The Bone Marrow Protects and Optimizes Immunological Memory during Dietary Restriction.
Nicholas Collins1, Seong-Ji Han1, Michel Enamorado1
1Metaorganism Immunity Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Cell
|August 24, 2019
Summary
Dietary restriction causes memory T cells to relocate to the bone marrow, conserving energy. This immune system adaptation enhances protection against infections and tumors during nutritional stress.
Area of Science:
- Immunology
- Nutritional Immunology
- Cellular Biology
Background:
- Mammalian immune systems face fluctuating food availability.
- Adaptation of the immune system to transient nutritional stress is poorly understood.
Purpose of the Study:
- To investigate how memory T cells adapt to dietary restriction.
- To understand the role of the bone marrow in immune memory during nutritional stress.
Main Methods:
- Studied memory T cell dynamics in secondary lymphoid organs and bone marrow under dietary restriction.
- Analyzed the role of glucocorticoids, adipocytes, and specific molecular interactions (CXCR4-CXCL12, S1P-S1P1R) in T cell homing.
- Assessed the impact of bone marrow T cell accumulation on protection against infections and tumors.
Main Results:
- Memory T cells decreased in secondary lymphoid organs but accumulated in the bone marrow during dietary restriction.
- Bone marrow T cells adopted an energy-conserving state.
- Dietary restriction induced bone marrow remodeling, including increased T cell homing factors, erythropoiesis, and adipogenesis.
- Adipocytes and specific molecular interactions facilitated T cell accumulation in the bone marrow.
- Bone marrow-homed memory T cells provided enhanced protection against infections and tumors.
Conclusions:
- The immune system reorganizes memory T cells into bone marrow "safe havens" during nutritional challenges.
- This spatial reorganization sustains immunological memory and enhances host defense under dietary restriction.
- Glucocorticoids play a key role in coordinating this adaptive immune response.
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