KLRG1+ Effector CD8+ T Cells Lose KLRG1, Differentiate into All Memory T Cell Lineages, and Convey Enhanced Protective Immunity

Publication date: Available online 3 April 2018
Source:Immunity
Author(s): Dietmar Herndler-Brandstetter, Harumichi Ishigame, Ryo Shinnakasu, Valerie Plajer, Carmen Stecher, Jun Zhao, Melanie Lietzenmayer, Lina Kroehling, Akiko Takumi, Kohei Kometani, Takeshi Inoue, Yuval Kluger, Susan M. Kaech, Tomohiro Kurosaki, Takaharu Okada, Richard A. Flavell
Protective immunity against pathogens depends on the efficient generation of functionally diverse effector and memory T lymphocytes. However, whether plasticity during effector-to-memory CD8⁺ T cell differentiation affects memory lineage specification and functional versatility remains unclear. Using genetic fate mapping analysis of highly cytotoxic KLRG1⁺ effector CD8⁺ T cells, we demonstrated that KLRG1⁺ cells receiving intermediate amounts of activating and inflammatory signals downregulated KLRG1 during the contraction phase in a Bach2-dependent manner and differentiated into all memory T cell linages, including CX3CR1^int peripheral memory cells and tissue-resident memory cells. "ExKLRG1" memory cells retained high cytotoxic and proliferative capacity distinct from other populations, which contributed to effective anti-influenza and anti-tumor immunity. Our work demonstrates that developmental plasticity of KLRG1⁺ effector CD8⁺ T cells is important in promoting functionally versatile memory cells and long-term protective immunity.

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Teaser

Herndler-Brandstetter et al. demonstrate that KLRG1⁺IL-7Rα⁺ effector CD8⁺ T cells downregulate KLRG1 in a Bach2-dependent manner and differentiate into long-lived circulating and tissue-resident "exKLRG1" memory cells. Developmental plasticity of KLRG1⁺ effector cells therefore drives functional diversity within memory T cell lineages and promotes enhanced anti-influenza and anti-tumor immunity.


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