title: Rapid proliferation of activated lymph node CD4(+) T cells is achieved by greatly curtailing the duration of gap phases in cell cycle progression.
abstract: Peripheral T cells are in G0 phase and do not proliferate. When they encounter an antigen, they enter the cell cycle and proliferate in order to initiate an active immune response. Here, we have determined the first two cell cycle times of a leading population of CD4(+) T cells stimulated by PMA plus ionomycin in vitro. The first cell cycle began around 10 h after stimulation and took approximately 16 h. Surprisingly, the second cell cycle was extremely rapid and required only 6 h. T cells might have a unique regulatory mechanism to compensate for the shortage of the gap phases in cell cycle progression. This unique feature might be a basis for a quick immune response against pathogens, as it maximizes the rate of proliferation.
authors.affiliation: Laboratory of Human Molecular Genetics, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kakuma-machi, Kanazawa, 920-1192, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Mishima
authors.forename: Shoko
authors.initials: S
authors.lastname: Toda
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Ando
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Matsunaga
authors.forename: Manabu
authors.initials: M
authors.lastname: Inobe
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000502:physiology*; D002455:Cell Division; D049109:Cell Proliferation; D002478:Cells, Cultured; D008198:Lymph Nodes / Q000166:cytology; D008213:Lymphocyte Activation; D051379:Mice; D016192:Resting Phase, Cell Cycle