scholarly journals Chimeric Virus-Like Particles of Prawn Nodavirus Displaying Hepatitis B Virus Immunodominant Region: Biophysical Properties and Cytokine Response

2021 ◽  
Vol 22 (4) ◽  
pp. 1922
Author(s):  
Nathaniel Nyakaat Ninyio ◽  
Kok Lian Ho ◽  
Chean Yeah Yong ◽  
Hui Yee Chee ◽  
Muhajir Hamid ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Cd Spectroscopy ◽  
Cytokine Response ◽  
Enzyme Linked Immunosorbent Assay ◽  
Thermally Stable ◽  
Biophysical Properties ◽  
Virus Like Particles ◽  
B Virus ◽  
Hepatitis B Vaccines

Hepatitis B is a major global health challenge. In the absence of an effective treatment for the disease, hepatitis B vaccines provide protection against the viral infection. However, some individuals do not have positive immune responses after being vaccinated with the hepatitis B vaccines available in the market. Thus, it is important to develop a more protective vaccine. Previously, we showed that hepatitis B virus (HBV) ‘a’ determinant (aD) displayed on the prawn nodavirus capsid (Nc) and expressed in Spodoptera frugiperda (Sf9) cells (namely, Nc-aD-Sf9) self-assembled into virus-like particles (VLPs). Immunisation of BALB/c mice with the Nc-aD-Sf9 VLPs showed significant induction of humoral, cellular and memory B-cell immunity. In the present study, the biophysical properties of the Nc-aD-Sf9 VLPs were studied using dynamic light scattering (DLS) and circular dichroism (CD) spectroscopy. Enzyme-linked immunosorbent assay (ELISA) was used to determine the antigenicity of the Nc-aD-Sf9 VLPs, and multiplex ELISA was employed to quantify the cytokine response induced by the VLPs administered intramuscularly into BALB/c mice (n = 8). CD spectroscopy of Nc-aD-Sf9 VLPs showed that the secondary structure of the VLPs predominantly consisted of beta (β)-sheets (44.8%), and they were thermally stable up to ~52 °C. ELISA revealed that the aD epitope of the VLPs was significantly antigenic to anti-HBV surface antigen (HBsAg) antibodies. In addition, multiplex ELISA of serum samples from the vaccinated mice showed a significant induction (p < 0.001) of IFN-γ, IL-4, IL-5, IL-6, IL-10, and IL-12p70. This cytokine profile is indicative of natural killer cell, macrophage, dendritic cell and cytotoxic T-lymphocyte activities, which suggests a prophylactic innate and adaptive cellular immune response mediated by Nc-aD-Sf9 VLPs. Interestingly, Nc-aD-Sf9 induced a more robust release of the aforementioned cytokines than that of Nc-aD VLPs produced in Escherichia coli and a commercially used hepatitis B vaccine. Overall, Nc-aD-Sf9 VLPs are thermally stable and significantly antigenic, demonstrating their potential as an HBV vaccine candidate.

scholarly journals Efficient Production of Chimeric Hepatitis B Virus-Like Particles Bearing an Epitope of Hepatitis E Virus Capsid by Transient Expression in Nicotiana benthamiana

Life ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 64
Author(s):  
Gergana Zahmanova ◽  
Milena Mazalovska ◽  
Katerina Takova ◽  
Valentina Toneva ◽  
Ivan Minkov ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Nicotiana Benthamiana ◽  
Hepatitis E Virus ◽  
Chimeric Protein ◽  
Hepatitis E ◽  
Core Antigen ◽  
Efficient Production ◽  
Virus Like Particles ◽  
B Virus

The core antigen of hepatitis B virus (HBcAg) is capable of self-assembly into virus-like particles (VLPs) when expressed in a number of heterologous systems. Such VLPs are potential carriers of foreign antigenic sequences for vaccine design. In this study, we evaluated the production of chimeric HBcAg VLPs presenting a foreign epitope on their surface, the 551–607 amino acids (aa) immunological epitope of the ORF2 capsid protein of hepatitis E virus. A chimeric construct was made by the insertion of 56 aa into the immunodominant loop of the HBcAg. The sequences encoding the chimera were inserted into the pEAQ-HT vector and infiltrated into Nicotiana benthamiana leaves. The plant-expressed chimeric HBcHEV ORF2 551–607 protein was recognized by an anti-HBcAg mAb and anti-HEV IgG positive swine serum. Electron microscopy showed that plant-produced chimeric protein spontaneously assembled into “knobbly” ~34 nm diameter VLPs. This study shows that HBcAg is a promising carrier platform for the neutralizing epitopes of hepatitis E virus (HEV) and the chimeric HBcAg/HEV VLPs could be a candidate for a bivalent vaccine.

scholarly journals Development and evaluation of an in-house ELISA to detect hepatitis B virus surface antigen in resource-limited settings

2014 ◽  
Vol 39 (2) ◽  
pp. 65-68 ◽  
Author(s):  
K Fatema ◽  
S Tabassum ◽  
A Nessa ◽  
M Jahan
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Surface Antigen ◽  
Hbv Infection ◽  
Health Concern ◽  
Enzyme Linked Immunosorbent Assay ◽  
Virus Surface ◽  
B Virus ◽  
Commercial Kits ◽  
Checkerboard Titration

Hepatitis B virus (HBV) infection is of global public health concern. Among various serological tests used for the diagnosis and screening of HBV infection, the enzyme-linked immunosorbent assay (ELISA) to detect hepatitis B surface antigen (HbsAg) is most widely used. The present study was designed to develop and standardize a cost effective in-house ELISA for the detection of HbsAg and compare its performance with two established commercial kits. The concentrations of coating antibody, conjugates and sera were fixed by checkerboard titration. Using known HBsAg positive and negative sera, four different concentrations (1, 0.5, 0.25 and 0.125 ?g/well) of coating anti-HBs were applied. Similarly, serial dilutions of patients’ sera (1 in 2, 1 in 3, 1 in 5 and 1 in 9) and conjugates (1 in 2, 1 in 3, 1 in 5, 1 in 9 and 1 in 17) were evaluated by checkerboard titration. The optimal concentration of coating antibody was determined at 0.25 ?g/well and 1 in 9 dilution for both conjugates and sera. The performance comparison of our in-house ELISA showed excellent correlation with two commercial kits (Pearson 0.957, P=0.001 for monoclonal antibody coated kit and Pearson 0.929, P=0.000 for polyclonal antibody coated kit) when OD values were compared. All commercial kit proven positive samples was positive while all negative samples were negative with the in-house ELISA resulting in 100% sensitivity and specificity. The results of our study demonstrated that our inhouse ELISA for detection of HBsAg was equally as sensitive and specific as two well-known commercial kits. Thus, this system may be a useful tool for diagnostic and screening purposes, as well as outbreak investigations. DOI: http://dx.doi.org/10.3329/bmrcb.v39i2.19644 Bangladesh Med Res Counc Bull 2013; 39: 65-68

scholarly journals Characterization of a G-quadruplex from hepatitis B virus and its stabilization by binding TMPyP4, BRACO19 and PhenDC3

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Orsolya Réka Molnár ◽  
András Végh ◽  
Judit Somkuti ◽  
László Smeller
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Binding Constants ◽  
Temperature Stability ◽  
Cd Spectroscopy ◽  
Parallel Structure ◽  
Hybrid Form ◽  
B Virus ◽  
G Quadruplex

AbstractSpecific guanine rich nucleic acid sequences can form non-canonical structures, like the four stranded G-quadruplex (GQ). We studied the GQ-forming sequence (named HepB) found in the genome of the hepatitis B virus. Fluorescence-, infrared- and CD-spectroscopy were used. HepB shows a hybrid form in presence of K+, but Na+, Li+, and Rb+ induce parallel structure. Higher concentrations of metal ions increase the unfolding temperature, which was explained by a short thermodynamic calculation. Temperature stability of the GQ structure was determined for all these ions. Na+ has stronger stabilizing effect on HepB than K+, which is highly unusual. The transition temperatures were 56.6, 53.8, 58.5 and 54.4 °C for Na+, K+, Li+, and Rb+ respectively. Binding constants for Na+ and K+ were 10.2 mM and 7.1 mM respectively. Study of three ligands designed in cancer research for GQ targeting (TMPyP4, BRACO19 and PhenDC3) showed unequivocally their binding to HepB. Binding was proven by the increased stability of the bound form. The stabilization was higher than 20 °C for TMPyP4 and PhenDC3, while it was considerably lower for BRACO19. These results might have medical importance in the fight against the hepatitis B virus.

Prevalence and genotyping of hepatitis B virus: a cross-sectional study conducted with female sex workers in the Marajó Archipelago, Brazil

2019 ◽  
Vol 30 (9) ◽  
pp. 902-910 ◽  
Author(s):  
Paula CR Frade ◽  
Nairis C Raiol ◽  
Luana M da Costa ◽  
Luiz ML Pinheiro ◽  
Gláucia C Silva-Oliveira ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Sex Workers ◽  
Female Sex Workers ◽  
Hbv Infection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Hepatitis D ◽  
Female Sex ◽  
Hbv Genotypes ◽  
B Virus

In South America, the Amazon basin is considered an endemic area of hepatitis B virus (HBV) infection. However, epidemiological studies with vulnerable groups are scarce. Female sex workers (FSWs) are highly vulnerable to sexually transmitted infections due to a combination of their sexual behavior and socio-economic conditions. Thus, this study investigated the prevalence of HBV infections and HBV–hepatitis C virus, HBV–hepatitis D virus, HBV–HIV, and HBV–human T-lymphotropic virus co-infections among FSWs in the Marajó Archipelago, northern Brazil, as well as identifying the HBV genotypes circulating in this population. A total of 153 FSWs in 5 towns and 18 riverside communities were included in the study. The HBV infection and co-infections were diagnosed by enzyme-linked immunosorbent assay and real-time polymerase chain reaction. The HBV genotypes were detected by sequencing and were then analyzed phylogenetically. Most of the FSWs surveyed were single, young, heterosexual, and born locally, with low levels of education. Overall, 21 (13.7%) had been exposed to HBV, and HBV-DNA was detected in 13 (8.5%). Genotypes A (69.2%), D (23.1%), and F (7.7%) were detected. Seven cases of co-infections with other viruses were detected. These findings indicate a clear need for urgent measures to control the spread of HBV and other pathogens, and to promote the health of the local FSWs.

scholarly journals Occult hepatitis B virus infection among hemodialysis patients

2018 ◽  
Vol 91 (2) ◽  
Author(s):  
Rahil Nahid Samiei ◽  
Somayeh Shokri ◽  
Shahab Mahmoudvand ◽  
Manoochehr Makvandi ◽  
Heshmatollah Shahbazian ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Hbv Dna ◽  
Enzyme Linked Immunosorbent Assay ◽  
Hepatitis B Infection ◽  
Nested Polymerase Chain Reaction ◽  
Occult Hepatitis ◽  
B Virus ◽  
The World ◽  
Occult Hepatitis B

Hepatitis B virus is a major public health impasse all over the world. Recently a new form of hepatitis B infection named Occult hepatitis B Infection (OBI) has appeared globally. The OBI is defined as the presence of HBV DNA in the liver and/or blood in the absence of detectable serum HBsAg with/without anti-HBc or anti-HBs. The prevalence of OBI has been reported in hemodialysis (HD) patients in different regions of the world. Thus, this study investigated the prevalence of OBI among HD patients. The cross-sectional study was carried out on 84 HD patients. These sera were checked for HBsAg, HBc-IgG assessment using Enzyme linked immunosorbent assay. The DNA was extracted from the sera samples and tested for HBVDNA detection using Nested Polymerase Chain Reaction (Nested PCR). The liver function tests including serum alanine aminotransferase and aspartate aminotransferase levels were carried out for all the HD individuals. 52/84(61.9%) of HD were males and 32/84 (38.1%) were females. The patient’s age ranged from 25 to 64 with a mean age of 52.4±15.2 years. HBsAg and HBc-IgG were detected in 1(1.1%) female. 2 (2.4%; a female and a male) patients were positive for HBsAg. 14/84 (16.7%; 6 female and 8 male) HD patients were positive for anti-HBc but negative for HBsAg, among them 4(28.6%; 2 female and 2 male) cases were positive for HBV DNA, indicating the presence of OBI in HD patients. Even distribution of OBI among the HD was found in 2(2.36%) male and 2(2.36%) female (P>.0.05). In the present study the moderate rate of 4.76% OBI has been observed in HD patients. The prevalence of seropositive OBI among the gender was 2(2.36%) male and 2(2.36%) female. The seronegative OBI have not been detected in the present study but requires further investigation. In this study the affliction of OBI in HD patients is not clear.

scholarly journals Expression Level of Small Envelope Protein in Addition to Sequence Divergence inside Its Major Hydrophilic Region Contributes to More Efficient Surface Antigen Secretion by Hepatitis B Virus Subgenotype D2 than Subgenotype A2

Viruses ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 967
Author(s):  
Qianru Wang ◽  
Shuwen Fu ◽  
Jing Zhang ◽  
Quan Yuan ◽  
Jisu Li ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Surface Antigen ◽  
Envelope Protein ◽  
Hepatitis B Surface Antigen ◽  
Site Directed Mutagenesis ◽  
Enzyme Linked Immunosorbent Assay ◽  
S Protein ◽  
Huh7 Cells ◽  
B Virus

Hepatitis B surface antigen (HBsAg) promotes persistent hepatitis B virus (HBV) infection. It primarily corresponds to small (S) envelope protein secreted as subviral particles. We previously found that genotype D clones expressed less S protein than genotype A clones but showed higher extracellular/intracellular ratio of HBsAg suggesting more efficient secretion. The current study aimed to characterize the underlying mechanism(s) by comparing a subgenotype A2 clone (geno5.4) with a subgenotype D2 clone (geno1.2). Five types of full-length or subgenomic constructs were transfected to Huh7 cells at different dosage. HBsAg was quantified by enzyme linked immunosorbent assay while envelope proteins were detected by Western blot. We found that ratio of extracellular/intracellular HBsAg decreased at increasing amounts of DNA transfected. Conflicting findings from two types of subgenomic construct confirmed stronger secretion inhibitory effect of the genotype D-derived large envelope protein. Chimeric constructs followed by site-directed mutagenesis revealed geno1.2 specific V118/T127 and F161/A168 in the S protein as promoting and inhibitory of HBsAg secretion, respectively. In conclusion, more efficient HBsAg secretion by subgenotype D2 than subgenotype A2 is attributed to lower level of S protein expression in addition to V118 and T127 in S protein, although its F161 and A168 sequences rather reduce HBsAg secretion.

Dual-Antigen-Loaded Hepatitis B Virus Core Antigen Virus-like Particles Stimulate Efficient Immunotherapy Against Melanoma

2020 ◽  
Vol 12 (48) ◽  
pp. 53682-53690
Author(s):  
Keman Cheng ◽  
Tao Du ◽  
Yao Li ◽  
Yingqiu Qi ◽  
Huan Min ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Core Antigen ◽  
Virus Like Particles ◽  
Virus Core ◽  
B Virus

Hepatitis B virus-like particles expressing Plasmodium falciparum epitopes induce complement-fixing antibodies against the circumsporozoite protein

Vaccine ◽  
2019 ◽  
Vol 37 (12) ◽  
pp. 1674-1684 ◽  
Author(s):  
Natalie J. Kingston ◽  
Liriye Kurtovic ◽  
Renae Walsh ◽  
Carina Joe ◽  
George Lovrecz ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Circumsporozoite Protein ◽  
Virus Like Particles ◽  
B Virus
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