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Journal of Biomedicine and Biotechnology
Volume 2010 (2010), Article ID 263810, 10 pages
http://dx.doi.org/10.1155/2010/263810
Review Article

Immune Response of Cytotoxic T Lymphocytes and Possibility of Vaccine Development for Hepatitis C Virus Infection

Division of Gastroenterology, Department of Medicine, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8666, Japan

Received 11 November 2009; Revised 25 January 2010; Accepted 15 March 2010

Academic Editor: Zhengguo Xiao

Copyright © 2010 Kazumasa Hiroishi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Linked References

  1. Q.-L. Choo, G. Kuo, A. J. Weiner, L. R. Overby, D. W. Bradley, and M. Houghton, “Isolation of a cDNA clone derived from a blood-borne non-A, non-B viral hepatitis genome,” Science, vol. 244, no. 4902, pp. 359–362, 1989. View at Scopus
  2. K. L. Yap, G. L. Ada, and I. F. C. McKenzie, “Transfer of specific cytotoxic T lymphocytes protects mice inoculated with influenza virus,” Nature, vol. 273, no. 5659, pp. 238–239, 1978. View at Scopus
  3. R. M. Zinkernagel, E. Haenseler, T. Leist, A. Cerny, H. Hengartner, and A. Althage, “T cell-mediated hepatitis in mice infected with lymphocytic choriomeningitis virus. Liver cell destruction by H-2 class I-restricted virus-specific cytotoxic T cells as a physiological correlate of the 51Cr-release assay?” Journal of Experimental Medicine, vol. 164, no. 4, pp. 1075–1092, 1986. View at Scopus
  4. C. E. Samuel, “Antiviral actions of interferons,” Clinical Microbiology Reviews, vol. 14, no. 4, pp. 778–809, 2001. View at Publisher · View at Google Scholar · View at Scopus
  5. Y.-J. Liu, H. Kanzler, V. Soumelis, and M. Gilliet, “Dendritic cell lineage, plasticity and cross-regulation,” Nature Immunology, vol. 2, no. 7, pp. 585–589, 2001. View at Publisher · View at Google Scholar · View at Scopus
  6. H. Watarai, E. Sekine, S. Inoue, R. Nakagawa, T. Kaisho, and M. Taniguchi, “PDC-TREM, a plasmacytoid dendritic cell-specific receptor, is responsible for augmented production of type I interferon,” Proceedings of the National Academy of Sciences of the United States of America, vol. 105, no. 8, pp. 2993–2998, 2008. View at Publisher · View at Google Scholar · View at Scopus
  7. A. Ahmad and F. Alvarez, “Role of NK and NKT cells in the immunopathogenesis of HCV-induced hepatitis,” Journal of Leukocyte Biology, vol. 76, no. 4, pp. 743–759, 2004. View at Publisher · View at Google Scholar · View at Scopus
  8. J. Banchereau and R. M. Steinman, “Dendritic cells and the control of immunity,” Nature, vol. 392, no. 6673, pp. 245–252, 1998. View at Publisher · View at Google Scholar · View at Scopus
  9. D. Kägi, F. Vignaux, B. Ledermann, et al., “Fas and perforin pathways as major mechanisms of T cell-mediated cytotoxicity,” Science, vol. 265, no. 5171, pp. 528–530, 1994. View at Scopus
  10. H. Kojima, N. Shinohara, S. Hanaoka, et al., “Two distinct pathways of specific killing revealed by perforin mutant cytotoxic T lymphocytes,” Immunity, vol. 1, no. 5, pp. 357–364, 1994. View at Scopus
  11. K. Ando, K. Hiroishi, T. Kaneko, et al., “Perforin, Fas/Fas ligand, and TNF-α pathways as specific and bystander killing mechanisms of hepatitis C virus-specific human CTL,” Journal of Immunology, vol. 158, no. 11, pp. 5283–5291, 1997. View at Scopus
  12. K. Ando, T. Moriyama, L. G. Guidotti, et al., “Mechanisms of class I restricted immunopathology. A transgenic mouse model of fulminant hepatitis,” Journal of Experimental Medicine, vol. 178, no. 5, pp. 1541–1554, 1993. View at Publisher · View at Google Scholar · View at Scopus
  13. H. Doi, K. Hiroishi, T. Shimazaki, et al., “Magnitude of CD8+ T-cell responses against hepatitis C virus and severity of hepatitis do not necessarily determine outcomes in acute hepatitis C virus infection,” Hepatology Research, vol. 39, no. 3, pp. 256–265, 2009. View at Publisher · View at Google Scholar · View at Scopus
  14. G. M. Lauer, E. Barnes, M. Lucas, et al., “High resolution analysis of cellular immune responses in resolved and persistent hepatitis C virus infection,” Gastroenterology, vol. 127, no. 3, pp. 924–936, 2004. View at Publisher · View at Google Scholar · View at Scopus
  15. D. Yerly, D. Heckerman, T. M. Allen, et al., “Increased cytotoxic T-lymphocyte epitope variant cross-recognition and functional avidity are associated with hepatitis C virus clearance,” Journal of Virology, vol. 82, no. 6, pp. 3147–3153, 2008. View at Publisher · View at Google Scholar · View at Scopus
  16. K. Hiroishi, H. Kita, M. Kojima, et al., “Cytotoxic T lymphocyte response and viral load in hepatitis C virus infection,” Hepatology, vol. 25, no. 3, pp. 705–712, 1997. View at Publisher · View at Google Scholar · View at Scopus
  17. S. Zeuzem, “Hepatitis C virus: kinetics and quasispecies evolution during anti-viral therapy,” Forum, vol. 10, no. 1, pp. 32–42, 2000. View at Scopus
  18. S. Guglietta, A. R. Garbuglia, L. Salichos, et al., “Impact of viral selected mutations on T cell mediated immunity in chronically evolving and self limiting acute HCV infection,” Virology, vol. 386, no. 2, pp. 398–406, 2009. View at Publisher · View at Google Scholar · View at Scopus
  19. A. L. Hughes, M. A. K. Hughes, and R. Friedman, “Variable intensity of purifying selection on cytotoxic T-lymphocyte epitopes in hepatitis C virus,” Virus Research, vol. 123, no. 2, pp. 147–153, 2007. View at Publisher · View at Google Scholar · View at Scopus
  20. A. Maki, M. Matsuda, M. Asakawa, H. Kono, H. Fujii, and Y. Matsumoto, “Decreased CD3 ζ molecules of T lymphocytes from patients with hepatocellular carcinoma associated with hepatitis C virus,” Hepatology Research, vol. 27, no. 4, pp. 272–278, 2003. View at Publisher · View at Google Scholar · View at Scopus
  21. G. Missale, E. Cariani, and C. Ferrari, “Role of viral and host factors in HCV persistence: which lesson for therapeutic and preventive strategies?” Digestive and Liver Disease, vol. 36, no. 11, pp. 703–711, 2004. View at Publisher · View at Google Scholar · View at Scopus
  22. V. Francavilla, D. Accapezzato, M. De Salvo, et al., “Subversion of effector CD8+ T cell differentiation in acute hepatitis C virus infection: exploring the immunological mechanisms,” European Journal of Immunology, vol. 34, no. 2, pp. 427–437, 2004. View at Publisher · View at Google Scholar · View at Scopus
  23. S. Urbani, B. Amadei, D. Tola, et al., “PD-1 expression in acute hepatitis C virus (HCV) infection is associated with HCV-specific CD8 exhaustion,” Journal of Virology, vol. 80, no. 22, pp. 11398–11403, 2006. View at Publisher · View at Google Scholar · View at Scopus
  24. L. Golden-Mason, B. Palmer, J. Klarquist, J. A. Mengshol, N. Castelblanco, and H. R. Rosen, “Upregulation of PD-1 expression on circulating and intrahepatic hepatitis C virus-specific CD8+ T cells associated with reversible immune dysfunction,” Journal of Virology, vol. 81, no. 17, pp. 9249–9258, 2007. View at Publisher · View at Google Scholar · View at Scopus
  25. L. Golden-Mason, J. Klarquist, A. S. Wahed, and H. R. Rosen, “Cutting edge: programmed death-1 expression is increased on immunocytes in chronic hepatitis C virus and predicts failure of response to antiviral therapy: race-dependent differences,” Journal of Immunology, vol. 180, no. 6, pp. 3637–3641, 2008. View at Scopus
  26. N. Nakamoto, H. Cho, A. Shaked, et al., “Synergistic reversal of intrahepatic HCV-specific CD8 T cell exhaustion by combined PD-1/CTLA-4 blockade,” PLoS Pathogens, vol. 5, no. 2, Article ID e1000313, 2009. View at Publisher · View at Google Scholar · View at Scopus
  27. M. Kriegs, T. Bürckstümmer, K. Himmelsbach, et al., “The hepatitis C virus non-structural NS5A protein impairs both the innate and adaptive hepatic immune response in vivo,” Journal of Biological Chemistry, vol. 284, no. 41, pp. 28343–28351, 2009. View at Publisher · View at Google Scholar · View at Scopus
  28. Z. Q. Yao, D. T. Nguyen, A. I. Hiotellis, and Y. S. Hahn, “Hepatitis C virus core protein inhibits human T lymphocyte responses by a complement-dependent regulatory pathway,” Journal of Immunology, vol. 167, no. 9, pp. 5264–5272, 2001. View at Scopus
  29. D. J. Kittlesen, K. A. Chianese-Bullock, Z. Q. Yao, T. J. Braciale, and Y. S. Hahn, “Interaction between complement receptor gC1qR and hepatitis C virus core protein inhibits T-lymphocyte proliferation,” Journal of Clinical Investigation, vol. 106, no. 10, pp. 1239–1249, 2000. View at Scopus
  30. Z. Q. Yao, A. Eisen-Vandervelde, S. Ray, and Y. S. Hahn, “HCV core/gC1qR interaction arrests T cell cycle progression through stabilization of the cell cycle inhibitor p27Kip1,” Virology, vol. 314, no. 1, pp. 271–282, 2003. View at Publisher · View at Google Scholar · View at Scopus
  31. K. V. Konan, T. H. Giddings Jr., M. Ikeda, K. Li, S. M. Lemon, and K. Kirkegaard, “Nonstructural protein precursor NS4A/B from hepatitis C virus alters function and ultrastructure of host secretory apparatus,” Journal of Virology, vol. 77, no. 14, pp. 7843–7855, 2003. View at Publisher · View at Google Scholar · View at Scopus
  32. P. Sarobe, J. J. Lasarte, A. Zabaleta, et al., “Hepatitis C virus structural proteins impair dendritic cell maturation and inhibit in vivo induction of cellular immune responses,” Journal of Virology, vol. 77, no. 20, pp. 10862–10871, 2003. View at Publisher · View at Google Scholar · View at Scopus
  33. G. Szabo and A. Dolganiuc, “Subversion of plasmacytoid and myeloid dendritic cell functions in chronic HCV infection,” Immunobiology, vol. 210, no. 2–4, pp. 237–247, 2005. View at Publisher · View at Google Scholar · View at Scopus
  34. P.-Y. Lozach, H. Lortat-Jacob, A. de Lacroix de Lavalette, et al., “DC-SIGN and L-SIGN are high affinity binding receptors for hepatitis C virus glycoprotein E2,” Journal of Biological Chemistry, vol. 278, no. 22, pp. 20358–20366, 2003. View at Publisher · View at Google Scholar · View at Scopus
  35. S. Pöhlmann, J. Zhang, F. Baribaud, et al., “Hepatitis C virus glycoproteins interact with DC-SIGN and DC-SIGNR,” Journal of Virology, vol. 77, no. 7, pp. 4070–4080, 2003. View at Publisher · View at Google Scholar · View at Scopus
  36. C. Aloman, S. Gehring, P. Wintermeyer, N. Kuzushita, and J. R. Wands, “Chronic ethanol consumption impairs cellular immune responses against HCV NS5 protein due to dendritic cell dysfunction,” Gastroenterology, vol. 132, no. 2, pp. 698–708, 2007. View at Publisher · View at Google Scholar · View at Scopus
  37. T. Boettler, H. C. Spangenberg, C. Neumann-Haefelin, et al., “T cells with a CD4+CD25+ regulatory phenotype suppress in vitro proliferation of virus-specific CD8+ T cells during chronic hepatitis C virus infection,” Journal of Virology, vol. 79, no. 12, pp. 7860–7867, 2005. View at Publisher · View at Google Scholar · View at Scopus
  38. D. Accapezzato, V. Francavilla, M. Paroli, et al., “Hepatic expansion of a virus-specific regulatory CD8+ T cell population in chronic hepatitis C virus infection,” Journal of Clinical Investigation, vol. 113, no. 7, pp. 963–972, 2004. View at Publisher · View at Google Scholar · View at Scopus
  39. M. Sakaki, K. Hiroishi, T. Baba, et al., “Intrahepatic status of regulatory T cells in autoimmune liver diseases and chronic viral hepatitis,” Hepatology Research, vol. 38, no. 4, pp. 354–361, 2008. View at Publisher · View at Google Scholar · View at Scopus
  40. A. J. MacDonald, M. Duffy, M. T. Brady, et al., “CD4 T helper type 1 and regulatory T cells induced against the same epitopes on the core protein in hepatitis C virus-infected persons,” Journal of Infectious Diseases, vol. 185, no. 6, pp. 720–727, 2002. View at Publisher · View at Google Scholar · View at Scopus
  41. F. Belardelli, “Role of interferons and other cytokines in the regulation of the immune response,” APMIS, vol. 103, no. 3, pp. 161–179, 1995. View at Scopus
  42. S.-H. Fang, L.-H. Hwang, D.-S. Chen, and B.-L. Chiang, “Ribavirin enhancement of hepatitis C virus core antigen-specific type 1 T helper cell response correlates with the increased IL-12 level,” Journal of Hepatology, vol. 33, no. 5, pp. 791–798, 2000. View at Publisher · View at Google Scholar · View at Scopus
  43. D. F. Tough, P. Borrow, and J. Sprent, “Induction of bystander T cell proliferation by viruses and type I interferon in vivo,” Science, vol. 272, no. 5270, pp. 1947–1950, 1996. View at Scopus
  44. K. Hiroishi, T. Tüting, and M. T. Lotze, “IFN-α-expressing tumor cells enhance generation and promote survival of tumor-specific CTLs,” Journal of Immunology, vol. 164, no. 2, pp. 567–572, 2000. View at Scopus
  45. S. Gehring, S. H. Gregory, N. Kuzushita, and J. R. Wands, “Type 1 interferon augments DNA-based vaccination against hepatitis C virus core protein,” Journal of Medical Virology, vol. 75, no. 2, pp. 249–257, 2005. View at Publisher · View at Google Scholar · View at Scopus
  46. C. B. Willberg, S. M. Ward, R. F. Clayton, et al., “Protection of hepatocytes from cyototoxic T cell mediated killing by interferon-alpha,” PLoS One, vol. 2, no. 8, article e791, 2007. View at Publisher · View at Google Scholar · View at Scopus
  47. A. J. Freeman, G. Marinos, R. A. Ffrench, and A. R. Lloyd, “Intrahepatic and peripheral blood virus-specific cytotoxic T lymphocyte activity is associated with a response to combination IFN-α and ribavirin treatment among patients with chronic hepatitis C virus infection,” Journal of Viral Hepatitis, vol. 12, no. 2, pp. 125–129, 2005. View at Publisher · View at Google Scholar · View at Scopus
  48. H. Kita, T. Moriyama, T. Kaneko, et al., “HLA B44-restricted cytotoxic T lymphocytes recognizing an epitope on hepatitis C virus nucleocapsid protein,” Hepatology, vol. 18, no. 5, pp. 1039–1044, 1993. View at Publisher · View at Google Scholar · View at Scopus
  49. H. Kita, K. Hiroishi, T. Moriyama, et al., “A minimal and optimal cytotoxic T cell epitope within hepatitis C virus nucleoprotein,” Journal of General Virology, vol. 76, no. 12, pp. 3189–3193, 1995. View at Scopus
  50. T. Kaneko, I. Nakamura, H. Kita, K. Hiroishi, T. Moriyama, and M. Imawari, “Three new cytotoxic T cell epitopes identified within the hepatitis C virus nucleoprotein,” Journal of General Virology, vol. 77, no. 6, pp. 1305–1309, 1996. View at Scopus
  51. T. Hakamada, K. Funatsuki, H. Morita, et al., “Identification of novel hepatitis C virus-specific cytotoxic T lymphocyte epitopes by ELISpot assay using peptides with human leukocyte antigen-A2402-binding motifs,” Journal of General Virology, vol. 85, no. 6, pp. 1521–1531, 2004. View at Publisher · View at Google Scholar · View at Scopus
  52. K. Ito, K. Shiraki, K. Funatsuki, et al., “Identification of novel hepatitis C virus-specific cytotoxic T lymphocyte epiotpe in NS3 region,” Hepatology Research, vol. 36, no. 4, pp. 294–300, 2006. View at Publisher · View at Google Scholar · View at Scopus
  53. T. Mashiba, K. Udaka, Y. Hirachi, et al., “Identification of CTL epitopes in hepatitis C virus by a genome-wide computational scanning and a rational design of peptide vaccine,” Immunogenetics, vol. 59, no. 3, pp. 197–209, 2007. View at Publisher · View at Google Scholar · View at Scopus
  54. Y. Takao, A. Yamada, S. Yutani, et al., “Identification of new immunogenic peptides in conserved regions of hepatitis C virus (HCV) 1b with the potentiality to generate cytotoxic T lymphocytes in HCV1b+HLA-A24+ patients,” Hepatology Research, vol. 37, no. 3, pp. 186–195, 2007. View at Publisher · View at Google Scholar · View at Scopus
  55. S. Matsueda, A. Yamada, Y. Takao, et al., “A new epitope peptide derived from hepatitis C virus 1b possessing the capacity to induce cytotoxic T-lymphocytes in HCV1b-infected patients with HLA-A11, -A31, and -A33,” Cancer Immunology, Immunotherapy, vol. 56, no. 9, pp. 1359–1366, 2007. View at Publisher · View at Google Scholar · View at Scopus
  56. D. Yerly, D. Heckerman, T. Allen, et al., “Design, expression, and processing of epitomized hepatitis C virus-encoded CTL epitopes,” Journal of Immunology, vol. 181, no. 9, pp. 6361–6370, 2008. View at Scopus
  57. T. Kaneko, T. Moriyama, K. Udaka, et al., “Impaired induction of cytotoxic T lymphocytes by antagonism of a weak agonist borne by a variant hepatitis C virus epitope,” European Journal of Immunology, vol. 27, no. 7, pp. 1782–1787, 1997. View at Publisher · View at Google Scholar · View at Scopus
  58. S. Gehring, S. H. Gregory, P. Wintermeyer, M. San Martin, C. Aloman, and J. R. Wands, “Generation and characterization of an immunogenic dendritic cell population,” Journal of Immunological Methods, vol. 332, no. 1-2, pp. 18–30, 2008. View at Publisher · View at Google Scholar · View at Scopus
  59. S. Gehring, S. H. Gregory, P. Wintermeyer, C. Aloman, and J. R. Wands, “Generation of immune responses against hepatitis C virus by dendritic cells containing NS5 protein-coated microparticles,” Clinical and Vaccine Immunology, vol. 16, no. 2, pp. 163–171, 2009. View at Publisher · View at Google Scholar · View at Scopus
  60. H. Yu, H. Huang, J. Xiang, L. A. Babiuk, and S. van Drunen Littel-van den Hurk, “Dendritic cells pulsed with hepatitis C virus NS3 protein induce immune responses and protection from infection with recombinant vaccinia virus expressing NS3,” Journal of General Virology, vol. 87, no. 1, pp. 1–10, 2006. View at Publisher · View at Google Scholar · View at Scopus
  61. P. Li, Q. Wan, Y. Feng, et al., “Engineering of N-glycosylation of hepatitis C virus envelope protein E2 enhances T cell responses for DNA immunization,” Vaccine, vol. 25, no. 8, pp. 1544–1551, 2007. View at Publisher · View at Google Scholar · View at Scopus
  62. M. Liu, H. Chen, F. Luo, et al., “Deletion of N-glycosylation sites of hepatitis C virus envelope protein E1 enhances specific cellular and humoral immune responses,” Vaccine, vol. 25, no. 36, pp. 6572–6580, 2007. View at Publisher · View at Google Scholar · View at Scopus
  63. P. Martin, B. Simon, Y.-C. Lone, et al., “A vector-based minigene vaccine approach results in strong induction of T-cell responses specific of hepatitis C virus,” Vaccine, vol. 26, no. 20, pp. 2471–2481, 2008. View at Publisher · View at Google Scholar · View at Scopus
  64. D. Thammanichanond, S. Moneer, P. Yotnda, et al., “Fiber-modified recombinant adenoviral constructs encoding hepatitis C virus proteins induce potent HCV-specific T cell response,” Clinical Immunology, vol. 128, no. 3, pp. 329–339, 2008. View at Publisher · View at Google Scholar · View at Scopus
  65. A. A. Haller, G. M. Lauer, T. H. King, et al., “Whole recombinant yeast-based immunotherapy induces potent T cell responses targeting HCV NS3 and Core proteins,” Vaccine, vol. 25, no. 8, pp. 1452–1463, 2007. View at Publisher · View at Google Scholar · View at Scopus
  66. Q. Qiu, R. Y.-H. Wang, X. Jiao, et al., “Induction of multispecific Th-1 type immune response against HCV in mice by protein immunization using CpG and Montanide ISA 720 as adjuvants,” Vaccine, vol. 26, no. 43, pp. 5527–5534, 2008. View at Publisher · View at Google Scholar · View at Scopus
  67. C. Hartoonian, M. Ebtekar, H. Soleimanjahi, et al., “Effect of immunological adjuvants: GM-CSF (granulocyte-monocyte colony stimulating factor) and IL-23 (interleukin-23) on immune responses generated against hepatitis C virus core DNA vaccine,” Cytokine, vol. 46, no. 1, pp. 43–50, 2009. View at Publisher · View at Google Scholar · View at Scopus
  68. G. Liao, Y. Wang, J. Chang, et al., “Hepatitis B virus precore protein augments genetic immunizations of the truncated hepatitis C virus core in BALB/c mice,” Hepatology, vol. 47, no. 1, pp. 25–34, 2008. View at Publisher · View at Google Scholar · View at Scopus
  69. A. Memarnejadian and F. Roohvand, “Fusion of HBsAg and prime/boosting augment Th1 and CTL responses to HCV polytope DNA vaccine,” Cellular Immunology, vol. 261, no. 2, pp. 93–98, 2010. View at Publisher · View at Google Scholar · View at Scopus
  70. Y. Niu, N. Komatsu, Y. Komohara, et al., “A peptide derived from hepatitis C virus (HCV) core protein inducing cellularresponses in patients with HCV with various HLA class IA alleles,” Journal of Medical Virology, vol. 81, no. 7, pp. 1232–1240, 2009. View at Publisher · View at Google Scholar · View at Scopus
  71. S. Yutani, N. Komatsu, S. Shichijo, et al., “Phase I clinical study of a peptide vaccination for hepatitis C virus-infected patients with different human leukocyte antigen-class I-A alleles,” Cancer Science, vol. 100, no. 10, pp. 1935–1942, 2009. View at Publisher · View at Google Scholar · View at Scopus
  72. V. Schlaphoff, C. S. Klade, B. Jilma, et al., “Functional and phenotypic characterization of peptide-vaccine-induced HCV-specific CD8+ T cells in healthy individuals and chronic hepatitis C patients,” Vaccine, vol. 25, no. 37-38, pp. 6793–6806, 2007. View at Publisher · View at Google Scholar · View at Scopus
  73. C. S. Klade, H. Wedemeyer, T. Berg, et al., “Therapeutic vaccination of chronic hepatitis C nonresponder patients with the peptide vaccine IC41,” Gastroenterology, vol. 134, no. 5, pp. 1385–1395.e1, 2008. View at Publisher · View at Google Scholar · View at Scopus
  74. H. Wedemeyer, E. Schuller, V. Schlaphoff, et al., “Therapeutic vaccine IC41 as late add-on to standard treatment in patients with chronic hepatitis C,” Vaccine, vol. 27, no. 37, pp. 5142–5151, 2009. View at Publisher · View at Google Scholar · View at Scopus
  75. D. Drane, E. Maraskovsky, R. Gibson, et al., “Priming of CD4+ and CD8+ T cell responses using a HCV core ISCOMATRIXTM vaccine: a phase I study in healthy volunteers,” Human Vaccines, vol. 5, no. 3, pp. 151–157, 2009. View at Publisher · View at Google Scholar · View at Scopus
  76. L. Alvarez-Lajonchere, N. H. Shoukry, B. Grá, et al., “Immunogenicity of CIGB-230, a therapeutic DNA vaccine preparation, in HCV-chronically infected individuals in a Phase I clinical trial,” Journal of Viral Hepatitis, vol. 16, no. 3, pp. 156–167, 2009. View at Publisher · View at Google Scholar · View at Scopus