Jianfeng Yao

A novel small-molecule tumor necrosis factor α inhibitor attenuates inflammation in a hepatitis mouse model.

Background: Most commercial TNFα inhibitors are biomacromolecules. Results: A lead compound named C87 was identified using computer-aided drug design and could attenuate murine acute hepatitis. Conclusion: C87 was one of the first effective small-molecule inhibitors of TNFα identified to date. Significance: The study highlights the effectiveness of combining virtual screening with functional assays for developing novel small-molecule TNFα inhibitors. Overexpression of tumor necrosis factor α (TNFα) is a hallmark of many inflammatory diseases, including rheumatoid arthritis, inflammatory bowel disease, and septic shock and hepatitis, making it a potential therapeutic target for clinical interventions. To explore chemical inhibitors against TNFα activity, we applied computer-aided drug design combined with in vitro and cell-based assays and identified a lead chemical compound, (E)-4-(2-(4-chloro-3-nitrophenyl) (named as C87 thereafter), which directly binds to TNFα, potently inhibits TNFα-induced cytotoxicity (IC50 = 8.73 μm) and effectively blocks TNFα-triggered signaling activities. Furthermore, by using a murine acute hepatitis model, we showed that C87 attenuates TNFα-induced inflammation, thereby markedly reducing injuries to the liver and improving animal survival. Thus, our results lead to a novel and highly specific small-molecule TNFα inhibitor, which can be potentially used to treat TNFα-mediated inflammatory diseases.

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.

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.

Combination of cytogenetic classification and MRD status correlates with outcome of autologous versus allogeneic stem cell transplantation in adults with primary acute myeloid leukemia in first remission

Both autologous and allogeneic stem cell transplantation (auto- and allo-SCT) are treatment choice for adults with acute myeloid leukemia (AML) after complete remission (CR). However, the decision-making remains controversial in some situations. To figure out the treatment choice, we retrospectively investigated 172 consecutive patients with primary AML who received auto- (n=46) or allo-SCT (n=126) from a single transplant center. Auto- and allo-SCT group demonstrated comparable overall survival (OS) and disease-free survival (DFS) (P=0.616, P=0.559, respectively). Cytogenetic classification and minimal residual disease (MRD) after one course of consolidation were identified as independent risk factors for DFS (hazard ratio (HR), 1.800; 95% CI, 1.172-2.763; P=0.007; HR, 2.042; 95%CI, 1.003-4.154; P=0.049; respectively). We subsequently found that auto- and allo-SCT offered comparable DFS to patients with favorable or intermediate risk and were tested MRDneg after one course of consolidation (P=0.270) otherwise auto-SCT were inferior due to increased risk of leukemia relapse. Our study indicated that the combination of cytogenetic classification and MRD monitoring correlated with outcome of auto- versus allo-SCT and might help the choice between the two types of SCT for adults with primary AML, which is of significance for patients with expected intermediate prognosis in the current scenario.

BCR-ABL enhances the prolyl isomerase activity of Pin 1 by interacting with DAPK1 in ph+ALL

Philadelphia chromosome (Ph)/BCR‐ABL‐positive (ph+) ALL is the most common genetic abnormality associated with ALL and has been shown to confer the worst prognosis to both children and adults. Increasing evidence has revealed that the dysregulation of prolyl isomerase Pin 1 contributes to multicancer development and progression, including ALL, although the underlying molecular mechanisms remain unclear. Here, we report that the expression of Pin 1 was enhanced in ph+ ALL patient samples and was associated positively with the expression of BCR‐ABL. Genetically or pharmacologically inhibiting Pin 1 expression or activity produces potent therapeutic efficacy against ph+ ALL. We further demonstrated that BCR‐ABL enhances the prolyl isomerase activity of Pin 1 by decreasing the phosphorylated level of Pin 1 at Ser 71 and interacting with DAPK1. The inhibition of BCR‐ABL activity by imatinib in human ph+ ALL cells reduces the prolyl isomerase activity of Pin 1, further suggesting a key role of the newly identified BCR‐ABL‐Pin 1 axis in ph+ ALL progression. Thus, the combined suppression of Pin 1 and BCR‐ABL proteins may be exploited as an additional target therapy for ph+ ALL.

Effect of Antithymocyte Globulin Source on Outcomes of HLA-Matched Sibling Allogeneic Hematopoietic Stem Cell Transplantation for Patients with Severe Aplastic Anemia

We wanted to evaluate efficacy of porcine antithymocyte globulin (ATG) in HLA-matched sibling donor allogeneic hematopoietic stem cell transplantation (MSD-HSCT) for patients with severe aplastic anemia (SAA). The clinical data of 113 SAA patients who received MSD-HSCT from January 2005 to November 2016 were analyzed retrospectively. Of these, 58 patients received rabbit ATG as a part of conditioning regimen (R-ATG group), whereas the other 55 patients received porcine ATG (P-ATG group). Patient baseline characteristics and donor conditions of the 2 groups were similar, except patients were older and more received peripheral blood stem cell transplantation in the P-ATG group. All patients engrafted in 2 groups. There were significant differences in the incidence of acute (20.7% ± 5.3% versus 43.4% ± 7.0%, P = .015) and chronic graft-versus- host disease (GVHD; 20.1% ± 5.8% versus 46.0% ± 7.9%, P = .003) between the R-ATG and P-ATG groups. However, there were no significant differences in terms of 3-year overall survival (93.1% ± 3.3% versus 84.4% ± 5.7%, P = .235), grades III to IV acute GVHD (3.4% ± 2.4% versus 12.3% ± 4.7%, P = .098), moderate to severe chronic GVHD (12.6% ± 4.9% versus 11.5% ± 4.9%, P = .905), or graft rejection (7.4% ± 3.6% versus 5.5% ± 3.1%, P = .852). There was also no significant difference with regard to the incidence of severe bacterial infection (P = .075), invasive fungal disease (P = .701), or cytomeglovirus viremia (P = .770). P-ATG showed satisfactory efficacy and safety compared with R-ATG in the setting of MSD-HSCT for SAA patients. P-ATG could be a potential alternative preparation for R-ATG, further offering the advantage of lower costs.

Inflammation-Associated Cytokines IGFBP1 and RANTES Impair the Megakaryocytic Potential of HSCs in PT Patients after Allo-HSCT

Prolonged isolated thrombocytopenia (PT) is a severe complication in patients after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Whether the megakaryoctic potential of hematopoietic stem cells (HSCs) in bone marrow is intact and what factors drive the pathological process of PT remain elusive. A retrospective study in patients (n = 285) receiving HSCT revealed that the occurrence of PT was approximately 8% and the number of platelets and megakaryocytes in PT patients is much lower compared with control subjects. To test whether the deficiency of thrombopoiesis was caused by the activities of HSCs, the megakaryocytic differentiation potential of HSCs before or after transplantation was assessed. Interestingly, a substantial decrease of megakaryocytic differentiation was observed 2 weeks after transplantation of HSCs in all of the allo-HSCT recipients. However, 4 weeks after transplantation, the ability of HSCs to generate CD41+CD42b+ megakaryocytes in successful platelet engraftment patients recovered to the same level as those of HSCs before implantation. In contrast, HSCs derived from PT patients throughout the postimplantation period exhibited poor survival and failed to differentiate properly. A protein array analysis demonstrated that multiple inflammation-associated cytokines were elevated in allo-HSCT recipients with PT. Among them, insulin-like growth factor-binding protein 1 and regulated on activation, normal T cell expressed and secreted were found to significantly suppress the proliferation and megakaryocytic differentiation of HSCs in vitro. Our results suggested that the occurrence of PT may be attributed, at least partially, to the damage to HSC function caused by inflammation-associated cytokines after HSCT. These findings shed light on the mechanism underlying HSC megakaryocytic differentiation in PT patients and may provide potential new strategies for treating PT patients after HSCT.

Impact of Human Leukocyte Antigen Loci and Haplotypes on Intestinal Acute Graft-versus-host Disease after Human Leukocyte Antigen-matched Sibling Peripheral Blood Stem Cell Transplantation

Background: Acute graft-versus-host disease (aGVHD) is a common and severe complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Some studies have found that the presence of certain specific human leukocyte antigen (HLA) loci could affect the occurrence of aGVHD. Meanwhile, the impact of HLA haplotypes on aGVHD has been rarely studied. This study aimed to investigate the effects of HLA loci and haplotypes on intestinal aGVHD. Methods: Totally, 345 consecutive patients undergoing first HLA-matched sibling peripheral blood stem cell transplantation (PBSCT) from February 2004 to June 2013 at Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, were enrolled in this study. HLA loci and haplotypes of recipients with frequency over 5% were searched and their effects on intestinal aGVHD were investigated. Other important factors including donor age, recipient age, donor-recipient sex combinations, and conditioning regimens were also evaluated using logistic regression. Pure upper gastrointestinal tract aGVHD without diarrhea was excluded because the histological proof was unavailable. The follow-up end-point was 6 months after HSCT. Results: The cumulative incidence of intestinal aGVHD was 19.4%, with 18.0% of the patients classified as classic aGVHD and 1.4% as persistent, recurrent, or late aGVHD. Multivariate analysis showed that HLA-A31 locus (odds ratio [OR] 2.893, 95% confidence interval [CI] [1.054, 7.935], P = 0.039), HLA B40-DR15 (OR 3.133, 95% CI [1.250, 7.857], P = 0.015), and HLA B46-DR9 haplotypes (OR 2.580, 95% CI [1.070, 6.220], P = 0.035), female donor for male recipient (OR 2.434, 95% CI [1.319, 4.493], P = 0.004) were risk factors for intestinal aGVHD. Conclusion: The presence of certain HLA loci and haplotypes may influence the occurrence of intestinal aGVHD in PBSCT with HLA-identical sibling donors.

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

The Funding section is incorrect. The correct funding information is as follows: This study was supported by grants from the National Basic Research Program of China (2012CB966403 and 2015CB964903), the Chinese National Natural Science Foundation (31271484, 31471116, and 31171431), and the Tianjin Natural Science Foundation (12JCZDJC24600).