Author/Authors :
Norouzi, Mehdi Iranian National Institute for Genetic Engineering and Biotechnology, Tehran , Ghorashi, Ali Iranian National Institute for Genetic Engineering and Biotechnology, Tehran , Ataei, Behrooz Infectious Diseases and Tropical Medicine Research Center - Isfahan University of Medical Sciences , Yaran, Majid Infectious Diseases and Tropical Medicine Research Center - Isfahan University of Medical Sciences , Malekzadeh, Reza Digestive Disease Research Center - Shariati Hospital, Tehran , Alavian, Moayyed Baqiyatallah University of Medical Sciences - Baqiyatallah Research Centre for Gastroenterology and Liver Disease, Tehran , Judaki, Mohammad Ali Hepatitis B Molecular Laboratory - Department of Virology - School of Public Health - Tehran University of Medical Sciences , Ghamari, Shiva Hepatitis B Molecular Laboratory - Department of Virology - School of Public Health - Tehran University of Medical Sciences , Namazi, Alireza Hepatitis B Molecular Laboratory - Department of Virology - School of Public Health - Tehran University of Medical Sciences , Rahimnia, Ramin Hepatitis B Molecular Laboratory - Department of Virology - School of Public Health - Tehran University of Medical Sciences , Khedive, Abolfazl Hepatitis B Molecular Laboratory - Department of Virology - School of Public Health - Tehran University of Medical Sciences , Jazayeri, Mohammad Hepatitis B Molecular Laboratory - Department of Virology - School of Public Health - Tehran University of Medical Sciences
Abstract :
Objective(s) The aim of this study was to characterize the hepatitis B virus surface protein genotypes and sequence variations among hepatitis B virus surface antigen (HBsAg) positive chronic patients in Hormozgan province, south of Iran. Materials and Methods A total of 8 patients enrolled in this study. The surface gene was amplified and directly sequenced. Genotypes and nucleotide/amino acid substitutions were identified compared to the sequences obtained from the database. Results
All strains belonged to genotype D. Overall 77 “mutations” occurred at 45 nucleotide positions, of them, 44 (57.14%) were silent (no amino acid altering) and 33 (42.86%) were missense (amino acid changing). A number of 24 (80%) out of 30 amino acid changes occurred in different immune epitopes within surface protein, of
which, 9 (30%) in B cell epitopes in 7 residues (2 occurred in “a” determinant region); 8 (42.1%) in T helper epitopes in 7 residues and 7 (10%) in 4 residues inside CTL epitopes. Conclusion Hepatitis B virus genome containing mutated immune epitopes no longer could be recognized by specific Tcells of the host immune surveillance and did not enhance anti-HBs production. This could led to the progression of chronicity of hepatitis B virus infection.
Keywords :
HBV genotypes , HBV genotype D , HBV genotype in Iran , HBV immune epitopes
