Gagliardi M C, Nisini R, Benvenuto R, De Petrillo G, Michel M L, Barnaba V
Istituto I Clinica Medica, University of Rome La Sapienza, Italy.
Eur J Immunol. 1994 Jun;24(6):1372-6. doi: 10.1002/eji.1830240620.
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 (HBenvAg) 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 HBenvAg 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 HBenvAg 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.
在先前的一项研究中，我们确定转铁蛋白受体（TfR）是乙型肝炎病毒（HBV）进入T细胞所利用的受体。我们证明，乙型肝炎包膜抗原（HBenvAg）被活化的T细胞通过TfR摄取，在内体区室中加工，并在II类分子上呈递给特异性CD4+T细胞克隆。在此，我们报告在TfR介导的内吞作用中，HBenvAg需要与可溶性铁转铁蛋白（Tf）结合。因此，在无血清培养基中未观察到活化T细胞呈递HBenvAg，而添加可溶性Tf可恢复其呈递。此外，我们提供证据表明，HBenvAg的前S2和S区域包含与可溶性Tf相互作用的关键残基。我们的数据不仅解释了HBV进入多种宿主活化细胞的机制，还可能有助于制定改变慢性HBV感染进程的策略。
