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Dive into the research topics where Su-Hyung Park is active.

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Featured researches published by Su-Hyung Park.


Hepatology | 2005

Sustained E2 antibody response correlates with reduced peak viremia after hepatitis C virus infection in the chimpanzee.

Jin-Won Youn; Su-Hyung Park; Dimitri Lavillette; François-Loïc Cosset; Se-Hwan Yang; Chang Geun Lee; Hyun-Tak Jin; Chang-Min Kim; Mohamed T. Shata; Dong-Hun Lee; Wolfram Pfahler; Alfred M. Prince; Young Chul Sung

Immune correlates of protection against hepatitis C virus (HCV) infection are not well understood. Here we investigated 2 naive and 6 immunized chimpanzees before and after intravenous challenge, 12 weeks after the last immunization, with 100 50% chimpanzee infectious doses (CID50) of heterologous genotype 1b HCV. Vaccination with recombinant DNA and adenovirus vaccines expressing HCV core, E1E2, and NS3‐5 genes induced long‐term HCV‐specific antibody and T‐cell responses and reduced peak viral load about 100 times compared with controls (5.91 ± 0.38 vs. 3.81 ± 0.71 logs, respectively). There was a statistically significant inverse correlation between peak viral loads and envelope glycoprotein 2 (E2)‐specific antibody responses at the time of challenge. Interestingly, one vaccinee that had sterilizing immunity against slightly heterologous virus generated the highest level of E2‐specific total and neutralizing antibody responses as well as strong NS3/NS5‐specific T‐cell proliferative responses. The other four vaccinees with low levels of E2‐specific antibody had about 44‐fold reduced peak viral loads but eventually developed persistent infections. In conclusion, vaccine‐induced E2‐specific antibody plays an important role in prevention from nonhomologous virus infection and may provide new insight into the development of an effective HCV vaccine. (HEPATOLOGY 2005;42:1429–1436.)


Vaccine | 2003

Efficient induction of T helper 1 CD4+ T-cell responses to hepatitis C virus core and E2 by a DNA prime-adenovirus boost.

Su-Hyung Park; Se-Hwan Yang; Chang Geun Lee; Jin-Won Youn; Jun Chang; Young Chul Sung

Hepatitis C virus (HCV) is an important causative agent of liver disease, but currently there is no available prophylactic vaccine against HCV infection. Here, we investigated the HCV E2- and core-specific T-cell responses induced by DNA (D) and/or recombinant adenovirus (A) vaccines. In single (D versus A) or double immunizations (D-D versus A-A), the recombinant adenovirus vaccines induced higher levels of IFN-gamma secreting T-cell response and cytotoxic T lymphocytes (CTL) response than the DNA vaccines. However, a heterologous (D-A) regimen elicited the highest level of T helper 1 (Th1) CD4(+) T-cell responses. Furthermore, three E2-specific CTL epitopes were mapped using a peptide pool spanning the E2 protein sequence (a.a. 384-713) in BALB/c mice, and one of these (E2 405-414: SGPSQKIQLV) was shown to be immunodominant. Interestingly, no significant differences were found in the repertoire of E2-specific T-cell responses or in the immunodominance hierarchy of the three epitopes induced by D-D, D-A, A-A, and A-D, indicating that the breadth and hierarchy of T-cell responses is independent of these different vaccination regimens. In conclusion, the heterologous DNA prime-recombinant adenovirus boost regimen described offers an efficient promising strategy for the development of an effective T-cell-based HCV vaccine.


Journal of Virology | 2003

Optimal Induction of T-Cell Responses against Hepatitis C Virus E2 by Antigen Engineering in DNA Immunization

Jin-Won Youn; Su-Hyung Park; Jae Ho Cho; Young Chul Sung

ABSTRACT Although DNA immunization is a safe and efficient method for inducing cellular immune responses, it generates relatively weak and slow immune responses. Here, we investigated the effect of hepatitis C virus (HCV) antigen modifications on the induction of T-cell responses in DNA immunization. It is likely that the strength of T-cell responses has an inverse relationship with the length of the insert DNA. Interestingly, a mixture of several plasmids carrying each gene induced a higher level of T-cell responses than a single plasmid expressing a long polyprotein. Moreover, the presence of a transmembrane domain in HCV E2 resulted in stronger T-cell responses against E2 protein than its absence. Taken together, our results indicate that the tailored modifications of DNA-encoded antigens are capable of optimizing the induction of T-cell responses which is required for eliminating the cells chronically infected with highly variable viruses such as HCV and human immunodeficiency virus.


Gut and Liver | 2011

Serum IP-10 Levels Correlate with the Severity of Liver Histopathology in Patients Infected with Genotype-1 HCV

Chan Ran You; Su-Hyung Park; Sung Won Jeong; Hyun Young Woo; Si Hyun Bae; Jong Young Choi; Young Chul Sung; Seung Kew Yoon

Background/Aims Interferon-γ-inducible protein 10 (IP-10) plays important roles in the pathogenesis of hepatitis C virus (HCV) infection. We investigated the association between serum IP-10 levels and liver pathology in patients with chronic HCV infection. Methods The serum IP-10 concentration was assessed in 85 patients with chronic HCV infection using a solid phase sandwich enzyme-linked immunosorbent assay, and a liver biopsy specimen was obtained. The pathology was scored using the Knodell histologic activity index (HAI). Results Of the 85 patients, 58 had genotype 1 HCV infection, 21 had genotype non-1, and 6 were undetermined. The serum IP-10 levels did not differ between patients infected with genotype 1 and genotype non-1 (p=0.472). In patients with genotype 1 infection, the total HAI score and the stage of fibrosis were highly correlated with the serum IP-10 level (r=0.555, r=0.578, p<0.001). Furthermore, the serum IP-10 concentrations of patients with severe fibrosis (stages 3, 4) were higher than those of patients with mild fibrosis (stages 0 to 2; 214.4 vs. 72.3 pg/mL, p=0.002) among patients with genotype 1 infection. However, in patients without genotype 1 infection, the histopathology was not associated with the serum IP-10 level. A multivariate analysis showed that serum IP-10 was an independent predictor of fibrosis (stages 3, 4) in patients with genotype 1 infection (odds ratio, 1.034; 95% confidence interval, 1.006 to 1.064; p=0.018). Conclusions Serum IP-10 concentration was significantly correlated with the severity of liver histology in genotype 1 HCV infection.


Cancer Gene Therapy | 2008

Adenovirus-mediated gene transfer of interleukin-23 shows prophylactic but not therapeutic antitumor effects

Hyun-Tak Jin; Jin-Won Youn; Choi Sy; Sang-Hwan Seo; Su-Hyung Park; Song My; Yang Sh; Young-Chul Sung

A novel cytokine interleukin (IL)-23 bears a structural and functional resemblance to IL-12. A recombinant adenovirus expressing IL-23N220L (recombinant replication-defective adenovirus (rAd)/IL-23N220L) that selectively secrets IL-23 was constructed and compared with rAd/IL-12N220L in terms of immunological and antitumor effects. In a prophylactic setting, vaccination with rAd/ovalbumin (OVA) and rAd/IL-23N220L enhanced OVA-specific CD8+ T-cell responses that were closely associated with complete protection against the subsequent challenge of OVA-expressing E.G7 thymoma. However, in a therapeutic setting, the intratumoral injection of rAd/IL-23N220L showed only marginal antitumor activity against several established tumors such as E.G7, CT26 and B16F10. Interestingly, whereas IL-23 still induced tumor-specific CD8+ T-cell responses, it could not activate natural killer (NK) cells in vitro and in vivo. In addition, the adoptive transfer of activated NK cells partially restored the therapeutic antitumor effect of IL-23, indicating that NK cells are one of the crucial factors responsible for the regression of established tumors. Taken together, we demonstrated that adenovirus-mediated gene transfer of IL-23 induces a potent prophylactic, but not a therapeutic, antitumor effect.


Immune Network | 2010

Codelivery of IL-7 Augments Multigenic HCV DNA Vaccine-induced Antibody as well as Broad T Cell Responses in Cynomolgus Monkeys.

Su-Hyung Park; Mi-Young Song; Hyo Jung Nam; Se Jin Im; Young-Chul Sung

Background A crucial limitation of DNA vaccines is its weak immunogenicity, especially in terms of eliciting antibody responses in non-human primates or humans; therefore, it is essential to enhance immune responses to vaccination for the development of successful DNA vaccines for humans. Methods Here, we approached this issue by evaluating interleukin-7 (IL-7) as a genetic adjuvant in cynomolgus monkeys immunized with multigenic HCV DNA vaccine. Results Codelivery of human IL-7 (hIL-7)-encoding DNA appeared to increase DNA vaccine-induced antibody responses specific for HCV E2 protein, which plays a critical role in protecting from HCV infection. HCV-specific T cell responses were also significantly enhanced by codelivery of hIL-7 DNA. Interestingly, the augmentation of T cell responses by codelivery of hIL-7 DNA was shown to be due to the enhancement of both the breadth and magnitude of immune responses against dominant and subdominant epitopes. Conclusion Taken together, these findings suggest that the hIL-7-expressing plasmid serves as a promising vaccine adjuvant capable of eliciting enhanced vaccine-induced antibody and broad T cell responses.


Vaccine | 2008

Codelivery of PEG-IFN-α inhibits HCV DNA vaccine-induced T cell responses but not humoral responses in African green monkeys

Su-Hyung Park; Sang Rae Lee; Byung Hwa Hyun; Byong-Moon Kim; Young Chul Sung

Although pegylated interferon alpha (PEG-IFN-alpha) with ribavirin treatment constitutes an effective means of treatment for chronic hepatitis C, novel approaches are needed due to the inefficient effects of the current therapy against chronic infection with genotype 1 virus. In this study, the immunomodulatory effects of PEG-IFN-alpha on multigenic HCV DNA vaccine-induced immunity were investigated in African green monkeys. Multigenic HCV DNA vaccination with and without PEG-IFN-alpha was safe and well tolerated, and induced significant long-term T cell and antibody responses. In addition, the induced immune responses were gradually increased by repeated injection. Interestingly, co-treatment with PEG-IFN-alpha significantly suppressed HCV DNA vaccine-induced T cell responses, but not antibody responses, which demonstrated that IFN-alpha could act as a negative regulator of T cell immune induction. However, the suppression of T cell responses by PEG-IFN-alpha could be overcome by two times more DNA vaccination, which suggests that combined therapy of DNA vaccine with PEG-IFN-alpha might be possible. Our results provide valuable information for the design of an effective therapeutic regimen to treat chronic HCV infection and to understand the immunomodulatory roles of PEG-IFN-alpha in immune induction by DNA vaccination.


Vaccine | 2005

The synthetic peptide Trp-Lys-Tyr-Met-Val-d-Met as a novel adjuvant for DNA vaccine

Chang Geun Lee; So Young Choi; Su-Hyung Park; Ki Seok Park; Sung Ho Ryu; Young Chul Sung


Archive | 2003

Vaccine enhancing the protective immunity to hepatitis c virus using plasmid DNA and recombinant adenovirus

Young Chul Sung; Jin-Won Youn; Se-Hwan Yang; Su-Hyung Park; Chang Geun Lee


Immune Network | 2007

Enhancement of Antigen-specific Antibody and CD8+ T Cell Responses by Codelivery of IL-12-encapsulated Microspheres in Protein and Peptide Vaccination

Su-Hyung Park; Jun Chang; Se-Hwan Yang; Hye-Ju Kim; Hyun-Hee Kwak; Byong-Moon Kim; Sung-Hee Lee; Young Chul Sung

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Young Chul Sung

Pohang University of Science and Technology

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Se-Hwan Yang

Pohang University of Science and Technology

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Chang Geun Lee

Pohang University of Science and Technology

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Jin-Won Youn

Pohang University of Science and Technology

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Hyun-Tak Jin

Pohang University of Science and Technology

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Jun Chang

Ewha Womans University

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So Young Choi

Pohang University of Science and Technology

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Young-Chul Sung

Pohang University of Science and Technology

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Byung Hwa Hyun

Korea Research Institute of Bioscience and Biotechnology

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Chan Ran You

Catholic University of Korea

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