scholarly journals Serodiagnosis of Hepatitis B Virus Using PreS Antigen from Pakistani Isolate SBS001

2021 ◽  
pp. 246-255
Author(s):  
Saima Iftikhar ◽  
Farheen Aslam ◽  
Muhammad Akhtar
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Recombinant Protein ◽  
High Titer ◽  
Protein A ◽  
Gene Encoding ◽  
Pakistani Population ◽  
Enhanced Sensitivity ◽  
Escherchia Coli ◽  
B Virus

Background: An estimated 325 million people worldwide live with hepatitis B and/or C and approximately, 5 million people are affected with hepatitis B. in Pakistan.This study aimed at developing PreS protein from Hepatitis B Virus Pakistani isolate (SBS001) with enhanced sensitivity to detect antibodies in serum as a diagnostic method. Methods: Gene encoding PreS region from hepatitis B Virus was cloned and expressed in Escherchia coli. The recombinant protein preS-His was purified by Ni-IDA affinity chromatography. Antibodies were raised in rabbit. This protein was screened for detection of antibodies in HBV patients’ sera through ELISA. This ELISA procedure was compared with commercially available Kit used for diagnosis of HBV infection. Results: Single band purified recombinant PreS protein was obtained with high titer of antibodies raised in rabbits. This recombinant protein was used in ELISA as antigen coated on the plate. That efficiently detected antibodies present in HBV patients. It was concluded that preS-His antigen/ protein A HRP-conjugate ELISA method was more sensitive than the commercial kit for detecting the antibodies present in HBV patient sera. Conclusion: It was concluded that SBS001 PreS recombinant protein can be used in ELISA kits for detection of HBV in Pakistani population.

scholarly journals Translation of hepatitis B virus (HBV) surface proteins from the HBV pregenome and precore RNAs in Semliki Forest virus-driven expression

2004 ◽  
Vol 85 (11) ◽  
pp. 3343-3351 ◽  
Author(s):  
Anna Zajakina ◽  
Tatyana Kozlovska ◽  
Ruta Bruvere ◽  
Jekaterina Aleksejeva ◽  
Paul Pumpens ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Semliki Forest Virus ◽  
Expression System ◽  
Protein A ◽  
Direct Repeat ◽  
Infection Process ◽  
Surface Proteins ◽  
B Virus ◽  
Internal Translation

Hepatitis B virus (HBV) pregenome RNA (pgRNA) serves as a translation template for the HBV core (HBc) protein and viral polymerase (Pol). HBV precore RNA (pcRNA) directs the synthesis of the precore (preC) protein, a precursor of the hepatitis B e antigen (HBeAg). pgRNA and pcRNA were expressed in the Semliki Forest virus (SFV) expression system. Besides the HBc and preC proteins, there was revealed the synthesis of all three forms of HBV surface (HBs) proteins: long (LHBs), middle (MHBs) and short (SHBs), the start codons of which are located more than 1000 nt downstream of the HBc and preC start codons. Moreover, other HBV templates, such as 3′-truncated pgRNA lacking 3′ direct repeat and Pol mRNA, both carrying internally the HBs sequences, provided the synthesis of three HBs protein forms in the SFV-driven expression system. Maximal production of the HBs was provided by Pol mRNA, while HBc- and preC-producing templates showed relatively low internal translation of the HBs. These data allow the proposal of a ribosome leaky scanning model of internal translation initiation for HBs proteins. The putative functional role of such exceptional synthesis of the HBs proteins from the pgRNA and pcRNA templates in the natural HBV infection process needs further evaluation.

scholarly journals A pocket-factor–triggered conformational switch in the hepatitis B virus capsid

2021 ◽  
Vol 118 (17) ◽  
pp. e2022464118
Author(s):  
Lauriane Lecoq ◽  
Shishan Wang ◽  
Marie Dujardin ◽  
Peter Zimmermann ◽  
Leonard Schuster ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Core Protein ◽  
Hot Spot ◽  
Protein A ◽  
Structural Variations ◽  
Interaction Hypothesis ◽  
B Virus ◽  
Alternative Conformation ◽  
Main Culprit

Viral hepatitis is growing into an epidemic illness, and it is urgent to neutralize the main culprit, hepatitis B virus (HBV), a small-enveloped retrotranscribing DNA virus. An intriguing observation in HB virion morphogenesis is that capsids with immature genomes are rarely enveloped and secreted. This prompted, in 1982, the postulate that a regulated conformation switch in the capsid triggers envelopment. Using solid-state NMR, we identified a stable alternative conformation of the capsid. The structural variations focus on the hydrophobic pocket of the core protein, a hot spot in capsid–envelope interactions. This structural switch is triggered by specific, high-affinity binding of a pocket factor. The conformational change induced by the binding is reminiscent of a maturation signal. This leads us to formulate the “synergistic double interaction” hypothesis, which explains the regulation of capsid envelopment and indicates a concept for therapeutic interference with HBV envelopment.

scholarly journals Age-wise and Gender-wise Prevalence of Hepatitis B Virus (HBV) Infection in Lahore, Pakistan

2019 ◽  
Vol 01 (04) ◽  
pp. 20-28
Author(s):  
Aqib Nazeer ◽  
Shahid Ali ◽  
Imran Tipu
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Hepatitis B Surface Antigen ◽  
Hbv Infection ◽  
Age Group ◽  
Pakistani Population ◽  
Blood Samples ◽  
Significant Difference ◽  
B Virus ◽  
And Gender

Background The prevalence of hepatitis B virus (HBV) in the Pakistani population has been reported previously, however, studies with a city-oriented approach and focus on age and gender distribution are very limited. Therefore, the current study was designed to unravel the age-wise and gender wise prevalence of HBV in Lahore, Pakistan. Methods A total of 350 blood samples of both male and female patients who visited National Genetic Laboratory, Lahore between February 2019 and July 2019 and who were suspected of HBV infection were screened. Sandwich based ELISA was used to detect rapid hepatitis B surface antigen (HbsAg) according to the manufacturer’s instruction. Real time PCR was used to detect HBV using HBV Rotor Gene PCR kit. Results Out of 350 blood samples screened for HBV infection (n= 350), 180 (51.43%) were of males and 170 (48.57%) were of females. Mean age (years) with SD (standard deviation) of the screened population was 37.22 ± 12.16 years. Overall, 224 samples (64%) were found to be positive for HBV infection. In our study, the number of females with this infection (52.24%) was slightly higher than males (47.76%). However, we observed no statistically significant difference (p = 0.225) between them. Conclusion Our study concludes that HBV is highly prevalent in Lahore, Pakistan. Females are slightly more susceptible to HBV infection as compared to males. This study also reports that HBV is more prevalent in the 20-40 age group.

scholarly journals Epidemiological patterns and risk factors associated with hepatitis B virus in Pakistani population

2010 ◽  
Vol 4 (4) ◽  
pp. 547-554 ◽  
Author(s):  
Yasir Waheed ◽  
Talha Bin-Rahat ◽  
Sher Zaman Safi ◽  
Ishtiaq Qadri
Keyword(s):  
Risk Factors ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Viral Transmission ◽  
International Standards ◽  
Surgical Instruments ◽  
Pakistani Population ◽  
Factors Associated ◽  
B Virus ◽  
Hbv Transmission

Abstract Hepatitis B virus prevalence is increasing in Pakistani population. National level estimates regarding the prevalence are missing. People are unaware of the risk factors involved in HBV transmission. The objective of the study was to review the prevalence, genotypes, and risk factors associated with HBV transmission in Pakistani Population. Literature search was done by using keyword HBV prevalence, genotypes and risk factors from Pakistani population at Pubmed, PakMediNet and Google scholar. Six different studies showed that the percentage prevalence of HBV in general population was 4.61±0.73%, and 21 different studies showed the percentage prevalence of 2.33±0.46% in blood donors. High prevalence of 7.94±1.49% and 12.86±4.52% were observed in multi transfused and IDU populations. Six different studies showed that the major prevalent genotype was D. Awareness regarding various risk factors involved in-viral transmission was very low. Prevalence of HBV was very high in multitransfused populations due to non-implementations of international standards regarding blood transfusions. Barbers were unaware of the risk factors associated with their shops in viral transmission. Practices of unsterilized dental and surgical instruments and recycling of syringes were major factors in viral transmission. Massive awareness and vaccination programs are required to decrease the future burden of HBV from Pakistani population.

scholarly journals Hepatitis B Virus DNA Replication Is Coordinated by Core Protein Serine Phosphorylation and HBx Expression

2005 ◽  
Vol 79 (15) ◽  
pp. 9810-9820 ◽  
Author(s):  
Margherita Melegari ◽  
Sarah K. Wolf ◽  
Robert J. Schneider
Keyword(s):  
Hepatitis B Virus ◽  
Dna Replication ◽  
Hepatitis B ◽  
Viral Replication ◽  
Core Protein ◽  
Regulatory Protein ◽  
Protein A ◽  
Serine Phosphorylation ◽  
Hbv Replication ◽  
B Virus

ABSTRACT The hepatitis B virus (HBV) core protein forms the capsid of viral particles and is essential for viral genome DNA replication and maturation. The C terminus of core protein contains three serines at positions 155, 162, and 170, phosphorylation of which is important for viral DNA replication. We demonstrate that the phosphorylation of these serines is stimulated by the viral HBx protein, a regulatory protein that activates signal transduction pathways and viral replication. HBx is therefore shown to stimulate HBV replication by increasing core serine phosphorylation. Mutational, biochemical, and mixing studies of C-terminal core serine mutants demonstrate that multiple serine phosphorylations occur on the same core protein. Mutation of individual core protein serines is shown to inhibit HBV replication at distinct stages corresponding to encapsidation of viral pregenomic RNA, reverse transcription, and restriction to synthesis of specific DNA replicative intermediates. We therefore demonstrate that a primary target of HBV replication that is regulated by HBx protein corresponds to increased phosphorylation of the viral core protein. We also demonstrate that core phosphorylation mediated by HBx promotes sequential progression of viral replication through the assembly of capsids primed for different stages of DNA synthesis.

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