Expert consensus on nucleic acid amplification test of respiratory pathogens in children / 中华实用儿科临床杂志

Acute respiratory tract infection is the most common infectious disease in children, which seriously threatens children′s health.Rapid and accurate etiological diagnosis is of great significance for the clinical treatment and control of these diseases.Pathogen nucleic acid test was applied and became the main method of respiratory tract infection diagnosis for its high sensitivity and specificity.To regulate the application of pathogen nucleic acid amplification test in respiratory tract infection in children, improve the diagnosis level, expert consensus on nucleic acid amplification test of respiratory pathogens in children was prepared to guide the application and promote pathogens diagnosis ability.

Construction and identification of infectious clone of S191 virus strain used for the production of live attenuated measles vaccine / 中华微生物学和免疫学杂志

Objective To construct a stable infectious clone of S191 virus strain used for the pro-duction of live attenuated measles vaccine. Methods Full length cDNA of S191 strain and gene fragments encoding nucleocapsid(N),phosphoprotein(P)and RNA polymerase(L)were synthesis and respectively cloned into the vector pVAX1. The 293T cells were respectively transfected with the recombinant expression plasmids and co-cultured with Vero cells. The supernatants of cell culture were collected for identifying res-cued viruses. The indirect immunofluorescence assay was performed for virus identification. The rescued viruses at different passages in Vero cells and the sequences of the rescued viruses were analyzed. Results Restriction enzyme digestion and sequence analysis showed that the recombinant expression plasmids contai-ning the full length cDNA with an artificially engineered mutation at nucleotide 2101(C-A)and gene frag-ments encoding N,P and L proteins of S191 strain were constructed successfully. The N and P proteins were detected in Vero cells with immunofluorescence assay. A cytopathogenic effect on Vero cells was induced by rescued viruses. Conclusion The stable infectious clones of S191 virus used for the production of live at-tenuated measles vaccine were rescued successfully. An approach by using reverse genetics technique for S191 strain study was established which could be used for the development of new chimeric vaccines against measles virus.

Study of fusion expression effect on conformation and immune activity of polyepitope protein,M.RCAg-1 / 中华微生物学和免疫学杂志

ObjectiveTo explore the effects of vector fusion peptides on the conformation and immune reactivity of recombinant polyepitope antigens,M.RCAg-1.MethodsWe subcloned polyepitope artificial antigen gene,M.RCAg-1,into prokaryotic expression vectors,pDS-ex,that contain different fusion tags at the N-terminus or no any tag by different restriction enzyme cutting site.Three recombinant proteins expressed by these vectors,named P312-1,P312-2,and P312-3,were purified and purity is greater than 95％.Then BALB/c mice were vaccinated with the three proteins formulated with Freund's adjuvant through intranasal.Serum were collected to detect specific antibodies of M.RCAg-1 and individual epitope by ELISA ; natural parasite antigen was recognized by indirect immunofluorescence assay; mouse specific T lymphocyte activation was detected by enzyme-linked immunosorbent spot test (ELISPOT) ; and the growth of Plasmodium falciparum in vitro to evaluate by growth inhibition assay(GIA),and analyze secondary and tertiary structures of recombinant proteins from different expression vectors by bioinformatics and circular dichroism technique.ResultsThe P312-1,P312-2 have almost the same amino acid sequence,and the three proteins have the same immunogenicity in animal models(P＞0.05),however,the different proteins elicited various T-cell responses,the rabbit antibody induced by these proteins showed diverse efficacy in malaria parasite growth inhibition assaysin vitro ( respectively,93.9％,14.7％,54.3％ ).The significant differences of secondary and tertiary structures were shown in recombinant proteins from different expression vectors,analyzed by bioinformatics and circular dichroism technique,which demonstrated the change of protein molecule spaces conformation,and the obviously change of some epitope locations.ConclusionThese results suggest that the expressed polyepitope artificial antigens originating from the different vector fusion peptides indeed affect the protein folding and,subsequently,the epitope exposure.Thus,these proteins are able to induce both distinct humoral and cellular immune responses in animal models,and they affect the efficacy of immune inhibition against the parasite,the enhancement or suppresses.

The research on the immunogenicity and in vitro protective efficacy of a polyepitope Plasmodium falciparum candidate vaccine, M.RCAg-1 formulation with different adjuvants / 中华微生物学和免疫学杂志

ObjectiveTo detect the difference of cytokines and antibodies productions by immunologic system from mice and rabbits vaccinated with the M.RCAg-1 chimeric protein,expressed in E.coli,formulation with different adjuvants,including Freund's adjuvant and three clinically acceptable adjuvants,namely,Al(OH)3,Montanide ISA720 and Montanide ISA51.MethodsSix weeks female BALB/c mice were vaccinated with recombinant protein formulated with different adjuvants through intranasal.Serum were collected to detect specific antibodies of M.RCAg-1 and individual Epitope by ELISA ; natural parasite antigen was recognized by indirect immunofluorescence assay; mouse specific T lymphocyte activation was detected by enzyme-linked immunosorbent spot test (ELISPOT) ; Affinity assay between protein and immune IgG of rabbits with the biosensor,and the growth of Plasmodiumfalciparum in vitro to evaluate by growth inhibition assay(GIA).ResultsDifferent formulation can induce different levels of antibody titers,the effection of ISA51 adjuvant was most closely with Freund's adjuvant,and can induce a higher specific antibody of 11 epitopes within proteins,can effectively stimulate cellular immune response based on the IFN-γ,to avidity Montanide ISA51 adjuvant immune antibodies and M.RCAg-1 protein affinity than the other two adjuvants;and Montanide ISA720 adjuvants and Al (OH)3 adjuvant group in mice can't induce a significant IFN-γresponse(P＞0.05).On avidity assay,the Montanide ISA51 formulation group was better than the other two adjuvants; and Montanide ISA720 and Al (OH)3 adjuvant formulation group can't induce a significant IFN-γresponse in mice(P＞0.05) ; the inhibition rates were 60% and 100% in 3D7 and Dd2 Plasmodium falciparum at a concentration of 2 mg/ml IgG by Montanide ISA51 formulated protein,and IgG of Al( OH)3 formulation could not effectively inhibit the in vitro growth of Plasmodium falciparum( 10% ),while IgG of Montanide ISA720 formulation could not inhibit growth of parasite in vitro.ConclusionBy comparing three clinically acceptable adjuvants and Freund's adjuvant in BALB/c mice and New Zealand rabbit,Montanide ISA51 adjuvants can be acceptable formulated M.RCAg-1 protein induced humoral and cellular immune responses,can be used as one of the candidate adjuvants.

The study on the immunizing efficiencies of distinct adjuvants on recombinant P6 protein through different immunization routes / 中华微生物学和免疫学杂志

Objective To detect the difference of cytokines and antibodies productions by immunologic system from mice vaccinated with recombinant P6 protein with different immunization routes and adiuvants.Methods 6 weeks female BALB/c mice were vaccinated with meombinant protein P6 combined with A1(OH)3,CpG ODN or the mix of them through intramuscular and intranasal.The mice were boosted twice with the same dose by the same route.Serum and respiratory tract specimen were collected to detect rP6 specific antibodies by ELISA.Results In the 6th week after immunization.The higher titer of serum rP6 specific IgG antibody were detected from the two groups vaccinated with A1(OH)3+CpG ODN+rP6 by intramuscular and vaccinated with CpG ODN+rP6 by intranasal(F=41.259.P=0.000).The ELISPOT experiment showed that,Inoculation with the CpG ODN+rP6 either by intranasal or intramuscular immunization could induce a large number of antigen-specific T lymphocyte activation.In addition.The mice vaccinated with the CpG ODN+rP6 through intranasal can be detected high titer rP6 specific mucosal IgA antibody(F=70.966.P=0.000).Conclusion Inoculation with the CoG ODN+rP6 by jntranasal immunization not only can induce high-titer serum IgG antibody,but also can induce high-titer mucosal IsA antibody and CD4+Th1.CD8+T lymphoeyte activation.

Recombination expression and immunoprotective effects of the P6 outer membrane protein of nontypeable Haemophilus influenzae / 中华微生物学和免疫学杂志

Objective To clone and express recombinant outer membrane protein P6, determine its optimal expression conditions and to investigate the immunoprotective effects of the P6 protein on mice. Methods The P6 gene of nontypeable Haemophilus influertzae(NTHi) was amplified by PCR from the NTHi genome and cloned into expression vector pET-32a (+) to generate the pET-32a-P6 recombinants. They were confirmed by nuclease digestion and sequence analysis. The verified recombinant was transformed into E. coli BL21 (DE3). Its optimal expression conditions were determined such as engineering strains, the concentration of IPTG, inducing temperature, inducing time, different medium etc. The recombinant protein was purified by Q Sepharose~(TM) XL ion exchange and gel filtration chromatography. The protein was analyzed by SDS-PAGE, Western blot and sequencing. BALB/c mice were immunized with recombinant protein be-fore challenged by NTHi through intraperitoneal injection. Then the mortality rate of different group was com-pared. Results The recombinant P6 of NTHi was successfully constructed and expressed in E. coli at a rel-atively high level. The purity was up to 95% after purification. The relative molecular mass of the protein is 14 145. 848. The recombinant protein was confirmed to show specific reaction on the antiserum through Western blot. The animal experiments showed the mortality rates of immunization groups were significantly lower than that of the control group (P < 0.05). Conclusion The successful expression of the recombinant P6 will be very helpful for the further study on development of vaccine, its purified, immunological activity and antibody preparation.