Highly homologous simian T-cell leukemia virus type 1 genome in Japanese macaques: a large cohort study

• Published in: Virology journal Vol. 21; no. 1; p. 166
• Main Authors: Hiraga, Kou, Kitamura, Tomoya, Kuramitsu, Madoka, Murata, Megumi, Tezuka, Kenta, Okuma, Kazu, Hamaguchi, Isao, Akari, Hirofumi, Mizukami, Takuo
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 30.07.2024; BioMed Central; BMC
• Subjects: adults; Analysis; Animals; Antiviral agents; Apobec3G; Cohort Studies; Control; Deltaretrovirus Infections - epidemiology; Deltaretrovirus Infections - veterinary; Deltaretrovirus Infections - virology; DNA sequencing; Dosage and administration; Epidemiology; etiological agents; Genetic Variation; genome; Genome sequencing; Genome, Viral; HTLV-1; Humans; Identification and classification; Japan; Japanese macaques; leukemia; Macaca fuscata; Macaca fuscata - genetics; Molecular Epidemiology; Nucleotide sequencing; Phylogeny; Primate T-lymphotropic virus 1; RNA viruses; Sequence Analysis, DNA; Simian T-lymphotropic virus 1 - genetics; Simian T-lymphotropic virus 1 - isolation & purification; STLV-1; T-lymphocytes; viruses; Japan; Apobec3G; HTLV-1; STLV-1; Phylogeny; Genome sequencing; Japanese macaques
• DOI: 10.1186/s12985-024-02434-7
• ISSN: 1743-422X

Simian T-cell leukemia virus type 1 (STLV-1) is a retrovirus closely related to human T-cell leukemia virus type 1 (HTLV-1), the causative agent of adult T-cell leukemia (ATL). It has been shown that Japanese macaques (Macaca fuscata, JMs) are one of the main hosts of STLV-1 and that a high percentage of JMs (up to 60%) are infected with STLV-1; however, the molecular epidemiology of STLV-1 in JMs has not been examined. In this study, we analyzed full-length STLV-1 genome sequences obtained from 5 independent troops including a total of 68 JMs. The overall nucleotide heterogeneity was 4.7%, and the heterogeneity among the troops was 2.1%, irrespective of the formation of distinct subclusters in each troop. Moreover, the heterogeneity within each troop was extremely low (>99% genome homology) compared with cases of STLV-1 in African non-human primates as well as humans. It was previously reported that frequent G-to-A single-nucleotide variants (SNVs) occur in HTLV-1 proviral genomes in both ATL patients and HTLV-1 carriers, and that a G-to-A hypermutation is associated with the cellular antiviral restriction factor, Apobec3G. Surprisingly, these SNVs were scarcely observed in the STLV-1 genomes in JMs. Taken together, these results indicate that STLV-1 genomes in JMs are highly homologous, at least in part due to the lack of Apobec3G-dependent G-to-A hypermutation.