ISSN 1673-6184 CN 31-1966/R
Objective To investigate the potential of co-expression or co-delivery of HBV core gene with plasmid DNA to shift HBsAg-specific Th2 immune response induced by gene-gun to Thl type.Methods pIRES/Core, pIRES/C 149,pIRES/S,pIRES/S/Core and pIRES/S/C149 were constructed and expression of recombinant plasmids were confirmed in eukaryotic cells. BALB/c mice were immunized by gene-gun. After being boosted twice, humoral and cellular immunities in immunized mice were monitored. Results HBV core gene enhanced the HBsAg-specific Thl type immune responses in gene-gun-DNA-immunized BALB/c mice, including increasing the liter of IgG2a, ratio of IgG2a/IgG1,CTL activity as well as IFN-γsecretion. Conclusion Co-delivery or co-expression of HBV core gene with HBsAg DNA vaccine by gene gun can shift the HBsAg-specific Th2 immune response to Th1 type.
Objective Duck hepatitis B virus (DHBV) infected animal model was used to evaluate the inactivation of DNA virus by methylene blue photodynamic method. Methods DHBV was purified by Ultra-centrifugation. Purified DHBV was sequentially diluted and added to human plasma or RBC components respectively, followed by inactivation with methylene blue photodynamic method. These samples were inactivated into one-day-old ducklings by intravenous injection. Sera from ducks were collected at different intervals and detected by dot hybridization with DHBV probe labeled with 32P for DHBV DNA, and confirmed by southern blot hybridization for DHBV DNA in duck livers. Results The infectivity of DHBV (ID50) in the blood components was calculated before and after the treatment with methylene blue photodynamic method. Before viral inactivation, the ID50 of DHBV mixed with human plasma for one-day-old duckling was 1033.3 copies, and the ID50 of DHBV mixed with human RBC in one-day-old duckling was 103.50 copies. After inactivation with methylene blue photodynamic, the ID50 of DHBV mixed with plasma in one-day-old duckling was 1010 copies, while the ID50 of DHBV-RBC in one-day-old duckling was 108.35 copies. Treatement of methylene blue photodynamic the viral titer of DHBV-plasma decreased 6 logs, and DHBV-RBC decreased 5 logs. Conclusion Methylene blue photodynamic can inactivate DNA virus(using DHBV as a marker) in human blood or RBC, and the inactivation effect is better for virus in the plasma than that in RBC. The DHBV infected ducks could be used as a model for evaluating the effect of DNA virus inactivation in vivo.
Objective To study the emergence of HIV-1 drug-resistance mutations and HIV-1 subtype distribution in Shanghai. Methods 33 HIV-1 isolates from cases with HIV-1 infection/AIDS were detected by drug-resistance mutation ami genotyping assay. Results PIs(protease inhibitors) drug-resistance mutations were not found in all of 33 HIV-1 isolates. The rates of NRTIs (nucleoside reverse transcriptase inhibitors)and/or NNRTIs (non-nucleoside reverse transcriptase inhibitors)drug-resistance and transitional mutations were 70% and 20% respectively in 10 HIV-1 isolates from cases failed in HAART therapy, whereas the rates of that were 4.3% and 13% respectively in 23 HIV-1 isolates from cases untreated with HAART therapy. All the transitional mutations above mentioned were T215S. In 15 hemophilia cases transmitted with contaminated blood products, all of the HIV-1 subtypes were B (belonging to group M) and in 18 intravenous drug users and sexual transmission cases , the HIV-1 subtypes were B(38. 9%),CRP01-AE(33.4%)and others including C、D、G、K and CRF02-AG. Conclusion High HIV-1 drug resistance mutation rates were found in cases which failed in HAART therapy and incomplete inhibition of replication in this area. In addition to the main subtypes B and CRP01-AE, some uncommon HIV-1 subtypes including C、D、G、K and CRF02-AG were also detected in Shanghai in China.
Objective To identify a sporadic case of brucellosis found in Shanghai by bacteriological and molecular biological methods. Methods Blood culture combined with automatic biochemical identification system was used to isolate the Brucella strain from a patient suspected of brucellosis and a Brucella's specific secretary gene was amplified from the strain and analyzed by sequencing. We firstly multiple loci VNTR (Variable Number of Tandem Repeats) was used to analyze the Brucella genotype, by which Brucella dendrogram tree was established based on VNTR fingerprints according to the international published VNTR genotypes data. Results The isolated strain from this sporadic case was identified by bacteriological and molecular biological method as a kind of Brucella species. Although biochemical analysis and special gene sequencing could not identify the biovar of Brucella species, VNTR dendrogram of clustered VNTR genotypes indicated the case of brucellosis belonged to Brucella suis biovar 2.Conclusion Conventional bacterial cultures with biochemical and Brucella VNTR analysis can be used to identify the infection of Brucella and it is important investigate the molecular epidemiological profile of strains isolated in our country.
