BACKGROUNDConstruction of replication-deficient recombinant adenovirus expressing gag-pol and env genes of human immunodeficiency virus (HIV) in mice.

METHODSgag-polDelta and gp140TM genes were cloned into shuttle vector pAdTrack-CMV respectively, and then the plasmids containing gag-polDelta or gp140TM gene were cotransformed with the backbone of adenovirus into E.coli BJ5183. Transfections of the recombinants were performed to obtain recombinant adenoviruses. Its immunogenicity was evaluated by testing antibody levels of mice primed with DNA vaccines and boosted with recombinant adenoviruses.

RESULTSThe replication-deficient recombinant adenovirus could express Gp140TM, Gag P55 and P24 proteins correctly. The mice primed with DNA vaccines and boosted with recombinant adenoviruses elicited high titer of HIV-1-specific antibody compared with that inoculated with DNA vaccines only.

CONCLUSIONReplication-deficient recombinant adenovirus expressing gag-polDelta and gp140TM can elicit high titer HIV-1-specific antibodies.

AIDS Vaccines ; immunology ; Adenoviridae ; genetics ; Animals ; Female ; Fusion Proteins, gag-pol ; biosynthesis ; genetics ; Gene Products, env ; biosynthesis ; genetics ; HIV-1 ; genetics ; immunology ; Mice ; Mice, Inbred BALB C ; Recombination, Genetic ; Transfection ; Vaccines, DNA ; immunology ; env Gene Products, Human Immunodeficiency Virus

Human metapneumovirus (hMPV) is associated with acute respiratory tract infections (ARTI) in all age groups. However, there is limited information of genetic analysis of hMPV circulating in Beijing. To learn the characteristics of structural protein genes of human metapneumovirus circulating in children in Beijing, sequence analysis of matrix (M), small hydrophobic (SH) and attachment (G) proteins of hMPV from 2006 to 2010 was performed. Phylogenetic analysis of nucleotide sequences of 42 full length M genes, 49 SH gene and 55 G gene revealed that the hMPVs from pediatric patients were divided into sub-genotypes A2, B1 and B. There were highly conserved identities among M gene, with 7 conserved mutations of amino acids between A and B genotypes which were fairly conserved in the same genotype A or B. The amino acid identities of SH were 60.7% to 64.4% between different genotypes, 93.3% - 100% among same sub-genotype and 84.7% - 88.7% between different sub-genotypes. Use of alternative transcription-termination codon, nucleotide deletion and insertion resulted in variable length of nucleotide and deduced amino acid of G protein. Amino acid identities within same genotype ranged from 81.5% - 100%, whereas sequence identities between two genotypes ranged from 34.0% - 38.6% at the amino acid level. A new cluster of G genes in sub-genotype B2 appeared due to the same mutations and insertion of two amino acids in G protein encoding genes amplified from specimens collected from 2008 to 2010. Prediction of antigen sites of SH and G protein indicated that the variation of antigen sites between different sub-genotypes existed.
Child ; China ; epidemiology ; Genetic Variation ; Genotype ; Humans ; Metapneumovirus ; genetics ; Paramyxoviridae Infections ; blood ; epidemiology ; virology ; Phylogeny ; Retroviridae Proteins, Oncogenic ; blood ; genetics ; Viral Envelope Proteins ; blood ; genetics ; Viral Matrix Proteins ; blood ; genetics

OBJECTIVETo investigate the relationship between retroviruses and autoimmune diseases, to clone the novel retroviral NP9 gene from human endogenous retrovirus (HERV), and to construct its expression vector.

METHODSThe viral NP9 gene was amplified and cloned by RT-PCR and T-A clone techniques, and its sequence was determined with Perkin-Elmer 377 DNA Sequencer. The amplified viral NP9 gene was subcloned into the prokaryotic express vector pQE30. The recombinant plasmids were identified by restriction endonuclease digestion and sequencing. The recombinant pQE30-NP9 protein was expressed in M15 host cells under the IPTG induction and showed with SDS-PAGE,and the corresponding NP9 viral protein was identified with Western blot analysis.

RESULTA specific band of 250 bp was amplified using RT-PCR from total RNA of peripheral blood mononuclear cells (PBMCs) from patients with systemic lupus erythematosus (SLE) and confirmed as the NP9 gene via T-A clone and DNA sequencing analyses. SDS-PAGE profile showed a clear protein band with a relative molecular weight 9 kD in the IPTG-induced samples, which was confirmed as viral NP9 protein by Western blot analysis.

CONCLUSIONThe NP9 gene has been successfully isolated and cloned from PBMCs of SLE patients and the corresponding NP9 viral protein expressed in prokaryotic expression vector.

Amino Acid Sequence ; Base Sequence ; Cloning, Molecular ; Gene Products, env ; biosynthesis ; genetics ; Genetic Vectors ; Humans ; Lupus Erythematosus, Systemic ; genetics ; virology ; Molecular Sequence Data ; Retroviridae ; genetics ; metabolism ; Retroviridae Proteins ; biosynthesis ; genetics

Strict regulation of HIV-1 PR function is critical for efficient production of mature viral particles. During viral protein expression and viral assembly, HIV-1 PR located within Gag-Pol precursor must be inactive to prevent premature cytoplasmic processing of the viral Gag and Gag-Pol precursors. Premature activation of HIV-1 precursors leads to major defects in viral assembly and production of viral particles. A cell-level premature activation of HIV-1 precursors assay using bioluminescence resonance energy transfer (BRET) was established. Three thousand compounds were screened to evaluate this assay. The results showed that the assay is sensitive, specific and stable (Z' factor is 0.905).
Anti-HIV Agents ; pharmacology ; Benzoxazines ; pharmacology ; Bioluminescence Resonance Energy Transfer Techniques ; methods ; Fusion Proteins, gag-pol ; genetics ; metabolism ; HEK293 Cells ; HIV Protease ; metabolism ; physiology ; HIV-1 ; enzymology ; High-Throughput Screening Assays ; methods ; Humans ; Plasmids ; genetics ; Protein Precursors ; metabolism ; physiology ; Pyridazines ; pharmacology ; Transfection ; Virion ; growth & development ; Virus Assembly ; gag Gene Products, Human Immunodeficiency Virus ; genetics ; metabolism

Foamy virus can establish lifelong persistent infection in mammal hosts without inducing diseases. Such special characteristic stimulates the interests of researchers. As reported, the accessory protein Bet of foamy virus could regulate the gene expression and infection cycle of foamy virus and take part in the generation of chronic viral infection. And also, Bet might prevent the host cellular defense factor APO-BEC3 from interfering the replication of virus and play a role in maintaining viral persistent infection. In order to elucidate the roles of Bet in the foamy virus replication and infection, this review summarized the research progress of Bet protein reported in recent years.
Animals ; Gene Expression Regulation, Viral ; Humans ; Retroviridae Infections ; immunology ; virology ; Retroviridae Proteins ; genetics ; metabolism ; Spumavirus ; genetics ; metabolism

OBJECTIVETo investigate the subtype distribution and the prevalence of sequence characteristics of HIV-1 strains in Beijing residents during 2006 and to analyze the relationship between distribution of HIV-1 subtypes and transmission routines.

METHODSBlood samples from 32 new confirmed HIV-1 infected individuals from Beijing residents in 2006 and separated plasma specimens were collected. RNAs were extracted and the gag and env gene were amplified by RT-PCR and nest-PCR. PCR products were sequenced directly and phylogenetic analyses of gag and env gene were performed using the MEGA2 software.

RESULTSAmong 32 HIV-1 plasma samples, 22 gag and 4 env gene fragments were amplified and analyzed. Five HIV-1 subtypes or circulating recombinant forms(CRFs) of HIV-1 including Thai B (2 strains), B (9 strains), C (2 strains), CRF07_BC (5 strains), CRF01 AE (4 strains) were identified being circulated in Beijing. The gene divergences of gag gene inside the subtypes were 6.6%, 4.3%, 6.8%, 4.9% and 3.0% in subtype B, Thai B, C, CRF01_AE and CRF07_BC respectively. Subtypes B were predominant in Beijing, accounted for 40.9% among 22 samples.

CONCLUSIONFive HIV-1 subtypes were identified in Beijing and the surveillance of HIV-1 gene variation should be paid more attention to.

China ; HIV-1 ; classification ; genetics ; Humans ; Polymerase Chain Reaction ; Reverse Transcriptase Polymerase Chain Reaction ; env Gene Products, Human Immunodeficiency Virus ; genetics ; gag Gene Products, Human Immunodeficiency Virus ; genetics

Carrier Proteins ; metabolism ; physiology ; HIV-1 ; physiology ; Models, Biological ; Proteins ; metabolism ; physiology ; Retroviridae Infections ; virology

This study was purposed to construct the recombinant retroviral vector containing human homeobox gene hoxA10 and to establish the packaging cell lines which stably produce viruses. The whole coding region of hoxA10 gene was amplified by PCR and inserted into the retroviral vector MSCVneo. The recombinant vector was identified by DNA sequencing. The recombinant and control retroviral vectors were transfected into the packaging cell line PT67 by liposome Lipofectamine(TM) 2000. These cell lines stably producing retrovirus were isolated following G418 selection. The viral suspension was harvested and the viral titer was determined by NIH3T3 cells. The results showed that the recombinant retroviral vector was proved to encode hoxA10 genes by sequencing. The cell lines efficiently producing virus were screened by G418 and designated as PT67/MSCVneo and PT67/MSCVneo-hoxA10. The titers of them were 5 x 10(5) CFU/ml and 4 x 10(4) CFU/ml respectively. It is concluded that the recombinant retroviral vector containing homeobox gene hoxA10 and the stably packaging cell lines which efficiently and correctly produce viruses are successfully constructed, which provides a basis for further exploration of the hoxA10 gene function in the regulation of hematopoiesis.
Cell Line ; Genes, Homeobox ; Genetic Vectors ; Homeodomain Proteins ; genetics ; Humans ; Retroviridae ; genetics ; Transfection

A quantitative real-time PCR assay was developed to measure the proviral load of human T-lymphotropic virus type I (HTLV-I) in peripheral blood. The technology utilizes special primers and Taqman MGB fluorescence probe to measure amplification products from the gag-pro-pol polyprotein gene of HTLV-I. HTLV-I copy number was normalized to the amount of cellular DNA by quantitation of the beta-actin gene, The amplification system was sensitive to detect 5 copy/microL. The standard curve had a good linearity when the quantity for the gene was between 10(3) and 10(7) copy/microL (R2 = 0.999). Good reproducibility was observed in each intra- and inter-assay. We also measured proviral load in peripheral blood in 12 HTLV-I seropositive former blood donors. Proviral load for HTLV-I infected donors ranged from 0.015 to 12.819 copy/cell in WBC with the mean of 3.116 copy/cell.
Gene Products, gag ; genetics ; Gene Products, pol ; genetics ; Human T-lymphotropic virus 1 ; genetics ; isolation & purification ; Humans ; Molecular Probes ; Polymerase Chain Reaction ; methods ; Viral Proteins ; genetics

This study was purposed to establish a retrovirus-mediated murine model with MLL-AF9 leukemia, so as to provide a basis for further investigation of the pathogenesis and therapeutic strategy of MLL associated leukemia. Murine (CD45.2) primary hematopoietic precursor positively selected for expression of the progenitor marker c-Kit by means of MACS were transduced with a retrovirus carrying MLL-AF9 fusion gene. After cultured in vitro, the transduced cells were injected intravenously through the tail vein into the lethally irradiated mice (CD45.1). PCR, flow cytometry and morphological observation were employed to evaluate the murine leukemia model system. The results showed that MLL-AF9 fusion gene was expressed in the infected cells, and the cells had a dramatically enhanced potential to generate myeloid colonies with primitive and immature morphology. Flow cytometric analysis revealed that the immortalized cells highly expressed myeloid lineage surface markers Gr-1 and Mac-1. Moreover, the expression levels of Hoxa9 and Meis1 mRNA were significantly higher in the MLL-AF9 cells than that in control. The mice transplanted with MLL-AF9 cells displayed typical signs of leukemia within 6-12 weeks. Extensive infiltration leukemic cells was observed in the Wright-Giemsa stained peripheral blood smear and bone marrow, and also in the histology of liver and spleen. Flow cytometric analysis of the bone marrow and spleen cells demonstrated that the CD45.2 populations expressed highly myeloid markers Gr-1 and Mac-1. The leukemic mice died within 12 weeks. It is concluded that the retrovirus-mediated murine model with MLL-AF9 leukemia is successfully established, which can be applied in the subsequent researches.
Animals ; Disease Models, Animal ; Leukemia, Biphenotypic, Acute ; Mice ; Mice, Inbred C57BL ; Oncogene Proteins, Fusion ; genetics ; Retroviridae ; genetics ; Transfection