[HTML][HTML] Hepatitis C virus–specific CD4+ T cell phenotype and function in different infection outcomes

DY Chen, D Wolski, J Aneja… - The Journal of …, 2020 - Am Soc Clin Investig
DY Chen, D Wolski, J Aneja, L Matsubara, B Robilotti, G Hauck, PSF de Sousa, S Subudhi
The Journal of clinical investigation, 2020Am Soc Clin Investig
CD4+ T cell failure is a hallmark of chronic hepatitis C virus (HCV) infection. However, the
mechanisms underlying the impairment and loss of virus-specific CD4+ T cells in persisting
HCV infection remain unclear. Here we examined HCV-specific CD4+ T cells longitudinally
during acute infection with different infection outcomes. We found that HCV-specific CD4+ T
cells are characterized by expression of a narrower range of T cell inhibitory receptors
compared with CD8+ T cells, with initially high expression levels of PD-1 and CTLA-4 that …
CD4+ T cell failure is a hallmark of chronic hepatitis C virus (HCV) infection. However, the mechanisms underlying the impairment and loss of virus-specific CD4+ T cells in persisting HCV infection remain unclear. Here we examined HCV-specific CD4+ T cells longitudinally during acute infection with different infection outcomes. We found that HCV-specific CD4+ T cells are characterized by expression of a narrower range of T cell inhibitory receptors compared with CD8+ T cells, with initially high expression levels of PD-1 and CTLA-4 that were associated with negative regulation of proliferation in all patients, irrespective of outcome. In addition, HCV-specific CD4+ T cells were phenotypically similar during early resolving and persistent infection and secreted similar levels of cytokines. However, upon viral control, CD4+ T cells quickly downregulated inhibitory receptors and differentiated into long-lived memory cells. In contrast, persisting viremia continued to drive T cell activation and PD-1 and CTLA-4 expression, and blocked T cell differentiation, until the cells quickly disappeared from the circulation. Our data support an important and physiological role for inhibitory receptor–mediated regulation of CD4+ T cells in early HCV infection, irrespective of outcome, with persistent HCV viremia leading to sustained upregulation of PD-1 and CTLA-4.
The Journal of Clinical Investigation