De-Min Yu1, Xin-Hua Li2, Vannary Mom3, Zhong-Hua Lu4, Xiang-Wei Liao1, Yue Han1, Christian Pichoud3, Qi-Ming Gong1, Dong-Hua Zhang1, Yan Zhang5, Paul Deny6, Fabien Zoulim7, Xin-Xin Zhang8. 1. Department of Infectious Disease, Institute of Infectious and Respiratory Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China. 2. Department of Infectious Disease, Institute of Infectious and Respiratory Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China; The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, People's Republic of China. 3. INSERM, U1052, 151 cours Albert Thomas, 69424 Lyon cedex 03, France. 4. Wu Xi Hospital of Infectious Diseases, People's Republic of China. 5. Ministry of Education Key Laboratory of Systems Biomedicine, Shanghai Center for Systems Biomedicine (SCSB), Shanghai Jiao Tong University, People's Republic of China. 6. INSERM, U1052, 151 cours Albert Thomas, 69424 Lyon cedex 03, France; University Paris 13, Groupe des Hôpitaux Universitaires Paris Seine Saint Denis, Paris, France. 7. INSERM, U1052, 151 cours Albert Thomas, 69424 Lyon cedex 03, France; Lyon University and Hospices Civils de Lyon, Lyon, France. Electronic address: fabien.zoulim@inserm.fr. 8. Department of Infectious Disease, Institute of Infectious and Respiratory Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China. Electronic address: zhangxinxin@rjh.com.cn.
Abstract
BACKGROUND & AIMS: HBV immune escape represents a challenge to prevention, diagnosis, and treatment of hepatitis B. Here, we analyzed the molecular and clinical characteristics of HBV immune escape mutants in a Chinese cohort of chronically infected patients. METHODS: Two hundred sixteen patients with HBsAg and anti-HBs were studied, with one hundred eighty-two HBV carriers without anti-HBs as a control group. Recombinant HBsAg bearing the most frequent N-glycosylation mutations were expressed in CHO and HuH7 cells. After confirming N-glycosylation at the most frequent sites (129 and 131), together with inserted mutations, functional analysis were performed to study antigenicity and secretion capacity. RESULTS: One hundred twenty-three patients had the wild-type HBs gene sequence, 93 patients (43%) had mutants in the major hydrophilic region (MHR), and 47 of the 93 patients had additional N-glycosylation mutations, which were transmitted horizontally to at least 2 patients, one of whom was efficiently vaccinated. The frequency of N-glycosylation mutation in the case group was much higher than that of the control group (47/216 vs. 1/182). Compared with wild-type HBsAg, HBsAg mutants reacted weakly with anti-HBs using a chemiluminescent microparticle enzyme immunoassay. Native gel analysis of secreted virion in supernatants of transfected HuH7 cells indicated that mutants had better virion enveloping and secretion capacity than wild-type HBV. CONCLUSIONS: Our results suggest that specific HBsAg MHR N-glycosylation mutations are implicated in HBV immune escape in a high endemic area.
BACKGROUND & AIMS: HBV immune escape represents a challenge to prevention, diagnosis, and treatment of hepatitis B. Here, we analyzed the molecular and clinical characteristics of HBV immune escape mutants in a Chinese cohort of chronically infectedpatients. METHODS: Two hundred sixteen patients with HBsAg and anti-HBs were studied, with one hundred eighty-two HBV carriers without anti-HBs as a control group. Recombinant HBsAg bearing the most frequent N-glycosylation mutations were expressed in CHO and HuH7 cells. After confirming N-glycosylation at the most frequent sites (129 and 131), together with inserted mutations, functional analysis were performed to study antigenicity and secretion capacity. RESULTS: One hundred twenty-three patients had the wild-type HBs gene sequence, 93 patients (43%) had mutants in the major hydrophilic region (MHR), and 47 of the 93 patients had additional N-glycosylation mutations, which were transmitted horizontally to at least 2 patients, one of whom was efficiently vaccinated. The frequency of N-glycosylation mutation in the case group was much higher than that of the control group (47/216 vs. 1/182). Compared with wild-type HBsAg, HBsAg mutants reacted weakly with anti-HBs using a chemiluminescent microparticle enzyme immunoassay. Native gel analysis of secreted virion in supernatants of transfected HuH7 cells indicated that mutants had better virion enveloping and secretion capacity than wild-type HBV. CONCLUSIONS: Our results suggest that specific HBsAg MHR N-glycosylation mutations are implicated in HBV immune escape in a high endemic area.
Authors: X Y Wang; T J Harrison; X He; Q Y Chen; G J Li; M H Liu; H Li; J Y Yang; Z L Fang Journal: Epidemiol Infect Date: 2015-04-23 Impact factor: 4.434