• IMMUNE NETWORK
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• v.14 no.4
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• pp.207-218
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• 2014

Chronic virus infection leads to the functional impairment of dendritic cells (DCs) as well as T cells, limiting the clinical usefulness of DC-based therapeutic vaccine against chronic virus infection. Meanwhile, B cells have been known to maintain the ability to differentiate plasma cells producing antibodies even during chronic virus infection. Previously, ${\alpha}$-galactosylceramide (${\alpha}GC$) and cognate peptide-loaded B cells were comparable to DCs in priming peptide-specific $CD8^+$ T cells as antigen presenting cells (APCs). Here, we investigated whether B cells activated by ${\alpha}GC$ can improve virus-specific T cell immune responses instead of DCs during chronic virus infection. We found that comparable to B cells isolated from naïve mice, chronic B cells isolated from chronically infected mice with lymphocytic choriomeningitis virus (LCMV) clone 13 (CL13) after ${\alpha}GC$-loading could activate CD1d-restricted invariant natural killer T (iNKT) cells to produce effector cytokines and upregulate co-stimulatory molecules in both naïve and chronically infected mice. Similar to naïve B cells, chronic B cells efficiently primed LCMV glycoprotein (GP) 33-41-specific P14 $CD8^+$ T cells in vivo, thereby allowing the proliferation of functional $CD8^+$ T cells. Importantly, when ${\alpha}GC$ and cognate epitope-loaded chronic B cells were transferred into chronically infected mice, the mice showed a significant increase in the population of epitope-specific $CD8^+$ T cells and the accelerated control of viremia. Therefore, our studies demonstrate that reciprocal activation between ${\alpha}GC$-loaded chronic B cells and iNKT cells can strengthen virus-specific T cell immune responses, providing an effective regimen of autologous B cell-based therapeutic vaccine to treat chronic virus infection.

• Korean Journal of Pharmacognosy
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• v.49 no.4
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• pp.291-297
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• 2018

Coxsackievirus B3 (CVB3) is a very well-known causative agent for viral myocarditis and meningitis in human. However, the effective vaccine and therapeutic drug are not developed yet. CVB3 infection activates host cell AKT signaling. Inhibition of AKT signaling pathway may attenuate CVB3 replication and prevent CVB3-mediate viral myocarditis. In this study, we determined antiviral effect of the selected natural plant extract to develop a therapeutic drug for CVB3 treatment. We screened several chemically extracted natural compounds by using HeLa cell-based cell survival assay. Among them, Linum usitatissimum L. extract was selected for antiviral drug candidate. L. usitatissimum extract significantly decreased CVB3 replication and cell death in CVB3 infected HeLa cells with no cytotoxicity. CVB3 protease 2A induced eIF4G1 cleavage and viral capsid protein VP1 production were dramatically decreased by L. usitatissimum extract treatment. In addition, virus positive and negative strand genome amplification were significantly decreased by 1 mg/ml L. usitatissimum extract treatment. Especially, L. usitatissimum extract was associated with inhibition of AKT signal and maintain mTOR activity. In contrast, Atg12 and LC3 expression were not changed by L. usitatissimum extract treatment. In this study, the potential AKT signal inhibitor, L. usitatissimum extract, was significantly inhibited viral genome replication and protein production by inhibition of AKT signal. These results suggested that L. usitatissimum extract is a novel therapeutic agent for treatment of CVB3-mediated diseases.

• Animal cells and systems
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• v.3 no.3
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• pp.337-341
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• 1999

Hepatitis C virus (HCV) is a positive strand RNA virus of the Flaviviridae family and the major cause of post-transfusion non-A, non-B hepatitis. Vaccine development for HCV is essential but has been slowed by poor understanding of the type of immunity that naturally terminates HCV infection. The DNA-based immunization technique offers the potential advantage of including cellular immune responses against conserved internal proteins of a virus, as well as the generation of antibodies to viral surface proteins. Here, we demonstrate that cell lines expressing the HCV core and/or NS3 proteins can induce a specific CTL response in mice, and these results suggest a possibility that the HCV core and NS3 DNA can be used to induce CTL activity against the antigen in mice and can be further developed as a therapeutic and preventive DNA vaccine.

• KSBB Journal
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• v.19 no.5
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• pp.341-347
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• 2004

Several gene delivery therapies are being developed for treatment of serum protein deficiency. EPO is one of the most promising therapeutic agent for this treatment which is currently being investigated in depth. This study has the ultimate purpose of improving the gene delivery system for an increase of red blood cell production. A plasmid DNA was constructed smaller than other plasmids for an increase in penetration into animal cells, and two genes were cloned into each vector as a co-delivery system to express erythropoietin, and interluekin-3 or thrombopoietin, which can act on erythroid cell, thus activating hematopoiesis synergically. This co-delivery system has an advantage of decreasing the labour required for industrial production of DNA vaccine. A new plasmid vector, pVAC, in size 2.9 kb, was constructed with the essential parts from PUC 19 and pSectagB, which is much smaller than other plasmid vector and is the size of 2.9 kb. Co-delivery system was constituted by cloning human erythropoietin with each of human interluekin-3 gene or human thrombopoietin gene into both pVAC and pSectagB. As a result, the transfection efficiency of pVAC was higer than that of pSectagB in vitro, and hematocrit level of the mice injected with pVAC is higher than that of other mice. And co-delivery system, made of several plasmid DNAs, was expressed in vitro.

• IMMUNE NETWORK
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• v.5 no.3
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• pp.163-171
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• 2005

Background: To perform the successful dendritic cell-based cancer immunotherapy one of the main issues to be solved is the source of antigen for DC pulsing. Limitations occur by using auto-tumor lysate due to the difficulties obtaining enough tumor tissue(s) quantitatively as well as qualitatively. In this study the possibility of allogeneic tumor cell lysate as a DC pulsing antigen has been tested in mouse melanoma pulmonary me tastasis model. Methods: B16F10 melanoma cells $(1{\timeS}10^5/mouse)$ were inoculated intra venously into the C57BL/6 mouse. Therapeutic DCs were cultured from the bone marrow myeloid lineage cells with GM-CSF and IL-4 (1,000 U/ml each) for 7 days and pulsed with lysate of either autologous B16F10 (B-DC), allogeneic K1735 (C3H/He origin; K-DC) or CloneM3 (DBA2 origin; C-DC) melanoma cells for 18 hrs. Pulsed-DCs $(1{\times}10^6/mouse)_{[CGP1]}$ were injected i.p. twice with one week interval starting from the day 1 after tumor cell inoculation. Results: Without observable toxicity, allogeneic tumor cell lysate pulsed-DC induced the significantly better anti-tumor response (tumor scale: $2.7{\pm}0.3,\;0.7{\pm}0.3\;and\;0.3{\pm}0.2$ for saline, B-DC and C-DC treated group, respectively). Along with increased tumor specific lymphocyte proliferations, induction of IFN-${\gamma}$ secretion against both auto- and allo-tumor cell lysates was observed from the DC treated mice. (w/B16F10-lysate: $44.97{\pm}10.31,\;1787.94{\pm}131.18,\;1257.15{\pm}48.27$, w/CloneM3 lysate: 0, $1591.13{\pm}1.83,\;1460.47{\pm}86.05pg/ml$ for saline, B-DC and C-DC treated group, respectively) Natural killer cell activity was also increased in the mice treated with tumor cell lysate pulsed-DC ($8.9{\pm}_{[CGP2]}0.1,\;11.6{\pm}0.8\;and\;12.6{\pm}0.7%$ specific NK activity for saline, B-DC and C-DC treated group, respectively). Conclusion: Conclusively, promising data were obtained that allogeneic-tumor cell lysate can be used as a tumor antigen for DC-based cancer immunotherapy.

• IMMUNE NETWORK
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• v.6 no.3
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• pp.154-162
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• 2006

Background: Dendritic cell (DC)-based cancer immunotherapy is studied for several years. However, it is mainly derived from autologous PBMC or leukapheresis from patient, which has limitations about yield and ability of DC production according to individual status. In order to solve these problems, inquiries about allogeneic DCs are performed but there are no preclinical trial answers for effect or toxicity of allogeneic DC to use for clinical trial. In this study, we compared the anti-tumor effect of allogeneic and autologous DCs from mouse bone marrow stem cells in mouse metastatic melanoma model. Methods: B16F10 melanoma cells ($5{\times}10^4$/mouse) were injected intravenously into the C57BL/6 mouse. Therapeutic DCs were differentiated from autologous (C57BL/6: CDC) or allogeneic (B6C3F1: BDC) bone marrow stem cells with GM-CSF, SCF and IL-4 for 13days and pulsed with B16F10 tumor cell lysate (Blys) for 18hrs. DC intra-peritoneal injections began on the 8th day after the tumor cell injection by twice with one week interval. Results: Anti-tumor response was observed by DC treatment without any toxicity especially in allogeneic DC treated mice (tumor burden score: $2.667{\pm}0.184,\;2.500{\pm}0.463,\;2.000{\pm}0.286,\;1.500{\pm}0.286,\;1.667 {\pm}0.297$ for saline, CDC/unpulsed-DC: U-DC, CDC/Blys-DC, BDC/U-DC and BDC/Blys-DC, respectively). IFN-${\gamma}$ secretion was significantly increased in allogeneic DC group stimulated with B16F10 cell lysate ($2,643.3{\pm}5,89.7,\;8,561.5{\pm}2,204.9.\;6,901.2{\pm}141.1pg/1{\times}10^6$ cells for saline, BDC/U-DC and BDC/Blys-DC, respectively) with increased NK cell activity. Conclusion: Conclusively, promising data was obtained that allogeneic DC can be used for DC-based cancer immunotherapy.

• IMMUNE NETWORK
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• v.11 no.1
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• pp.79-94
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• 2011

Background: Dendritic cell (DC)-based vaccines are currently being evaluated as a novel strategy for tumor vaccination and immunotherapy. However, inducing long-term regression in established tumor-implanted mice is difficult. Here, we show that deoxypohophyllotoxin (DPT) induces maturation and activation of bone marrow-derived DCs via Toll-like receptor (TLR) 4 activation of MAPK and NF-${\kappa}B$. Methods: The phenotypic and functional maturation of DPT-treated DCs was assessed by flow cytometric analysis and cytokine production, respectively. DPT-treated DCs was also used for mixed leukocyte reaction to evaluate T cell-priming capacity and for tumor regression against melanoma. Results: DPT promoted the activation of $CD8^+$ T cells and the Th1 immune response by inducing IL-12 production in DCs. In a B16F10 melanoma-implanted mouse model, we demonstrated that DPT-treated DCs (DPT-DCs) enhance immune priming and regression of an established tumor in vivo. Furthermore, migration of DPT-DCs to the draining lymph nodes was induced via CCR7 upregulation. Mice that received DPT-DCs displayed enhanced antitumor therapeutic efficacy, which was associated with increased IFN-${\gamma}$ production and induction of cytotoxic T lymphocyte activity. Conclusion: These findings strongly suggest that the adjuvant effect of DPT in DC vaccination is associated with the polarization of T effector cells toward a Th1 phenotype and provides a potential therapeutic antitumor immunity.