Expression and preliminary functional analysis of Siglec-F on mouse macrophages

Sialic acid-binding immunoglobulin-like lectin (Siglec)-F is a mouse functional paralog of human Siglec-8 that induces apoptosis in human eosinophils, and therefore may be useful as the basis of treatments for a variety of disorders associated with eosinophil hyperactivity, such as asthma. The expression pattern and functions of this protein in various cell types remain to be elucidated. The aim of this study was to determine the expression of Siglec-F on mouse macrophages by immunocytochemical staining, and also to investigate the effects of Siglec-F engagement by a Siglec-F antibody on phagocytic activity of macrophages. The results showed that Siglec-F expression was detected on mouse alveolar macrophages, but not on peritoneal macrophages. Furthermore, Siglec-F engagement did not affect the phagocytic activity of alveolar macrophages in the resting state or in the activated state following stimulation by the proinflammatory mediator tumor necrosis factor alpha (TNF-α) or lipopolysaccharide (LPS). Siglec-F expression on alveolar macrophages may be a result of adaptation. Macrophages actively regulate immune responses via production of cytokines. Therefore, further investigation of the effects of Siglec-F engagement on immune mediators or cytokines released by alveolar macrophages is required.     

制何首乌致小鼠网状内皮系统对血流中惰性炭粒的吞噬廓清能力的影响

目的：研究不同浓度的制何首乌水煎浓缩液致小鼠网状内皮系统对血流中惰性炭粒的吞噬廓清能力的影响,探讨制何首乌调整免疫的最佳浓度。方法：以小鼠为实验对象,用2g/mL（大剂量）、1g/mL（中剂量）、0.5g/mL（小剂量）三种不同浓度的制何首乌水煎液给小鼠灌胃12d,采用炭粒廓清法来检测RES吞噬异物的能力。结果：大剂量能明显增强RES吞噬功能,中、小剂量组无显著性差异。结论：制何首乌浓度为2g/ml时可显著提高实验小鼠非特异性免疫功能,具有扶正固本的作用。