Genetic analysis of env and gag gene fragments of bovine leukemia virus identified in cattle from Korea / 대한수의학회지

Bovine leukemia virus (BLV) is the causative agent of enzootic bovine leukosis. This study was conducted to clarify the molecular characteristics of BLVs obtained from a specific region in Korea. Proviral BLVs were detected in anti-BLV antibody-positive blood samples by PCR. Env and gag fragments were sequenced and compared to previously published reference sequences. Analysis of the env gene sequence revealed that the YI strain was highly similar to genotype 1, including United States and Japanese strains. The gag gene sequence had the highest degree of similarity with a Japanese strain.

Subtype and characterization of gag gene of HIV-1 strains prevalent in some areas of China / 军事医学科学院院刊

Objective:To investigate the subtype distribution of HIV-1 strains prevalent in four areas of China,and to study the characteristics of gag gene variation and changes in antigen epitopes under the host immune pressures. Methods:The plasma of HIV-1 infected people from Henan, Guangdong, Sichuan and Beijing in China were collected. Virion RNA was extracted directly from plasma after the virion was condensed. The gag gene was amplified by RT-PCR and nested-PCR.Sequences were subtyped by Genotyping Tool software, and phylogenetic analysis of gag gene were performed using the MEGA 4.1 software.The gene distances intra each subtype were calculated by Distance program. The Ks/Ka ratios were calculated using SNAP program. The variation analysis of CTL antigen epitopes restricted by main HLA-Ⅰ specificities in China was performed.Results:Six subtypes or circulating recombinant forms(CRFs)of HIV-1,including B',CRF07_BC,CRF01_AE,B,CRF08_BC and CRF02_AG,were identified in four areas of China.The gene distances intra each subtype were CRF01_AE>B>CRF08_BC> CRF07_BC>B' listed in order of size, meanwhile the order of Ks/Ka ratios was CRF01_AE>B>CRF08_BC>B'>CRF07_BC. Far more diversity of antigen epitopes in P17 region was observed than that in P24.Epitope mutations intra subtypes were CRF01_AE>B>B'>CRF07_BC listed in order of size. Conclusion:Itseems that CRF01_AE is under the strongest immune pressures,and displays the most diversity of gene and variation of epitopes intra subtypes prevalent in China, followed by subtype B, B' and CRF07_BC. The discrepancy of epitope mutations intra the subtypes is significant.

Immunogenicity of DNA and Recombinant Sendai Virus Vaccines Expressing the HIV-1 gag Gene / 中国病毒学·英文版

Combinations of DNA and recombinant-viral-vector based vaccines are promising AIDS vaccine methods because of their potential for inducing cellular immune responses. It was found that Gag-specific cytotoxic lymphocyte (CTL) responses were associated with lowering viremia in an untreated HIV-1 infected cohort. The main objectives of our studies were the construction of DNA and recombinant Sendal virus vector (rSeV) vaccines containing a gag gene from the prevalent Thailand subtype B strain in China and trying to use these vaccines for therapeutic and prophylactic vaccines. The candidate plasmid DNA vaccine pcDNA3.1(+)-gag and recombinant Sendai virus vaccine (rSeV-gag) were constructed separately. It was verified by Western blotting analysis that both DNA and rSeV-gag vaccines expressed the HIV-1 Gag protein correctly and efficiently. Balb/c mice were immunized with these two vaccines in different administration schemes. HIV-1 Gag-specific CTL responses and antibody levels were detected by intracellular cytokine staining assay and enzyme-linked immunosorbant assay (ELISA) respectively. Combined vaccines in a DNA prime/rSeV-gag boost vaccination regimen induced the strongest and most long-lasting Gag-specific CTL and antibody responses. It maintained relatively high levels even 9 weeks post immunization. This data indicated that the prime-boost regimen with DNA and rSeV-gag vaccines may offer promising HIV vaccine regimens.

Sequencing of gag gene for classification of HIV subtype from the patients living in the Northern area of Vietnam

Using nested PCR with the specific primers for gag gene and the sequencing data from blood samples of HIV patients, we demonstrated that subtype E is also very common in the Northern area of Vietnam. This method can be applied for the cloning of HIV genes and molecular epidemiology of HIV-l in Vietnam.