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Objective To establish a CVS-11 pseudovirus particles ( pp)-based assay for detec-tion of neutralizing antibody against rabies virus. Methods An improved rapid fluorescence focus inhibition test ( RFFIT) for detection of neutralizing antibody against rabies virus ( RVNA) was established based on the CVS-11 pseudovirus expressing a luciferase reporter gene. Forty-six human serum samples were analyzed with the improved RFFIT and the results were compared with those by using standard RFFIT. Moreover, the improved RFFIT was used to detect the titers of RVNA in 91 serum samples collected from pet dogs and pet-breeders in Beijing. Results The coincidence rate of the improved RFFIT and the standard RFFIT was 100% regarding to the analysis of 46 human serum samples and 5 negative reference serum samples. Moreo-ver, the RVNA titers of all serum samples obtained with CVS-11 pseudovirus-based assay showed a signifi-cant high correlation with those obtained with standard RFFIT (n=46, r=0. 94, P<0. 000 1). All of the 91 serum samples collected from pet dogs and pet-breeders in Beijing were positive for RVNA as indicated by the improved RFFIT with a mean titer of 33. 01 IU/ml. Conclusion We established an improved RFFIT based on the CVS-11 pp expressing luciferase reporter gene, which might be used as a reliable alternative RFFIT for measuring RVNA titer. Analysis of the 91 serum samples collected in Beijing with the improved RFFIT showed that all samples were positive for RVNA.
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Objective To evaluate the immuno-potentiating effects of CpG-ODN plus alum as a composite adjuvant on influenza split virion vaccine.Methods BALB/c mice were immunized with various amounts of 2009 H1N1 influenza split virion vaccine,alone or in combination with CpG-ODN,alum,or both (composite adjuvant).Antigen-specific humoral immune responses were evaluated by ELISA,hemagglutination inhibiting (HI) assay and neutralizing assay.Antigen-specific cellular immune responses were evaluated by ELISPOT assay,intracellular cytokine staining assay and in vivo CTL assay.Results Compared with the control group immunized with antigen alone,a single use of either adjuvant weakly enhanced the humoral immune responses,as indicated by the increase of antigen-specific IgG titers,HI titers and neutralizing titers by 3-6 folds,2-4 folds and 4-8 folds,respectively,after two immunizations.In contrast,the composite adjuvant induced more potent humoral immune responses; the antigen-specific IgG titers,HI titers and neutralizing titers were increased by 23-57 folds,9-20 folds and 16-64 folds,respectively.Consequently,the composite adjuvant achieved antigen-sparing by at least 16 folds.In addition,the composite adjuvant significantly enhanced the antigen-specific cellular immune responses,as revealed by the increase of IFN-γ-secreting CD4+ T cells and the enhancement of CTL activity in immunized mice.Conclusion CpG-ODN plus alum as a composite adjuvant can enhance the immunogenicity of influenza split virion vaccine and achieve the antigen-sparing effect.
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Objective To compare the adjuvanticity of type-A,B and C CpG-ODN in mice.Methods Three types of CpG-ODN were identified through in vitro stimulation of murine splenocytes with various CpG-ODN.BALB/c mice were immunized with HBsAg,together with different types of CpG-ODN,and antigen-specific IgG.IgG1 and IgG2a titers were measured 4 weeks later by indirect ELISA.Resuits Compared with the control group.all 3 types of CpG-ODN enhanced humoral immune response to HBsAg.However,type-B and C CpG-ODN induced much higher levels of antigen-specific IgG and IgG2a than type A CpG-ODN.Type-C CpG-ODN induced a similar TH 1-biased immune response as type-B CpG-ODN,revealed by decreased IsG1 to IgG2a ratio.In contrast,although type-A CpG-ODN increased IgG titers,it did not switch the balance between TH1 and TH2 immune responses.Conclusion All 3 types of CpG-ODN can enhance the humoral immune response to vaccines,but their aaiuvanticity could be mediated through different mechanisms.
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Objective:To investigate the antitumor effect of CpG-ODN combining non-replicating recombinant vaccinia virus in tumor immunotherapy.Methods: CpG-ODN and constructed vaccinia virus v△11?75 were combined to study the antitumor effects in the walker′s rat tumor model.Results: Recombinant vaccinia virus v△11?75 lost the replicating capacity on human cell line,143TK - cell.The genes between HindⅢ C & K fragment of vaccinia virus TianTan strain were deleted,verified with Southern-blot. In the Walker′s tumor model of Wistar rats,Combinational immunotherapy with CpG-ODN and non-replicating vaccinia virus-modified WRC256 oncolysates resulted in prolonged life span and reduced tumor hyperplasia. Conclusion: CpG-ODN can enhance the antitumor effects of non-replicating vaccinia virus-modified oncolysates,providing a new route of tumor therapy.