited a significantly higher Interleukin-8 (IL-8) level ( p = 0.017). In contrast, the U2 small nuclear RNA auxiliary factor 1 ( U2AF1 ) group displayed significantly lower levels of IL-1β ( p = 0.033), IL-10 ( p = 0.033), and Tumour Necrosis Factor-α (TNF-α) ( p = 0.009)., Conclusion: Distinct variations exist in the immune microenvironment of MDS associated with different genetic mutations. Further studies are imperative to delve into the underlying mechanisms that drive these differences.

Objective: This experiment will explore the role of TIGIT/PVR signaling pathway in the pathogenesis of MDS immune tolerance through in vitro co-culture of NK cells and MDSC cells., Methods: Flow cytometry was used to detect the expression percentage of MDSCs and CD155 on MDSCs in the bone marrow of MDS patients and controls. The expression of NK cell surface receptors (NKG2D, NKp30, NKp46), secreted cytokines (perforin, granzyme B, CD107a, IFN-γ) and NK cell apoptosis rate were detected by flow cytometry to evaluate the effect of MDSCs on NK cell function., Results: The number of MDSCs in bone marrow of MDS patients was notably higher than that of the control group (8.39 ± 7.01 vs 2.31 ± 1.65, P  = 0.0001). Compared with the control group, the expression of CD155 on MDSCs in MDS group was increased (31.81 ± 21.33 vs. 10.49 ± 6.53, P  < 0.0001). After NK cells were co-cultured with MDSCs, NKG2D, NKp30, NKp46, CD107a, IFN-γ, perforin and granzyme B were decreased, and the NK function partially recovered after the addition of inhibitors., Conclusion: Compared with the normal control, MDSCs and CD155 on MDSCs were highly expressed in MDS patients. After co-culture with MDSCs, the expression of NK cells' surface receptors decreased, the secretion of cytokines decreased and the apoptosis rate increased. After blocking TIGIT/CD155 pathway, NK cell function was reversed, but NK cell apoptosis was not reduced.

Background: Myelodysplastic syndrome (MDS) is a type of heterogeneous myeloid clonal disorder usually diagnosed based on a combination of multiple laboratory examinations, including analysis of peripheral blood cells, bone marrow cell morphology and cytogenetics. However, there is a certain difficulty in cases with no distinct changes in hematology and marrow cell morphology., Methods: We adopt flow cytometry to quantitatively analyze the immunophenotypic changes of marrow monocytes according to the surface antigens and their combinations at different differentiation stages, so as to study the changes of monocytes during differentiation in patients with bone marrow failure. In the meantime, the relationship between the immunophenotypic changes of marrow monocytes and IPSS-R score and prognosis of MDS patients was analyzed., Results: Our results demonstrated disorders of maturation and differentiation of monocytes in patients with MDS and clonal cytopenias of undetermined significance as compared to those with aplastic anemia and healthy individuals. In addition, the differentiation abnormality gradually increased with the disease progression. Furthermore, CD300e expression was found to show significant associations with the clinical stage and disease progression of MDS, and the progression-free survival and AML-free survival were much longer in MDS patients highly expressing CD300e on monocytes., Conclusions: CCUS and MDS patients have disorders of differentiation and maturation of monocytes, which tends to be more critical with MDS progression or transforms to AML. Moreover, high CD300e expression has the potential to be a favorable prognostic marker for MDS. This study provides important insights to the role of monocyte immunotyping in the diagnosis, differentiation and prognosis of MDS., (© 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

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-1β, IL-18) and CEACAM1 were raised in bone marrow supernatants and MDSC culture supernatants. Blocking or neutralizing TIM3/CEACAM1 and IL-1β/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-1β 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-1β 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., (© 2022 John Wiley & Sons Ltd.)

Myelodysplastic syndrome (MDS) is a heterogeneous group of myeloid clonal diseases with diverse clinical courses, and immune dysregulation plays an important role in the pathogenesis of MDS. However, immune dysregulation is complex and heterogeneous in the development of MDS. Lower-risk MDS (LR-MDS) is mainly characterized by immune hyperfunction and increased apoptosis, and the immunosuppressive therapy shows a good response. Instead, higher-risk MDS (HR-MDS) is characterized by immune suppression and immune escape, and the immune activation therapy may improve the survival of HR-MDS. Furthermore, the immune dysregulation of some MDS changes dynamically which is characterized by the coexistence and mutual transformation of immune hyperfunction and immune suppression. Taken together, the authors think that the immune dysregulation in MDS with different risk stratification can be summarized by an advanced philosophical thought "Yin-Yang theory" in ancient China, meaning that the opposing forces may actually be interdependent and interconvertible. Clarifying the mechanism of immune dysregulation in MDS with different risk stratification can provide the new basis for diagnosis and clinical treatment. This review focuses on the manifestations and roles of immune dysregulation in the different risk MDS, and summarizes the latest progress of immunotherapy in MDS., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Peng, Zhu, Di, Tang, Guo, Liu, Bai, Li, Li and Zhang.)

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., (© 2019 The Authors. Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.)

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-β 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., Competing Interests: Competing interests: None declared., (© American Federation for Medical Research 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Most of the International Prognostic Scoring System (IPSS) high-risk patients with myelodysplastic syndrome partly responded to hypomethylating therapy even with transient remission, while arsenic trioxide (ATO) had partial effect in patients with MDS. Therefore, we sought to investigate the effects and possible mechanisms of the combination of ATO and decitabine (DAC) in MDS cells. In our study, the MUTZ-1 and SKM-1 cells were treated with ATO, DAC or both. Cell viability, cell apoptosis, levels of reactive oxygen species (ROS) and expressions of the endoplasmicreticulum (ER) stress-associated genes and proteins were examined. Results showed the combination of ATO and DAC synergistically inhibited the proliferation and induced apoptosis of MDS cells. Through the RNA-sequence and GSEA gene function analysis, ER stress-related pathway played an important role in apoptosis of MDS cells induced by the combination of ATO and DAC. ER stress-related genes DNA damage inducible transcript 3, GRP78, and activating transcription factor-6 were significantly highly expressed in combination group than those in single agent groups; proteins were confirmed by western blot. The levels of ROS significantly increased in the combination group. Furthermore, the apoptosis of (ATO+DAC) group MDS cells could be partially reversed by antioxidant agent N-acetylcysteine, accompanied by decreased expression of intracellular ROS and ER stress-related genes. These results suggested that the combination of ATO and DAC synergistically induced the apoptosis of MDS cells by increased ROS-related ER stress in MDS cells., Competing Interests: Competing interests: None declared., (© American Federation for Medical Research 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

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., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The objective of the study was to examine levels of intracellular iron, reactive oxygen species (ROS) and the expression of JNK and p38MAPK in NK cells and hematopoietic stem/progenitor cells (HSPCs) in MDS patients, and explore potential mechanisms by which iron overload (IOL) promotes MDS progression. Thirty-four cases of MDS and six cases of AML transformed from MDS (MDS/AML) were included. HSPCs and NK cells were isolated by magnetic absorption cell sorting. We used flow cytometry to detect the levels of ROS and intracellular JNK and P38 in NK cells and HSPCs. Total RNA and protein were extracted from NK cells and CD34 + cells to examine the expression of JNK and p38MAPK using RT-PCR and Western blotting. Intracellular iron concentration was detected. Data were analyzed by SPSS 21 statistical software. Intracellular iron concentration and ROS were increased in both NK cells and HSPCs in MDS patients with iron overload (P < 0.05). MDS patients with iron overload had higher JNK expression and lower p38 expression in NK cells, and higher p38 expression in HSPCs compared with non-iron overload group. IOL may cause alterations in NK cells and HSPCs through the JNK and p38 pathways, and play a role in the transformation to AML from MDS.

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., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Chidamide as a newly designed and synthesized histone deacetylase inhibitor induces an antitumor effect in various cancer, and it has been used in several clinical trials such as peripheral T cell lymphoma (PTCL). Here we demonstrate that Chidamide was able to increase the acetylation levels of histone H3 and decrease HDAC activity in MDS cell lines(SKM-1,MUTZ-1)and AML cell line(KG-1). In vitro, at low concentration (<250nM) of Chidamide inhibited cell proliferation and delayed G0/G1 cell cycle progression by down-regulating CDK2 and regulating p-P53 and P21 protein expression. Meanwhile,it also induced cell apoptosis by down-regulating Bcl-2 and up-regulating cleaved Caspase-3 and Bax protein expression.The results of the present study demonstrates the potential utility of Chidamide for the treatment of Myelodysplastic syndromes., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)

Objective: To detect the expression level of growth differentiation factor 11 (GDF11) in patients with myelodysplastic syndrome (MDS), and to evaluate the relationship between GDF11 level and erythropoiesis functions., Methods: A total of 44 MDS patients (18 low-risk group patients and 26 high-risk group patients) in Department of Hematology in Tianjin Medical University General Hospital and 10 normal controls were selected from September 2014 to June 2015. The concentration of GDF11 in peripheral blood was detected using enzyme-linked immunosorbent assay (ELISA). GDF11 mRNA expression in bone marrow mononuclear cells (BMMNC) was detected using RT-PCR method. The percentage of erythroid cells (CD235a) in bone marrow was detected by flow cytometry. The correlation between these indexes and erythropoiesis functions (including red blood cell count (RBC), hemoglobin level (Hb), hematocrit (Hct), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), reticulocyte percentage (Ret%), and proportion of nucleated eryhrocyte in bone marrow) were evaluated., Results: (1) The GDF11 level in peripheral blood was significantly higher in high-risk group ((128.67±47.62) μg/L) than in low-risk group ((65.96±36.55) μg/L, P<0.01) and in normal controls ((29.76±10.10) μg/L, P<0.01), also significantly higher in low-risk group than in normal controls (P<0.05). The concentration of GDF11 in severe/moderate anemic MDS patients ((80.97±9.94) μg/L) was higher than that in normal controls/ mild anemic MDS patients((66.82±19.52) μg/L), but with no statistically significant (P>0.05). (2) The percentages of CD235a(+) cells in high-risk and low-risk groups were 38.49%±5.42% and 42.64%±7.36%, respectively, showing no statistically significant difference (P>0.05). (3) In high-risk group, the GDF11 level in peripheral blood was negatively correlated with Hb, RBC and Hct in peripheral blood (r=-0.437, -0.430, -0.306, all P<0.05), and positively correlated with nucleated eryhrocyte, Ret%, MCV and CD235a(+) cells in bone marrow (r=0.465, 0.392, 0.505, 0.387, all P<0.05), but not correlated with MCH and MCHC (both P>0.05). In low-risk group, the GDF11 level in peripheral blood was positively correlated with CD235a(+) cells in bone marrow (r=0.429, P<0.05), and not correlated with Hb, RBC, Ret%, MCHC, MCV, MCH, Hct and nucleated eryhrocyte (all P>0.05). (4) The mRNA expression of GDF11 in MDS patients (39.82±14.55) was higher than that in the controls (1.84±0.64, P<0.01)., Conclusions: GDF11 level in peripheral blood is higher in patients with MDS and increases with the disease risk. The more severe the anemia, the higher the GDF11 level. It may be closely correlated with erythropoiesis indicators in MDS.

Objective: To investigate the change of autophagy level of bone marrow mononuclear cells（BMMNCs）in patients with myelodysplastic syndromes（MDS）., Methods: Thirty- eight patients with MDS and 26 megaloblastic anemia patients were enrolled in this study. The autophagic vacuoles were observed by transmission electron microscopy （TEM） and the quantity of autophagic vacuoles was detected by monodansylcadaverine （MDC） staining. The LC3 protein positive cells were counted by immunofluorescence assays. The expression of Beclin 1, LC3A, mTOR mRNA were measured by real time PCR. The expression of Beclin 1 proteins were detected by Western blotting., Results: The autophgic vacuoles of double membrane that surrounds lysosomes appeared in MDS patients. The percentage of MDC positive cells was significantly higher in MDS patients［（9.75±2.63）%］than that of controls［（2.90± 0.89）%, P＜0.05）. The percentage of LC3 protein cells was also increased in MDS patients（6.13±1.03）% vs（1.5±0.58）%, P＜0.05）. The expression of Beclin 1 and LC3A mRNA in low-risk and intermediate-1 MDS were higher compared with controls （3.61 ± 3.02 vs 1.55 ± 1.03 and 6.56 ± 3.97 vs 1.21 ± 0.95 respectively, both P＜0.05）. The expression of mTOR mRNA was down- regulated in low- risk and intermediate-1 MDS compared with controls（0.39±0.37 vs 1.50±1.03, P＜0.05）. There were no significant difference in expression of Beclin 1, LC3 and mTOR mRNA among intermediate-2 and high-risk MDS and controls. Beclin 1 protein expression was higher in low- risk and intermediate- 1 MDS patients（1.257 ± 0.197）than that of controls（0.528±0.086）and inermediate-2 and high-risk MDS patients（0.622±0.118）., Conclusion: The autophagy levels were increased in low- risk and intermediate- 1 MDS, while not enhanced in intermediate-2 MDS. Autophagy might be considered as a cell protective mechanism in MDS. The relatively defective autophagy in intermediate- 2 and high- risk MDS might contribute to disease's progression.

Aims and Background: To investigate the expressions of TET2 mRNA in bone marrow CD3(+) and CD34(+) cells of the patients with myelodysplastic syndromes (MDS) and to study the effect of silencing TET2 by small interfering RNA (siRNA) on the biological characteristics of CD34(+) cells., Methods: CD3(+) and CD34(+) cells were sorted by magnetic activated cell-sorting system from bone marrow of MDS patients and controls. The mRNA expressions of TET2 in bone marrow CD3(+) and CD34(+) cells of 28 MDS patients and 20 controls were detected by qPCR. The silencing effect of RNA interference (RNAi) on TET2 expression in CD34(+) bone marrow cells of normal control was identified by qPCR and Western blot analysis. The cell cycle kinetics and cell apoptosis were then detected by flow cytometry., Results: The expression of TET2 mRNA in CD3(+) and CD34(+) cells was down-regulated in MDS compared with that in controls [(0.16 ± 0.11) vs. (1.05 ± 0.32) (P<0.001); (0.58 ± 0.26) vs. (1.25 ± 0.94) (P<0.005)]. The siRNA targeting TET2 suppressed the expression of TET2 in normal CD34(+) cells. Meanwhile, the proliferation activity was significantly enhanced [G0/G1: (87.82 ± 8.25)% vs. (92.65 ±7.06)% and (93.60 ± 5.54)%, P<0.05; S: (11.50 ± 8.31)% vs. (6.92 ± 7.04)% and (5.95 ± 5.53)%, P<0.05] and the apoptosis rate was declined [(21.28 ± 9.73)% vs. (26.17 ± 9.88)% and (26.20 ± 9.78)%] in the cells which transfected with TET2 siRNA as compared to those in the cells transfected with scrambled siRNA and control cells., Conclusions: The TET2 expression of in CD3(+) and CD34(+) cells of MDS patients was decreased. Suppression of TET2 expression renders the CD34(+) cells harboring more aggressive phenotype. This preliminary finding suggests that CD34(+) cells lowering expression of TET2 may play an oncogenic role on myeloid tumor and CD3(+) T cells of MDS patients may be derived from the malignant clone.

Background: Our goal was to detect the expression of CD96 and CD123 in myelodysplastic syndromes (MDS) and their proliferation and differentiation characteristics., Methods: Forty-three patients with MDS, thirteen AML patients diagnosed in the Hematology Department of General Hospital of Tianjin Medical University, and sixteen healthy controls were enrolled in this study. The expressions of CD96 and CD123 on CD34+CD38- bone marrow cells (BMC) of these patients and controls were measured by FACS. CD114 (GCSFR), EPOR, and CD110 (TPOR) expression on their CD34+CD38-CD96+ and CD34+CD38-CD96- BMC and these cells' apoptosis (Annexin V) were also detected by FACS., Results: MDS patients had a significantly higher proportion of CD34+CD38-/CD34+ BMC (22.72 ± 23.91%) than normal controls (8.63 ± 9.35%) (p < 0.01). The expressions of CD34+CD38-CD96+/CD34+CD38- BMC and CD34+ CD38-CD123+/CD34+CD38- BMC of MDS patients (21.18 ± 24.06%, 31.62 ± 28.42%, respectively) were significantly higher than those of normal controls (11.23 ± 17.91%, 9.29 ± 12.63%) (p < 0.01). The expressions of CD34+CD38-CD96+/CD34+CD38- BMC and CD34+CD38-CD123+/CD34+CD38- BMC in the high-risk MDS group (26.25 ± 27.64%, 37.56 ± 31.01%) was significantly higher than those in the low-risk group (11.44 ± 10.88, 15.53 ± 10.96%) (p < 0.05). The expression levels of CD123 and CD96 were significantly correlated with the proportion of bone marrow blasts (r = 0.384, p < 0.05; r = 0.625, p < 0.05). The expressions of CD114, CD110, and Annexin V in CD34+CD38-CD96+ BMC (7.23 ± 10.25%, 0.52 ± 1.23%, 2.96 ± 3.84%, respectively) were significantly lower than those in CD34+CD38-CD96- BMC (24.35 ± 21.74%, 12.03 ± 10.91%, 13.69 ± 17.98%, respectively) of MDS patients (p < 0.05)., Conclusions: There was a higher proportion of CD34+CD38-CD96+ and CD34+CD38-CD123+ cells in bone marrow of MDS patients. Those cells expressed lower cytokine receptors and displayed lower apoptosis. Leukemia stem cells (LSC) in MDS might be contained in those cells.

Objective: To analyze the percentage and functional changes of natural kill (NK) cell in peripheral blood of myelodysplastic syndrome (MDS) patients so as to evaluate the relationships between these changes and hematopoietic functions and explore the role of NK cell in the pathogenesis of MDS., Methods: By flow cytometry, the percentage of NK cell (CD3⁻CD56⁺CD16⁺) in peripheral blood lymphocytes was detected in 20 MDS patients, 15 acute myelogenous leukemic (AML) and 15 normal controls from March 2013 to November 2013 at our hospital.NK cell activation receptors (NKG2D, NKp44), inhibitory receptors (CD158a, CD158b), perforin and granzyme-β of patients and normal controls were also detected. The correlation between these changes and hematopoietic functions, including the percentages of neutrophil granulocyte (ANC%), lymphocyte (Lym%), reticulocyte (RET%) and hemoglobin, thrombocyte in peripheral blood and the hematopoietic function in bone marrow (CD34⁺%) were evaluated., Results: (1) The percentage of NK cell (3.87% ± 0.97%) in MDS patients was significantly lower than that of normal controls (6.08% ± 1.37%, P < 0.05) and higher than that of AML patients (2.58% ± 0.78%, P < 0.05).(2) The expression of NKG2D in MDS patients (52.83%) was significantly lower than that of normal controls (86.36%, P < 0.05) and higher than that of AML patients (42.00%, P < 0.05). The expression of NKp44 in MDS patients (2.41%) was significantly higher than that of normal controls (0.62%) and AML patients (0.92%) (both P < 0.05). (3) The expression of CD158a in MDS and AML patients (5.46% ± 2.40%, 4.05% ± 1.89%) were significantly both lower than those of normal controls (7.97% ± 2.85%, both P < 0.05). The expression of CD158b had no significant difference among the 3 groups. (4) The expression of perforin in MDS patients (17.83%) was significantly lower than that of normal controls (59.79%, P < 0.05) and higher than that of AML patients (13.06%, P < 0.05). The expressions of granzyme-β in MDS and AML patients (21.54%, 30.65%) were significantly both lower than those of normal controls (83.42%, both P < 0.05). (5) The percentage of NK cell and the expression of NKG2D and NKp44 in MDS patients with low-risk group were in turn higher than those of high-risk group (4.06% ± 0.56% vs 3.59% ± 1.37%, 53.42% ± 6.85% vs 47.29% ± 8.08%, 2.46% vs 2.07%, all P < 0.05) , the expression of CD158a and CD158b were in turn lower than those of high-risk group, but both P > 0.05.(6) The percentage of NK was positively correlated with ANC% (r = 0.780, P < 0.05), but negatively with Lym% and the CD34⁺% in bone marrow (r = -0.543, -0.610, both P < 0.05). The expression of CD158a was positively correlated with CD34⁺% in bone marrow (r = 0.612, P < 0.05). The expressions of NKp44, CD158a, perforin and granzyme-β of NK cells had no correlation with hematopoiesis (all P > 0.05)., Conclusion: The lowered percentage and function of NK may cause the immunological dysfunction and lead to underkill of pathological hematopoietic cells in MDS.

The increased LSC in MDS has correlation with the progression to AML, which the mechanism of immune evasion is unclear. Our study showed the expression of CD47 on LSC of the patients in high-risk MDS based on IPSS/WPSS score was higher than that of in low-risk MDS and controls. The level of CD47 on erythroblast of MDS patients had a significant positive correlation with their peripheral RBC count. It suggested that the proportion of CD34(+)CD38(-)CD47(+) cells increased in high-risk MDS which might protect LSC from avoiding phagocytosis, and low-expression of CD47 on erythroblast in MDS might be correlated to anemia., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Background: The definitive establishment of a causal relationship between gut microbiota and myelodysplastic syndrome (MDS) has not been achieved. Furthermore, the involvement of immune cells in mediating the connection between gut microbiota and MDS is presently unclear. Methods: To elucidate the bidirectional correlation between gut microbiota and MDS, as well as to investigate the mediating role of immune cells, a bidirectional two-sample, two-step Mendelian randomization (MR) study was conducted. Summary statistics were obtained from genome-wide association studies (GWAS), including MDS (456,348 individuals), gut microbiota (18,340 individuals), and 731 immune cells signatures (3757 individuals). Results: Genetically predicted eight gut microbiota traits were significantly associated with MDS risk, but not vice versa. Through biological annotation of host-microbiome shared genes, we found that immune regulation may mediate the impact of gut microbiota on MDS. Subsequently, twenty-three immunophenotypes that exhibited significant associations with MDS risk and five of these immunophenotypes were under the causal influence of gut microbiota. Importantly, the causal effects of gut microbiota on MDS were significantly mediated by five immunophenotypes, including CD4 +T cell %leukocyte, CD127 on CD45RA − CD4 not regulatory T cell, CD45 on CD33 + HLA DR + WHR, CD33 on basophil, and Monocyte AC. Conclusions: Gut microbiota was causally associated with MDS risk, and five specific immunophenotypes served as potential causal mediators of the effect of gut microbiota on MDS. Understanding the causality among gut microbiota, immune cells and MDS is critical in identifying potential targets for diagnosis and treatment. [ABSTRACT FROM AUTHOR]

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‐1β, IL‐18) and CEACAM1 were raised in bone marrow supernatants and MDSC culture supernatants. Blocking or neutralizing TIM3/CEACAM1 and IL‐1β/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‐1β 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‐1β 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. [ABSTRACT FROM AUTHOR]

Background and Aim: Many studies indicated that eltrombopag and romiplostim could improve hematopoietic function in patients with myelodysplastic syndromes (MDS), but their toxicity and efficacy were not known. This meta-analysis aimed to investigate the safety and efficacy of eltrombopag and romiplostim in MDS. Methods: A full-scale search strategy was used to search relevant published studies in PubMed, Embase, Web of Science, ClinicalTrials.gov and the Cochrane Library until January 2020 using a random-effects model and the pooled risk ratio (RR) with 95% confidence interval as the effect indicator. Statistical analyses were performed using RevMan 5.3. Results: This meta-analysis included eight studies comprising 1047 patients. A lower RR of overall response rate (ORR) (RR: 0.65; 95% CI, 0.47–0.9) and grade ≥3 bleeding events (RR: 0.36; 95% CI, 0.36–0.92) were observed after romiplostim and eltrombopag treatment compared with placebo. The pooled RR for the ORR and grade ≥3 bleeding events were 0.58 (95% CI: 0.41–0.83, P = 0.003) and 0.6 (95% CI: 0.37–0.96, P = 0.03) in eltrombopag, respectively. A lower ORR in intermediate- or high-risk MDS (RR: 0.63; 95% CI: 0.45–0.88, P = 0.006) was observed. No difference in mortality, serious adverse events, platelet transfusion, hematologic improvement, and AML transformation was observed. Conclusions: Thrombopoietin receptor agonists (TPO-RAs) romiplostim and eltrombopag were effective in reducing bleeding events, especially grade ≥3 bleeding events. However, it might reduce the ORR of MDS, especially in eltrombopag treatment group or high-risk MDS group. Due to the limited treatment of MDS and the poor response to the drug, this may be a selection method for MDS combined with fatal bleeding, although further research is needed to confirm the effectiveness of this approach. [ABSTRACT FROM AUTHOR]

Objective: Targeting immune checkpoints, such as PD-1, represents a promising approach for cancer immunotherapy, achieving long-term disease remission rates in numerous types of cancer. T cell immunoglobulin and ITIM domain (TIGIT) is a checkpoint receptor associated with the antitumor roles of NK and T cells. Notably, the blockade of TIGIT has been revealed as a potential promising approach in cancer immunotherapy. However, the therapeutic potential of blocking TIGIT in myelodysplastic syndrome (MDS) remains unclear and further research is required to reveal their role. Methods: Fresh peripheral blood (PB) and bone marrow (BM) were obtained from patients with MDS and healthy donors (HDs) at the Tianjin Medical University General Hospital between January 21 2018 and March 22 2019. The present study investigated the expression levels of TIGIT on NK and T cells using flow cytometry (FCM) and PCR. In addition, other checkpoint receptors, such as CD226 and PD-1, were also investigated. To determine the mechanisms of antitumor immunity, the functions of NK and T cells expressing TIGIT were determined. Results: TIGIT was found to be highly expressed on NK and T cells of the PB, where it was involved in disease progression and the immune escape of MDS. The high expression levels of TIGIT were associated with decreased NK and T cell function, and significantly lower secretions of activation factors, such as CD107a, IFN-γ and TNF-α. Notably, blocking TIGIT enhanced the antitumor effects of NK and T cells. Conclusion: The results of the present study suggested that targeting TIGIT alone or in combination with PD-1 may be a promising anticancer therapeutic strategy in MDS. [ABSTRACT FROM AUTHOR]

Background: Chromosomal abnormalities play an important role in the diagnosis and prognosis of patients with myelodysplastic syndromes (MDSs). The single-nucleotide polymorphism array (SNP-A) technique has gained popularity due to its improved resolution compared to that of metaphase cytogenetic (MC) analysis. Methods: A total of 376 individuals were recruited from two medical centers in China, including 350 patients and 26 healthy individuals. Among these patients, 200 were diagnosed with de novo MDS, 25 with myeloproliferative neoplasm (MPN), 63 with primary acute myeloid leukemia (AML), and 62 with idiopathic cytopenia of undetermined significance (ICUS). We evaluated the significance of abnormal chromosomes detected by SNP-A in the diagnosis and prognosis of MDS-related disorders. Results: (1) When certain chromosomal abnormalities could not be detected by conventional MC methods, these abnormalities could be detected more efficiently by the SNP-A method. With SNP-A, the detection rates of submicroscopic or cryptic aberrations in the MDS, MPN, and AML patients with normal MC findings were 32.8, 30.8, and 30%, respectively. (2) The chromosomal abnormalities detected by SNP-A had a very important value for the prognosis of patients with MDSs, especially in the low-risk group. The survival of patients with abnormal chromosomes detected by SNP-A was significantly lower than that of patients with no detected chromosomal abnormalities; this difference was observed in overall survival (OS) (P = 0.001) and progression-free survival (PFS) [24 months vs. not reach (NR); P = 0.008]. The patients with multiple chromosomal abnormalities detected by SNP-A had an inferior prognosis, and SNP-A abnormalities (≥3 per patient) were found to be an independent predictor of poor prognosis in patients with MDSs [hazard ratio (HR) = 2.40, P = 0.002]. (3) Patients with ICUS may progress to myeloid malignancies, but most patients often maintain a stable ICUS status for many years without progression. An ICUS patient found to have an MDS-related karyotype would be rediagnosed with MDS. SNP-A can efficiently detect chromosomal abnormalities, which would be important for assessing the evolution of ICUS. In our study, 17 ICUS patients with SNP-A-detected abnormalities developed typical MDSs. Conclusions: SNP-A can help evaluate the prognosis of patients with MDSs and better assess the risk of disease progression for patients with ICUS. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Myelodysplastic syndromes (MDS) are clonal stem cell disorders characterized by ineffective hematopoiesis that lead to leukemia. Disorders of the immune system serve important functions in the pathophysiology and progression of this disease. Different levels or mechanisms of natural killer (NK) cells in patients with MDS have been measured in previous studies, making it challenging to understand the pathogenesis of NK cytotoxicity. The present study investigated the frequency of NK cell-mediated antibody-dependent cellular cytotoxicity and explored the function of NK cells by their activating receptors, inhibition signals, degranulation and cytotoxicity factors. In the present study, levels of cluster of differentiation (CD)3-CD56+ NK cells, CD16+-expressing NK cells and subset CD56dim NK cells were decreased in the peripheral blood of patients with MDS. Altered expression of NK protein 44, NK group 2 member D, killer cell immunoglobulin-like receptor 2DL1 (KIR2DL1) and KIR2DL3 on NK cell effector signaling pathways may trigger tumor cell lysis in patients with MDS. The weak cellular adhesion and decreased cytotoxicity of NK cells may lead to ineffective antitumor activity in MDS. These observations suggested that NK cells may serve as immunological determinants in MDS and may permit the development of NK cell-based immunotherapy for the treatment of patients with MDS. [ABSTRACT FROM AUTHOR]