Real-time tracking of cell cycle progression during CD8+ effector and memory T-cell differentiation.

Ichiko Kinjyo,Osami Kanagawa,Lois L Cavanagh,Atsushi Miyawaki,Asako Sakaue-Sawano,Michio Tomura,Jim Qin,Wolfgang Weninger,Philip D Hodgkin,William Ritchie,Atsushi Doi,Sioh-Yang Tan,Paulus Mrass,Cameron J Wellard

doi:10.1038/ncomms7301

Abstract

The precise pathways of memory T-cell differentiation are incompletely understood. Here we exploit transgenic mice expressing fluorescent cell cycle indicators to longitudinally track the division dynamics of individual CD8+ T cells. During influenza virus infection in vivo, naive T cells enter a CD62Lintermediate state of fast proliferation, which continues for at least nine generations. At the peak of the anti-viral immune response, a subpopulation of these cells markedly reduces their cycling speed and acquires a CD62Lhi central memory cell phenotype. Construction of T-cell family division trees in vitro reveals two patterns of proliferation dynamics. While cells initially divide rapidly with moderate stochastic variations of cycling times after each generation, a slow-cycling subpopulation displaying a CD62Lhi memory phenotype appears after eight divisions. Phenotype and cell cycle duration are inherited by the progeny of slow cyclers. We propose that memory precursors cell-intrinsically modulate their proliferative activity to diversify differentiation pathways.

Highlights

The precise pathways of memory T-cell differentiation are incompletely understood
SIINFEKL peptide in vitro, we found that mKusabira-Orange 2 (mKO2) þþ naive cells became mKO2 þ mAG þ, mKO2 mAG þ or mKO2 mAG (double negative (DN)) after entry into the first cell cycle (Supplementary Fig. 1a; 20 h)
We found that the cells with longer mKO2 þ phases were smaller in cell size than fast-proliferating mAG þ cells, and were mostly CD62Lhi

Summary

Introduction

The precise pathways of memory T-cell differentiation are incompletely understood. At the peak of the anti-viral immune response, a subpopulation of these cells markedly reduces their cycling speed and acquires a CD62Lhi central memory cell phenotype. Construction of T-cell family division trees in vitro reveals two patterns of proliferation dynamics. While cells initially divide rapidly with moderate stochastic variations of cycling times after each generation, a slow-cycling subpopulation displaying a CD62Lhi memory phenotype appears after eight divisions. T cells initiate proliferation and differentiate into effector cells equipped with cytotoxic molecules and cytokines. Following eradication of foreign or tumour antigens, the effector population contracts and leaves behind a smaller pool of antigen-specific memory T cells that achieve quick recall responses upon antigen re-encounter[1,2,3,4]

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Conclusion