Open Access

Rapid proliferation of activated lymph node CD4+ T cells is achieved by greatly curtailing the duration of gap phases in cell cycle progression

  • Takuya Mishima1,
  • Shoko Toda1,
  • Yoshiaki Ando1,
  • Tsukasa Matsunaga1 and
  • Manabu Inobe1Email author
Cellular & Molecular Biology LettersAn International Journal201419:219

Received: 4 July 2014

Accepted: 7 November 2014

Published: 25 November 2014


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.


CD4+ T cellsCell cycleG0/G1 transitionGap phaseIn vitroPMA plus ionomycinProliferationT cell activation