Levels of regulatory B cells do not predict serological responses to hepatitis B vaccine

Abstract

This study investigated the immunomodulatory influence of IL10 producing B regulatory cells, Bregs (CD19+CD24hiCD38hi) to standard Twinrix® vaccination. We also investigated HBsAg specific T-cell mediated IFN-γ responses to Twinrix® which in theory could provide effective immunity despite low anti-HBs titer. A total of 309 hepatitis B negative health care students and workers completed a standard Twinrix® vaccination schedule (0, 1 and 6 months). Depending on the vaccination response the participants were divided in to non-, low- and high responders according to anti-HBs titer (<10, <100 and >1000 mIU/mL respectively) two months after completed vaccination schedule. Blood samples from baseline and after vaccination from all non- and low-responders (23 participants) and the same number of high-responders were used for flow cytometric analyses of IL10 producing Bregs and T-cell mediated IFN-γ responses. A decrease in levels of IL10 producing Bregs was observed after vaccination in high responders compared to non- and low-responders. Compiling non-and low-responders against high-responders showed a lower T-cell mediated IFN-γ response at baseline in non-and low-responders when stimulated with Engerix® vaccine. In contrary no positive correlation between IL10 producing Bregs or IFN-γ positive T-cells and anti-HBs titer was observed. Hence this study cannot prove that levels of IL10 producing Bregs or IFN-γ positive T cell affect HBV vaccine response.

Keywords: Hepatitis B; Interferon γ; Interleukin 10; Twinrix; clinical; flow cytometry; hepatitis; non-responders; vaccinology.

Figure 1.

Changes in proportion of Breg of total B lymphocytes from baseline to follow-up in low-responders and high-responders. A significant decrease in Bregs/CD19⁺ number after vaccination was found in the high-responder group (right graph), and not in the non-/low-responder group (left graph). *Significant p-values.

Figure 2.

Results from Engerix® (A) and HBsAg (B) stimulated baseline samples and Engerix® (C) and HBsAg (D) stimulated follow-up samples. Plots of the ratio of IFN-γ positive CD4+ T-cells for non-/low-responders and high-responders (Anti-HBs <100 mIU/ml and >1000 mIU/ml, respectively). Higher ratio of IFN-γ positive CD4+ T cells at baseline was found in samples from high-responders stimulated with Engerix® compared to non-/low-responders (Figure 2A). No difference was observed in ratios of IFN-γ positive CD4+ T cells in baseline samples when stimulated with HBsAg (Figure 2B). At follow-up, we observed no difference between the non-/low-responders and the high-responders in ratios of IFN-γ positive CD4+ T cells when stimulated with Engerix® or HBsAg (Figure 2C, D). *Significant p-values. A: ENG/US (Engerix®/Media), B = HBsAg/CM (HBsAg/Conditioned Media).