Follicular T helper cells shape the HCV-specific CD4+ T cell repertoire after virus elimination
Maike Smits, … , Robert Thimme, Tobias Boettler
Maike Smits, … , Robert Thimme, Tobias Boettler
Published November 7, 2019
Citation Information: J Clin Invest. 2020;130(2):998-1009. https://doi.org/10.1172/JCI129642.
View: Text | PDF
Clinical Medicine Immunology Infectious disease

Follicular T helper cells shape the HCV-specific CD4+ T cell repertoire after virus elimination

Abstract

BACKGROUND Chronic hepatitis C virus (HCV) infection is characterized by a severe impairment of HCV-specific CD4+ T cell help that is driven by chronic antigen stimulation. We aimed to study the fate of HCV-specific CD4+ T cells after virus elimination.METHODS HCV-specific CD4+ T cell responses were longitudinally analyzed using MHC class II tetramer technology, multicolor flow cytometry, and RNA sequencing in a cohort of patients chronically infected with HCV undergoing therapy with direct-acting antivirals. In addition, HCV-specific neutralizing antibodies and CXCL13 levels were analyzed.RESULTS We observed that the frequency of HCV-specific CD4+ T cells increased within 2 weeks after initiating direct-acting antiviral therapy. Multicolor flow cytometry revealed a downregulation of exhaustion and activation markers and an upregulation of memory-associated markers. Although cells with a Th1 phenotype were the predominant subset at baseline, cells with phenotypic and transcriptional characteristics of follicular T helper cells increasingly shaped the circulating HCV-specific CD4+ T cell repertoire, suggesting antigen-independent survival of this subset. These changes were accompanied by a decline of HCV-specific neutralizing antibodies and the germinal center activity.CONCLUSION We identified a population of HCV-specific CD4+ T cells with a follicular T helper cell signature that is maintained after therapy-induced elimination of persistent infection and may constitute an important target population for vaccination efforts to prevent reinfection and immunotherapeutic approaches for persistent viral infections.FUNDING Deutsche Forschungsgemeinschaft (DFG, German Research Foundation), the National Institute of Allergy and Infectious Diseases (NIAID), the European Union, the Berta-Ottenstein-Programme for Advanced Clinician Scientists, and the ANRS.

Authors

Maike Smits, Katharina Zoldan, Naveed Ishaque, Zuguang Gu, Katharina Jechow, Dominik Wieland, Christian Conrad, Roland Eils, Catherine Fauvelle, Thomas F. Baumert, Florian Emmerich, Bertram Bengsch, Christoph Neumann-Haefelin, Maike Hofmann, Robert Thimme, Tobias Boettler

×

Figure 6

Emergence of a Tfh signature on HCV-specific CD4+ T cells after antigen removal.

Options: View larger image (or click on image) Download as PowerPoint
Emergence of a Tfh signature on HCV-specific CD4+ T cells after antigen ...
(A) HCV-specific (gray bars and filled dots) and bulk CD4+ T cells (white bars and empty dots) were analyzed for coexpression of CXCR5 and PD-1 (indicating Tfh differentiation; red dots) or for CXCR5–CXCR3+CCR6– expression (indicating Th1 differentiation, blue dots) at baseline and follow-up (Tfh, n = 16; Th1, n = 8). (B and C) RNA sequencing was performed on HCV-specific CD4+ T cells, cTfh cells (CXCR5+PD-1+CXCR3–), and Th1 cells (CXCR3+CCR6–) of 3 patients (P3, P30, and P13) at 3 time points (baseline, W2, follow-up). (B) Principal component analysis was generated using the differentially expressed genes (FDR < 0.05; 297 genes) between bulk Th1 and bulk cTfh cells. (C) Differentially expressed genes between HCV-specific CD4+ T cells at baseline and bulk cTfh cells were used to generate a gene set of 198 genes. The heatmaps were generated using this gene set in longitudinal samples (baseline, W2, follow-up) to analyze changes of HCV-specific CD4+ T cells. Cutoff for generation of the heatmaps was FDR < 0.01. (D) CXCL13 levels, indicating germinal center activity, were measured by ELISA in the plasma of patients undergoing DAA therapy (n = 27). (E) Neutralizing antibodies were assessed in the plasma of patients using infection of Huh7.5.1 cells with lentiviral HCVpp bearing HCV envelope glycoproteins. Neutralization of genotype-matched HCVpp compared with control (100%) by individual sera is shown (n = 37). Each symbol represents 1 patient, bars represent medians. FU12, 12 weeks after the end of treatment; FU24, 24 weeks after the end of treatment. *P < 0.05, **P < 0.01, ****P < 0.0001; nonparametric distribution with Wilcoxon’s matched-pairs signed-rank test between indicated groups (A). Due to multiple comparisons (n = 3–4), significance level was adjusted using Bonferroni’s correction and P values of < 0.01 were considered statistically significant. Thus, P values > 0.01 are not indicated (D and E).