CD81 and infection: In the current study, the expression of SR-B1, CLDN-1, CLDN-6 and OCLN, in addition to CD5 and CD81, in HCV-prone and resistant T cell lines and in peripheral blood mononuclear cells (PBMC) and PBMC-derived primary T lymphocytes was investigated to assess whether they may contribute to infection of lymphocytes with authentic, patient-derived HCV and to compare their expression with that in JFH-1 strain-prone hepatoma Huh7.5 and JFH-1-resistant HepG2 cell lines.