Effect of clodronate-encapsulated liposome administration on mononuclear phagocyte progenitors

2015 Fiscal Year Final Research Report

• Project/Area Number: 26670238
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Immunology
• Research Institution: Yokohama City University
• Principal Investigator: TAMURA Tomohiko 横浜市立大学, 医学(系)研究科(研究院), 教授 (50285144)
• Co-Investigator(Kenkyū-buntansha): KUROTAKI Daisuke 横浜市立大学, 医学部, 助教 (10568455)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: 単核貪食細胞 / 貪食 / 前駆細胞 / 分化

Outline of Final Research Achievements

Monocytes/macrophages and dendritic cells are mononuclear phagocytes (Mph), which are important for host defense against pathogens and tissue homeostasis. In this study, we unexpectedly found that the administration of clodronate-encapsulated liposomes (CLL) causes depletion of not only monocytes/macrophages but also Mph progenitors. These progenitors, however, did not incorporate fluorescent-labeled liposomes, suggesting that the disappearance of the progenitors was caused by an indirect effect of CLL injection. We found that the level of a cytokine important for Mph growth and differentiation was significantly elevated in the blood of CLL-injected mice. This promoted the differentiation of Mph progenitors, causing their transient depletion. These results suggest that Mph progenitors sense and respond to the decrease in mature Mph counts via the cytokine to maintain the Mph system.

Free Research Field

血液学、免疫学、分子生物学