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 6

Validation in an Asian patient cohort (cohort 2) of the increased frequencies of circulating HBV core and polymerase-specific T cells in chronic HBV patients undergoing NUC therapy that did not flare upon therapy discontinuation.

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Validation in an Asian patient cohort (cohort 2) of the increased freque...
HBV-specific T cells were assessed after 10-day expansion of patient PBMCs with a panel of overlapping 15-mer peptides spanning the HBV proteome, followed by IFN-γ ELISPOT in the presence of peptides pooled according to the single proteins (x, core, env, and pol). Results are expressed as spot-forming cells relative to 105 PBMCs. (A) Total HBV-specific T cell responses during NUC therapy (n = 26). (B) Deconvolution of the HBV-specific T cell response from A into single HBV proteins. (C) PD-1+ and PD-1– T cells were sorted ex vivo from peripheral blood of patients (n = 6) and expanded in the presence of autologous antigen-presenting cells pulsed with HBV core and polymerase peptides. Expanded PD-1+ and PD-1– cells were tested for recognition of HBV peptides by IFN-γ. Data are summarized for 6 patients (C) and are shown for the single patients (D). (E–G) Pooled data from cohorts 1 and 2 show IFN-γ production of ex vivo–sorted PD-1+ and PD-1– cells after in vitro expansion (n = 13; E), total HBV-specific T cell responses during therapy (n = 43; F), and the HBV-specific T cell response to single HBV proteins (G). The dotted line in G marks the threshold of HBV-specific T cell response associated with absence of hepatic flares upon therapy withdrawal. Circle and triangle symbols in F and G represent patients from cohort 1 and 2, respectively. Statistics were calculated using the nonparametric, 2-tailed Mann-Whitney U test except for in C and E, where the nonparametric Wilcoxon matched-pairs signed rank test was used. *P ≤ 0.05; **P ≤ 0.01; ***P ≤ 0.001; ****P ≤ 0.0001.