BACKGROUNDNon-invasive nasopharyngeal carcinoma (NPC) screening usually involves serological testing for the presence of IgA antibodies to Epstein-Barr virus (EBV) capsid antigen (VCA). The present meta-analysis determined the accuracy of VCA-IgA in the diagnosis of NPC.

METHODSA systematic review of studies was conducted and data on the accuracy of VCA-IgA concentrations in the diagnosis of NPC were pooled using random effects models. Receiver operating characteristic curves were used to summarize the overall test performance.

RESULTSTwenty studies met the inclusion criteria for the meta-analysis. The summary estimates for VCA-IgA in the diagnosis of NPC were: sensitivity 0.91 (95% confidence interval (CI): 0.90 - 0.92), specificity 0.92 (95%CI: 0.92 - 0.93), positive likelihood ratio 31.65 (95%CI: 10.99 - 91.15), negative likelihood ratio 0.10 (95%CI: 0.07 - 0.13) and diagnostic odds ratio 414.59 (95%CI: 174.96 - 982.42). The area under the summary receiver operating characteristic curves was 0.98.

CONCLUSIONThe sensitivity and the specificity of serum VCA-IgA are very high, suggesting that the presence of VCA-IgA in peripheral blood is a valuable predictor for NPC.

Antigens, Viral ; immunology ; Capsid Proteins ; immunology ; Carcinoma ; diagnosis ; immunology ; Humans ; Immunoglobulin A ; immunology ; Nasopharyngeal Neoplasms ; diagnosis ; immunology

Antigens, Viral ; genetics ; Humans ; Mutation ; Orthomyxoviridae ; classification ; genetics ; immunology

OBJECTIVETo observe anti-HEV IgG response to vaccination of recombinant antigen fragments and evaluate its protection from Hepatitis E Virus infection in rhesus monkeys (Macaca mulatta).

METHODSTwelve monkeys were divided into three groups and immunized respectively with three different recombinant antigens: namely Ag1 (carboxyl terminal 431 amino acids of ORF2), Ag2 (128aa fragment at the carboxyl terminal of ORF2), and Ag3 (full length ORF3 ligated with two ORF2 fragments encoded by 6743-7126nt and 6287-6404nt). The monkeys were challenged intravenously with fecal suspension from experimentally infected rhesus monkeys, and the other three monkeys served as the placebo group for challenge with HEV. The dynamic changes of the levels of ALT and anti-HEV IgG were examined. Pathological changes of liver tissue were observed by light microscope. Excretion of virus was detected by RT-nPCR.

RESULTSHepatic histopathology of two monkeys in the placebo group was consistent with acute viral hepatitis, and ALT was elevated 3-4 weeks after inoculated with virus, up to 10-20 times higher than normal level. The liver tissue of monkeys immunized with antigen kept normal, ALT in several monkeys elevated mildly, and anti-HEV IgG conversation occurred at 1-2 weeks after vaccination, with the titer reaching 1:12,800. The virus RNA could be detected by RT-nPCR from days 7 to 50 in monkeys of control group, and from days 7 to 21 in vaccinated monkeys after challenged with virus.

CONCLUSIONSThe recombinant antigens could induce the production of anti-HEV IgG, which protected rhesus monkeys from acute Hepatitis symptoms related to HEV infection.

Animals ; Antigens, Viral ; immunology ; Hepatitis E ; prevention & control ; Hepatitis E virus ; immunology ; Immunoglobulin G ; immunology ; Macaca mulatta ; RNA, Viral ; blood ; Recombinant Proteins ; immunology ; Vaccination ; Viral Hepatitis Vaccines ; immunology

E2 gene of classical swine fever virus (CSFV) was cloned into secretory pPIC9K Pichia pastoris expression vector. After being linearized by digestion, the vector was transformed into Pichia pastoris by electroporation to integrate with the genome, the transformants with high copies were screened by G418 and were induced to express with methonal. The results of SDS-PAGE and Western blot demonstrated that the supernatant of the induced P. pastoris culture contained protein E2. The results of the study on the immunological activity indicated that the protein E2 expressed in P. pastoris can elicit animal bodies to produce antibodies against protein E2.
Animals ; Antibodies, Viral ; immunology ; Antigens, Viral ; genetics ; immunology ; Classical swine fever virus ; genetics ; immunology ; Cloning, Molecular ; Gene Expression ; Pichia ; Rabbits ; Swine ; Viral Envelope Proteins ; genetics ; immunology

BACKGROUNDTo determine the antigenicity of HGV NS5 recombinant proteins expressed in E.coli.

METHODSHGV NS5a,NS5b and core/NS5b fusion genes were cloned into pThioC vector. Three expression plasmids were transformed into JM109(DE3) competent cells then expressed with induction by IPTG. Western blot and ELISA were used to determine the antigenicity after the three recombinant proteins were purified.

RESULTSAfter identification by restriction enzyme and sequencing, it was confirmed that the expressed was target proteins espected. Purified expression proteins were found strongly immunoreactive among anti HGV positive sera by Western blot and ELISA. Compared with mixed recombinant antigen (including core, NS5a synthetic peptide and NS3 recombinant proteins), in the 22 positive sera detected with mixed antigen, 68%(15/22), 90%(20/22) and 73%(16/22) were positive by P5a,P5b and Pc?5b antigens; In the 70 negative samples with mixed antigen, 7%(5/70), 1%(1/70) and 6%(4/70) were positive by P5a, P5b and Pc?5b antigens. The positive alone was found among RTPCR positive specimen using these recombinant antigens.

CONCLUSIONSNS5 gene expressed in E.coli?which couldn't be covered with other regions of antigens was one of the essential epitopes to HGV immunologic diagnosis.

Antibodies, Viral ; blood ; Antigens, Viral ; blood ; Epitopes ; immunology ; GB virus C ; genetics ; immunology ; Humans ; Plasmids ; genetics ; Recombinant Proteins ; biosynthesis ; immunology ; Viral Nonstructural Proteins ; genetics ; immunology

This article aimed to study the antigenicity of nucleocapsid proteins (NPs) in six pathogenic phleboviruses and to provide theoretical evidence for the development of serological diagnostic reagents. NPs of six pathogenic phleboviruses were expressed and purified using a prokaryotic expression system and rabbits were immunized with individual recombinant NPs. Cross-reactions among NPs and rabbit sera were determined by both indirect ELISA and Western blotting analyses, and the sera titer was determined by indirect ELISA. Furthermore, sera from SFTS patients were also detected by each recombinant NP as a coating antigen using indirect ELISA. The cross-reactions and the sera titer were subsequently determined. Both the concentration and purity of recombinant NPs of six pathogenic phleboviruses met the standards for immunization and detection. The results of indirect ELISA and Western blotting showed that each anti-phlebovirus NP rabbit immune serum had potential serological cross-reactivity with the other five virus NP antigens. Furthermore, the sera from SFTS patients also had cross-reactivity with the other five NP antigens to a certain extent. Our preliminary study evaluated the antigenicity and immune reactivity of six pathogenic phleboviruses NPs and laid the foundation for the development of diagnostic reagents.
Animals ; Antibodies, Viral ; immunology ; Antigens, Viral ; genetics ; immunology ; Cross Reactions ; Humans ; Nucleocapsid Proteins ; genetics ; immunology ; Phlebotomus Fever ; diagnosis ; immunology ; virology ; Phlebovirus ; classification ; genetics ; immunology ; isolation & purification ; Rabbits

OBJECTIVEIn order to investigate the relationship between selection pressure and the prevalence of antigenic clusters, we sequenced and analyzed the H3N2 influenza virus from China between 1992 and 2012.

METHODSThe H3N2 influenza virus (n = 1206) in China from 1992 to 2012 was analyzed, include global selection pressure and sites positive selection pressure analysis.

RESULTSConsidering all the H3N2 influenza viruses during these 21 years, a total of four amino acid sites subject to positive selection. The global selection pressure varies with the variation of different antigenic clusters and three years with peak bottom selection pressure were identified.

CONCLUSIONThe global selection pressure rise from the peak bottom, a new antigenic clusters will appear andprevalent in the population, indicating the best time to replace the vaccine strain.

Antigens, Viral ; immunology ; China ; Influenza A Virus, H3N2 Subtype ; genetics ; immunology ; Influenza Vaccines ; Selection, Genetic ; Time Factors

Animals ; Epstein-Barr Virus Nuclear Antigens ; immunology ; Immunization ; Mice ; Mice, Inbred BALB C ; Viral Matrix Proteins ; immunology ; Viral Vaccines

Human cytomegalovirus (HCMV) gB is known to play important roles in cell surface attachment, virion penetration, spread of infection from cell to cell, and provocation of neutralizing antibody. This study was performed to determine the role of anti-HCMV gB antibody in overall neutralizing response in patients with HCMV infection and healthy control with past infection. HCMV gB was stably expressed in 293 cells. With the stable cell line expressing gB as a specific immunosorbent, anti-gB antibody was removed from the current and past HCMV-infected sera and the remaining neutralizing activity was measured by plaque assay. It was shown that 19-50% of the total virus-neutralizing activity of sera with past HCMV infections was derived from anti-gB antibody, but anti-gB antibody had little effect on the total serum virus-neutralizing activity in patients currently infected with HCMV. This result suggests that neutralizing antibody to HCMV gB may reflect disease status.
Adult ; Antibodies, Monoclonal ; Antibodies, Viral/immunology* ; Antibodies, Viral/blood ; Antigens, Viral/immunology ; Antigens, Viral/genetics ; Cells, Cultured ; Cytomegalovirus/immunology* ; Cytomegalovirus Infections/prevention & control ; Cytomegalovirus Infections/immunology* ; Female ; Fetus/cytology ; Fibroblasts/cytology ; Gene Expression Regulation, Viral/immunology ; Human ; Immunosorbents ; Lung/cytology ; Male ; Middle Age ; Neutralization Tests ; Recombinant Proteins/genetics ; Viral Envelope Proteins/immunology* ; Viral Vaccines

Animals ; Antigens, CD ; immunology ; Cytokines ; metabolism ; Hepacivirus ; immunology ; Hepatitis C ; immunology ; prevention & control ; virology ; Hepatitis C Antibodies ; biosynthesis ; immunology ; Hepatitis C Antigens ; immunology ; Humans ; Killer Cells, Natural ; immunology ; T-Lymphocytes ; immunology ; metabolism ; T-Lymphocytes, Regulatory ; immunology ; metabolism ; Viral Proteins ; immunology