Xiaobing Jiang

The enhanced anti-angiogenic and antitumor effects of combining flk1-based DNA vaccine and IP-10

The purpose of the present study was to evaluate the anti-vasculature effects and the anti-tumor effects of attenuated Salmonella typhimurium vaccine strain encoding murine vascular endothelial growth factor (VEGF) receptor-2 (flk1) in combination with plasmid DNA vector encoding the murine interferon-induced protein of 10kDa (IP-10 or CXCL10) gene. Mouse models of malignant melanoma (B16-F10) were treated with combining orally given attenuated S. typhimurium vaccine strain encoding flk1 with direct intratumoral injection of a non-viral plasmid DNA vector encoding the murine IP-10 gene. The volumes of tumors and survival of mice bearing B16-F10 tumors were observed. Cytolytic T lymphocyte (CTL) response was measured by cytotoxic assay, vessel density and tumor-cell proliferation were observed by immunostaining, and tumor apoptosis was determined by TUNEL staining. The results revealed the combination therapy groups showed more significantly inhibited tumor growth, apoptosis of tumor cells, and reduced neovascularization, cell proliferation, and developed a strong CTL response in these mice. In summary, the therapy of attenuated S. typhimurium vaccine strain encoding flk1 combined with the IP-10 gene has significant synergistic effect against tumors.

Improved therapeutic efficacy using vaccination with glioma lysate-pulsed dendritic cells combined with IP-10 in murine glioma.

The purpose of the present study was to evaluate the therapeutic efficacy of glioma lysate-pulsed DCs in combination with plasmid DNA vector encoding the murine interferon-induced protein of 10kDa (IP-10 or CXCL10) gene. Mouse models of brain glioma (GL261) were treated with combining glioma lysate-pulsed DCs with direct intratumoral injection of a nonviral plasmid DNA vector encoding the murine IP-10 gene. The survival of mice bearing GL261 glioma was observed. Enzyme-linked immuno-spot assay was used to determine the frequency of brain-infiltrating lymphocytes (BILs) capable of responding to GL261. Cytolytic T lymphocyte (CTL) response was measured by cytotoxic assay, vessel density and tumor cell proliferation were observed by immunostaining, and tumor apoptosis was determined by TUNEL staining. The results revealed that the combination therapy groups showed more significantly enhanced anti-tumor activity, attraction of lymphocytes into tumor tissues, apoptosis of tumor cells, and reduced neovascularization, cell proliferation, and developed a strong CTL response in these mice. In summary, the therapy of glioma lysate-pulsed DCs combined with the IP-10 gene has significant synergistic effect against glioma.

Adoptive transfer of pTRP2-specific CTLs expanding by bead-based artificial antigen-presenting cells mediates anti-melanoma response

Cytotoxic CD8(+) T cells are key effectors in the immunotherapy of malignant and viral diseases. However, the lack of efficient methods for their in vitro priming and expansion has become a bottleneck to the development of vaccines and adoptive transfer strategies. Synthetic artificial antigen-presenting cells (aAPCs) are now emerging as an attractive tool for eliciting and expanding CTL responses. This study reported a novel approach for targeting malignant melanoma with pTRP2-specific cytotoxic T lymphocytes (CTLs) expanded from the C57BL/6 splenocytes by multiple stimulations with aAPCs made by coating H-2K(b)-Ig/pTRP2 dimeric complexes, anti-CD28 antibody, 4-1BBL molecules and CD83 molecules to cell-sized latex beads. The induced CTLs exhibited specific lysis against RMA-S cells pulsed with the peptide pTRP2 and H-2K(b+) melanoma cells expressing TRP2, while a murine Lewis lung carcinoma cell line 3LL could not be recognized by the CTLs. The peptide-specific activity was inhibited by anti-H-2K(b) monoclonal antibody Y3. Adoptive Transfer of CTLs specific for malignant melanoma expanding by the aAPCs can mediate effective anti-melanoma response. These results suggested the bead-based aAPCs coated with an MHC-Ig/peptide complex, anti-CD28 antibody, 4-1BBL and CD83 could provide a useful tool for the reproducible expansion of specific CTLs for adoptive immunotherapy.

Dendritic Cell-Based Vaccine for the Treatment of Malignant Glioma: A Systematic Review

Objective: Glioblastoma multiforme (GBM) has a poor prognosis. The purpose of this systematic review and meta-analysis was to analyze the outcomes of clinical trials which compared immunotherapy with conventional therapy for the treatment of malignant gliomas. Methods: PubMed, Cochrane and Google Scholar databases were searched for relevant studies. The 2-year survival rate was used to evaluate effectiveness of immunotherapy. Results: Of 171 studies identified, six comparative trials were included in the systematic review. Immunotherapy was associated with a significantly longer OS and 2-year survival compared to conventional therapy. Conclusion: Immunotherapy may improve the survival of patients with GBM.

HLA Tetramer ^ Based Artificial Antigen-Presenting Cells Efficiently Stimulate CTLs Specific for Malignant Glioma

Purpose: The interleukin-13 receptor α2 (IL-13Rα2) is a glioma-restricted cell-surface epitope not otherwise detected within the central nervous system. Here, we report a novel approach for targeting malignant glioma with IL-13Rα2–specific CTLs. Experimental Design: Artificial antigen-presenting cells (aAPC) were made by coating human leukocyte antigen (HLA)-A2/pIL-13Rα2345-354 tetrameric complexes, anti-CD28 antibody, and CD83 molecules to cell-sized latex beads, and used to stimulate IL-13Rα2–specific CTLs from the peripheral blood mononuclear cells of HLA-A2+ healthy donors. After multiple stimulations, the induced CTLs were analyzed for tetramer staining, IFN-γ production, and CTL reactivity. Results: Tetramer staining assay showed that the induced CTLs specifically bound HLA-A2/pIL-13Rα2345-354 tetramers. The CTLs specifically produced IFN-γ in response to the HLA-A2/pIL-13Rα2345-354-aAPCs and exhibited specific lysis against T2 cells pulsed with the peptide pIL-13Rα2345-354 and HLA-A2+ glioma cells expressing IL-13Rα2345-354, whereas HLA-A2− glioma cell lines that express IL-13Rα2345-354 could not be recognized by the CTLs. The peptide-specific activity was inhibited by anti–HLA class I monoclonal antibody. Conclusion: The induced CTLs specific for IL-13Rα2345-354 peptide could be a potential target of specific immunotherapy for HLA-A2+ patients with malignant glioma.

MiR-338-5p suppresses proliferation, migration, invasion, and promote apoptosis of glioblastoma cells by directly targeting EFEMP1

OBJECTIVE We aimed to investigate the effect of miR-338-5p on proliferation, migration and invasion of glioblastoma (GBM) cells by regulating EFEMP1. METHODS The expression of miR-338-5p and EFEMP1 was measured by qRT-PCR and western blot. Transfection was conducted to regulate the expression of miR-338-5p and EFEMP1 in U87 cell lines. Cell proliferation, apoptosis, migration and invasion were evaluated using CCK-8 assay, flow cytometry and Transwell assay respectively. Dual luciferase reporter assay was performed to verify whether miR-338-5p directly targeted EFEMP1. RESULTS MiR-338-5p was significantly down-regulated in human GBM tumor tissues and cells while EFEMP1 was strongly upregulated (P<0.05). Upregulated miR-338-5p was able to suppress cell proliferation, migration, invasion, and promote cell apoptosis in GBM cells (P<0.05). Dual luciferase reporter gene assay determined that miR-338-5p directly targeted EFEMP1 (P<0.05). CONCLUSIONS MiR-338-5p suppressed proliferation, migration and invasion of GBM cells through inhibiting EFEMP1.

A novel recombinant protein of IP10-EGFRvIIIscFv and CD8+ cytotoxic T lymphocytes synergistically inhibits the growth of implanted glioma in mice

AbstractThe epidermal growth factor receptor (EGFR) mutant of EGFRvIII is highly expressed on glioma cells and has been thought to be an excellent target molecule for immunotherapy. IP-10 is a potent chemokine and can recruit CXCR3+ T cells, including CD8+ T cells that are important for the control of tumor growth. This study is aimed at investigating the therapeutic efficacy of a novel fusion protein of IP10-EGFRvIIIscFv (IP10-scFv) in combination with glioma lysate-pulsed DCs-activated CD8+ cytotoxic T lymphocytes (CTLs) in a mouse model of glioma. A plasmid of pET-IP10-scFv was generated by linking mouse IP-10 gene with the DNA fragment for anti-EGFRvIIIscFv, a (Gly4Ser)3 flexible linker and a His-tag. The recombinant IP10-scFv in E. coli was purified by affinity chromatography and characterized for its anti-EGFRvIII immunoreactivity and chemotactic activity. C57BL/6 mice were inoculated with mouse glioma GL261 cells in the brain and treated intracranially with IP10-scFv and/or intravenously with CTL for evaluating the therapeutic effect. The glioma-specific immune responses were examined. The IP10-scFv retained anti-EGFRvIII immunoreactivity and IP-10-like chemotactic activity. Treatment with both IP10-scFv and CTL synergistically inhibited the growth of glioma and prolonged the survival of tumor-bearing mice, accompanied by increasing the numbers of brain-infiltrating lymphocytes (BILs) and the frequency of CXCR3+CD8+ T cells, enhancing glioma-specific IFN-γ responses and cytotoxicity, and promoting glioma cell apoptosis in mice. Our novel data indicate that IP10-scFv and CTL have synergistic therapeutic effects on inhibiting the growth of mouse glioma in vivo.

In vivo anti-melanoma efficacy of allo-restricted CTLs specific for melanoma expanded by artificial antigen-presenting cells

Cytotoxic CD8+ T cells are key effectors in the immunotherapy of malignant and viral diseases. However, autologous T cell responses to tumor antigens presented by self-MHC are usually weak and ineffective. Allo-restricted T cells represent a potent source of tumor-specific T cells for adoptive immunotherapy. This study reports in vivo anti-melanoma efficacy of the pTRP2-specific allo-restricted CTLs expanded from the BALB/c splenocytes by multiple stimulations with aAPCs made by coating H-2Kb-Ig/pTRP2 dimeric complexes, anti-CD28 antibody, 4-1BBL molecules and CD83 molecules to cell-sized latex beads. The induced allo-restricted CTLs exhibited specific lysis against RMA-S cells pulsed with the peptide pTRP2 and H-2Kb+ melanoma cells expressing TRP2, while a murine Lewis lung carcinoma cell line 3LL could not be recognized by the CTLs. The peptide-specific activity was inhibited by anti-H-2Kb monoclonal antibody Y3. Adoptive transfer of the allo-restricted CTLs specific for malignant melanoma expanded by the aAPCs can mediate effective anti-melanoma response in vivo. These results suggested that the specific allo-restricted CTLs expanded by aAPCs coated with an MHC-Ig/peptide complex, anti-CD28 antibody, 4-1BBL and CD83 could be a potential option of specific immunotherapy for patients with malignant melanoma.

Human IP10-scFv and DC-induced CTL synergistically inhibit the growth of glioma in a xenograft model

The epidermal growth factor receptor (EGFR) mutant of EGFRvIII is highly expressed in glioma cells, and the EGFRvIII-specific dendritic cell (DC)-induced tumor antigen-specific CD8+ cytotoxic T lymphocytes (CTLs) may hold promise in cancer immunotherapy. Interferon (IFN)-γ-inducible protein (IP)-10 (IP-10) is a potent inhibitor of angiogenesis and can recruit CXCR3+ T cells, including CD8+ T cells, which are important for the control of tumor growth. In this study, we assessed if the combination of IP10-EGFRvIIIscFv with DC-induced CTLs would improve the therapeutic antitumor efficacy. IP10-scFv was generated by linking the human IP-10 gene with the DNA fragment for anti-EGFRvIIIscFv with a (Gly4Ser)3 flexible linker, purified by affinity chromatography, and characterized for its anti-EGFRvIII immunoreactivity and chemotactic activity. DCs were isolated from human peripheral blood monocyte cells and pulsed with EGFRvIII-peptide, then co-cultured with autologous CD8+ T cells. BALB/c-nu mice were inoculated with human glioma U87-EGFRvIII cells in the brain and treated intracranially with IP10-scFv and/or intravenously with DC-induced CTLs for evaluating the therapeutic effect. Treatment with both IP10-scFv and EGFRvIII peptide-pulsed, DC-induced CTL synergistically inhibited the growth of glioma and prolonged the survival of tumor-bearing mice, which was accompanied by the inhibition of tumor angiogenesis and enhancement of cytotoxicity, thereby increasing the numbers of brain-infiltrating lymphocytes (BILs) and prolonging the residence time of CTLs in the tumor.

Current status and potential challenges of mesenchymal stem cell-based therapy for malignant gliomas

Glioma, which accounts for more than 30% of primary central nervous system tumours, is characterised by symptoms such as headaches, epilepsy, and blurred vision. Glioblastoma multiforme is the most aggressive, malignant, and lethal brain tumour in adults. Even with progressive combination treatment with surgery, radiotherapy, and chemotherapy, the prognosis for glioma patients is still extremely poor. Compared with the poor outcome and slowly developing technologies for surgery and radiotherapy, the application of targeted chemotherapy with a new mechanism has become a research focus in this field.Moreover, targeted therapy is promising for most solid tumours. The tumour-tropic ability of stem cells, including neural stem cells and mesenchymal stem cells, provides an alternative therapeutic approach. Thus, mesenchymal stem cell-based therapy is based on a tumour-selective capacity and has been thought to be an effective anti-tumour option over the past decades. An increasing number of basic studies on mesenchymal stem cell-based therapy for gliomas has yielded complex outcomes.In this review, we summarise the biological characteristics of human mesenchymal stem cells, and the current status and potential challenges of mesenchymal stem cell-based therapy in patients with malignant gliomas.