哺乳相关巨噬细胞存在于小鼠乳腺组织和母乳中，这一成果由瑞士苏黎世大学Melanie Greter小组经过不懈努力而取得。2023年6月19日出版的《自然—免疫学》杂志发表了这项成果。

研究人员发现了小鼠哺乳期间存在的巨噬细胞群。通过多参数流式细胞术和单细胞RNA测序，研究人员鉴定了哺乳期诱导的CD11c⁺ CX3CR1⁺ Dectin-1⁺巨噬细胞群（liMac），该群体与孕前存在的两个常驻F4/80^hi和F4/80^lo巨噬细胞亚群不同。LiMacs主要由单核细胞衍生而来，并伴随哺乳在原位增殖扩增。LiMac发育不依赖于IL-34，但需要CSF-1信号传导，并且部分依赖于微生物群。它们存在于肺泡基底细胞附近并外渗到母乳中。研究人员在母乳中发现了几个类似于liMac的巨噬细胞亚群。

总的来说，这些发现揭示了存在于哺乳期乳腺和乳汁中的独特巨噬细胞。

据介绍，巨噬细胞参与免疫防御、器官发生和组织稳态。巨噬细胞在乳腺发育、怀孕和哺乳后退化的不同阶段发挥功能。然而对乳腺巨噬细胞在哺乳期的功能知之甚少。

附：英文原文

Title: Lactation-associated macrophages exist in murine mammary tissue and human milk

Author: Cansever, Dilay, Petrova, Ekaterina, Krishnarajah, Sinduya, Mussak, Caroline, Welsh, Christina A., Mildenberger, Wiebke, Mulder, Kevin, Kreiner, Victor, Roussel, Elsa, Stifter, Sebastian A., Andreadou, Myrto, Zwicky, Pascale, Jurado, Nicole Puertas, Rehrauer, Hubert, Tan, Ge, Liu, Zhaoyuan, Blriot, Camille, Ronchi, Francesca, Macpherson, Andrew J., Ginhoux, Florent, Natalucci, Giancarlo, Becher, Burkhard, Greter, Melanie

Issue&Volume: 2023-06-19

Abstract: Macrophages are involved in immune defense, organogenesis and tissue homeostasis. Macrophages contribute to the different phases of mammary gland remodeling during development, pregnancy and involution postlactation. Less is known about the dynamics of mammary gland macrophages in the lactation stage. Here, we describe a macrophage population present during lactation in mice. By multiparameter flow cytometry and single-cell RNA sequencing, we identified a lactation-induced CD11c⁺CX3CR1⁺Dectin-1⁺ macrophage population (liMac) that was distinct from the two resident F4/80^hi and F4/80^lo macrophage subsets present pregestationally. LiMacs were predominantly monocyte-derived and expanded by proliferation in situ concomitant with nursing. LiMacs developed independently of IL-34, but required CSF-1 signaling and were partly microbiota-dependent. Locally, they resided adjacent to the basal cells of the alveoli and extravasated into the milk. We found several macrophage subsets in human milk that resembled liMacs. Collectively, these findings reveal the emergence of unique macrophages in the mammary gland and milk during lactation.

DOI: 10.1038/s41590-023-01530-0

Source: https://www.nature.com/articles/s41590-023-01530-0