近日，HCV体外培养系统取得了里程碑的进展。来自美国洛克菲勒大学（The Rockefeller University）的 Charles M. Rice 教授实验室通过在转有人全基因cDNA文库的Huh-7.5 肝癌细胞系中发现了一个基因SEC14L2，在不同肝癌细胞系中表达这一基因都能够实现HCV感染复制。这一研究结果在线发表在8月12日的《Nature》上。
Mohsan Saeed, Ursula Andreo, Hyo-Young Chung, Christine Espiritu, Andrea D. Branch, Jose M. Silva & Charles M. Rice
Since its discovery in 1989, efforts to grow clinical isolates of the hepatitis C virus (HCV) in cell culture have met with limited success. Only the JFH-1 isolate has the capacity to replicate efficiently in cultured hepatoma cells without cell culture-adaptive mutations1, 2, 3. We hypothesized that cultured cells lack one or more factors required for the replication of clinical isolates. To identify the missing factors, we transduced Huh-7.5 human hepatoma cells with a pooled lentivirus-based human complementary DNA (cDNA) library, transfected the cells with HCV subgenomic replicons lacking adaptive mutations, and selected for stable replicon colonies. This led to the identification of a single cDNA, SEC14L2, that enabled RNA replication of diverse HCV genotypes in several hepatoma cell lines. This effect was dose-dependent, and required the continuous presence of SEC14L2. Full-length HCV genomes also replicated and produced low levels of infectious virus. Remarkably, SEC14L2-expressing Huh-7.5 cells also supported HCV replication following inoculation with patient sera. Mechanistic studies suggest that SEC14L2 promotes HCV infection by enhancing vitamin E-mediated protection against lipid peroxidation. This provides a foundation for development of in vitro replication systems for all HCV isolates, creating a useful platform to dissect the mechanisms by which cell culture-adaptive mutations act.