• Korean Journal of Microbiology
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• v.42 no.3
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• pp.230-234
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• 2006

To study the mechanism of syncytium formation, novel syncytia-inducing ecotropic murine retrovirus was used. Our previous result showed that amino acid substitutions at the RBD (receptor binding domain) of envelope glycoprotein contribute to syncytium formation. In this study, we have investigated if this fusion phenomenon could occur with retroviral vectors pseudotyped with the novel syncytia-inducing ecotropic murine leukemia virus Env. We have found that these vectors were not able to mediate virus-to-cell fusion in M. dunni murine cell lines. These findings indicate that syncytia-inducing ecotropic murine leukemia virus is capable of generating syncytia during its replication. There was also no correlation between the level of ecotropic murine leukemia virus receptor (mCAT-1) and the fusogenic effect.

• Journal of Microbiology
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• v.44 no.4
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• pp.447-452
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• 2006

The murine ecotropic retroviral receptor has been demonstrated to function as a mouse cationic amino acid transporter 1(mCAT1), and is comprised of multiple membranespanning domains. Feral mouse (Mus dunni) cells are not susceptible to infection by the ecotropic Moloney murine leukemia virus (MoMLV), although they can be infected by other ecotropic murine leukemia viruses, including Friend MLV and Rauscher MLV. The relative inability of MoMLV to replicate in M. dunni cells has been attributed to two amino acids $(V_{214}\;and\;G_{236})$ located within the third extracellular loop of the M. dunni CAT1 receptor (dCAT1). Via the exchange of the third extracellular loop of the mCAT1 cDNA encoding receptor from the permissive mouse and the corresponding portion of cDNA encoding for the nonpermissive M. dunni receptor, we have identified the most critical amino acid residue, which is a glycine located at position 236 within the third extracellular loop of dCAT1. We also attempted to determine the role of the third extracellular loop of the M. dunni CAT1 receptor with regard to the formation of the syncytium. The relationship between dCAT1 and virus-induced syncytia was suggested initially by our previous identification of two MLV isolates (S82F in Moloney and S84A in Friend MLV), both of which are uniquely cytopathic in M. dunni cells. In an attempt to determine the relationship existing between dCAT1 and the virally-induced syncytia, we infected 293-dCAT1 or chimeric dCAT1 cells with the S82F pseudotype virus. The S82F pseudotype virus did not induce the formation of syncytia, but did show increased susceptibility to 293 cells expressing dCATl. The results of our study indicate that S82F-induced syncytium formation may be the result of cell-cell fusion, but not virus-cell fusion.

• Korean Journal of Microbiology
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• v.26 no.2
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• pp.101-105
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• 1988

6M-MuLV mutants containing deldtions around the putative packaging signal were constructed by using recombinant DNA technique and transfected into NIH/3T3 cell. 2 of 6 mutants can not be packaged into virions even in the presence of the wild type helper virus. The boundary between the packagible and the non-packagible genome is located around Pvu I site, 421 nucleotide downstream from the 5' end of M-MuLV genome. 10 base pair inverted repeat sequence (GAGUCCAAAA) which can make stem structure around Pvu Isite could be the putative packaging signal.

• Journal of Applied Biological Chemistry
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• v.48 no.4
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• pp.170-177
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• 2005

Oriental medicinal herb extracts (OHE) showing anticancer activities were investigated for effectiveness as antiviral drugs. Infection of MuLV to cell line resulted in formation of giant syncytia. Number of giant syncytia in culture treated with OHE decreased by 40% compared to that of non-OHE-treated cell culture. To determine OHE effects on progeny release, RT-PCR was performed. In vivo animal studies demonstrated effectiveness of OHE as antiviral drug when administered orally. After OHE administration, viral cytopathic effects decreased. Infected mice showed splenomegaly and over-proliferation of lymphocytes with decreased CD4+ cell counts. These symptoms decreased in OHE-treated mice, indicating OHE maybe useful therapeutics against MuLV/MAIDS as Human Immunodeficiency Virus (HIV)/AIDS animal model. Results show XC plaque assay and in vivo MAIDS model using MuLV are suitable tools for screening anti-retroviral drug candidates.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.3669-3673
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• 2012

A role for the xenotropic murine leukemia virus (XMRV) in prostate cancer development has been postulated. To answer questions regarding the prevalence of XMRV in Iranian patients with prostate cancer and its association with the RNASEL R462Q polymorphism, we here investigated a series of cases in Kerman, in the Southeast of Iran, and sought to verify the association with the R462Q using Real Time PCR Method. Prostate tissue specimens of 200 patients with prostate cancer were genotyped for R462Q by real time polymerase chain reaction allelic discrimination and were screened for XMRV proviral DNA by real time polymerase chain reaction specific for the envelope gene. Of 200 patients in this study 8 (4%) cases were positive for XMRV, the QQ allele being the most frequenct regarding the R426Q polymorphism while in negative patients it was the RQ allele. There was significant correlation between high pathological scores and XMRV positive samples. No significant relationship was found between age groups and XMRV results. XMRV was only found in patients with QQ and RQ alleles, not RR. XMRV is detectable in tumor prostate tissue from some patients with prostate cancer, independent of R462Q.

• Journal of Microbiology and Biotechnology
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• v.18 no.4
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• pp.799-804
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• 2008

Retrovirus tropism can be restricted by host cell factors such as Fv1, TRIM5${\alpha}$, and LvI that inhibit infection by targeting the incoming viral capsid. The Fv1 gene inhibits murine leukemia virus infection in mice, but the precise mechanism of Fv1-mediated restriction is poorly understood. Our previous studies had demonstrated that Fv1-mediated viral tropism can be determined within the capsid protein at position 114. To study the interaction between Fv1 and CA, we introduced amino acid substitution and deletion at this site in the N-tropic AKV capsid gene. The mutated two-LTR proviral DNAs were introduced into SC-1 cells by transfection. After transfection, cell supernatants collected from transfected cells were tested for host range susceptibility. The result indicated that substitution of amino acids did not alter tropism, but the deletion of 114His produced a virus with unusual tropism. The novel phenotype produced here failed to replicate in Fv1-expressing cells. This mutant virus showing such an extreme restriction pattern would be useful for studying the mechanism of Fv1-mediated restriction.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.11
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• pp.6929-6933
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• 2013

Background: Multiple etiologies have been hypothesized for prostate cancer, including genetic defects and infectious agents. A recently reported gamaretrovirus, xenotropic murine leukemia virus-related virus (XMRV) has been reported to be detected in prostate cancer. However, this virus has not been detected in similar groups of patients in other studies. Herein, we sought to detect XMRV in prostate cancers and benign controls in Sanandaj, west of Iran. Materials and Methods: In a case-control study, genomic DNA was extracted from formalin fixed and paraffin embedded prostate tissues from a total of 163 Iranian patients. We developed a conventional and a nested PCR assay using primers targeting to an env specific sequence of XMRV. PCR assays were carried out on 63 prostate cancers and 100 benign prostate hyperplasias. Results: Beta-actin sequences were successfully detected in the DNA extracts from all prostate tissues, confirming DNA extraction integrity. We did not detect XMRV in samples either from prostate cancers or benign prostate hyperplasias using XMRV specific primers. Conclusions: We conclude that in our population XMRV does not play a role in genesis of prostate cancer.

• Korean Journal Plant Pathology
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• v.11 no.1
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• pp.73-79
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• 1995

Complementary DNAs (cDNAs) to the coat protein gene of an ordinary Korean strain of potato virus Y (PVY-OK) isolated from potato (cv. Superior) were synthesized and cloned into a plasmid pUC119 and sequenced. The RNA of the virus propagated in tobacco (Nicotinaa sylvestris) was extracted by the method of phenol extraction. The first strand of cDNAs to the coat protein penomic RNA of the virus was made by Moloney murine leukemia virus reverse transcriptase. The cDNA were synthesized and amplified by the method of polymerase chain reaction (PCR) using a pair of oligonucleotide primers. PVYCP3P and PVYCP3M. The size of cDNAs inserted in pUC119 plasmid was estimated as about 840 bp upon agarose gel electrophoresis. Double stranded cDNAs were transformed into the competent cell of E. coli JM109. Sequence analysis of cDNAs was conducted by the dideoxynucleotide chain termination method. Homology of cDNAs of the PVY-OK coat protein genomic RNA with those of PVY-O (Japan), PVY-T (Japan), PVY-TH (Japan), PVYN (The Netherlands),and PVYY (France) was represented as 97.3%, 88.9%, 89.3%, 89.6% and 98.5%, respectively. Homology at the amino acid level turned out to the be 97.4%, 92.5%, 92.9%, 92.9% and 98.5%, respectively.

• Molecules and Cells
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• v.40 no.5
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• pp.339-345
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• 2017

Retroviral and lentiviral vectors are mostly pseudotyped and often purified and concentrated via ultracentrifugation. In this study, we quantified and compared the stabilities of retroviral [murine leukemia virus (MLV)-based] and lentiviral [human immunodeficiency virus (HIV)-1-based] vectors pseudotyped with relatively mechanically stable envelope proteins, vesicular stomatitis virus glycoproteins (VSVGs), and the influenza virus WSN strain envelope proteins against ultracentrifugation. Lentiviral genomic and functional particles were more stable than the corresponding retroviral particles against ultracentrifugation when pseudotyped with VSVGs. However, both retroviral and lentiviral particles were unstable when pseudotyped with the influenza virus WSN strain envelope proteins. Therefore, the stabilities of pseudotyped retroviral and lentiviral vectors against ultracentrifugation process are a function of not only the type of envelope proteins, but also the type of viral internal core (MLV or HIV-1 core). In addition, the fraction of functional viral particles among genomic viral particles greatly varied at times during packaging, depending on the type of envelope proteins used for pseudotyping and the viral internal core.

• Preventive Nutrition and Food Science
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• v.10 no.2
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• pp.161-166
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• 2005

We investigated the effect of pycnogenol (PYC) supplementation on retarding the immune dysfunction of CS7BL/6 mice after murine AIDS (MAIDS) development. Dysfunction of T and B cell mitogenesis from primary cultured splenocytes has been observed with retrovirus infection and PYC supplementation partially recovered the dysfunction of T and B cells. There was an abnormal shift of cytokine pattern with retrovirns infection, which was designated by the decreased secretion of Th1 cytokines and increased secretion of Th2 cytokines. PYC supplementation increased IL-2 and $IFN-\gamma$ secretion and decreased IL-4, IL-6, and $TNF-\alpha$ secretion, but it was not sufficient enough to maintain the normal level of these cytokines. Hepatic vitamin E level was significantly decreased by retrovirns infection, in accordance with increased hepatic lipid peroxidation level, whereas PYC supplementation normalized the hepatic level of vitamin E and lipid peroxidation. This study suggests that PYC supplementation may partially help retard the incidence of symptoms during MAIDS.