High level of PD-1 expression on hepatitis C virus (HCV)-specific CD8+ and CD4+ T cells during acute HCV infection, irrespective of clinical outcome.
Kasprowicz V., Schulze Zur Wiesch J., Kuntzen T., Nolan BE., Longworth S., Berical A., Blum J., McMahon C., Reyor LL., Elias N., Kwok WW., McGovern BG., Freeman G., Chung RT., Klenerman P., Lewis-Ximenez L., Walker BD., Allen TM., Kim AY., Lauer GM.
We monitored expression of PD-1 (a mediator of T-cell exhaustion and viral persistence) on hepatitis C virus (HCV)-specific CD8(+) and CD4(+) T cells from blood and liver during acute and chronic infections and after the resolved infection stage. PD-1 expression on HCV-specific T cells was high early in acute infection irrespective of clinical outcome, and most cells continued to express PD-1 in resolved and chronic stages of infection; intrahepatic expression levels were especially high. Our results suggest that an analysis of PD-1 expression alone is not sufficient to predict infection outcome or to determine T-cell functionality in HCV infection.