Hepatitis B virus (HBV) infection can cause the severe threat to the health of the people around the world. It depends upon the development of efficient diagnostic reagent and vaccine to prevent the prevalence of HB. In this study, we constructed the high expression recombinant Pichia pastoris and performed the screening tests in shake flasks to obtain the optimal values of several key fermentation parameters. Based on their effects on the growth and expression level of recombinant strains, FBS was the optimal industrial medium. The optimal values for the dissolve oxygen (DO), the final concentrations of methanol and the pH values were 50 mL, 1% (V/V) and 5.4-6.0, respectively. The optimal values of the parameters simulated in shake flasks were successfully scaled up to 10 L bioreactors to achieve high-throughput production: 310 OD600 in biomass and 27 mg/L in recombinant HBsAg. The expressed recombinant HBsAg in P. Pastoris was confirmed by SDS-PAGE and Western blotting. Electron microscopy examination showed that the purified protein could be self-assembled to 22 nm virus-like particles. The results provided a basis for industrial scale-up production of diagnostic reagent and vaccine of next generation against HB.
Bioreactors ; Fermentation ; Hepatitis B Surface Antigens ; biosynthesis ; genetics ; Humans ; Pichia ; genetics ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics

OBJECTIVETo explore use of retroviral vector in gene therapy of hepatitis B.

METHODSThe recombinant vector Plxsn-HBs was constructed by inserting HBV S gene into pLXSN. The pseudovirus, which was produced from PA317 after transferring with pLXSN-HBs by electroporation, were frozen at different temperature. The activities of the pseudovirus to infect eukaryotic cells and express antigen were determined by comparing the numbers of G418-resistant clones and assaying HBsAg in the supernatant of the cells with ELISA after infection HepG2, NIH3T3 and 293 cells.

RESULTSIt was hard to find changes in HBsAg amount at different intervals and different temperatures. G418 resistant clones, however, were variable. When frozen at -20 degrees C, the numbers of clones were half less than that of the beginning after 6 months, few clones were formed after 12 months, and no clone was found after 24 months. When frozen at -40 degrees C, the numbers of clones were 121, 332 and 89 42, 137 and 43 for HepG2, NIH3T3 and 293 cell lines at 12 and 24 months, respectively. When frozen at -70 degrees C, the numbers of clones were 159 463 and 112 for HepG2, NIH3T3 and 293 cell lines at 24 months, respectively. There was no statistical difference compared to that of zero months.

CONCLUSIONSThe activity of the peseudovirus to infect eukaryotic cells and expressed antigen was not changed after 2 years frozen at -70 degrees C.

Cell Line ; Genetic Vectors ; Hepatitis B Surface Antigens ; biosynthesis ; genetics ; Retroviridae ; genetics ; Temperature ; Transfection

OBJECTIVEA multiplex PCR system for screening rare blood group antigens K and Yt(b) was constructed to study the distribution of the two blood groups in a Uygur population in Xinjiang, China.

METHODSSequence-specific primers (SSP) were designed based on single nucleotide polymorphism sites of KEL and ACHE alleles encoding the two blood group antigens. The system was designed for simultaneously detecting the two antigens by optimizing the PCR reaction. Three hundred and sixty-two randomly selected healthy individuals were screened. Products of PCR were further analyzed for heterozygosity.

RESULTSThe system was set up successfully. No KK sample was identified and 9 K+ k+ , 41 Yt (a+ b+ ), 4 Yt (a- b+ ) were found among the 362 samples.

CONCLUSIONThe established PCR-SSP based multiple PCR system is efficient to screen the rare blood group antigens K and Yt(b). The information of rare blood donors obtained from the screening can be used to improve the capability of compatible transfusion.

Antigens, Bacterial ; genetics ; Antigens, Surface ; genetics ; Blood Donors ; Blood Group Antigens ; genetics ; Blood Transfusion ; methods ; China ; Humans ; Multiplex Polymerase Chain Reaction ; methods ; Polymorphism, Single Nucleotide

Amino Acid Sequence ; Hepatitis B Surface Antigens ; classification ; genetics ; immunology ; Hepatitis B virus ; immunology ; Mutation

OBJECTIVE: To understand the infection of hepatitis B virus(HBV) in blood donors, and to evaluate the effectiveness and necessity of TMA technology for HBV-DNA screening in blood donors. METHODS: Using the ELISA/NAT model, routine serology test and NAT were performed in the 169 160 donors，including voluntary blood donors and some of donors returned to donor team. For some donors with test positive NAT, nucleic acid identification test was performed. And the HBsAg neutralized and confirmed assay would conduct in blood donors with unilateral HBsAg positive and HBV-DNA negative result. RESULTS: Among 169 160 donation cases-times, the donors of bilateral positive of HBsAg detection was 803, accounted for 0.476%; donors of unilateral positive was 243, accounted for 0.144%. For 40 specimens with HBV-DNA negative, unilateral HBsAg positive, the neutralization and confirmed assay was performed.In result, only 4 specimens were confirmed to be HBsAg positive, the confirmed positive rate was 10%. Among detected 1003 specimens with HBV-DNA positive specimens, both HBsAg and HBV-DNA positive were 739, the consistency rate between 2 kinds of detection was 73.7%. The comparision of positive rate detected by using 3 kinds of reagents showed that there were statistical differences (P＜0.05); moreover, there were statistical difference in positive rate detected by using Murex reagent and In Tec reagent (P＜0.0125). The comparison of detected rate of HBsAg and HBV-DNA during March 2016-February 2017 showed no statistical difference (P＞0.05). Among 60 blood donors with HBsAg and HBV-DNA who has retured to the donor team, 1 donor presented the transformation of HBsAg from negative to positive, suggesting the HBV infection of window period, HBsAg of the other 59 was negative. The detection of HBV-DNA showed that the HBV-DNA in 28 donors was negative, and the HBV-DNA in 31 donors was positive, 1 donor showed HBV-DNA was uncertain. CONCLUSION The routine TMA technology combined with ELISA HBsAg can effectively shorten the window period for detection of HBV infection, effectively detect the occult HBV infection, and reduce the potential risk of hepatitis B spread due to blood transfusion.
Blood Donors ; DNA, Viral ; Hepatitis B ; Hepatitis B Surface Antigens ; Hepatitis B virus ; genetics ; Humans

OBJECTIVE: To evaluate the risk of reentry in HBV reactive blood donors and feasibility of HBV reentry strategy. METHODS: HBsAg⁺ or HBV DNA⁺ donors who had been quarantined for more than 6 months in Jiangsu Province could propose for reentry application. Blood samples were routinely screened by dual-ELISA for HBsAg, anti-HCV, HIV Ab/Ag, and anti- Treponema pallidum and those non-reactive ones were tested by minipool nucleic acid testing (NAT) for three times. To identify occult HBV donors, samples of NAT non-reactive were further tested by electrochemiluminescence immunoassay (ECLIA) for HBV seromarkers (including HBsAg, HBsAb, HBeAg, HBeAb, and HBcAb). Donors of only 4 ECLIA patterns were accepted to reentry, including all 5 HBV seromarkers negative, anti-HBs only but having history of hepatitis B vaccine injection, HBcAb only, HBsAb⁺ / HBcAb⁺ with HBsAb more than 200 IU/L. Additionally, the detection rate of HBV infection was compared between routine screening mode and ECLIA, as well as the reentry qualified rate of HBsAg⁺ and HBV DNA⁺ blood donors. RESULTS: From Oct. 2016 to Aug. 2019, a total of 737 HBV reactive donors had applied for reentry, including 667 HBsAg⁺ reactive and 70 HBV DNA⁺ reactive donors. Among 3 screening methods, the highest HBV detection rate (43.15%, 318/737) was observed on ECLIA, while only 4.75% (35/737) on ELISA and 3.12% (23/737) on NAT, respectively. Among 4 qualified patterns of HBV serological markers, the highest proportion was found in the all negative group (22.90%, 155/677), followed by the group with HBsAb⁺ only and history of hepatitis B vaccine injection (19.35%, 131/677), and the median concentration of HBsAb was 237.7 IU/L. The unqualified rate of HBV DNA⁺ donors was 82.86%, which was significantly higher than 47.98% of HBsAg⁺ donors. CONCLUSION Routine screening tests merely based on ELISA and NAT could miss occult HBV donors and may not be sufficient for blood safety. HBsAb concentration and vaccine injection history should be included in the evaluation of HBV reactive donors who intend to apply for reentry. There is a relatively larger residual risk of occult HBV infection in blood donors quarantined for HBV DNA reactive.
Blood Donors ; DNA, Viral ; Hepatitis B ; Hepatitis B Surface Antigens ; Hepatitis B virus/genetics* ; Humans

OBJECTIVETo screen and clone the genes of proteins in hepatocytes interacting with hepatitis B virus (HBV) PreS2 by yeast-two hybridization technique.

METHODSThe HBV PreS2 gene was amplified by polymerase chain reaction (PCR) and HBV PreS2 bait plasmid was constructed by using yeast-two hybridization system 3, then transformed into yeast AH109, followed by mating with yeast Y187 containing liver cDNA library plasmid in 2 YPDA medium. Diploid yeast was plated on synthetic dropout nutrient medium (SD/-Trp-Leu-Ade-His) and synthetic dropout nutrient medium (SD/-Trp-Leu-Ade-His) containing X-alpha-gal for selecting positive blue clones, then amplified by PCR, sequenced, and performed bioinformatics analysis.

RESULTSHBV PreS2 gene was cloned successfully and expressed in yeast AH109.Twenty-six positive colonies were selected, among them, twelve containing metallothionein 2A, one cytochrome C oxidase II, two cytochrome P450 subfamily IV4F, two cytochrome c oxidase subunit 4 isoform 1, three albumin (ALB), one Na(+)K(+) transporting ATPase beta-1 polypeptide, two prealbumin, one lectin galactoside-binding subunit, and Two new genes with unknown function.

CONCLUSIONGenes of HBV PreS2 interacting proteins have been successfully cloned, which brings some new clues for studying the biological functions of HBV PreS2 and related proteins.

Cloning, Molecular ; Hepatitis B Surface Antigens ; genetics ; physiology ; Plasmids ; Protein Precursors ; genetics ; physiology ; Two-Hybrid System Techniques ; Yeasts ; genetics

OBJECTIVETo screen rare blood groups Fy(a-), s-, k-, Di(b-) and Js(b-) in an ethnic Zhuang population.

METHODSSequence-specific primers were designed based on single nucleotide polymorphism (SNP) sites of blood group antigens Fy(b) and s. A specific multiplex PCR system I was established. Multiplex PCR system II was applied to detect alleles antigens Di(b), k, Js(b)1910 and Js(b) 2019 at the same time. The two systems was were used to screen for rare blood group antigens in 4490 randomly selected healthy donors of Guangxi Zhuang ethnic origin.

RESULTSWe successfully made the multiplex PCR system I. We detected the rare blood group antigens using the two PCR system. There are five Fy(a-), three s(-), two Di(b-) in 4490 Guangxi zhuang random samples. The multiplex PCR system I has achieved good accuracy and stability. With multiplex PCR systems I and II, 4490 samples were screened. Five Fy(a-), three s(-) and two Di(b-) samples were discovered.

CONCLUSIONMultiplex PCR is an effective methods, which can be used for high throughput screening of rare blood groups. The rare blood types of Guangxi Zhuang ethnic origin obtained through the screening can provide valuable information for compatible blood transfusion. Through screening we obtained precious rare blood type materials which can be used to improve the capability of compatible infusion and reduce the transfusion reactions.

Blood Group Antigens ; genetics ; Duffy Blood-Group System ; genetics ; Genotype ; Humans ; Multiplex Polymerase Chain Reaction ; methods ; Receptors, Cell Surface ; genetics

OBJECTIVETo determine the main genotype of hepatitis B virus (HBV) detected from Tibetans in China and provide basic data for hepatitis control and prevention.

METHODSThe S gene and C gene were amplified by PCR from the sera of HBsAg positive Tibetans. After sequencing, the gene sequences were analyzed and the phylogenetic trees were drawn by the software MEGA3.

RESULTSIn trees based on S gene, the sequences of most samples clustered at genotype D, while in trees based on C gene, the sequences of all samples clustered at genotype C.

CONCLUSIONThe dominant genotype of HBV detected from Tibetans in China is a C/D hybrid.

Genotype ; Hepatitis B ; blood ; epidemiology ; virology ; Hepatitis B Core Antigens ; genetics ; Hepatitis B Surface Antigens ; blood ; genetics ; Hepatitis B virus ; classification ; genetics ; immunology ; Humans ; Phylogeny ; Tibet ; epidemiology

OBJECTIVETo investigate the effect of miR-122 on the expression of hepatitis B virus (HBV) proteins.

METHODSAnti-sense oligodeoxynucleotide (ASODN) of two different sequences against miR-122, anti-miR-122 and LNA-antimiR-122 (Locked nucleic acid), human miR -122 (hsa-miR-122), or the negative control anti-GFP were designed and synthesized, then transfected into HepG2.2.15 cells. After 24 h and 48 h, the levels of HBsAg and HBeAg in the supernatant were determined with a time-resolved immunofluorometric assay (TRFIA). HBV DNA in supernatant and miR-122 in cells were measured by quantitative real-time PCR.

RESULTSAfter 48 h expressions of miR-122 in the LNA-antimiR-122 and anti-miR-122 groups were significantly suppressed and lower than those in the negative control (P<0.001), while the level of miR-122 in the hsa-miR-122 group was higher than that in the negative control (P<0.001). The expression of HBeAg and HBsAg in hsa-miR-122 group was lower than that in the negative control (P<0.01) 24 h and 48 h after transfection. The expression of HBeAg and HBsAg in the anti-miR-122 group and LNA-antimiR-122 group was significantly lower than that in negative control (P>0.001). The levels of viral DNA at both time-points in the various test groups were not significantly different from those of negative control group (P>0.05).

CONCLUSIONmiR-122 may regulate HBV antigens and potentially affect the progress of pathogenesis, which might be the new targets for treatment of HBV infection.

DNA, Viral ; genetics ; Hep G2 Cells ; Hepatitis B Surface Antigens ; metabolism ; Hepatitis B e Antigens ; metabolism ; Hepatitis B virus ; genetics ; Humans ; MicroRNAs ; genetics ; metabolism ; Transfection