In Yugoslavia, hemorrhagic fever with renal syndrome (HFRS) is one of the important national health problem, but no vaccine has been used to prevent HFRS. Since first HFRS case in 1952, sporadic cases of HFRS occurred every year and over 4,000 registered cases with $1{\sim}16%$ mortality so far. We performed a prospective, randomized double-blind placebo-controlled trial to evaluate the effectiveness of $Hantavax^{TM}$ against HFRS in 3,900 healthy adults living in the endemic areas of Yugoslavia. 1,900 people were given 0.5 ml of Hantavax subcutaneously twice at one month interval and a booster shot at one year after. For controls other 2,000 healthy people were given 0.5 ml of physiolosical saline as a placebo. We investigated HFRS cases in both the vaccinated and nonvaccinated groups by monitoring the program for patient registration in the areas from 1996 to 1998, and the effect of vaccine was analyzed epidemiologically. No confirmed case of HFRS was observed among 1,900 Hantavax vaccinees, while 20 confirmed cases were observed among 2,000 nonvaccinated control group. There were no remarkable side effects among the vaccinees either locally or in general after inoculation of the vaccine. The Hantavax vaccine showed statistically significant protective efficacy against HFRS among Yugoslavian people.

Reovirus was found to inhabit both the respiratory and the enteric tract of human and animals. The genome of reovirus comprises 10 segments of double-stranded RNA, total size 24 kbp. Nine strains of reovirus were isolated from human and field mice in Korea. Aseptically collected sera from human and lung tissues from field mice were used for virus isolation. For serotype determination, hemagglutination inhibition test was used, and three strains were confirmed to type 2 and six strains to type 3. To determine the genomic diversity and molecular phylogeny of reoviruses isolated in Korea, part of S4 genomic segment of reovirus was enzymatically amplified and directly sequenced. In nucleotide level, Apo98-35 strain showed 15.4%, 19.3%, and 14.4% differences compared to type 1 (T1L, Lang), type 2 (T2J), and type 3 reference strains, respectively. In amino acid level, Apo98-35 strain showed 10.5%, 13.7%, and 9.5% differences compared to type 1, type 2, and type 3 reference strains, respectively. Using the maximum parsimony method based on 285 bp spaning region of the S4 genomic segment, phylogenetic analysis indicated that Apo98-35 from Korea formed different phylogenetic branch. Our data obtained by sequence and phylogenetic analyses of reoviruses are consistent with the distinct geographically dependent evolution of reoviruses in Korea.

Rotaviruses belong to Reoviridae causes diarrhea in human beings as well as domestic animals. This study was conducted to see what type of human rotaviruses are distributed in Seoul and Kyung-gi province. Twenty two of 81 patients showed rotavirus positive with diagnostic kit and RNA electropherosis. We isolated all of rotaviruses from the patients. Electropherotypes of 22 isolates showed 4:2:3:2 pattern whereas those migration patterns were long type. All of those isolates belonged to group A. Twenty out of 22 isolates reacted with monoclonal antibodies specific to G1, P1A and subgroup II, whereas rest of them, A-29 and K-30 reacted with subgroup I specific monoclonal antibody. The nucleotide sequence of an isolate K-21 showed $98{\sim}100%$ and $90{\sim}96%$ homologies with those of Wa and KU strain, respectively.

It has long been known that lactoferrin prevents human beings from infection of virus. To prove this activity of lactoferrin, we evaluated the activities of different lactoferrins to an isolate human rotavirus K-21. Bovine lactoferrin inhibited infection of K-21 to MA-104 cell at the concentration of $25.9\;{\mu}M$ whereas bovine hydrolysed lactoferrin prevented rotavirus infection at $103.8\;{\mu}M$. However human lactoferrin prevented infection of K-21 at the concentration of $217.5\;{\mu}M$. These data suggested that lactoferrin activity may be unaffected by the intestinal digestive enzymes and bovine lactoferrin is more active than human lactoferrin with respect to prevention of rotavirus infection.

BamHI restriction pattern and genomic library of Herpes simplex virus type 2 (HSV-2) strain G were constructed, and locations of the glycoproteins gB and gD, and tk genes on the fragments were detected by Southern blot analysis. HSV-2 genomic DNAs were cleaved into twenty-seven fragments by BamHI enzyme in the range of 0.72 to 15.08 (total 150.44 kb), which were cloned into the BamHI site of pBluescript SK(+) to construct genome library of the HSV-2. The library was named by the order of the fragment size from smallest one to largest one. HSV-2 glycoprotein gD gene was located in pHLA2-21 and pHLA2-22 recombinant plasmids, gB gene in pHLA2-24 plasmid, and tk gene in pHLA2-11 clone by Southern blot analysis.

To characterize the molecular nature of human immunodeficiency virus (HIV)-1, we determined the full-length HIV-1 sequences from cultured peripheral blood mononuclear cells (PBMC) of a Korean long-term nonprogressor (LTNP). Without antiretroviral therapy, the individual has maintained CD4+ T counts over $500/{\mu}l$ from 1989 to 1999. Plasma viral RNA copy was 992 U/ml in 1998. Culture supernatant showed positive from culture days 9. A series of 9 overlapping PCR products were amplified from cultured PBMC and cloned About 9.2 kb from R of 5' LTR to R of 3' LTR was determined by automated sequencing. The G-to-A hypermutations were shown throughout the entire region. As a result of G to A hypermutations, premature stop codon was found in integrase coding region. Though there was no recombination between subtypes over all genomes, TATA box in both LTRs was TAAAA which is detected in subtype E instead of TATAA in subtype B. And, there were nucleotide GC insertion between $NF-{\kappa}B$ I and Sp1 III, and duplication of $TCF-1{\alpha}$ in LTR. We could not find any deletion of amino acid in Nef, Gag, Pol and Env gene. This study is the first report on molecular nature of full genomes of HIV-1 isolated in Korea.

Phylogenetic analysis was conducted to monitor transmission of HIV and to investigate the genetic structure of primary isolates from 12 HIV-1 subtype A infected Koreans. The individuals infected with subtype A viruses had been diagnosed as HIV-1 seropositives during the period 1987 to 1995 and blood samples have been collected from 1991 to 1997. DNA of each individual was isolated from uncultured or cultured peripheral blood mononuclear cells. V3-V5 (0.7 kb) fragment of HIV-1 env gene was amplified by nested polymerase chain reaction and the PCR products were sequenced. The mean value of the divergence of nucleotide of HIV-1 env V3-V5 fragment was $17.0{\pm}4.06%$ ($8.6{\sim}25.8%$) within HIV-1 subtype A isolates from Koreans. This diversity was higher than those of African isolates ($13.7{\pm}2.66%$). In the phylogenetic tree, Korean subtype A isolates were not grouped together, but intermingled into African isolates. The results of this study suggested that HIV-1 subtype A variants be introduced from multiple sites of Africa into Korea and the big genetic diversity of Korea HIV-1 subtype A isolates may be further influenced by the range of geographic locations in which the infection occurred rather than the elapsed time between infection and collection of samples and the disease progression.

Transient transfection assay has been done to evaluate whether the c-jun activation would be prerequisite to the induction of permissiveness against human cytomegalovirus using in vitro cell model in which U937 has been induced to express CD11b and CD14 to become potential monocyte/macrophage cells by TPA treatment. U937 cells were treated with $10\;{\mu}M$, $50\;{\mu}M$ or $100\;{\mu}M$ of TPA. The cell morphology change was observed and the expression of the CD11b and CD14 was confirmed by FACS. Differentiated cells were transfected with pJLuc reporter vector which contained the wild type murine c-jun promoter spanning the SP1, CTF, ATF/CREB and MEF-2 binding sites upstream of the firefly luciferase gene. After 48 hrs of transfection, the cells were infected with HCMV Towne strain and the luciferase activity was assessed at 1 hand 4 h pi. The transfection assay showed no activation of the c-jun promoter at 1 h pi, instead, it showed 2 times increase of the its activity at 4 h pi. There was no difference of the c-jun promoter activation between TPA treated and untreated U937 cells, implying that c-jun activation might not be prerequisite for allowing cells to be premissive to HCMV, although HCMV infection itself could activate c-jun promoter.

Transformation efficiency, virus multiplication and foreign gene expression were characterized in the insect cells transformed with Autographa californica nuclear polyhedrosis virus (AcNPV) immediate early 1 gene (IE1). Transformation efficiency of insect cells by AcNPV IE1 gene vector horboring foreign gene was approximately 8-fold higher in the Sf9 cells transformed previously with AcNPV IE1 gene than in the normal Sf9 cells. Virus multiplication and foreign gene expression of recombinant baculovirus in the Sf9 cells transformed with AcNPV IE1 gene were similar to those of the normal Sf9 cells. These results suggest that transformed cells displaying foreign gene product by using AcNPV IE1 gene promoter will be useful for the diverse applications of insect cells.