N-Glycosylation Mutations within Hepatitis B Virus Surface Major Hydrophilic Region Contribute Mostly to Immune Escape
De-Min Yu a ,
Xin-Hua Lia, f,
Vannary Mom b,
Zhong-Hua Lu d,
Xiang-Wei Liao a,
Yue Han a,
Christian Pichoud b,
Qi-Ming Gong a,
Dong-hua Zhang a,
Yan Zhang e,
Paul Deny b,
Fabien Zoulimb, c,
Xin- XinZhang a, Corresponding author contact information, E-mail the corresponding author, E-mail the corresponding author
a 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
b INSERM, U1052, 151 cours Albert Thomas, 69424 Lyon cedex 03, France
c Lyon University and Hospices Civils de Lyon, Lyon, France
d Wu Xi Hospital of Infectious Diseases, People’s Republic of China
e Ministry of Education Key Laboratory of Systems Biomedicine, Shanghai Center for Systems Biomedicine (SCSB), Shanghai Jiao Tong University, People’s Republic of China
f The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, People’s Republic of China
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.
Conclusion
Our results suggest that specific HBsAg MHR N-glycosylation mutations are implicated in HBV immune escape in a high endemic area. 作者: StephenW 时间: 2013-11-18 18:36