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Six strains of human immunodeficiency virus type 1 isolated in Japan and their molecular phylogeny
N Shimizu1, Y Takeuchi, T Naruse
1Department of Hygiene, Gunma University School of Medicine, Japan.
Insights
This study analyzed six human immunodeficiency virus type 1 (HIV-1) strains from Japanese hemophilia patients and a Canadian homosexual male. Phylogenetic analysis using restriction maps revealed distinct viral strains, with Japanese isolates showing closer ties to US strains than African ones.
Area of Science:
- Virology
- Molecular Biology
- Epidemiology
Background:
- Human immunodeficiency virus type 1 (HIV-1) is a global health concern.
- Hemophilia patients are at increased risk of HIV-1 infection due to blood product exposure.
- Understanding the genetic diversity of HIV-1 strains is crucial for tracking transmission and developing interventions.
Purpose of the Study:
- To characterize and compare the genetic makeup of newly isolated HIV-1 strains.
- To determine the phylogenetic relationships of Japanese HIV-1 isolates.
- To investigate the origins and transmission patterns of HIV-1 in Japan.
Main Methods:
- Isolation and culture of HIV-1 strains from patient samples.
- Restriction endonuclease cleavage mapping of proviral genomes.
- Phylogenetic tree construction using restriction maps and nucleotide sequences.
Main Results:
- Six distinct HIV-1 strains were identified: five from Japanese hemophilia patients and one from a Canadian homosexual male.
- Restriction maps indicated significant genetic variation among the isolates.
- Phylogenetic analyses demonstrated that Japanese HIV-1 isolates were more closely related to US strains than to African strains.
- Specific Japanese isolates (GUN-1, GUN-2) clustered with a San Francisco isolate (ARV2), while others (GUN-5, GUN-6) grouped with HTLV-IIIB-related isolates.
Conclusions:
- Restriction maps provide a reliable method for phylogenetic analysis of HIV-1 isolates.
- The genetic relatedness suggests potential transmission links between Japan and the United States.
- Further research is needed to elucidate the complete transmission networks of HIV-1 globally.
Abstract:
Five strains of human immunodeficiency virus type 1 (HIV-1) were isolated from five Japanese hemophilia patients. Two isolates, HIV-1[GUN-1] and HIV-1[GUN-2], were from brother patients with hemophilia B and the other three isolates, HIV-1[GUN-3], HIV-1[GUN-4], and HIV-1[GUN-5], were from hemophilia A patients. Another HIV-1 strain, HIV-1[GUN-6], was isolated from a Canadian male homosexual with AIDS. The restriction endonuclease cleavage maps of the proviral genomes of these six HIV-1 strains revealed that they were apparently different from each other. The phylogenetic trees constructed using restriction maps and nucleotide sequences were quite similar, indicating that phylogenetic analyses of Japanese HIV-1 isolates can be done using restriction maps of the proviruses. Phylogenetic analyses showed that they were more closely related to HIV-1s which had been reported to be isolated from homosexual patients in the United States than those isolated from African patients. In particular, GUN-1 and GUN-2 isolates were on the branch of a San Francisco isolate, ARV2, while GUN-5 and GUN-6 isolates were on the branch of HTLV-IIIB-related isolates.