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4. DNA Methylation-Mediated Silencing of Mir-204 Enhances the Occurrence of T-Cell Acute Lymphoblastic Leukemia By Upregulating MMP-2 and MMP-9 through the NF-Κb Signaling Pathway

Author

Chen, Dabing, primary, Xiao, Tingting, additional, Lin, Dandan, additional, Zhu, Haojie, additional, Xu, Jingjing, additional, Luo, Xiaofeng, additional, Ren, Jinhua, additional, Zheng, Zhihong, additional, Chen, Zhizhe, additional, Hu, Jianda, additional, and Yang, Ting, additional

Published
2020
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6. Antibodies to Hepatitis B Surface Antigen (HBsAb) Are Acquired after Allogeneic Stem Cell Transplantation in Non-B Hepatitis Virus-Infected Patients but Disappear over Time

Author

Ren, Jinhua, primary, Xiao, Tingting, additional, Weng, Yingxi, additional, Zheng, Rong, additional, Zhang, Yu, additional, Xu, Jingjing, additional, Luo, Xiaofeng, additional, Zheng, Zhihong, additional, Chen, Zhizhe, additional, Hu, Jianda, additional, and Yang, Ting, additional

Published
2020
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9. Co-Transplantation of Mesenchymal Stem Cells Further Improves the Prognosis of Allo-HSCT in the Treatment of High Risk and Refractory/Relapse Hematologic Malignancies: A Single-Center Retrospective Study of 175 Patients

Author

Ren, Jinhua, primary, Luo, Xiaofeng, additional, Chen, Minmin, additional, Xiao, Min, additional, Li, Qian, additional, Lin, Kangni, additional, Zheng, Zhihong, additional, Chen, Zhizhe, additional, Hu, Jianda, additional, and Yang, Ting, additional

Published
2019
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21. Platelet-Targeted Gene Transfer Induces Antigen-Specific Immune Tolerance

Author

Luo Xiaofeng, Juan Chen, Jocelyn A. Schroeder, Qizhen Shi, Jianda Hu, and Christina K Baumgartner

Subjects
Genetic enhancement, Transgene, Immunology, Cell Biology, Hematology, Gene delivery, Biology, Biochemistry, Immune tolerance, Transplantation, Immune system, Platelet, Expression cassette
Abstract

Induction of antigen-specific immune tolerance is desirable in autoimmune diseases, transplantation, and gene therapy. Our previous studies have demonstrated that FVIII or FIX expression ectopically targeted to platelets under control of the platelet-specific αIIb promoter results in transgene protein storage in platelet α-granules. Further studies have demonstrated that lentivirus-mediated platelet-specific gene delivery to hematopoietic stem cells (HSCs) not only restores hemostasis but also induces antigen-specific immune tolerance in hemophilic mice. We wanted to explore whether platelet-specific gene transfer can be used as a means of immune tolerance induction. In the current study, we used ovalbumin (OVA) as a non-coagulant protein to further examine the potential of a platelet gene therapy-based immune tolerance induction approach. We constructed a lentiviral vector (LV) in which OVA is driven by the αIIb promoter (2bOVA). Evidence suggests that VWF propeptide can reroute unrelated secreting proteins to a storage pathway. Thus, we designed another vector, 2bVpOVA, which contains VWF propeptide to secure OVA storage in platelet granules. HSCs from wild type B6/CD45.2 mice were transduced with 2bOVA or 2bVpOVA LV and transplanted into B6/CD45.1 recipients preconditioned with 660 cGy total body irradiation. We found that 96% of OVA expression in whole blood was stored in platelets with a level of 51.3 ± 22.5 ng/108 platelets (n = 5) while 4% was detectable in plasma in 2bOVA-transduced recipients at 12-week after transplantation. This distribution is very similar to the results we obtained from the FIX study. In contrast, 98% of OVA was stored in platelets with a level of 3.9 ± 3.3 ng/108 platelets (n = 5) in 2bVpOVA-transduced recipients. The lower total OVA expression level in the 2bVpOVA group could be due to the size effect of transgene expression cassette as the 2bVpOVA cassette is 3-fold larger than the 2bOVA cassette. To investigate whether anti-OVA immune tolerance was established in recipients after platelet-specific OVA gene transfer, 16-weeks post-transplantation, animals were challenged with OVA. The titer of anti-OVA total IgG determined by ELISA assay was 640 ± 101 in the 2bOVA group and 320 ± 0 in the 2bVpOVA group. These titers were significantly lower than that obtained from the untransduced control group (10210 ± 3636), demonstrating that platelet-specific OVA gene delivery to HSCs can suppress the anti-OVA immune response. Of note, the titer of anti-OVA total IgG in the 2bVpOVA group was significantly lower than in the 2bOVA group although the total OVA expression levels in the 2bOVA group is 13-fold higher than in the 2bVpOVA group. The percentage of regulatory T cells in peripheral blood in 2bOVA and 2bVpOVA-transduced recipients was significantly higher than in untransduced control animals. In summary, our data demonstrate that targeting transgene expression and storage in platelet a-granules is a potentially promising approach for inducing immune tolerance. Disclosures No relevant conflicts of interest to declare.

Published
2014

23. Life-Threatening Complications Suspected Due to Clinical Pharmacokinetic Interaction Between Cyclosporine A and Triazole Antifungal Agents in Allogeneic Hematopoietic Stem Cell Transplantation (allo-HSCT) Recipients.

Author

Yang, Ting, primary, Fu, Danhui, additional, Hu, Jianda, additional, Zheng, Xiaoyun, additional, Luo, Xiaofeng, additional, Qiu, Hongqiang, additional, Wu, Xuemei, additional, Chen, Ruling, additional, and Chen, Zhizhe, additional

Published
2009
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24. Immune Tolerance Developed in Platelet-Targeted FVIII Gene Therapy in Hemophilia Mice Is CD4+T Cell-Mediated

Author

Chen, Yingyu, Luo, Xiaofeng, Chen, Juan, Schroeder, Jocelyn, Baumgartner, Christina K, Hu, Jianda, and Shi, Qizhen

Abstract

Immune response to factor VIII (FVIII) is not only a severe complication in protein replacement therapy, but also a major concern in gene therapy of hemophilia A. Our previous studies have demonstrated that platelet-targeted FVIII (2bF8) gene therapy together with in vivodrug-selection of transduced cells can not only rescue the bleeding diathesis but also induce anti-FVIII specific immune tolerance in FVIIInullmice. In the current study, we investigated 1) whether our non-selectable lentiviral vector (LV) for the induction of platelet-FVIII expression is sufficient to induce immune tolerance and 2) which cell compartment is tolerized after platelet gene therapy. Platelet-specific FVIII expression was introduced by 2bF8LV-transduction of hematopoietic stem cells followed by syngeneic transplantation into FVIIInullmice preconditioned with 660 cGy total body irradiation (TBI) or Busulfan (Bu) plus ATG (anti-thymocyte globulin). After bone marrow transplantation and reconstitution, animals were analyzed by PCR, qPCR, FVIII:C assay, and tail clipping test to confirm the success of 2bF8 gene therapy. Sixteen weeks after transplantation, animals were challenged with recombinant human FVIII (rhF8) via retro-orbital venous administration at a dose of 50 U/kg weekly for 4 weeks. The titers of anti-FVIII inhibitory antibodies (inhibitors) were determined by Bethesda assay. The CFSE-labeled CD4 T cell proliferation assay and ELISPOT-based memory B cell maturation assay were used to determine which cell compartment is tolerized to FVIII after 2bF8 gene therapy. The level of platelet-FVIII expression was 1.44 ± 0.39 mU/108platelets (n = 6) in the 660 cGy group, which is not significantly different from the level obtained from the Bu+ATG group [3.04 ± 1.19 mU/108platelets (n = 6)]. Even after rhF8 challenge, no antibodies were detected in 2bF8LV-transduced recipients in either group. In contrast, all animals in the control group that did not undergo gene therapy developed various levels of inhibitors (204±97 BU/ml, n=7). The frequency of regulatory T cells in both 660 cGy TBI (11.01±0.52%) and Bu+ATG (11.02±0.68%) groups were significantly higher than the control group (8.05±0.57%). T cell proliferation assay demonstrated that CD4+T cells from 2bF8 LV-transduced recipients that had been challenged with rhF8 did not proliferate when restimulated with rhF8 in vitro.The daughter CD4+T cells in the group with 10 U/ml of rhF8 were 5.84 ± 2.49% (n = 6), which was not significantly different from the control group without no rhF8 stimulation (0 U/ml) (5.33 ± 1.72%). CD4+T cells from primed FVIIInullmice did proliferate after rhF8 restimulation. The proliferated daughter cell was 13.12 ± 6.76% (n = 7) in the group with rhF8 (10 U/ml) re-stimulation, which is significantly higher than the group without rhF8 co-culture (4.99 ± 1.16%). Since FVIII-specific memory B cell maturation is CD4+T cell dependent, we isolated CD4+T and memory B cells from 2bF8LV-transduced or FVIIInullmice after rhF8 immunization and co-cultured with rhF8 followed by ELISPOT assay to examine the antibody secreting cells. No spots were detected when memory B cells from rhF8-primed FVIIInullmice were co-cultured with CD4+T cells from 2bF8LV-transduced recipients. In contrast, when memory B cells from either rhF8 immunized 2bF8LV-transduced or untreated FVIIInullmice were cultured with CD4+T cells from rhF8-primed FVIIInullmice, there were 142 and 205 anti-FVIII antibody secreting cells, respectively, detected per 106cells seeded. These results indicate that CD4+T cells from 2bF8LV-transduced mice are tolerized to rhF8 stimulation. In conclusion, 2bF8 lentiviral gene transfer without in vivoselection of genetically manipulated cells can introduce FVIII-specific immune tolerance in hemophilia A mice and this immune tolerance is CD4+T cell-mediated.

Published
2015
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25. Clinical Implications Of Severe Isolated Hepatic Gvhd Post-DLI

Author

Yang, Ting, Huang, Xu, Luo, Xiaofeng, Yuan, Xiaohong, Fu, Danhui, Chen, Zhizhe, and Hu, Jianda

Abstract

Donor lymphocyte transfusion (DLI) may induce the graft-versus-leukemia (GVL) effect, but may also increase the risk of graft-versus-host disease (GVHD). Thus, the escalating-dose DLI and/or co-administration with short-term immunosuppressive agents are one of the clinical strategies to keep the balance between GVHD / GVL nowadays.

Published
2013
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