title: Immortalization of Epstein-Barr virus-negative human B lymphocytes with minimal chromosomal instability.
abstract: The genes required for immortalization of human B cells infected by Epstein-Barr virus are multiple, and the precise mechanism of this process remains to be elucidated. In the present study HPV16 E6 and E7 were retrovirally transduced into human primary B cells stimulated by CD40-CD40L interaction, thereby establishing an Epstein-Barr virus negative immortalized human B cell line, which continued to proliferate for more than 2 years (100 population doublings). The established cell line had a high telomerase activity from the beginning of the culture period, and no shortening of the telomere length was observed. A chromosomal analysis revealed that a large portion of the HPV16E6E7 transduced cells had retained a normal karyotype. Similar to human epithelial cells, human B lymphocytes seem to require two steps for immortalization, namely, the inactivation of the p16/Rb pathway and the activation of telomerase, the latter that can be induced by the CD40-CD40L interaction. Furthermore, using this system, it is possible to analyze the role of individual genes in human B lymphocyte immortalization without the influence of a pre-existing Epstein-Barr virus genome.
authors.affiliation: Department of Pathology, Nagoya University Graduate School of Medicine, Nagoya, Japan. k46581a@nucc.cc.nagoya-u.ac.jp
authors.forename: Yoriko
authors.initials: Y
authors.lastname: Yamashita
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Tsurumi
authors.forename: Naoyoshi
authors.initials: N
authors.lastname: Mori
authors.forename: Tohru
authors.initials: T
authors.lastname: Kiyono
mesh_terms: D001402:B-Lymphocytes / Q000201:enzymology / Q000473:pathology* / Q000821:virology; D019013:CD40 Antigens / Q000235:genetics / Q000378:metabolism; D023201:CD40 Ligand / Q000378:metabolism; D002461:Cell Line, Transformed; D002472:Cell Transformation, Viral; D043171:Chromosomal Instability / Q000235:genetics*; D005434:Flow Cytometry; D015967:Gene Expression Regulation, Viral / Q000502:physiology; D004854:Herpesvirus 4, Human / Q000502:physiology*; D006801:Humans; D016130:Immunophenotyping; D017403:In Situ Hybridization; D007621:Karyotyping; D009856:Oncogene Proteins, Viral / Q000235:genetics; D050725:Papillomavirus E7 Proteins; D012097:Repressor Proteins / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019098:Telomerase / Q000378:metabolism; D014161:Transduction, Genetic
chemical_list: D019013:CD40 Antigens; C068651:E6 protein, Human papillomavirus type 16; D009856:Oncogene Proteins, Viral; D050725:Papillomavirus E7 Proteins; D012097:Repressor Proteins; C059731:oncogene protein E7, Human papillomavirus type 16; D023201:CD40 Ligand; D019098:Telomerase