Sizhou Feng

The regulation of CD4+ T cell immune responses toward Th2 cell development by prostaglandin E2.

As an important immune mediator, PGE2 plays an important role in the immune tolerance, autoimmune diseases, immune regulation and tumor immunotolerance. PGE2 is considered to be a promising candidate for the control of the immune diseases. To further understand the immuno-modulating effects of PGE2 on CD4+ T cells, in vitro investigation was conducted in the present study. The results showed that PGE2 inhibited the proliferation of T cells in vitro in a dose-dependent manner. Gene expression profiling showed that 1716 genes were down regulated and 73 genes were up regulated with a change of 1.5 fold. Several signal transduction pathways were involved, such as TNF-α and NF-kB signaling pathway, T cell receptor signaling pathway, IL-2 signaling pathway, and MAPK pathway. The results showed that PGE2 inhibited IFN-γ, TNF-α and IL-4 production by CD4+ T cells 24h after cell culture. A comparison between IFN-γ and IL-4 production showed that PGE2 enhanced the relative ratio of IL-4 to IFN-γ in CD4+ T cells culture, and regulated CD4+ T cells toward Th2 cell development. The results of the present study indicated that PGE2 has the potential to treat Th1-mediated inflammatory diseases by regulating CD4+ T cells toward Th2 cell immune response.

Risk factors and prognosis of invasive fungal infections in allogeneic stem cell transplantation recipients: a single-institution experience

P. Zhang, E.‐L. Jiang, D.‐L. Yang, Z.‐S. Yan, Y. Huang, J.‐L. Wei, M. Wang, Q.‐L. Ma, Q.‐G. Liu, D.‐H. Zou, Y. He, L.‐G. Qiu, S.‐Z. Feng, M.‐Z. Han. Risk factors and prognosis of invasive fungal infections in allogeneic stem cell transplantation recipients: a single‐institution experience. Transpl Infect Dis 2010: 12: 316–321. All rights reserved

Extracellular Acidification Acts as a Key Modulator of Neutrophil Apoptosis and Functions.

In human pathological conditions, the acidification of local environment is a frequent feature, such as tumor and inflammation. As the pH of microenvironment alters, the functions of immune cells are about to change. It makes the extracellular acidification a key modulator of innate immunity. Here we detected the impact of extracellular acidification on neutrophil apoptosis and functions, including cell death, respiratory burst, migration and phagocytosis. As a result, we found that under the acid environment, neutrophil apoptosis delayed, respiratory burst inhibited, polarization augmented, chemotaxis differed, endocytosis enhanced and bacteria killing suppressed. These findings suggested that extracellular acidification acts as a key regulator of neutrophil apoptosis and functions.

Interferon-γ mediates the immunosuppression of bone marrow mesenchymal stem cells on T-lymphocytes in vitro.

ABSTRACT Objectives: In the present study, we first confirmed the suppressive function of MSCs in allogeneic T cell proliferation and then examined the underlying mechanisms for MSCs’ immunomodulation and the role of the pro-inflammatory cytokine interferon (IFN)-γ. Methods: Human MSCs were cultured in the presence or absence of IFN-γ. The expression level of prostaglandin E2 (PGE2), hepatocyte growth factor (HGF), transforming growth factor (TGF)-β1 and indoleamine 2,3-dioxygenase (IDO) by MSCs were measured. T lymphocytes were isolated from peripheral blood of healthy donors and then induced to proliferate under the stimulation of anti-human CD3 mAb and anti-human CD28 mAb. In the presence of MSCs, T cell proliferation was examined by BrdU incorporation. In addition, PGE2, HGF, TGF-β1, Kynurenine, recombinant human IFN-γ and anti-IFN-γ mAb were added and cell proliferation was examined. Results: Compared to the controls (MSCs alone), MSCs cocultured with IFN-γ expressed significantly higher concentrations of PGE2, HGF and TGF-β1. The mRNA level of IDO was remarkably increased. Human bone marrow-derived MSCs alone notably suppressed T lymphocytes proliferation in vitro. Addition of exogenous IFN-γ did not ablate the immunosuppressive effects of MSCs. Addition of anti-IFN-γ mAb partially restored suppression of T cell proliferation by MSCs. Conclusions: Human MSCs constitutively expressed immunosuppressive levels of PGE2, HGF and TGF-β1. The proinflammatory cytokine IFN-γ exhibited synergistic effects with MSCs on immunosuppression, possibly by up-regulating PGE2, HGF and TGF-β1 in MSCs and inducting MSCs expression of IDO, involved in tryptophan catabolism.

CD106 is a novel mediator of bone marrow mesenchymal stem cells via NF-κB in the bone marrow failure of acquired aplastic anemia

BackgroundAcquired aplastic anemia (AA) is characterized by deficiency or dysfunction of the bone marrow (BM) microenvironment. However, little is known about the impairment of BM-derived mesenchymal stem cells (MSCs) in AA patients.MethodsWe used Illumina HiSeqTM 2000 sequencing, quantitative real-time polymerase chain reaction (qRT-PCR), flow cytometry (FCM), and Western blotting to test the expression of CD106 gene (vascular cell adhesion molecule 1 (VCAM1)) and CD106 protein of BM-MSCs. Furthermore, we used hematoxylin and eosin (H&E) and histochemical staining analysis, immunofluorescence, and the formation of capillary-like structures to analyze capillary tube-like formation in vitro; we also used the Matrigel plug assay to test in vivo vasculogenesis, and an assay of colony forming units (CFUs) and colony-forming unit-megakaryocyte (CFU-MK) to detect the support function of MSCs in vitro. The in vivo engraftment of CD34+ cells and MSCs in NOD/SCID mice was tested by FACS and survival assay; the expression of NF-κB was tested by NanoPro analysis and immunofluorescence. NF-κB-regulated CD106 gene (VCAM1) was confirmed by tumor necrosis factor alpha (TNF-α)-stimulated and lipopolysaccharide (LPS)-stimulated MSCs, blockade assay, and immunofluorescence.ResultsHere, we report that BM-MSCs from AA patients exhibited downregulation of the CD06 gene (VCAM1) and low expression of CD106 in vitro. Further analysis revealed that CD106+ MSCs from both AA patients and healthy controls had increased potential for in vitro capillary tube-like formation and in vivo vasculogenesis compared with CD106– MSCs, and the results were similar when healthy MSCs were compared with AA MSCs. CD106+ MSCs from both AA patients and healthy controls more strongly supported in vitro growth and in vivo engraftment of CD34+ cells in NOD/SCID mice than CD106– MSCs, and similar results were obtained when healthy MSCs and AA MSCs were compared. The expression of NF-κB was decreased in AA MSCs, and NF-κB regulated the CD106 gene (VCAM1) which supported hematopoiesis.ConclusionsThese results revealed the effect of CD106 and NF-κB in BM failure of AA.

The impact of recipient HLA-Cw and donor killer immunoglobulin-like receptor genotyping on the outcome of patients receiving HLA-matched sibling donor hematopoietic stem cell transplantation for myeloid malignancies.

BACKGROUND The alloreactivity of natural killer cell and certain subsets of T lymphocyte are regulated by the interaction between killer immunoglobulin-like receptors (KIRs) of donor cells and human leukocyte antigen (HLA)-class I molecules on target cells. The interaction has been shown to influence the outcome of allogeneic haematopoietic stem cell transplantation (HSCT). Homozygous C1 or C2 and heterozygous C1/C2 were divided by HLA-Cw typing and they influenced the outcome of HSCT. OBJECTIVE The purpose of the study was to analyse the impact of interaction between recipient HLA-Cw and donor KIR on outcome. METHODS The genotypes of recipient HLA-Cw ligands and donor KIRs were correlated with the clinical outcomes of 52 patients who received HLA-matched, sibling donor HSCT for myeloid malignancies. RESULTS The incidence of chronic graft versus host disease (GVHD) was significantly lower in C1 or C2 homozygotes than in C1/C2 heterozygotes (p = 0.000). Higher overall survival (OS) and disease-free survival (DFS) rates were observed in C1 or C2 homozygotes than in C1/C2 heterozygotes (OS, 81% ± 8% vs 54% ± 10%, p = 0.034; DFS, 81% ± 8% vs 54% ± 10%, p = 0.024). A lower incidence of chronic GVHD and higher OS and DFS were observed in the HLA-KIR mismatched group (chronic GVHD, p = 0.007; OS, 84% ± 7% vs 47% ± 13%, p = 0.003; DFS, 84% ± 7% vs 47% ± 13%, p = 0.002). CONCLUSION The interaction between recipient HLA ligand and donor KIR had a significant impact on the outcome of patients receiving matched sibling HSCT. C1/C2 heterozygotes or HLA-KIR matched patients may benefit from additional intensified therapy with better outcome.

An evaluation of the RIFLE criteria for acute kidney injury after myeloablative allogeneic haematopoietic stem cell transplantation.

BACKGROUND Patients undergoing myeloablative allogeneic haematopoietic stem cell transplantation (HSCT) have a higher incidence of acute kidney injury (AKI). RIFLE is a newly developed classification for AKI that includes three grades of severity - AKI-R, AKI-I, AKI-F. OBJECTIVE The purpose of this study was to analyse retrospectively major risk factors for AKI at the time of myeloablative allo-HSCT and to use the RIFLE criteria to predict mortality in myeloablative allo-HSCT. METHODS Renal function was evaluated in 143 patients with allo-HSCT by RIFLE criteria in order to assess the incidence, risk factors and mortality rate of various degrees of AKI. RESULTS The results of this study showed that patients with hepatic veno-occlusive disease (HVOD) have a higher incidence of AKI-F than those without HVOD (P = 0.002). The incidence of AKI-I and AKI-F in patients with grade III-IV acute graft-versus-host disease (aGVHD) and increased total bilirubin was significantly higher than in those without (P = 0.001, P <0.001). HVOD was an independent risk factor of AKI-F (OR 5.058, 95% CI 1.317-19.424, P = 0.018), and increased total bilirubin was an independent risk factor for AKI-F (OR 5.126, 95% CI 1.403-18.998, P = 0.014). Worsening RIFLE category was associated with increased mortality of the patients in the 100 days post-transplant (P = 0.003). In addition, 180-day survival of patients in different AKI classes was significantly different (P = 0.0095). CONCLUSION AKI is common in patients with myeloablative allo-HSCT and is associated with increased risk of death. The RIFLE criteria appear to be an important tool for stratification of these patients on the basis of death risk.

Integrated Biophysical and Biochemical Signals Augment Megakaryopoiesis and Thrombopoiesis in a Three-Dimensional Rotary Culture System

Platelet transfusion has been widely used in patients undergoing chemotherapy or radiotherapy; however, the shortage of the platelet supply limits the care of patients. Although derivation of clinical‐scale platelets in vitro could provide a new source for transfusion, the devices and procedures for deriving scalable platelets for clinical applications have not been established. In the present study, we found that a rotary cell culture system (RCCS) can potentiate megakaryopoiesis and significantly improve the efficiency of platelet generation. When used with chemical compounds and growth factors identified via small‐scale screening, the RCCS improved platelet generation efficiency by as much as ∼3.7‐fold compared with static conditions. Shear force, simulated microgravity, and better diffusion of nutrients and oxygen from the RCCS, altogether, might account for the improved efficient platelet generation. The cost‐effective and highly controllable strategy and methodology represent an important step toward large‐scale platelet production for future biomedical and clinical applications.

Impaired Autophagy in Adult Bone Marrow CD34+ Cells of Patients with Aplastic Anemia: Possible Pathogenic Significance.

Aplastic anemia (AA) is a bone marrow failure syndrome that is caused largely by profound quantitative and qualitative defects of hematopoietic stem and progenitor cells. However, the mechanisms underlying these defects remain unclear. Under conditions of stress, autophagy acts as a protective mechanism for cells. We therefore postulated that autophagy in CD34+ hematopoietic progenitor cells (HPCs) from AA patients might be impaired and play a role in the pathogenesis of AA. To test this hypothesis, we tested autophagy in CD34+ cells from AA samples and healthy controls and investigated the effect of autophagy on the survival of adult human bone marrow CD34+ cells. We found that the level of autophagy in CD34+ cells from AA patients was significantly lower than in age/sex-matched healthy controls, and lower in cases of severe AA than in those with non-severe AA. Autophagy in CD34+ cells improved upon amelioration of AA but, compared to healthy controls, was still significantly reduced even in AA patients who had achieved a complete, long-term response. We also showed that although the basal autophagy in CD34+ cells was low, the autophagic response of CD34+ cells to “adversity” was rapid. Finally, impaired autophagy resulted in reduced differentiation and proliferation of CD34+ cells and sensitized them to death and apoptosis. Thus, our results confirm that autophagy in CD34+ cells from AA patients is impaired, that autophagy is required for the survival of CD34+ cells, and that impaired autophagy in CD34+ HPCs may play an important role in the pathogenesis of AA.

Outcomes of Adults with Acute Lymphoblastic Leukemia After Autologous Hematopoietic Stem Cell Transplantation and the Significance of Pretransplantation Minimal Residual Disease: Analysis from a Single Center of China

Background: The postremission therapies for adult patients generally contain consolidation chemotherapy, allogeneic hematopoietic stem cell transplantation and autologous hematopoietic stem cell transplantation (auto-HSCT). Because of the various results from different centers, the optimal therapy for adult acute lymphoblastic leukemia (ALL) patients is still uncertain. This study aimed to better understand predictive factors and role of auto-HSCT in the postremission therapy for adult ALL patients. Methods: The outcomes of 135 adult patients with ALL, who received the first auto-HSCT in Hematopoietic Stem Cell Transplantation Center of Blood Diseases Hospital, Chinese Academy of Medical Sciences from January 1, 1994 to February 28, 2014, were retrospectively analyzed. Survival curves were estimated using the Kaplan-Meier method and simultaneous effects of multiple covariates were estimated with the Cox model. Results: Overall survival (OS) and disease-free survival (DFS) at 5 years for the whole cohort were 59.1 ± 4.5% and 59.0 ± 4.4%, respectively. The cumulative nonrelapse mortality and relapse rate at 5 years were 4.5 ± 0.03% and 36.6 ± 0.19%. For both OS and DFS, acute T-cell lymphoblastic leukemia, high lactate dehydrogenase (LDH) at diagnosis, blast cell proportion ≥5% on the 15th day of induction therapy, and extramedullary infiltration before HSCT were the poor prognosis factors. In addition, age ≥35 years predicted poor DFS. Only T-ALL and high LDH were the independent undesirable factors associated with OS and DFS in Cox regression model. For 44 patients who had results of pretransplantation minimal residual disease (MRD), positive MRD (MRD ≥0.01%) indicated poor OS (P = 0.044) and DFS (P = 0.008). Furthermore, for the standard risk group, the patients with negative MRD (MRD <0.01%) had better results (OS at 18 months was 90.0 ± 9.5%, while for the patients with positive MRD OS was 50.0 ± 35.4%, P = 0.003; DFS at 18 months was 90.0 ± 9.5%, while for the positive MRD group DFS was 0%, P < 0.001). Conclusions: This study confirmed that auto-HSCT combined with posttransplantation maintenance chemotherapy could be an option for adult ALL patients and pretransplantation MRD may play a significant role in the direction of therapy for adult ALL patients.