期刊
AMERICAN JOURNAL OF RESPIRATORY CELL AND MOLECULAR BIOLOGY
卷 35, 期 2, 页码 227-235出版社
AMER THORACIC SOC
DOI: 10.1165/rcmb.2005-0241OC
关键词
alveolar macrophage; inflammation; lung; monocyte; turnover
In the acute respiratory distress syndrome, recruitment of peripheral blood monocytes results in expansion of the total pool of resident alveolar macrophages. The fate of resident macrophages, or whether recruited monocytes are selectively eliminated from the alveolar airspace or differentiate into resident alveolar macrophages during the resolving phase of inflammation, has not been determined. Here, we analyzed the kinetics of resident and recruited macrophage turnover within the alveolar airspace of untreated and LIPS-challenged mice. Using bone marrow chimeric CD45.2 mice that were generated by lethal irradiation of CD45.2 alloantigen-expressing recipient mice and bone marrow transplantation from CD45.1 alloantigen-expressing donor mice, we employed a flow cytometric approach to distinguish recipient donor-type macrophages in bronchoalveolar lavage fluids. Our data show that resident alveolar macrophages of untreated chimeric CD45.2 mice are very slowly replaced by constitutively immigrating CD45.1 positive monocytes, resulting in a replacement rate of similar to 40% by 1 yr. In contrast, more than 85% of the resident CD45.2 positive alveolar and lung homogenate macrophages were exchanged by donor CD45.1-expressing macrophages within 2 mo after treatment with Escherichia calf endotoxin (LPS). Importantly, fluorescence-activated cell sorter analysis of increased annexin V binding to both recipient and donor-type macrophages revealed increased apoptotic events to underlie this endotoxin-driven inflammatory macrophage turnover. Collectively, the data show that under baseline conditions the alveolar macrophage turnover exhibits very slow kinetics, whereas acute lung inflammation in response to treatment with LIPS triggers a brisk acceleration of recruitment of monocytes that replace the resident alveolar macrophage population.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据