Galectin-9 alleviates acute graft-versus-host disease after haplo-hematopoietic stem cell transplantation by regulating regulatory T cell/effector T cell imbalance.

BACKGROUND: Acute graft-versus-host disease (aGVHD) arises from the imbalance of host T cells. Galectin-9 negatively regulates CD4 effector T cell (Th1 and Th17) function by binding to Tim-3. However, the relationship between Galectin-9/Tim-3 and CD4+ T subsets in patients with aGVHD after Haplo-HSCT (haploidentical peripheral blood hematopoietic stem cell transplantation) has not been fully elucidated. Here, we investigated the role of Galectin-9 and CD4+ T subsets in aGVHD after haplo-HSCT. METHODS: Forty-two patients underwent Haplo-HSCT (26 without aGVHD and 16 with aGVHD), and 20 healthy controls were included. The concentrations of Galectin-9, interferon-gamma (IFN-γ), interleukin (IL)-4, transforming growth factor (TGF)-ß, and IL-17 in the serum and culture supernatant were measured using enzyme-linked immunosorbent assay or cytometric bead array. The expression levels of Galectin-9, PI3K, p-PI3K, and p-mTOR protein were detected by western blot analysis. Flow cytometry was used to analyze the proportions of CD4+ T cell subsets. Bioinformatics analysis was performed. RESULTS: In patients with aGVHD, regulatory T (Treg) cells and Galectin-9 decreased, and the Th1, Th17, and Treg cells were significantly imbalanced. Moreover, Treg and Galectin-9 were rapidly reconstituted in the early stage of patients without aGVHD after Haplo-HSCT, but Th17 cells were reconstituted slowly. Furthermore, Tim-3 upregulation on Th17 and Th1 cells was associated with excessive activation of the PI3K/AKT pathway in patients with aGVHD. Specifically, in vitro treatment with Galectin-9 reduced IFN-γ and IL-17 production while augmenting TGF-ß secretion. Bioinformatics analysis suggested the potential involvement of the PI3K/AKT/mTOR pathway in aGVHD. Mechanistically, exogenous Galectin-9 was found to mitigate aGVHD by restoring the Treg/Teffs (effector T cells) balance and suppressing PI3K. CONCLUSION: Galectin-9 may ameliorate aGVHD after haplo-HSCT by modulating Treg/Teffs balance and regulating the PI3K/AKT/mTOR pathway. Targeting Galectin-9 may hold potential value for the treatment of aGVHD.

Galectin-9 and myeloid-derived suppressor cell as prognostic indicators for chronic lymphocytic leukemia.

BACKGROUND: Galectin-9 and myeloid-derived suppressor cells (MDSCs) have an important role in tumors, but their clinical values in chronic lymphocytic leukemia (CLL) have not been fully elucidated. This study aimed to analyze the prognosis values of Galectin-9 and MDSCs in CLL. METHODS: The concentrations of Galectin-9, argininase-1, and inducible nitric oxide synthase in serum were detected by enzyme-linked immune sorbent assay. The expression of Tim-3 protein in peripheral blood mononuclear cell was detected by Western blot. Flow cytometry was used to analyze the percentages of Tim-3 on T-cells (CD3+ T, CD4+ T, and CD8+ T cells) and MDSCs. RESULTS: Our results showed that Galectin-9 and MDSCs significantly increased in CLL patients and were closely related to the disease progression. Patient's receiver operating characteristic, progression-free survival, and Cox regression analysis showed that Galectin9 and MDSCs were poor prognostic factors of CLL. CONCLUSION: Galectin-9 and MDSCs were associated with clinical progression and could be important prognostic indicators for CLL.

Expression and Clinical Significance of Helper T Cells 9 and Its Sytokines Interleukin 9 in Chronic Lymphocytic Leukemia / 中国实验血液学杂志

OBJECTIVE@#To investigate the expression and clinical significance of T helper cell 9 (Th9) and its cytokine interleukin 9(IL-9) in peripheral blood of patients with chronic lymphocytic leukemia(CLL).@*METHODS@#A total of 43 newly diagnosed patients with chronic lymphocytic leukemia in the First Affiliated Hospital of Xinjiang Medical University from June 2021 to June 2022 were selected as the case group. The patients were divided into Binet A group (13 cases), Binet B group (20 cases) and Binet C group (10 cases) by Binet staging system, and 20 healthy volunteers who underwent physical examinationin in our hospital in the same period served as control group. The proportion of Th9 cells in peripheral blood was detected by flow cytometry, the expression level of Th9 specific transcription factors PU.1 and IRF4 was detected by Western blot, and the expression level of serum cytokine IL-9 was detected by ELISA. The proportion of Th9, the expression of PU.1, IRF4 and IL-9 in each group were compared, and the correlation between the proportion of Th9, IL-9 and clinicopathological indexes of CLL patients was analyzed.@*RESULTS@#The proportion of Th9, the expression of PU.1, IRF4 and IL-9 in CLL group were significantly higher than those in control group (P<0.05), the proportion of Th9 and the expression of IL-9 in Binet B and C group were higher than those in Binet A group (P<0.05), but there was no significant difference in the proportion of Th9 cells between Binet B group and C group (P>0.05). The expression of IL-9 in Binet C group was significantly higher than that in Binet B group (P<0.05) . The proportion of Th9 cells and IL-9 were highly expression in patients with β2 microglobulin abnormality, IGHV unmutation, P53 abnormality and hepatosplenic lymph node enlargement(P<0.05), but not related to age and sex (P>0.05). The results of Spearman correlation analysis showed that the proportion of Th9 in patients with CLL was negatively correlated with the lymphocytic account and lymphocyte proportion(rs=-0.32，rs=-0.34). The proportion of Th9 and IL-9 were positively correlated with Binet stage, Rai stage and CLL-IPI Scoring (rs=0.79，rs=0.54，rs=0.58； rs=0.72，rs=0.63，rs=0.45), but not with WBC, CD4+ T cells and CD8+T cells (P>0.05). The proportion of Th9 was positively correlated with IL-9 (rs=0.53).@*CONCLUSION@#Th9 cells and IL-9 are abnormally highly expressed in CLL, which is related to the poor prognosis of CLL.