近日，美国国立卫生研究院国家过敏与传染病研究所Yasmine Belkaid及其团队的最新研究发现在饮食限制时，骨髓参与保护并优化免疫记忆。2019年8月22日，国际学术期刊《细胞》发表了这一成果。

研究人员发现在饮食限制（DR）的情况下，记忆T细胞在外周免疫器官中死亡但在骨髓（BM）中显著积累，并且在骨髓中记忆T细胞处在一种节能的状态。这种反应由糖皮质激素协调，并与骨髓腔室化重塑相关，其中包括T细胞归巢因子、红细胞和脂肪生成的增加。脂肪细胞以及CXCR4-CXCL12和S1P-S1P1R的相互作用有助于在饮食限制的情况下增强骨髓中T细胞的积累。在饮食限制时记忆T细胞向骨髓归巢有助于宿主对感染和肿瘤的抵抗。总之，这项工作揭示了宿主在营养缺乏的情况下维持和优化自身免疫记忆的基本策略，即利用“避风港”隔室内记忆T细胞库的重塑。

哺乳动物在食物供应波动的情况下进化。但是对于免疫系统是如何应对暂时的营养压力仍然知之甚少。

附：英文原文

Title: The Bone Marrow Protects and Optimizes Immunological Memory during Dietary Restriction

Author: Nicholas Collins,Seong-Ji Han,Michel Enamorado,Verena M. Link,Bonnie Huang,E. Ashley Moseman,Rigel J. Kishton,John P. Shannon,Dhaval Dixit,Susan R. Schwab,Heather D. Hickman,Nicholas P. Restifo,Dorian B. McGavern,Pamela L. Schwartzberg,Yasmine Belkaid

Issue&Volume: Volume 178 Issue 5

Abstract: Mammals evolved in the face of fluctuating food availability. How the immune system adapts to transient nutritional stress remains poorly understood. Here, we show that memory T cells collapsed in secondary lymphoid organs in the context of dietary restriction (DR) but dramatically accumulated within the bone marrow (BM), where they adopted a state associated with energy conservation. This response was coordinated by glucocorticoids and associated with a profound remodeling of the BM compartment, which included an increase in T cell homing factors, erythropoiesis, and adipogenesis. Adipocytes, as well as CXCR4-CXCL12 and S1P-S1P1R interactions, contributed to enhanced T cell accumulation in BM during DR. Memory T cell homing to BM during DR was associated with enhanced protection against infections and tumors. Together, this work uncovers a fundamental host strategy to sustain and optimize immunological memory during nutritional challenges that involved a temporal and spatial reorganization of the memory pool within “safe haven” compartments.

DOI: https://doi.org/10.1016/j.cell.2019.07.049

Source: https://www.cell.com/cell/fulltext/S0092-8674(19)30849-9