HBVsvp-Pulsed Dendritic Cell Immunotherapy Induces Th1 Polarization and Hepatitis B Virus-Specific Cytotoxic T Lymphocytes Production

Abstract

Background

In chronic hepatitis B virus (CHB) patients, both dendritic cells (DCs) and T cells are functionally impaired and consequently the HBV-specific cellular immune responses are downregulated. The present study aims to investigate whether monocyte-derived DC (MoDCs)-pulsed-HBV subviral particles (HBVsvp) can polarize Th1 cells to induce HBV-specific cytotoxic T-lymphocytes (CTL) responses in CHB patients.

Methods and Materials

To this end, the human hepatoma HepG2.2.15 cell line was used to produce HBVsvp as a culturing system, and HBVsvp were concentrated for highly virus titer using the polyethylene glycol protocol. Peripheral blood mononuclear cells (PBMCs), collected from CHB patients and healthy donors, were differentiated into MoDCs and T cells. PBMCs-derived MoDCs were first pulsed with HBVsvp and then cultured with PBMCs-derived T cells. MoDCs and/or T subsets cells were identified for phenotypic activation by FACS analysis. The cytokine secretion of IL-4, IL-12, and IFN-γ in the culture supernatants was detected.

Results

The MoDCs were restored for their activation upon pulsing with HBVsvp in vitro, as identified by significantly overexpression of both CD86 and HLA-DR, and overproduction of IL-4 and IL-12. Furthermore, MoDCs-pulsed-HBVsvp induced Th1 frequencies and activated HBV-specific CTL to produce significantly highest amount of IFN-γ. Enhanced HBV-specific CTL led to strong cytolytic capacity against HepG2.2.15.

Conclusion

Overall, our data suggest that in vitro activation of MoDCs with HBVsvp overcomes the functionally impaired DCs and T cells in CHB patients offering a promising tool for therapeutic or vaccine-based approaches against HBV.

Keywords:

• CHB
• MoDCs-pulsed-HBVsvp
• HBV-specific CTL
• immunotherapy

Acknowledgments

We thank Dr. Stefan Urban and his group at University of Heidelberg and for their kind gift of HepG2.2.15 cell line. We would like to thank Mahmoud Mostafa for his kind help. We would like to thank Dr. Albaraa El-Saied and Dr. Ehab Fathy for their support and assistance with statistical analysis. We would like to express our deepest gratitude to the Egyptian ministry for scientific research and Science and technology development fund (STDF) in Egypt for financing this work.

Abbreviations

Ags, antigens; APCs, antigen‐presenting cells; CD86, cluster of differentiation 86; CHB, chronic hepatitis B virus; CTL, cytotoxic T-lymphocytes; DC, dendritic cells; ELISA, enzyme linked immunosorbent assay; FACS, fluorescence-activated cell sorting; GMCSF, granulocyte macrophage colony-stimulating factor; HBV, hepatitis B virus; HBsAg, hepatitis B surface antigen; HBVsvp, hepatitis B virus subviral particles; HLA-DR, human leukocyte antigen-DR isotype; IFN-γ, interferon gamma; IL-4, interleukin 4; IL-12, interleukin 12; LPS, lipopolysaccharide; MoDCs, monocyte-derived DCs.

Ethics Approval and Consent

Informed written consent was obtained from all participants included in the study. The consent form and the research proposal were approved by the ethical committee at the CCHE and the liver institute(s) that the CHB patients were recruited, and the research was conducted in accordance with the principles of the Declaration of Helsinki.

Author Contributions

All authors contributed to study design, execution, acquisition of data, analysis and interpretations, drafting and revising the manuscript, giving final approval of the version to be published, and agree to be accountable for all aspects of the work and individually responsible for its content.

Disclosure

The authors report no conflicts of interest in this work.