Transcriptional profiles of macrophages in resolving inflammation. Mus musculus

We have performed a comprehensive transcriptional analysis of specific monocyte and macrophage (MØ) subsets during an acute self-resolving inflammatory insult. Following initial induction of acute inflammation, tissue resident (Resident) MØ are rapidly ‘cleared’ from the inflammatory foci, only becoming recoverable as inflammation resolves. Monocytes are recruited to the inflammatory lesion where they differentiate into MØ. We term these monocyte-derived MØ ‘inflammation-associated’ to distinguish them from Resident MØ which are present throughout the inflammatory response and can renew during the resolution of inflammation by proliferation. Comparative analysis of the Mo and MØ populations (both ‘inflammation-associated’ and Resident MØ) identifies select genes expressed in subsets of ‘inflammation-associated’ and Resident MØ that play important roles in the resolution of inflammation and/or for immunity, including molecules involved in antigen presentation, cell cycle and others associated with ‘immaturity’ and MØ activation. Overall design: We purified monocyte and macrophage populations from the peritoneal cavity of C57BL/6 mice 4, 18, 72 and 168 hours after the induction of inflammation with intraperitoneal administration of zymosan (2x10^7 particles). We also purified tissue resident macrophages and Ly-6B+ bone marrow monocytes from naive mice as reference populations.