Soluble transferrin mediates targeting of hepatitis B envelope antigen to transferrin receptor and its presentation by activated T cells

Publisher Website
Google Scholar
Abstract
In a previous study, we identified that transferrin receptor (TfR) is the receptor utilized by hepatitis B virus (HBV) to enter T cells. We demonstrated that hepatitis B envelope antigen (HBenv Ag) is taken up by activated T cells via TfR, processed in endosomal compartments, and presented on class II molecules to specific CD4+ T cell clones. Herein, we report that binding to soluble ferric Tf by HBenv Ag is needed in TfR‐mediated endocytosis. Accordingly, presentation of HBenvAg by activated T cells is not observed in serum‐free medium and is restored by addition of soluble Tf. Moreover, we provide evidence that pre‐S2 and S regions of HBenv Ag contain the critical residues for the interaction with soluble Tf. Our data not only explain HBV entry into a variety of host activated cells, but may also help in developing strategies to alter the course of chronic HBV infection.