No Abstract Available.
Genes, pol* ; Korea* ; Leukemia Virus, Bovine* ; Proviruses*

To investigate the kinship between the Inner Mongolia pandemic strain and representative strains of the Jaagsiekte sheep retrovirus (JSRV), total DNA from the lung tissue of a JSRV-infected sheep in Inner Mongolia was used to clone fragments of gag, pro and pol genes. The recombinant plasmid pMD-JSRV (including complete genomic sequence of the JSRV strain isolated from Inner Mongolia) was constructed by linking all the cloned fragments with long terminal repeat (LTR) and env gene fragments (cloned previous and reserved by our research team). Sequence analyses revealed that the genome was 7690 bp in length and contained several typical molecular markers for exogenous form of JSRV. These included the Sca I restriction site in the gag gene, two predicted "CCHC" motifs of zinc finger in the encoded nucleocapsid protein and the predicted "YXXM" motif in the TM region of Env. Homology analyses showed that the virus strain belonged to the JSRV type II. pMD-JSRV and AF105220 strains shared a nucleotide identification of 95%. The full length genomic clone of JSRV could provide a molecular basis for an infectious JSRV molecular clone as well as an experimental platform to study the detection and pathogenesis of JSRV.
Amino Acid Sequence ; Base Sequence ; Cloning, Molecular ; Genome, Viral ; Jaagsiekte sheep retrovirus ; genetics ; Pandemics ; Plasmids ; Proviruses ; genetics

The purpose of this study was to develop a multiplex PCR that can detect porcine endogenous retrovirus (PERV) proviral genes (pol, envA, envB, envC) and porcine mitochondrial DNA, using a dual priming oligonucleotide (DPO) system. The primer specifically detected the PERV proviral genes pol, envA, envB, envC, and porcine mitochondrial DNA only in samples of pig origin. The sensitivity of the primer was demonstrated by simultaneous amplification of all 5 target genes in as little as 10 pg of pig DNA containing PERV proviral genes and mitochondrial DNA. The multiplex PCR, when applied to field samples, simultaneously and successfully amplified PERV proviral genes from liver, blood and hair root samples. Thus, the multiplex PCR developed in the current study using DPO-based primers is a rapid, sensitive and specific assay for the detection and subtyping of PERV proviral genes.
Animals ; DNA Primers/genetics ; DNA, Mitochondrial/*genetics ; Gammaretrovirus/*genetics ; Polymerase Chain Reaction/*methods ; Proviruses/classification/*genetics ; Sensitivity and Specificity ; Sus scrofa/*genetics/*virology

Human contains large number of human endogenous retroviruses (HERVs) in its genome. One of the HERV families, HERV-K, entered human genome most recently and includes many members with full-length intact proviruses. Normally, these proviruses do not express but infrequently they seem to express in cancers or autoimmune disease patients. To investigate expression mechanisms of these endogenous retroviruses, a DNA copy of HERV-K was cloned and its expression was studied. The transfection of the full-length clone into human cell lines did not produce any detectable viral capsid protein, Gag, and the transcription from its own promoter in LTR was extremely poor. The transcription was less than 10 percent compare to the exogenous retrovirus. However, when the Gag coding region was cloned under CMV promoter, Gag could be expressed efficiently and secreted as particles, probably virus like particles. The efficient expression also required a nuclear export signal. The expressed Gag could also package its own genomic RNA. These results indicate that the LTR of HERV-K is normally not active but its genes have a potential to express and possibly produce infectious particles.
Autoimmune Diseases ; Capsid Proteins ; Cell Line ; Clinical Coding ; Clone Cells* ; DNA* ; Endogenous Retroviruses ; Genome ; Genome, Human ; Humans* ; Nuclear Export Signals ; Product Packaging* ; Proviruses ; Retroviridae ; RNA ; Transfection

BACKGROUNDThe CRF07_BC recombinant strain has been one of the most predominantly circulated HIV-1 strains in China, it is therefore necessary and urgent to develop a relevant animal model to evaluate candidate vaccines targeting HIV-1 CRF07_BC. A highly replication-competent simian/human immunodeficiency viruses (SHIV) construct containing the Chinese CRF07_BC HIV-1 env gene with the ability to infect Chinese rhesus monkeys would serve as an important tool in the development of HIV vaccines. The aim of this study was to examine whether SHIV XJDC6431 with the env fragment from a Chinese HIV-1 isolate virus could infect the human and monkey peripheral blood mononuclear cell (PBMC), establish infection in Chinese rhesus macaque.

METHODSA SHIV strain was constructed by replacing the rev/env genes of SHIV KB9 with the corresponding fragment derived from the HIV-1 CRF07_BC strain. The infectious activity of the SHIV clones was determined in vitro in PBMCs from both non-human primate animals and humans. Finally, one Chinese rhesus macaques (Macaca mulatta) was infected with one SHIV via intravenous infusion.

RESULTSOne SHIV clone designated as SHIV XJDC6431, was generated that could infect macaque and human PBMC. The virus produced from this clone also efficiently infected the CCR5-expressing GHOST cell lines, indicating that it uses CCR5 as its coreceptor. Finally, the virus was intravenously inoculated into one Chinese rhesus macaque. Eventually, the animal became infected as shown by the occurrence of viremia within 3 of infection. The viral load reached 105 copies of viral RNA per ml of plasma during the acute phase of infection and lasted for 10 weeks post infection.

CONCLUSIONSWe conclude that SHIV XJDC6431 is an R5-tropic chimeric virus, which can establish infection not only in vitro but also in vivo in the Chinese rhesus macaque. Although the animal inoculated with SHIV XJDC6431 became infected without developing a pathologic phenotype, the virus efficiently replicated with a persistent level of viral load in the plasma. This suggested that the SHIV could be used as a tool to test candidate AIDS vaccines targeting the Chinese HIV-1 CRF_07BC recombinant strain.

Animals ; Chimera ; Genes, env ; HIV-1 ; genetics ; physiology ; Humans ; Macaca mulatta ; Proviruses ; genetics ; Receptors, CCR5 ; physiology ; Simian Immunodeficiency Virus ; genetics ; physiology

The genomic DNA extracted from chicken embryo fibroblasts (CEF) of SPF chickens from three chicken farms was used as template to amplify the ALV proviral DNA by PCR with four pairs of primers, high positive detection rates of gag - gene (29/46), pol - gene (27/46), env - gene (24/46) and LTR fragment (31/46) were achieved. Eight continuous and overlapping fragments were amplified from one DNA sample with 8 pairs of primers according to published sequences, then cloned into the TA vector and se quenced. The complete sequence of the whole genome of ALV strain SD0501 was established and analyzed with DNAstar software. Comparisons of SD0501 sequence with that of other representative endogenous avian virus strains demonstrated that the genomes of ALV were relatively conservative, the nucleotide identity of all the strains was over 99.1%, and env - gene was over 98.5%. However, a low identity was demonstrated among the representative strains of different subgroups, especially, the env - gene showed obvious difference, the corresponding identity was as low as 56.3% - 91.5%.
Animals ; Avian Leukosis Virus ; genetics ; Base Sequence ; Chick Embryo ; Genome, Viral ; Polymerase Chain Reaction ; Proviruses ; genetics ; Sequence Analysis, DNA ; Specific Pathogen-Free Organisms ; Terminal Repeat Sequences

To evaluate factors associated with human immunodeficiency virus type 1 (HIV-1) proviral DNA load, we conducted a cross-sectional study of 36 chronically HIV-1- infected individuals with undetectable plasma viral RNA. We used real-time polymerase chain reaction to determine the number of HIV-1 proviral DNA copies per 10(6) peripheral blood mononuclear cells. The mean level of plasma viral RNA when the CD4+ T cell count was above 500 cells/microliter without highly active antiretroviral therapy (HAART) was significantly associated with proviral DNA load at the time of undetectable plasma HIV RNA with HAART. Strategies to reduce the level of plasma viral RNA when patients' CD4+ T cell counts are above 500 cells/microliter without HAART could help reduce HIV-1 proviral DNA load.
Anti-HIV Agents/therapeutic use ; Antiretroviral Therapy, Highly Active ; CD4-Positive T-Lymphocytes/virology ; Cross-Sectional Studies ; DNA, Viral/*analysis ; Female ; HIV Infections/drug therapy ; HIV-1/*genetics ; Humans ; Male ; Polymerase Chain Reaction ; Proviruses/*genetics ; RNA, Viral/blood

The bovine leukemia virus (BLV) is the causative agent of enzootic bovine leucosis. This study investigated the presence of the BLV in leukemia (179 acute lymphoblastic leukemia, 292 acute myeloid leukemia and 46 chronic myelogenous leukemia cases) and 162 lung cancer patients (139 adenocarcinoma, 23 squamous cell carcinoma) to determine if the BLV is a causative organism of leukemia and lung cancer in Koreans. A BLV infection was confirmed in human cells by PCR using a BLV-8 primer combination. All 517 cases of human leukemia and 162 lung cancer were negative for a PCR of the BLV proviral DNA. In conclusion, although meat has been imported from BLV endemic areas, the BLV infection does not appear to be the cause of human leukemia or lung cancer in Koreans. These results can be used as a control for further studies on the BLV in Koreans.
Acute Disease ; Adenocarcinoma/virology ; Cell Line ; DNA, Viral/*genetics/isolation & purification ; Humans ; Korea ; Leukemia/*virology ; Leukemia Virus, Bovine/*genetics ; Leukemia, Lymphocytic, Acute/virology ; Leukemia, Myeloid/virology ; Leukemia, Myeloid, Chronic/virology ; Lung Neoplasms/*virology ; Polymerase Chain Reaction/methods ; Proviruses/*genetics

Porcine endogenous retroviruses (PERVs) integrate into germline DNA as proviral genome that enables vertical transmission from parents to their offspring. The provirus usually survives as part of the host genome rather than as an infectious agent, but may become pathogenic if it crosses species barriers. Therefore, replication-competent PERV should be controlled through selective breeding or knockout technologies. Two microRNAs (miRNAs), dual LTR1 and LTR2, were selected to inhibit the expression of PERV in primary porcine kidney cells. The inhibition efficiency of the miRNAs was compared based on their inhibition of different PERV regions, specifically long terminal repeats (LTRs), gag, pol, and env. Gene expression was quantified using real-time polymerase chain reaction and the C-type reverse transcriptase (RT) activity was determined. The messenger RNA (mRNA) expression of the PERV LTR and env regions was determined in HeLa cells co-cultured with primary porcine kidney cells. The mRNA expression of the LTR, gag, pol, and env regions of PERV was dramatically inhibited by dual miRNA from 24 to 144 h after transfection, with the highest inhibition observed for the LTR and pol regions at 120 h. Additionally, the RT activity of PERV in the co-culture experiment of porcine and human cells was reduced by 84.4% at the sixth passage. The dual LTR 1+2 miRNA efficiently silences PERV in primary porcine kidney cells.
Coculture Techniques ; DNA ; Endogenous Retroviruses ; Gene Expression ; Genome ; HeLa Cells ; Humans ; Kidney ; MicroRNAs ; Parents ; Proviruses ; Real-Time Polymerase Chain Reaction ; RNA, Messenger ; RNA-Directed DNA Polymerase ; Selective Breeding ; Terminal Repeat Sequences ; Transfection

Adult T-cell leukemia/lymphoma (ATLL) is a human malignancy associated with human T-cell leukemia virus type I (HTLV-I), which frequently involves the skin. ATLL can be diagnosed based on clinicopathological findings and the presence of anti-HTLV-I serum antibodies and monoclonal integrated HTLV-I provirus in the DNA of tumor cells. It is characterized by leukemia, lymphadenopathy, hypercalcemia, and lytic bone lesions. We report a case of ATLL in a 59-year-old man who developed multiple, scattered papules on the face and trunk. He had a 3-month history of melena. The physical examination showed multiple cervical and axillary lymph node enlargements. On laboratory investigation, the white blood cell count was 113,900/mm(3) with 70% atypical lymphocytes. Histopathological and immunohistochemical analyses of a skin and stomach biopsy confirmed the diagnosis of T-cell lymphoma. Final diagnosis of ATLL was made based on HTLV-I positivity. The patient underwent multiple cycles of combination chemotherapy and combination therapy of zidovudine and interferon-alpha which produced some improvement, but he died of pulmonary complications 3 months after the initial diagnosis.
Adult* ; Antibodies ; Biopsy ; Diagnosis ; DNA ; Drug Therapy, Combination ; Human T-lymphotropic virus 1 ; Humans ; Hypercalcemia ; Interferon-alpha ; Leukemia ; Leukemia, T-Cell ; Leukemia-Lymphoma, Adult T-Cell ; Leukocyte Count ; Lymph Nodes ; Lymphatic Diseases ; Lymphocytes ; Lymphoma, T-Cell ; Melena ; Middle Aged ; Physical Examination ; Proviruses ; Skin ; Stomach ; T-Lymphocytes* ; Zidovudine