Prosurvival IL-7-Stimulated Weak Strength of mTORC1-S6K Controls T Cell Memory via Transcriptional FOXO1-TCF1-Id3 and Metabolic AMPKα1-ULK1-ATG7 Pathways

Aizhang Xu; Scot C Leary; Md Fahmid Islam; Zhaojia Wu; Kalpana Kalyanasundaram Bhanumathy; Anjuman Ara; Rajni Chibbar; Andrew Fleywald; Khawaja Ashfaque Ahmed; Jim Xiang

doi:10.4049/jimmunol.2100452

Prosurvival IL-7-Stimulated Weak Strength of mTORC1-S6K Controls T Cell Memory via Transcriptional FOXO1-TCF1-Id3 and Metabolic AMPKα1-ULK1-ATG7 Pathways

J Immunol. 2022 Jan 1;208(1):155-168. doi: 10.4049/jimmunol.2100452. Epub 2021 Dec 6.

Authors

Aizhang Xu^{1

2}, Scot C Leary³, Md Fahmid Islam^{1

2}, Zhaojia Wu^{1

2}, Kalpana Kalyanasundaram Bhanumathy^{1

2}, Anjuman Ara^{1

2}, Rajni Chibbar⁴, Andrew Fleywald⁴, Khawaja Ashfaque Ahmed⁵, Jim Xiang^{6

2}

Affiliations

¹ Cancer Research, Saskatchewan Cancer Agency, Saskatoon, Saskatchewan, Canada.
² Division of Oncology, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
³ Department of Biochemistry, Microbiology and Immunology, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
⁴ Department of Pathology and Laboratory Medicine, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada; and.
⁵ Department of Veterinary Pathology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
⁶ Cancer Research, Saskatchewan Cancer Agency, Saskatoon, Saskatchewan, Canada; jim.xiang@usask.ca.

PMID: 34872976
DOI: 10.4049/jimmunol.2100452

Abstract

CD8⁺ memory T (T_M) cells play a critical role in immune defense against infection. Two common γ-chain family cytokines, IL-2 and IL-7, although triggering the same mTORC1-S6K pathway, distinctly induce effector T (T_E) cells and T_M cells, respectively, but the underlying mechanism(s) remains elusive. In this study, we generated IL-7R-/and AMPKα1-knockout (KO)/OTI mice. By using genetic and pharmaceutical tools, we demonstrate that IL-7 deficiency represses expression of FOXO1, TCF1, p-AMPKα1 (T₁₇₂), and p-ULK1 (S₅₅₅) and abolishes T cell memory differentiation in IL-7R KO T cells after Listeria monocytogenesis rLmOVA infection. IL-2- and IL-7-stimulated strong and weak S6K (IL-2/S6K^strong and IL-7/S6K^weak) signals control short-lived IL-7R^-CD62L^-KLRG1⁺ T_E and long-term IL-7R⁺CD62L⁺KLRG1^- T_M cell formations, respectively. To assess underlying molecular pathway(s), we performed flow cytometry, Western blotting, confocal microscopy, and Seahorse assay analyses by using the IL-7/S6K^weak-stimulated T_M (IL-7/T_M) and the control IL-2/S6K^strong-stimulated T_E (IL-2/T_E) cells. We determine that the IL-7/S6K^weak signal activates transcriptional FOXO1, TCF1, and Id3 and metabolic p-AMPKα1, p-ULK1, and ATG7 molecules in IL-7/T_M cells. IL-7/T_M cells upregulate IL-7R and CD62L, promote mitochondria biogenesis and fatty acid oxidation metabolism, and show long-term cell survival and functional recall responses. Interestingly, AMPKα1 deficiency abolishes the AMPKα1 but maintains the FOXO1 pathway and induces a metabolic switch from fatty acid oxidation to glycolysis in AMPKα1 KO IL-7/T_M cells, leading to loss of cell survival and recall responses. Taken together, our data demonstrate that IL-7-stimulated weak strength of mTORC1-S6K signaling controls T cell memory via activation of transcriptional FOXO1-TCF1-Id3 and metabolic AMPKα1-ULK1-ATG7 pathways. This (to our knowledge) novel finding provides a new mechanism for a distinct IL-2/IL-7 stimulation model in T cell memory and greatly impacts vaccine development.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

AMP-Activated Protein Kinases / genetics
AMP-Activated Protein Kinases / metabolism*
Animals
Autophagy-Related Protein 7 / metabolism*
Autophagy-Related Protein-1 Homolog / metabolism*
CD8-Positive T-Lymphocytes / immunology*
Cell Differentiation
Cell Survival
Cells, Cultured
Cytotoxicity, Immunologic
Fatty Acids / metabolism
Forkhead Box Protein O1 / genetics
Forkhead Box Protein O1 / metabolism*
Gene Expression Regulation
Glycolysis
Hepatocyte Nuclear Factor 1-alpha / genetics
Hepatocyte Nuclear Factor 1-alpha / metabolism*
Immunologic Memory
Inhibitor of Differentiation Proteins / genetics
Inhibitor of Differentiation Proteins / metabolism*
Interleukin-7 / genetics
Interleukin-7 / metabolism*
Listeria monocytogenes / physiology*
Listeriosis / immunology*
Mechanistic Target of Rapamycin Complex 1 / metabolism*
Memory T Cells / immunology*
Mice
Mice, Inbred C57BL
Mice, Knockout
Receptors, Interleukin-7 / genetics
Ribosomal Protein S6 Kinases, 90-kDa / metabolism*
Signal Transduction
Vaccine Development

Substances

Atg7 protein, mouse
Fatty Acids
Forkhead Box Protein O1
Hepatocyte Nuclear Factor 1-alpha
Hnf1a protein, mouse
Inhibitor of Differentiation Proteins
Interleukin-7
Receptors, Interleukin-7
Idb3 protein, mouse
AMPK alpha1 subunit, mouse
Autophagy-Related Protein-1 Homolog
Mechanistic Target of Rapamycin Complex 1
Ribosomal Protein S6 Kinases, 90-kDa
Rps6ka1 protein, mouse
Ulk1 protein, mouse
AMP-Activated Protein Kinases
Autophagy-Related Protein 7

Grants and funding

419228/CIHR/Canada