Identification of pol Gene Mutation among BLV Proviruses Found in the Southern Province of Korea

Kwon, Oh-Sik The Korean Society of Virology 2000 Journal of Bacteriology and Virology Vol.29 No.1

Bovine leukemia virus (BLV) is an etiological agent of chronic diseases in cows worldwide. The BLV is one of retroviruses that contain a multi-functional enzyme, reverse transcriptase produced from the pol gene in its genome. We have sequenced some regions in the pol gene of BLV proviruses found in the Southern province of Korea from samples that turned out to be BL V positives by a PCR analysis. On the 5' side of the BLV pol gene (polymerase region), it was found that there were four leucines located at every 7 amino acids. They can form a leucine zipper motif that was not same as the pol gene of Japanese BLV isolate. The sequencing result of the proviral pol gene in Korean-type BLV also revealed some mutations leading to amino acid changes such as $CCT(Pro){\to}CTC(Leu)$, $AAT(Asn){\to}AAA(Lys)$, and non-sensible variations i.e., $TCT(Ser){\to}TCC(Ser)$, $ATT(Ile){\to}ATC(I1e)$ and $ACG(Thr){\to}ACA(Thr)$. On the 3' side of the pol gene (integrase region), some nucleotide sequences were mutated and led to amino acid changes. Among them, a mutation, $GAA(Glu){\to}GAC(Asp)$ occurred in many Korean-type BLV proviruses was very interesting because the amino acid was regarded as one of the most conserved amino acids in the retroviral integrase. It was also notable that the mutation on any leucine residue did not occur, in spite of its frequent appearance.

Biological Characterization of HIV-1 Isolates from Long-term non-progressors (LTNP) and Rapid Progressors (RP) in Korea

Nam, Jeong-Gu,Kang, Chun,Lee, Sung-Rae,Lee, Joo-Shil The Korean Society of Virology 1998 Journal of Bacteriology and Virology Vol.50 No.2

To analyze the correlation between biological phenotypes of HIV-1 isolates and disease progression, we selected 9 long-term non-progressors (LTNP) and 12 rapid progressors (RP) from HIV-1 infected Korean. We isolated HIV-1 isolates by culture of PBMC of LTNP and RP with normal PBMC and measured HIV-1 p24 antigen production. The HIV-1 isolation rate from LTNP was 55.6% (5/9). And 4 HIV-1 LTNP isolates were non-syncytium inducing (NSI) phenotype and showed slow/low replication. The HIV-1 isolation rate from RP was 91.7% (11/12) which was higher than that from LTNP. Besides 3 RP HIV-1 isolates which showed syncytium inducing (SI) phenotype, 8 RP HIV-1 isolates showed NSI phenotype in normal PBMC and MT-2 cell line. All RP HIV-1 isolates replicated more rapidly than LTNP HIV-1 isolates. Comparing the replication kinetics and syncytium forming capacity of HIV-1 isolates from LTNP and RP, we suggest that the difference of biological phenotype of HIV-1 isolates could be related with disease progression of HIV-1 infected persons.

Effects of Hantaan Virus and $IFN-{\gamma}$ on Induction of Surface ICAM-1 in Primary Cultured Human Nasal Epithelial Cells and Human Lung Fibroblasts

Park, Ho-Sun,Kim, Sung-Kwang The Korean Society of Virology 1998 Journal of Bacteriology and Virology Vol.50 No.2

The primary culture of human nasal epithelial cells was performed using the inferior nasal turbinate tissues, and infected with Hantaan virus to examine the hypothesis of airborne transmission of Hantaan virus in humans. The primary culture cells were identified as epithelial cells by morphologic and immunologic analyses. The viral antigens were detected in the primary human nasal epithelial cells infected with Hantaan virus by immunofluorescence staining. The ICAM-1 induction by Hantaan virus or $IFN-{\gamma}$ was examined in the primary human nasal epithelial cells and human lung fibroblasts (WI-38). Hantaan virus induced the surface ICAM-1 in WI-38 cells in a time-dependent manner, and $IFN-{\gamma}$ induced the surface ICAM-1 in a dose-dependent manner in HNEC and WI-38 cells. These results revealed that the human nasal epithelial cells are susceptible to Hantaan viral infection supporting the hypothesis of airborne transmission of Hantaan virus in humans. The human lung fibroblasts also might have an important role in the pathogenesis of Hantaan virus through the induction of ICAM-1.

PCR Approach for Detection and Typing of Epidermodysplasia Verruciformis-associated Human Papillomavirus Types

Shin, Yong-Jae,Choi, Hyun-Chul,Kim, Chan-Gil,Lee, Kwang-Ho The Korean Society of Virology 1999 Journal of Bacteriology and Virology Vol.29 No.1

Warts, or verrucae, are benign epithelial proliferations of the skin and mucosa caused by infection with human papillomaviruses (HPV). It is now recognized that there are many different HPV types. Especially type3 is most frequently observed in flat wart. Other types, such as type2, 10, 14, 27, 28, 29, 38, and 41 are rarely encounted in flat wart. We describe here a simple and economic method for detection and identification of epidermodysplasia verruciformis-associated HPV. The method is based on polymerase chain reaction (PCR) amplification and restriction analysis. The method has been developed with cloned HPV DNA and DNA from clinical samples. Clinical samples are from either frozen tissue or paraffin-embedded tissue. Genomic fragments were obtained from two different HPV types (3 and 10). The amplification fragments were identified by a form of miniature fingerprinting, with a set of restriction enzymes that gave a unique digestion pattern for each HPV type. We have tested 74 clinical samples. Only type3 among these clinical samples is detected, and one sample is involved in neither type3 nor type10.

Expression of Bovine Growth Hormone Gene in a Baculovirus, Hyphantria cunea Nuclear Polyhedrosis Virus

Park, Kap-Ju,Lee, Keun-Kwang,Kang, Bong-Ju,Cha, Sung-Chul,Lee, Hyung-Hoan The Korean Society of Virology 1998 Journal of Bacteriology and Virology Vol.28 No.2

Bovine growth hormone (bGH) gene was expressed in an insect Spodoptera frugiperda cell line using a Baculovirus, Hyphantria cunea nuclear polyhedrosis virus (HcNPV). The bGH gene in pbGH plasmid was sequenced and amplified by PCR technique with two primers containing NcoI sites. The bGH gene consisted of 654 bp (217 amino acid residues), the 5'-untranslated region of the cloned bGH cDNA contains 56 bp, and the 3'-untranslated region contains 145 bp and two pallindromic regions. The amplified bGH gene DNA fragment (654 bp) was inserted into the NcoI site of the pHcEVII vector, which was named pHcbGH. The pHcbGH transfer vector DNA and the wild type HcNPV DNA were cotransfected into S. frugiperda cells to construct a recombinant virus. Eight recombinant viruses were selected and named HcbGH. One clone, HcbGH-4-1 showed largest plaque size, therefore the recombinant virus was further studied. The multiplication pattern of the recombinant HcbGH-4-1 was similar to that of the wild type HcNPV. The bGH gene DNA in the HcbGH-4-1 recombinant was confirmed by Southern blot hybridization. The amount of the bGH (217 amino acid residues, 21 kDa) produced in S. frugiperda cells infected with the HcbGH-4-1 recombinant was approximately 5.5 ng per ml ($10^6$ cells) by radioimmunoassay.

Development of Zosteriform Models in Skin and Vagina of Mice using Herpes simplex Virus Strain McKrae

이형환,차성철,어홍선,조재경,이준근,장동준,김수영,Lee, Hyung-Hoan,Cha, Soung-Chul,Uh, Hong-Sun,Cho, Jae-Kyung,Lee, Jun-Keun,Chang, Dong-Jun,Kim, Soo-Young The Korean Society of Virology 1999 Journal of Bacteriology and Virology Vol.29 No.4

Zosteriform lesions, occurring after left flank and intravaginal inoculations of Balb/c mice with the Herpes simplex virus type 1 strain McKrae, developed in clinically normal skin via nerve endings. The developments of zosteriforms were standardized in 5 phases with the following references; formation of small vesicles (phase 1); occurrence of erosion and ulceration of local lesions (phase 2); occurrence of ulcerations (phase 3); occurrence of severe ulcerations (phase 4); and death (phase 5). These results provide two valuable zosteriform models to further investigate and analyze the pathological symptoms in susceptible animals infected with HSV-1 or HSV-2 and DNA vaccines.

Development of A Monkey Kidney Cell Line Which Expresses Poliovirus Capsid Protein

Choi, Weon-Sang The Korean Society of Virology 1998 Journal of Bacteriology and Virology Vol.50 No.2

The RNA genome of poliovirus encodes a long polyprotein precursor and this polyprotein is cleaved proteolytically by viral protease to yield mature proteins. The mature proteins derived from the P1 polyprotein precursor are the component of capsids. To further delineate the process of capsid assembly and encapsidation, in a first attempt, a cell line which expresses the authentic P1 polyprotein was established. CV-1 cells were transfected with the pRCRSVS1P1 plasmid DNA which contains 5'ncr sequences, whole authentic capsid gene of poliovirus and neomycin resistance gene. These cells were treated with G418 for 3 months, and eventually G418 resistant cells were selected and formed colonies. Each colony was picked and grown in the media containing G418. DNA analysis indicated that 1 of 13 neomycin resistant cell lines (R2-18) contains whole poliovirus P1 capsid gene segment which was incorporated into the genome. Immuneprecipitation of cell lysates with sera from rabbit immunized with inactivateded Sabin type 1 particles demonstrated the constitutive expression of the poliovirus P1 capsid protein from R2-18.

Expression of Human Papillomavirus Type 16, Prototype and Natural Variant E7 Proteins using Baculovirus Expression System

Han, Hee-Sung,Kee, Sun-Ho,Hwang, Soon-Bong,Kim, Hyung-Jun,Cho, Kyung-A,Kim, Yoon-Won,Cho, Min-Kee,Chang, Woo-Hyun The Korean Society of Virology 1998 Journal of Bacteriology and Virology Vol.28 No.1

Human papillomavirus (HPV) 16, E7 proteins derived from the prototype (Bac73) and natural variant (Bac101) E7 open reading frame were produced in Sf9 insect cells. The variant E7 gene occurred naturally by substitution mutation at the position of 88 nucleotide, resulting serine instead of asparagine. Using E7 specific monoclonal antibody (VD6), both E7 proteins were identified in recombinant baculovirus infected SF9 cells. Radiolabelling and immunoprecipitation analysis revealed that both E7 proteins were phosphoproteins. Immunostaining result showed that E7 proteins were mainly localized in the cytoplasm. Nuclear form of E7 proteins was also detected after a sequential fractionation procedure for removing chromatin structure. Considering that the VD6 recognition site in E7 protein is located within 10 amino acid at the N-terminus, this region appears to be blocked by the nuclear component. Western blot analysis revealed that nuclear form was more abundant than cytoplasmic E7 proteins. Time course immunostaining showed that the primary location of E7 protein was the nucleus and exported to the cytoplasm as proteins were accumulated. These events occurred similarly in both Bac73 and Bac101 infected Sf9 cells, suggesting that these two proteins may have similar biological functions.

Correlation of Virologic Property and Phylogenetic Analysis of Hantaan Viruses Isolated from Patients and Reservoirs in Korea

Jung, Yong-Tae,Lee, Sun-Ryang,Paik, Soon-Young,Kim, Gum-Ryong The Korean Society of Virology 1998 Journal of Bacteriology and Virology Vol.28 No.1

Twenty isolates of Hantavirus were isolated from patients and reserovirs from 1988 to 1994 in Korea. Isolation rate was 1.9% (10/538) in patients, 6.2% (5/81) in Apodemus sp., 2.6% (1/38) in Rattus sp. and 0.6% (4/677) in bats. Reciprocal mean IFA titers ranged from 27.5 to 1,024 at the specimen collection. According to the growth rate and reaching peak titier of infectivity, the isolates were grouped as rapid, intermediate, and slow growing groups. All isolates were confirmed as Hantaan type by the nested RT-PCR on the G1 region of the M segment. Comparison of nucleotide sequence (Nt: 2101 - Nt: 2280) of the G2 region revealed that the sequence homology bewteen Hantaan 76/118 virus and the isolates was more than 90%. Several nucleotide positions of the isolates showed high variation. The variation rate of patientisolates was about one-half when compared with that of rodentisolates. On the basis of phylogenetic analysis Hantaan viruses isolated were divided into two genogroups. These results indicate that Hantaan virus is highly dominant serotype in Korea and the virologic property and genogroup are not correlated.

Longevity of Antibodies to Live Orientia tsutsugamushi Inoculated in Sprague Dawley Rats

An, Chang-Nam,Kim, Sung-Min,Kim, Tae-Yeon,Bae, Luck-Ju,Kim, Chul-Joong,Shin, Kwang-Soon,Park, Song-Yong The Korean Society of Virology 1998 Journal of Bacteriology and Virology Vol.28 No.2

In Sprague Dawley (SD) rats, antibodies against strains of Orientia tsutsugamushi, Kato, Karp and Gilliam, were produced in order to investigate their longevity and cross-reactivities to their corresponding homologous and heterologous antigens. By immunofluorescence assay (IFA) of IgG and IgM, it was shown that the immunity to the homologous strains persisted at a higher level (longevity of at least 34 weeks with higher IFA titers). On the other hand, the immunity to the heterologous strains persisted at a lower level (longevity of 10 to 34 weeks with lower IFA titers). Since infection with one strain of O. tsutsugamushi does not preclude reinfection with other strains, understanding of the antigenic diversity of O. tsutsugamushi and duration of the immunity to both homologous and heterologous strain is very important in diagnosis of scrub typhus.