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Objective@#Evaluate GII.4 norovirus infection and blocking effects of serum antibodies against HBGAs binding to GII.4 norovirus of population in oyster culture area, provide references for screening of fully human monoclonal antibody.@*Methods@#Using a random survey method to collect blood and saliva samples in oyster culture area, select serum samples from the inland region of Guangdong as control group. Identification of salivary HBGA receptor phenotype and detection of serum antibody levels between two areas by ELISA. A vitro neutralization model was to determine the efficiency of serum antibodies blocking GII.4 norovirus and HBGA receptors binding.@*Results@#The age were (50.68 ± 15.17), (52.52 ± 15.90) and (51.37 ± 13.32) years old of 2015, 2016 in experimental group, and in control group, respectively. Males accounted for 5.9% (70/195), 36.6%(60/164), 40.8% (69/169) (χ2=0.93, P=0.334). The mean value of serum antibodies Absorbance value was 2.521±0.05 of 2015 and was 2.583±0.045 of 2016 in oyster culture area, the mean value was 2.249±0.05 in control group, there was a statistical difference among three group (F=13.28, P<0.001). The antibody prevalence in the three groups was 100%. BT50 geometric mean titer (GMT) of oyster culture area in 2015 was 423.1±40.11, culture group was 248.2±25.63, there was a statistical difference (t=3.73, P<0.001).@*Conclusion@#The population in oyster culture area does have more chance of exposure and infection GII.4 norovirus, Serum antibody of blocking ability in oyster culture areas is better than the general population in inland city. Suggesting that the population is more immunity resistant infected GII.4 norovirus.
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Objective To construct a prokaryotic expression system of norovirus (NoⅤ) G Ⅱ-4 strain P protein (P particle and P dimer) and to explore its binding activity and patterns with HBGAs receptor.Methods P domain sequence of GZ121 NoⅤ ORF2 gene was cloned and its phylogenic tree was constructed to identify the gene cluster.The pGEX-4T-1-based expression plasmids were constructed respectively by inserting P domain gene fragments with hinge and P-CDCRGDCFC without hinge,and then transformed into BL21 to express fusion proteins,which was induced with 0.6 mmol/L IPTG at 22℃ overnight.P proteins were purified by thrombin cutting and characterized by FPLC.The binding patterns of NoⅤ P protein to HBGAs antigens were analyzed by EIA.Results P region gene of GZ121 belonged to genotype G Ⅱ.4/2004 cluster.SDS-PAGE analysis showed the relative molecular weight of P particle and P dimer was about 36×103,which was consistent with other reports.The peak appeared at 830×103 confirmed the formation of P particle by FPLC.The expression of P protein was further confirmed by Western blot.The EIA results showed that GZ121 P protein could bind to saliva of A-group,B-group and O-group secretors,but not to nonsecretor.The binding affinity of P particle was 80-100 times higher than that of P dimer.Compared with VA387 P particle,it showed stronger binding affinity to O-group,but weaker to A-group.Conclusion The NoⅤ GⅡ-4 GZ121 P proteins including P particle and P dimer were successfully expressed and HBGAs receptor binding assays were established.This pave the way for further studies on the evolution dynamics of NoⅤ G Ⅱ.4 strains and the development of NoⅤ vaccines.
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During epidemiology teaching,it is important for teachers to use person-based teaching method according to different specialty bachelors to improve the teaching quality.
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Noroviruses are members of Caliciviridae family and are now the most commonly reported cause of outbreaks of nonbacterial gastroenteritis worldwide.Noroviruses gastroenteritis is difficult to control owing to the lack of a suitable antiviral agent or a vaccine to prevent infection.The tremendous disease burden of norovirus-associated gastroenteritis calls for an efficient preventive and therapeutic drugs.This review summarized the anti-noroviruses strategies targeting the nons-structural proteins,structural protein and so on.