Original Article
Copyright ©2012 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Mar 28, 2012; 18(12): 1319-1327
Published online Mar 28, 2012. doi: 10.3748/wjg.v18.i12.1319
Enhancement of CTLs induced by DCs loaded with ubiquitinated hepatitis B virus core antigen
Jian-Hua Chen, Yong-Sheng Yu, Xiao-Hua Chen, Hong-Hong Liu, Guo-Qing Zang, Zheng-Hao Tang
Jian-Hua Chen, Yong-Sheng Yu, Xiao-Hua Chen, Hong-Hong Liu, Guo-Qing Zang, Zheng-Hao Tang, Department of Infectious Diseases, Sixth People’s Hospital Affiliated to Shanghai Jiaotong University, Shanghai 200233, China
Author contributions: Tang ZH designed research; Chen JH performed research; Chen XH, Yu YS and Zang GQ provided reagents; Liu HH analyzed data; and Chen JH wrote the paper.
Supported by Natural Science Foundation of Shanghai, No. 11ZR1427100
Correspondence to: Dr. Zheng-Hao Tang, PhD, Department of Infectious Diseases, Sixth People’s Hospital Affiliated to Shanghai Jiaotong University, Shanghai 200233, China. tzhhao@hotmail.com
Telephone: +86-21-64369181 Fax: +86-21-64369181-58384
Received: December 9, 2011
Revised: February 1, 2012
Accepted: February 16, 2012
Published online: March 28, 2012
Abstract

AIM: To investigate whether hepatitis B virus (HBV) could induce a hepatitis B virus core antigen (HBcAg)-specific cytotoxic T lymphocyte (CTL) response in vitro by dendritic cells (DCs) transduced with lentiviral vector-encoding ubiquitinated hepatitis B virus core antigen (LV-Ub-HBcAg).

METHODS: Recombinant LV-Ub-HBcAg were transfected into highly susceptible 293 T cells to obtain high virus titres. Bone marrow-derived DCs isolated from BALB/c mice were cultured with recombinant granulocyte-macrophage colony-stimulating factor and recombinant interleukin (IL)-4. LV-Ub-HBcAg, lentiviral vector-encoding hepatitis B virus core antigen (LV-HBcAg), lentiviral vector (LV) or lipopolysaccharide were added to induce DC maturation, and the DC phenotypes were analyzed by flow cytometry. The level of IL-12 in the supernatant was detected by enzyme-linked immunosorbent assay (ELISA). T lymphocytes were proliferated using Cell Counting Kit-8. DCs were cultured and induced to mature using different LVs, and co-cultured with allogeneic T cells to detect the secretion levels of IL-2, IL-4, IL-10 and interferon-γ in the supernatants of T cells by ELISA. Intracellular cytokines of proliferative T cells were analyzed by flow cytometry, and specific CTL activity was measured by a lactate dehydrogenase release assay.

RESULTS: LV-Ub-HBcAg-induced DCs secreted more IL-12 and upregulated the expression of CD80, CD86 and major histocompatibility class II. DCs sensitised by different LVs effectively promoted cytokine secretion; the levels of IL-2 and interferon-γ induced by LV-Ub-HBcAg were higher than those induced by LV-HBcAg. Compared with LV-HBcAg-transduced DCs, LV-Ub-HBcAg-transduced DCs more efficiently stimulated the proliferation of T lymphocytes and generated HBcAg-specific cytotoxic T lymphocytes.

CONCLUSION: LV-Ub-HBcAg effectively induced DC maturation. The mature DCs efficiently induced T cell polarisation to Th1 and generated HBcAg-specific CTLs.

Keywords: Ubiquitin; Hepatitis B virus core antigen; Lentiviruses; Dendritic cells; Cytotoxic T lymphocytes