Recruitment and interaction of human dendritic and T cells in autologous liver slices experimentally infected with HCV produced in cell culture.

Studying the immunological processes taking place during the initial steps of acute hepatitis C virus (HCV) infection has been a challenge in patients. Shin et al. have recently reported that delayed induction, not impaired recruitment of specific CD8(+) T cells, causes the late onset of acute hepatitis C in chimpanzees (Gastroenterology, 2011). However, further elucidation of the underlying mechanisms is difficult in vivo. We made observations consistent with their conclusions in human liver slices inoculated ex vivo with HCV produced in cell culture (HCVcc). Autologous immune cells were purified from blood and differentially stained prior to their incubation with the slices for 2 hours. A two-photon confocal microscopic analysis revealed that many more stained dendritic and T cells contracted interactions within two-day infected slices than non-inoculated ones (p<0.001). While in the first instance some dendritic and T cells entered into closer interactions, they never did in the latter case. These results suggest that ex vivo infection of human liver slices with HCVcc may be useful for gaining experimental insight regarding the immunological processes taking place at early steps of HCV infections.