- 作者：Valeria Cento ; Formijn Van Hemert ; Maria Neumann-Fraune ; Carmen Mirabelli ; Velia-Chiara Di Maio ; Romina Salpini ; Ada Bertoli ; Valeria Micheli ; Guido Gubertini ; Sara Romano ; Michela Visca ; Giuseppe-Maria De Sanctis ; Ben Berkhout ; Nicoletta Marino ; Francesco Mazzotta ; Giuseppina Cappiello ; Alberto Span¨° ; Cesare Sarrecchia ; Francesca Ceccherini-Silberstein ; Massimo Andreoni ; et al.
- 关键词：HBV drug-resistance ; HBsAg stop codon ; Treatment failure ; HBsAg structure ; HBsAg secretion
- 刊名：Journal of Infection
- 出版年：2013
- 出版时间：October, 2013
- 年：2013
- 卷：67
- 期：4
- 页码：303-312
- 全文大小：1432 K
Summary
Introduction
The identification of novel reverse-transcriptase (RT) drug-resistance mutations is critical in predicting the probability of success to anti-HBV treatment. Furthermore, due to HBV-RT/HBsAg gene-overlap, they can have an impact on HBsAg-detection and quantification.Methods
356 full-length HBV-RT sequences from 197 drug-naive patients and 159 patients experiencing virological-breakthrough to nucleoside/nucleotide-analogs (NUCs) were analyzed. Mutants and wild-type HBs-antigens were expressed in HuH7-hepatocytes and quantified in cell-supernatants and cell-lysates by Architect HBsAg-assay.
Results
Ten novel RT-mutations (rtN53T-rtS78T-rtS85F-rtS135T-rtA181I-rtA200V-rtK212Q-rtL229V/F-rtM309K) correlated with specific NUC-treatments and classical drug-resistance mutations on divergent evolutionary pathways. Some of them reduced RT-binding affinity for anti-HBV drugs and altered S-antigen structure. Indeed, rtS78T (prevalence: 1.1 % in drug-na?ve and 12.2 % in adefovir-failing patients) decreased the RT-affinity for adefovir more than the classical adefovir-resistance mutations rtA181?T/V (WT:?9.63?kcal/mol, rtA181T:?9.30?kcal/mol, rtA181V:?7.96?kcal/mol, rtS78T:?7.37?kcal/mol). Moreover, rtS78T introduced a stop-codon at HBsAg-position 69, and completely abrogated HBsAg-quantification in both supernatants and cell-lysates, indicating an impaired HBsAg-secretion/production. Furthermore, the HBsAg-mutation sP217L, silent in RT, significantly correlated with M204V/I-related virological-breakthrough and increased HBsAg-quantification in cell-lysate.
Conclusions
Mutations beyond those classically known can affect drug-binding affinity of mutated HBV-RT, and may have potential effects on HBsAg. Their cumulative effect on resistance and HBV-pathogenicity indicates the importance of preventing therapeutic failures.