Role of the Coinhibitory Receptor Cytotoxic T Lymphocyte Antigen-4 on Apoptosis-Prone CD8 T Cells in Persistent Hepatitis B Virus Infection
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Published version
Embargoed until: 5555-01-01
Embargoed until: 5555-01-01
Volume
53
Pagination
1494 - 1503
DOI
10.1002/hep.24249
Journal
HEPATOLOGY
Issue
ISSN
0270-9139
Metadata
Show full item recordAbstract
An excess of coinhibitory signals has been proposed to drive the T-cell exhaustion characteristic of persistent viral infections. In this study we examined the contribution of the coinhibitory receptor cytotoxic T lymphocyte antigen-4 (CTLA-4) to CD8 T cell tolerance in chronic hepatitis B virus (HBV) infection (CHB). CD8 T cells in patients with CHB have an increased propensity to express the coinhibitory receptor CTLA-4 and this correlates with viral load. CTLA-4 is up-regulated on those HBV-specific CD8 T cells with the highest levels of the proapoptotic protein Bim, which we have previously shown mediates their premature attrition; abrogation of CTLA-4-mediated coinhibition can reduce Bim expression. Longitudinal study of CHB patients beginning antiviral therapy reveals that HBV DNA suppression induces transient reconstitution of HBV-specific CD8 T cells but does not reprogram their CTLA-4hiBimhi tolerogenic phenotype. Blocking CTLA-4 is able to increase the expansion of interferon gamma (IFN-γ)-producing HBV-specific CD8 T cells in both the peripheral and intrahepatic compartments. The rescue of anti-HBV responses by either CTLA-4 or PD-L1 blockade is nonredundant. Conclusion: CTLA-4 is expressed by HBV-specific CD8 T cells with high levels of Bim and helps to drive this proapoptotic phenotype. CTLA-4 blockade could form one arm of a therapeutic approach to modulate the diverse patterns of coregulation of T-cell exhaustion in this heterogeneous disease. (HEPATOLOGY 2011;)
Authors
Schurich, A; Khanna, P; Lopes, AR; Han, KJ; Peppa, D; Micco, L; Nebbia, G; Kennedy, PTF; Geretti, AM; Dusheiko, GCollections
- Centre for Immunobiology [1100]