HCV serum derived extracellular vesicles (EV) inhibit T cell receptor (TCR) signaling in primary human T lymphocytes.

<p>Healthy donor PBMCs were incubated with pooled serum extracellular vesicles (EV) obtained from HCV-infected patient sera (HCV+ EV; GT 1, 1a, 1b, 2, 2b and 3). TCR induced IL-2 (A) and CD69 surface expression (B) was measured. TCR induced IL-2 release by human T cells incubated with HCV-positive or negative serum for two hours at 37°C or 4°C (C). Analysis of CFSE positive serum EV (D) and uptake of CFSE-positive EV by primary human T cells (E) as determined by flow cytometry. HCV RNA was detected using RT-PCR in EVs from HCV-positive serum, and in human PBMCs incubated with HCV-positive but not HCV RNA negative serum (F). HCV RNA US = unstimulated cells. MFI = mean fluorescent intensity. Data represent the average of three technical replicates, and the standard deviation is shown. Each experiment was independently performed with three different donors with similar results. *P< 0.05; **P< 0.01.