Overcoming Immunotolerance in Chronic Hepatitis B: Efficacy of Granulocyte-Macrophage Colony-Stimulating Factor–Based Immunotherapy in Achieving Hepatitis B Surface Antigen Seroclearance

Abstract

Chronic hepatitis B (CHB) remains incurable due to the immune system's tolerance toward the hepatitis B virus (HBV) surface antigen (HBsAg). This study aimed to achieve a functional cure by breaking HBV tolerance through immunotherapy. CHB patients were treated with either standard nucleotide analog (NA) therapy (Adefovir Dipivoxil, ADV) (Cohort 1) or ADV combined with interferon-alpha (IFN-α) (Cohort 2). Additionally, a third cohort received the THRIL-GM-Vac regimen: three low-dose GM-CSF injections followed by one dose of the HBV vaccine, alongside standard treatment. THRIL-GM-Vac treatment (Cohort 3) achieved a significant 2log10 reduction in HBsAg levels in 21.7% of participants, and 8.7% HBsAg clearance in Cohort 3 compared to 0% and 4.17% in Cohorts 1 and 2, respectively. Furthermore, THRIL-GM-Vac significantly reduced HBV-specific tolerogenic T cells (Tregs), explaining the sustained HBsAg decrease. Upregulation of anti-HBV T cell responses confirmed THRIL-GM-Vac's ability to disrupt HBV tolerance and enhance HBsAg-specific cellular immunity. This suggests its potential effectiveness in treating individuals with moderate to low HBsAg levels. THRIL-GM-Vac treatment in Cohort 3 resulted in 8.7% HBsAg clearance alongside Treg depletion and enhanced anti-viral T cell responses. These findings present a promising strategy to overcome immunotolerance and potentially combat chronic HBV infection.

Keywords

functional cure / granulocyte-macrophage colony-stimulating factor / hepatitis B / hepatitis B virus surface antigen / immunotherapy / regulatory T cells

References

[1] WHO, Guidelines for the Prevention, Care and Treatment of Persons With Chronic Hepatitis B Infection (World Health Organization, 2015).

[2] European Association For The Study Of the Liver, EASL Clinical Practice Guidelines: Management of Chronic Hepatitis B Virus Infection. Journal of Hepatology 57, no. 1 (2012): 167–185.

[3] N. A. Terrault, N. H. Bzowej, K. Chang, J. P. Hwang, M. M. Jonas, and M. H. Murad, “AASLD Guidelines for Treatment of Chronic Hepatitis B,” Hepatology 63, no. 1 (2016): 261–283.

[4] G. Peng, S. Li, W. Wu, Z. Sun, Y. Chen, and Z. Chen, “Circulating CD4+ CD25+ Regulatory T Cells Correlate With Chronic Hepatitis B Infection,” Immunology 123, no. 1 (2008): 57–65.

[5] S. Suvas, U. Kumaraguru, C. D. Pack, S. Lee, and B. T. Rouse, “CD4+CD25+ T Cells Regulate Virus-Specific Primary and Memory CD8+ T Cell Responses,” Journal of Experimental Medicine 198, no. 6 (2003): 889–901.

[6] T. Chang, Y. Liaw, S. Wu, et al., “Long-Term Entecavir Therapy Results in the Reversal of Fibrosis/Cirrhosis and Continued Histological Improvement in Patients With Chronic Hepatitis B,” Hepatology 52, no. 3 (2010): 886–893.

[7] J. Chen, H. Yang, U. H. Iloeje, et al., “Carriers of Inactive Hepatitis B Virus Are Still at Risk for Hepatocellular Carcinoma and Liver-Related Death,” Gastroenterology 138, no. 5 (2010): 1747–1754.

[8] G. K. Lau, T. Piratvisuth, K. X. Luo, et al., “Peginterferon Alfa-2a, Lamivudine, and the Combination for HBeAg-Positive Chronic Hepatitis B,” New England Journal of Medicine 352, no. 26 (2005): 2682–2695.

[9] P. Marcellin, E. J. Heathcote, M. Buti, et al., “Tenofovir Disoproxil Fumarate Versus Adefovir Dipivoxil for Chronic Hepatitis B,” New England Journal of Medicine 359, no. 23 (2008): 2442–2455.

[10] R. C. Guptan, V. Thakur, S. N. Kazim, and S. K. Sarin, “Efficacy of Granulocyte-Macrophage Colony-Stimulating Factor or Lamivudine Combination With Recombinant Interferon in Non-Responders to Interferon in Hepatitis B Virus-Related Chronic Liver Disease Patients,” Journal of Gastroenterology and Hepatology 17, no. 7 (2002): 765–771.

[11] C. Lin, J. Zhu, Y. Zheng, et al., “Effect of GM-CSF in Combination With Hepatitis B Vaccine on Revacination of Healthy Adult Non-Responders,” Journal of Infection 60, no. 4 (2010): 264–270.

[12] G. Parmiani, C. Castelli, L. Pilla, M. Santinami, M. Colombo, and L. Rivoltini, “Opposite Immune Functions of GM-CSF Administered as Vaccine Adjuvant in Cancer Patients,” Annals of Oncology 18, no. 2 (2007): 226–232.

[13] X. Wang, A. Dong, J. Xiao, et al., “Overcoming HBV Immune Tolerance to Eliminate HBsAg-Positive Hepatocytes via Pre-Administration of GM-CSF as a Novel Adjuvant for a Hepatitis B Vaccine in HBV Transgenic Mice,” Cellular & Molecular Immunology 13, no. 6 (2016): 850–861.

[14] W. Zhao, G. Zhao, S. Zhang, X. Wang, X. Yu, and B. Wang, “Clearance of HBeAg and HBsAg of HBV in Mice Model by a Recombinant HBV Vaccine Combined With GM-CSF and IFN-Alpha as an Effective Therapeutic Vaccine Adjuvant,” Oncotarget 9, no. 76 (2018): 34213–34228.

[15] H. Jia, G. Yu, J. Yu, et al., “Immunomodulatory and Antiviral Therapy Improved Functional Cure Rate in CHB Patients With High HBsAg Level Experienced NA,” Journal of Clinical and Translational Hepatology 11, no. 5 (2023): 1003–1010.

[16] W. Zhang, J. Chen, W. Sun, et al., “The Impact of Hepatitis B Surface Antigen Seroconversion on the Durability of Functional Cure Induced by Pegylated Interferon Alpha Treatment,” Virology Journal 21, no. 1 (2024): 243.

[17] H. Wang, B. Wu, L. Li, et al., “Hepatic Expansion of Virus-Specific CD8(+)BTLA(+) T Cells With Regulatory Properties in Chronic Hepatitis B Virus Infection,” Cellular Immunology 311 (2017): 36–45.

[18] J. H. Kim, A. Ghosh, N. Ayithan, et al., “Circulating Serum HBsAg Level Is a Biomarker for HBV-Specific T and B Cell Responses in Chronic Hepatitis B Patients,” Scientific Reports 10, no. 1 (2020): 1835.

[19] Y. Zhang, J. Han, X. Zhang, et al., “Lower Frequency of MDSCs Was Significantly Related to Functional Cure in CHB Patients Treated With Peginterferon,” Liver International 43, no. 2 (2023): 329–339.

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