甲型肝炎病毒(H2株)快速适应变异株全基因序列分析

目的 探索甲型肝炎病毒（Ｈ２株）细胞适应的分于机制。方法 将甲型肝炎减毒活疫苗毒株（ＨＡＶ Ｈ２Ｋ７）在人胚肺二倍体细胞ＫＭＢ１７上快速连续传代增强适应（１４ｄ），检测连续传代后抗原滴度和感染性滴度，测定 第１８代（ＨＡＶ Ｈ２Ｋ７Ｐ１８）全基因组序列。结果 适应至第１８代抗原滴度达１：５１２，感染性滴度为７．５ＬｏｇＣＣＩＤ５０／ｍｌ。 整个基因组出现了１０个核苷酸突变，变异卒为０．１３％，变异较大区域位于５’末端非编码区（５’ＵＴＰ），有３个核苷酸 变异。编码区７个交变，２个是无义突变，５个有义突变导致５个氨基酸变化，分别位于 ＶＰ２ Ａ－Ｓ；２Ｃ，Ｑ－Ｐ；３Ａ，Ｒ－ Ｃ；３Ｃ，Ｔ－Ａ和３Ｄ，Ｖ－Ｇ。结论 ＨＡＶ Ｈ２Ｋ７４因组５’ＵＴＲ、２Ｃ区、３Ａ区、３Ｃ区和３Ｄ区变异协同作用促进在 ＫＭＢ１７ 细胞上快速增强适应。

Sequencing and Analysis of Whole Genome of Rapidly Adapted Variant of Hepatitis A Virus (H2 Strain)

Objective To explore the melecular mechanism of cellular adaptation of hepatitis A virus (HAV). Methods H2K7 strain was passaged in human embryo lung diploid cell KMB17 serially and rapidly for 14d. The antigen and infectious titers of the strain after being undergone 18 passages were detected, and the whole genome of HAVH2K7P18 was sequenced. Results The antigen and infectious titers of HAVH2K7P18 were 1: 512 and 7.5LogCCID50/ml respectively. Ten nucleotide mutations of the whole genome were observed. The mutation rate of it was 0.13%. Three mutations were observed in 5' non-ceding region (5'UTR), and the other 7 including 2 nonseme mutations in open reading hame(ORF). The 5 amino acid exchanges resulted from the rest 5 mutations in ORF were observed in VP2(A-S), 2C(Q-P), 3A(R- C), 3C(T-A) and 3D(V-G) respectively. Conclusion The mutations in 5'UTR, 2C, 3A, 3C and 3D regions synergistically promote the rapid adapation of HAVH2K7 in KMB17 cells.