Hepatitis B virus–specific T cells associate with viral control upon nucleos(t)ide-analogue therapy discontinuation
Laura Rivino, … , Patrick T.F. Kennedy, Antonio Bertoletti
Laura Rivino, … , Patrick T.F. Kennedy, Antonio Bertoletti
Published January 8, 2018
Citation Information: J Clin Invest. 2018;128(2):668-681. https://doi.org/10.1172/JCI92812.
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Clinical Research and Public Health Hepatology Immunology

Hepatitis B virus–specific T cells associate with viral control upon nucleos(t)ide-analogue therapy discontinuation

Abstract

BACKGROUND. The clinical management of chronic hepatitis B virus (HBV) patients is based exclusively on virological parameters that cannot independently determine in which patients nucleos(t)ide-analogue (NUC) therapy can be safely discontinued. NUCs efficiently suppress viral replication, but do not eliminate HBV. Thus, therapy discontinuation can be associated with virological and biochemical relapse and, consequently, therapy in the majority is life-long. METHODS. Since antiviral immunity is pivotal for HBV control, we investigated potential biomarkers for the safe discontinuation of NUCs within immune profiles of chronic HBV patients by utilizing traditional immunological assays (ELISPOT, flow cytometry) in conjunction with analyses of global non–antigen-specific immune populations (NanoString and CyTOF). Two distinct cohorts of 19 and 27 chronic HBV patients, respectively, were analyzed longitudinally prior to and after discontinuation of 2 different NUC therapy strategies. RESULTS. Absence of hepatic flares following discontinuation of NUC treatment correlated with the presence, during NUC viral suppression, of HBV core and polymerase-specific T cells that were contained within the ex vivo PD-1+ population. CONCLUSIONS. This study identifies the presence of functional HBV-specific T cells as a candidate immunological biomarker for safe therapy discontinuation in chronic HBV patients. Furthermore, the persistent and functional antiviral activity of PD-1+ HBV–specific T cells highlights the potential beneficial role of the expression of T cell exhaustion markers during human chronic viral infection. FUNDING. This work was funded by a Singapore Translational Research Investigator Award (NMRC/STaR/013/2012), the Eradication of HBV TCR Program (NMRC/TCR/014-NUHS/2015), the Singapore Immunology Network, the Wellcome Trust (107389/Z/15/Z), and a Barts and The London Charity (723/1795) grant.

Authors

Laura Rivino, Nina Le Bert, Upkar S. Gill, Kamini Kunasegaran, Yang Cheng, Damien Z.M. Tan, Etienne Becht, Navjyot K. Hansi, Graham R. Foster, Tung-Hung Su, Tai-Chung Tseng, Seng Gee Lim, Jia-Horng Kao, Evan W. Newell, Patrick T.F. Kennedy, Antonio Bertoletti

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Figure 5

Functional HBV-specific T cells are enriched in the PD-1+ T cell fraction.

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Functional HBV-specific T cells are enriched in the PD-1+ T cell fractio...
(A–C) mRNA expression of immune-regulatory genes was analyzed by NanoString in CD4+ and CD8+ T cells sorted from the peripheral blood of patients that flared (n = 7) or did not flare (n = 12) upon therapy discontinuation. The differentially expressed genes (>1.5-fold difference, P < 0.05) in CD4+ and CD8+ T cells from the 2 patient groups are shown by heatmap (A). PD1 expression by CD8+ T cells is also shown as normalized NanoString counts (B). Statistics are calculated by nonparametric, 2-tailed Mann-Whitney U test. The expression of immune-regulatory markers by CD4+ and CD8+ T cells from patients that did not flare or from those that flared upon therapy withdrawal was evaluated by CyTOF (C). Relative expression of each marker is plotted as z-score calculated for each experiment (n = 12 nonflare; n = 5 flare; see Methods). All differences are not statistically significant after correcting for multiple comparisons with Holm-Šidák or Šidák-Bonferroni method. (D) Pearson correlation of PD1 mRNA expression in total CD8+ T cells and frequencies of HBV-specific T cells. (E–F) PD-1+ and PD-1– T cells were sorted ex vivo from peripheral blood of patients (n = 7: n = 6 nonflare, n = 1 flare) and expanded in the presence of autologous antigen-presenting cells pulsed with HBV peptides. Expanded PD-1+ and PD-1– cells were tested for recognition of HBV peptides by IFN-γ. Data are summarized for 7 patients (E) and are shown for single patients (F). The ability of PD-1+ CD8+ T cells to produce cytokines and effector molecules following polyclonal stimulation was assessed by CyTOF in PBMCs of patients from the 2 groups (n = 12 nonflare; n = 5 flare) (G). Statistics were calculated using the nonparametric, 2-tailed Mann-Whitney U test except for in E, where the nonparametric Wilcoxon matched-pairs signed rank test was used. *P ≤ 0.05; **P ≤ 0.01.