Jeske Samuel D, Wettengel Jochen M, Gegenfurtner Florian, Fischer Konrad, Moosmüller Judith, Chakraborty Anindita, Ko Chunkyu, Burwitz Benjamin J, Schnieke Angelika, Protzer Ulrike
Institute of Virology, School of Medicine and Health, Technical University of Munich/Helmholtz Munich, Munich, Germany.
German Center for Infection Research (DZIF), Munich partner site, Munich, Germany.
Npj Viruses. 2024 Jul 23;2(1):30. doi: 10.1038/s44298-024-00041-5.
With 254 million chronically infected patients, hepatitis B virus (HBV) continues to be a severe health threat. While animal models play a crucial role in developing new therapies, the availability of preclinical HBV models is very limited. Therefore, novel in vivo infection models are urgently needed. The bona fide HBV receptor, sodium-taurocholate cotransporting polypeptide (NTCP), determines HBV's species and cell-type specificity. Recent studies have indicated that the expression of human NTCP is the only limiting factor for HBV infection in selected species, such as macaques or pigs. Here, we confirm HBV infection of pig hepatocytes expressing human NTCP and show that porcine NTCP does not support HBV binding. By gradually humanizing porcine NTCP and site-directed mutagenesis, we identified amino acids 158 and 167 in porcine NTCP, limiting HBV interaction. In a proof-of-concept experiment, we showed that the expression of porcine NTCP with humanized amino acids 157-167 renders primary porcine hepatocytes fully susceptible to HBV. These results pave the way for generating transgenic pigs with humanized porcine chimeric NTCP as a novel, fully immunocompetent infection model for developing and validating new curative HBV therapies.
乙肝病毒（HBV）感染的慢性患者多达2.54亿，仍然是严重的健康威胁。虽然动物模型在开发新疗法中发挥着关键作用，但临床前HBV模型的可用性非常有限。因此，迫切需要新型体内感染模型。HBV的真正受体——牛磺胆酸钠共转运多肽（NTCP），决定了HBV的物种和细胞类型特异性。最近的研究表明，人NTCP的表达是某些物种（如猕猴或猪）中HBV感染的唯一限制因素。在此，我们证实了表达人NTCP的猪肝细胞会被HBV感染，并表明猪NTCP不支持HBV结合。通过逐步对猪NTCP进行人源化和定点诱变，我们确定了猪NTCP中第158和167位氨基酸限制了HBV相互作用。在一项概念验证实验中，我们表明表达人源化第157 - 167位氨基酸的猪NTCP可使原代猪肝细胞对HBV完全易感。这些结果为培育具有人源化猪嵌合NTCP的转基因猪铺平了道路，这种转基因猪可作为一种新型的、具有完全免疫活性的感染模型，用于开发和验证新的HBV治愈性疗法。
