title: Subtype I BK polyomavirus strains grow more efficiently in human renal epithelial cells than subtype IV strains.
abstract: BK polyomavirus (BKPyV) is ubiquitous in human populations, infecting children without obvious symptoms and persisting in the kidney. BKPyV isolates have been classified into four subtypes (I-IV) using either serological or genotyping methods. In general, subtype I occurs most frequently, followed by subtype IV, with subtypes II and III rarely detected. As differences in growth capacity in human cells possibly determine the proportion of the four subtypes of BKPyV in human populations, here the growth properties of representative BKPyV strains classified as subtype I or IV in renal proximal tubule epithelial cells (HPTE cells) of human origin were analysed. HPTE cells were transfected with four and three full-length BKPyV DNAs belonging to subtypes I and IV, respectively, and cultivated in growth medium. Virus replication, detected using the haemagglutination assay, was observed in all HPTE cells transfected with subtype I BKPyV DNAs, whereas it was markedly delayed or not detected in those transfected with subtype IV BKPyV DNAs. It was confirmed that the transfected viral DNAs induced virus replication in HPTE cells. Furthermore, it was found that BKPyVs with archetypal transcriptional control regions replicated in HPTE cells, with only the occasional emergence of variants carrying rearranged transcriptional control regions. Essentially the same results as described above were obtained with renal epithelial cells derived from whole kidney. Thus, it was concluded that subtype I BKPyV replicates more efficiently than subtype IV BKPyV in human renal epithelial cells, supporting the hypothesis that growth capacity in human cells is related to the proportion of BKPyV subtypes in human populations.
authors.affiliation: Department of Microbiology, Kobe Institute of Health, Kobe, Hyogo 650-0046, Japan.
authors.forename: Souichi
authors.initials: S
authors.lastname: Nukuzuma
authors.affiliation: Department of Urology, Faculty of Medicine, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-8655, Japan.
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Takasaka
authors.affiliation: Japanese Foundation for AIDS Prevention, Tokyo 105-0001, Japan.|Department of Urology, Faculty of Medicine, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-8655, Japan.
authors.forename: Huai-Ying
authors.initials: HY
authors.lastname: Zheng
authors.affiliation: Department of Urology, Faculty of Medicine, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-8655, Japan.
authors.forename: Shan
authors.initials: S
authors.lastname: Zhong
authors.affiliation: Department of Urology, Faculty of Medicine, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-8655, Japan.
authors.forename: Qin
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Department of Urology, Faculty of Medicine, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-8655, Japan.
authors.forename: Tadaichi
authors.initials: T
authors.lastname: Kitamura
authors.affiliation: Department of Urology, Faculty of Medicine, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-8655, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Yogo
mesh_terms: D001739:BK Virus / Q000145:classification* / Q000235:genetics / Q000502:physiology*; D002478:Cells, Cultured; D002678:Chimera / Q000235:genetics; D004279:DNA, Viral / Q000235:genetics; D004847:Epithelial Cells / Q000821:virology; D016679:Genome, Viral; D006801:Humans; D007668:Kidney / Q000166:cytology / Q000821:virology; D007687:Kidney Tubules, Proximal / Q000166:cytology / Q000821:virology; D008954:Models, Biological; D008969:Molecular Sequence Data; D013045:Species Specificity; D014158:Transcription, Genetic; D014162:Transfection; D014776:Virus Cultivation; D014779:Virus Replication / Q000235:genetics / Q000502:physiology
chemical_list: D004279:DNA, Viral