Increased frequency of NS3 and NS4-specific CD4 T cells producing Th17 and Th1 cytokines during acute resolving HCV.

<p>CD25-depleted PBMC from patients with acute HCV infection (SR or CI) were stained with CFSE and stimulated with 1 µg/ml of HCV-recombinant proteins (NS3 or NS4). After 6 days of culture, cells were washed and re-stimulated with PMA/ionomycin as described in <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1003422#s4" target="_blank">Materials and Methods</a> to reveal the cytokine profile by ICS. Cells were gated on viable CD3⁺CD8<b>^neg</b> T cells to define the percent of IL-17A-, IL21-, IFN-γ– or TNF-α–producing CFSE^low cells. Data is presented as percent specific cytokine production after subtraction of background corresponding to un-stimulated cells. Samples from SR (n = 8-5) and CI (n = 10-5) patients were studied. Samples were not available for some patients at every time point or exhibited low proliferation. Samples from five SR and five CI patients were examined at all the time points tested. P-values were calculated using a two-tailed Mann Whitney U test.