Grant-in-Aid for Scientific Research (A)
|Allocation Type||Single-year Grants|
|Research Institution||NATIONAL INSTITUTE OF INFECTIOUS DISEASES|
TAKEBE Yutaka NATIONAL INSTITUTE OF INFECTIOUS DISEASES, AIDS RESEARCH CENTER, CHIEF, エイズ研究センター, 室長 (50126116)
ABE Kenji NATIONAL INSTITUTE OF INFECTIOUS DISEASES, SENIOR INVESTIGATOR, 感染病理部, 主任研究官 (60130415)
YAMAMOTO Naohiko NAGOYA UNIV., ASSOCIATE PROFESSOR, 医学部, 助教授 (40220488)
SHIOTA Tatsuo OSAKA UNIV., PROFESSOR, 微研免疫・ウイルス感染制御分野, 教授 (00187329)
TAKIMOTO Masafumi KUMAMOTO UNIV., PROFESSOR, 医学部エイズ学研究センター, 教授 (00183450)
YASUTOMI Yasuhiro MIE UNIV., ASSOCIATE PROFESSOR, 医学部, 助教授 (90281724)
|Project Period (FY)
1998 – 2000
Completed(Fiscal Year 2000)
|Budget Amount *help
¥18,800,000 (Direct Cost : ¥18,800,000)
Fiscal Year 2000 : ¥5,900,000 (Direct Cost : ¥5,900,000)
Fiscal Year 1999 : ¥5,900,000 (Direct Cost : ¥5,900,000)
Fiscal Year 1998 : ¥7,000,000 (Direct Cost : ¥7,000,000)
|Keywords||ASIA / AIDS / HIV / HBV / HCV / HGV / MOLECULAR EPIDEMIOLOGY / SURVEILLANCE / HVB|
(A)Molecular epidemiology of HIV in Asia
1)HIV outbreaks in northern Vietnam : We have investigated the nature of recent HIV outbreaks among injecting drug users (IDUs) near Vietnam-China border. HIV-1 subtype E was a principal strain distributed throughout country, regardless of risk factor. We found that the majority of HIV-1 subtype E among IDUs in northern Vietnam showed the significant clustering with those found in nearby Pingxiang city of China's Guangxi Province, sharing a unique valine substitution at 12 amino acids downstream of the V3 loop. The data indicated that HIV outbreaks among IDUs in northern Vietnam was caused by the recent introduction of a highly homogeneous subtype E variant(EV) of close origin of that prevailing in nearby southern China.
2)Emergence of various forms of HIV-1 intersubtype recombinants in Central Myanmar : In addition to two HIV-1 subtypes B' and E previously detected in our study, we have identified HIV-1 subtype C for the first time in Central Mya
nmar. Moreover, approximately 1/4 of specimens showed the discordance in gag (p17) and env (C2/V3) subtypes. The recombination breakpoint analyses revealed the presence of new forms of HIV-1 intersubtype C/B' and C/B'/E recombinants. The data suggest that multiple subtypes of B', C and E are co-circulating in Central Myanmar, leading to the evolution of new forms of intersubtype recombinants.
3)The genetic polymorphism influencing the susceptibility to HIV-1 and disease progression in Thai population : Cross-section study using discordant couples in Thailand revealed that CCR5 927T mutation is an important genetic predisposition related to resistance to HIV-1 infection in Thai population. This is one of the first reports done in Asian population. Theses results would provide the information crucial to future vaccine strategies for this particular areas in Asia.
B)Molecular epidemiology of hepatitis viruses in Asia
1)Identification of novel genotype of HGV in Southeast Asia : We recently identified a novel genotype of hepatitis G virus(HGV) in Southeast Asian countries. To characterize the viral genome in more detail, we cloned the full-length nucleotide sequence of the two different HGV isolates belonging to the novel genotype. These isolates were recovered from serum of Myanmarese (designated HGV-MY14) and Vietnamese (designated HGV-VT48) subjects, respectively. Both HGV isolates were composed of 9228 nucleotides (nt) and had a single open reading frame spanning 8529 nt and encoding 2843 amino acid residues.
2)HBV and HGV genotyping by PCR : A simple and precise genotyping system based on PCR using the type-specific primers was developed in order to allow for the determination of genotypes A through F of HBV and genotypes 1 through 4 of HGV. By this new method, the prevalence of genotypes of HBV and HGV was investigated in Southeast Asia. The results revealed that the most common viral genotypes were type C of HBV and type 4 of HGV in Myanmar and Vietnam. Interestingly, type B of HBV was also prevalent in Vietnam. This assay system is considered to be useful tool for molecular diagnosis of HBV infection and large-scale surveys. Less