Hepatitis B Vaccine Non-Responders Show Higher Frequencies of CD24highCD38high Regulatory B Cells and Lower Levels of IL-10 Expression Compared to Responders.

Nina Körber,Hedwig Roggendorf,Percy A Knolle,Birgit Weinberger,Laureen Pohl,Ulrike Protzer,Beatrix Grubeck-Loebenstein,Tanja Bauer,Andrea Wawer

doi:10.3389/fimmu.2021.713351

Abstract

BackgroundThe cellular mechanisms involved in the lack of protective antibody response after hepatitis B vaccination are still rather unclear. Regulatory B cells (Breg) known as modulators of B-and T-cell responses may contribute to poor vaccine responsiveness. The current study aimed to investigate the role of regulatory B cells (Breg) in hepatitis B vaccine non-responsiveness after immunization with second- or third-generation hepatitis B vaccines.MethodWe performed comparative phenotypic and frequency analysis of Breg subsets (CD24+CD27+ and CD24highCD38high Breg) in second-generation hepatitis B vaccine non-responders (2nd HBvac NR, n = 11) and responders (2nd HBvac R, n = 8) before (d0), on day 7 (d7), and 28 (d28) after booster vaccination. Cryopreserved peripheral blood mononuclear cells were stimulated ex vivo with a combination of CpG, PMA, and Ionomycin (CpG+P/I) and analyzed for numbers and IL-10 expression levels of Breg by flow cytometry-based analyses.ResultsFlow cytometry-based analyses revealed elevated frequencies of CD24+CD27+ Breg at all time points and significantly higher frequencies of CD24highCD38high Breg on d0 (p = 0.004) and 28 (p = 0.012) in 2nd HBvac NR compared to 2nd HBvac R. In parallel, we observed significantly lower levels of CpG+P/I-induced IL-10 expression levels of CD24+CD27+ and CD24highCD38high Breg (d0: p < 0.0001; d7: p = 0.0004; d28: p = 0.0003 and d0: p = 0.016; d7: p = 0.016, respectively) in 2nd HBvac NR compared to 2nd HBvac R before and after booster immunization. Frequencies of CD24+CD27+ and CD24highCD38high Breg significantly decreased after third-generation hepatitis B booster vaccination (d7: p = 0.014; d28: p = 0.032 and d7: p = 0.045, respectively), whereas IL-10 expression levels of both Breg subsets remained stable.ConclusionHere we report significantly higher frequencies of CD24highCD38high Breg in parallel with significantly lower IL-10 expression levels of CD24+CD27+ and CD24highCD38high Breg in 2nd HBvac NR compared to 2nd HBvac R. Anti-HBs seroconversion accompanied by a decrease of Breg numbers after booster immunization with a third-generation hepatitis B vaccine could indicate a positive effect of third-generation hepatitis B vaccines on Breg-mediated immunomodulation in hepatitis B vaccine non-responders.

Highlights

According to the World Health Organization (WHO) 260 million people are chronically infected with HBV and 887,000 people are dying each year due to hepatitis B virus (HBV) infection [1]
Comparison of the characteristics of Sci-B-Vac vaccine low(“3rd HBvac third-generation hepatitis B vaccine low-responder (LR)”; anti-HBs < 100 IU/L; n = 5) and high- (“3rd HBvac third-generation hepatitis B vaccine high-responder (HR)”; anti-HBs > 100 IU/L; n = 5) responders revealed no differences in age (mean: 25.6 and 23.4 years, respectively) (p = 0.524), gender (4 female, 1 male in each cohort), smoking habits, and in history of comorbidities and medication
Frequencies of CD24highCD38highIL-10+ regulatory B cells (Breg) were significantly lower in 2nd HBvac second-generation hepatitis B vaccine non-responder (NR) compared to 2nd HBvac R on day 0 and 7, but not on day 28 (d0: p = 0.016; d7: p = 0.016; d28: p = 0.111)

Summary

Introduction

According to the WHO 260 million people are chronically infected with HBV and 887,000 people are dying each year due to hepatitis B virus (HBV) infection [1]. Second-generation hepatitis B vaccines composed of the small HBV envelope protein (hepatitis B surface antigen; HBsAg) are currently used for universal vaccination and reduce the overall incidence of both hepatitis B and the associated long-term consequences such as chronic hepatitis B and liver cirrhosis [2, 3]. Third-generation hepatitis B vaccines containing additional HBV envelope proteins (pre-S1 and pre-S2) are known to be more immunogenic and superior in inducing protective antibody titers in non-responders to the conventional vaccines [9]. Regulatory B cells (Breg) known as modulators of B-and T-cell responses may contribute to poor vaccine responsiveness. The current study aimed to investigate the role of regulatory B cells (Breg) in hepatitis B vaccine non-responsiveness after immunization with second- or thirdgeneration hepatitis B vaccines

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Results

Discussion

Conclusion