Chen Jianhong, Liu Yan, Zhao Jun, Xu Zhihui, Chen Rongjuan, Si Lanlan, Lu Shanshan, Li Xiaodong, Wang Shuai, Zhang Kai, Li Jin, Han Juqiang, Xu Dongping
Institute of Infectious Diseases/Research Center for Clinical and Translational Medicine, Beijing 302 Hospital, Beijing 100039, China.
Department of liver disease, General Hospital of Beijing Military Region, Beijing 100700, China.
PLoS One. 2016 May 16;11(5):e0155654. doi: 10.1371/journal.pone.0155654. eCollection 2016.
The impact of hepatitis B virus (HBV) preS/S-gene mutations on occult HBV infection (OBI) is not fully understood. This study characterized multiple novel HBV preS/S-gene mutants obtained from an OBI patient.
PreS/S-gene mutants were analyzed by clonal sequencing. Viral replication and expression were analyzed by transfecting HBV genomic recombinants into HepG2 cells.
Twenty-one preS/S-gene mutants were cloned from four sequential serum samples, including 13 mutants that were not previously documented: (1) sI/T126V+sG145R; (2) preS1 nt 3014-3198 deletion; (3) preS1 nt 3046-3177 deletion; (4) preS1 nt 3046-3177 deletion+s115-116 "INGTST" insertion; (5) preS1 nt 3046-3177 deletion+s115-116 "INGTST" insertion+sG145R; (6) preS1 nt 3115-3123 deletion+sQ129N; (7) preS1 nt 3115-3123 deletion+s126-127 "RPCMNCTI" insertion; (8) s115-116 "INGTST" insertion; (9) s115-116 "INGTST" insertion+sG145R; (10) s126-127 "RPCMNCTI" insertion; (11) preS1 nt 2848-2862 deletion+preS2 initiation codon M→I; (12) s122-123 "KSTGLCK" insertion+sQ129N; and (13) preS2 initiation codon M→I+s131-133TSM→NST. The proportion of preS1 nt 3046-3177 deletion and preS2 initiation codon M→I+s131-133TSM→NST mutants increased in the viral pool with prolonged disease. The 13 novel OBI-related mutants showed a 51.2-99.9% decrease in HBsAg levels compared with that of the wild type. Additional N-glycosylation-associated mutations, sQ129N and s131-133TSM→NST, but not s126-127 "RPCMNCTI," greatly attenuated anti-HBs binding to HBsAg. Compared with the wild type, replication and surface antigen promoter II activity of the preS1 nt 3046-3177 deletion mutant decreased by 43.3% and 97.0%, respectively.
PreS/S-gene mutations may play coordinated roles in the presentation of OBI and might be associated with disease progression. This has implications for HBV diagnosis and vaccine improvement.
乙型肝炎病毒（HBV）前S/S基因变异对隐匿性HBV感染（OBI）的影响尚未完全明确。本研究对一名OBI患者体内获得的多个新型HBV前S/S基因突变体进行了特征分析。
采用克隆测序法分析前S/S基因突变体。通过将HBV基因组重组体转染至HepG2细胞来分析病毒复制和表达情况。
从四份连续血清样本中克隆出21个前S/S基因突变体，其中包括13个先前未报道的突变体：（1）sI/T126V + sG145R；（2）前S1第3014 - 3198位核苷酸缺失；（3）前S1第3046 - 3177位核苷酸缺失；（4）前S1第3046 - 3177位核苷酸缺失 + s115 - 116“INGTST”插入；（5）前S1第3046 - 3177位核苷酸缺失 + s115 - 116“INGTST”插入 + sG145R；（6）前S1第3115 - 3123位核苷酸缺失 + sQ129N；（7）前S1第3115 - 3123位核苷酸缺失 + s126 - 127“RPCMNCTI”插入；（8）s115 - 116“INGTST”插入；（9）s115 - 116“INGTST”插入 + sG145R；（10）s126 - 127“RPCMNCTI”插入；（11）前S1第2848 - 2862位核苷酸缺失 + 前S2起始密码子M→I；（12）s122 - 123“KSTGLCK”插入 + sQ129N；以及（13）前S2起始密码子M→I + s131 - 133TSM→NST。随着病程延长，病毒库中前S1第3046 - 3177位核苷酸缺失突变体和前S2起始密码子M→I + s131 - 133TSM→NST突变体的比例增加。与野生型相比，这13个新型OBI相关突变体的HBsAg水平降低了51.2% - 99.9%。其他与N - 糖基化相关的突变，sQ129N和s131 - 133TSM→NST，但不包括s126 - 127“RPCMNCTI”，极大地减弱了抗 - HBs与HBsAg的结合。与野生型相比，前S1第3046 - 3177位核苷酸缺失突变体的复制和表面抗原启动子II活性分别降低了43.3%和97.0%。
前S/S基因突变可能在OBI的表现中起协同作用，并可能与疾病进展相关。这对HBV诊断和疫苗改进具有重要意义。
