White adipose tissue bridges body organs and plays a fundamental role in host metabolism. To what extent adipose tissue also contributes to immune surveillance and long-term protective defense remains largely unknown. Here, we have shown that at steady state, white adipose tissue contained abundant memory lymphocyte populations. After infection, white adipose tissue accumulated large numbers of pathogen-specific memory T cells, including tissue-resident cells. Memory T cells in white adipose tissue expressed a distinct metabolic profile, and white adipose tissue from previously infected mice was sufficient to protect uninfected mice from lethal pathogen challenge. Induction of recall responses within white adipose tissue was associated with the collapse of lipid metabolism in favor of antimicrobial responses. Our results suggest that white adipose tissue represents a memory T cell reservoir that provides potent and rapid effector memory responses, positioning this compartment as a potential major contributor to immunological memory.

白色脂肪组织桥接人体器官，并在宿主新陈代谢中发挥重要作用。脂肪组织在多大程度上也有助于免疫监视，长期保护性防御仍然未知。在这里，我们已经表明，在稳态下，白色脂肪组织包含丰富的记忆淋巴细胞。感染后，白色脂肪组织积聚了大量病原体特异性记忆T细胞，包括组织驻留细胞。白色脂肪组织中的记忆T细胞表达独特的代谢谱，先前感染小鼠的白色脂肪组织足以保护未感染的小鼠免受致病性致病菌的攻击。在白色脂肪组织内诱发召回反应与脂质代谢的下降有关，有利于抗微生物反应。