Tentative T Cells: Memory Cells Are Quick to Respond, but Slow to Divide

PLoS Pathogens

Boreth Eam¹  Jason K. Whitmire¹  J. Lindsay Whitton¹ 

[1] Molecular and Integrative Neurosciences Department, The Scripps Research Institute, La Jolla, California, United States of America

关键词: T cells;    Memory T cells;    Cell cycle;    cell division;    Cytotoxic T cells;    Spleen;    Flow cytometry;    Immune response;    T helper cells;   

DOI  :  10.1371/journal.ppat.1000041

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

T cell memory is a cornerstone of protective immunity, and is the key element in successful vaccination. Upon encountering the relevant pathogen, memory T cells are thought to initiate cell division much more rapidly than their naïve counterparts, and this is thought to confer a significant biological advantage upon an immune host. Here, we use traceable TCR-transgenic T cells to evaluate this proposed characteristic in CD4+ and CD8+ memory T cells. We find that, even in the presence of abundant antigen that was sufficient to induce in vivo IFNγ production by memory T cells, both memory and naïve T cells show an extended, and indistinguishable, delay in the onset of proliferation. Although memory cells can detect, and respond to, virus infection within a few hours, their proliferation did not begin until ∼3 days after infection, and occurred simultaneously in all anatomical compartments. Thereafter, cell division was extraordinarily rapid for both naïve and memory cells, with the latter showing a somewhat accelerated accumulation. We propose that, by permitting memory T cells to rapidly exert their effector functions while delaying the onset of their proliferation, evolution has provided a safeguard that balances the risk of infection against the consequences of severe T cell–mediated immunopathology.

【 授权许可】

CC BY