The role of macrophage migration inhibitory factor in endotoxin shock

巨噬细胞移动抑制因子（MIF）是第一个在凝集素激活的T淋巴细胞中发现的淋巴因子。它最初是通过其在体外阻止巨噬细胞迁移出毛细管的能力来鉴定的。人巨噬细胞移动抑制因子（MIF）的cDNA是从T淋巴细胞中克隆的，其蛋白质由114个氨基酸残基组成。MIF一直被认为只在活化的T淋巴细胞中表达，但最近的研究表明巨噬细胞也是MIF的主要来源，并发现了许多新的生物学特性。MIF是垂体前叶细胞在脂多糖刺激下分泌的主要蛋白质，在内毒素血症中起重要作用。此外，我们成功地结晶的人和大鼠MIF，并阐明了大鼠MIF的三级结构在2.2分辨率。此外，我们还鉴定了MIF在人皮肤和角膜中的表达，这表明MIF的表达不仅限于T淋巴细胞和巨噬细胞。

Macrophage migration inhibitory factor (MIF) was the first lymphokine discovered in lectin-activated T lymphocytes. It was originally identified by its ability to prevent the migration of macrophages out of a capillary tube in vitro. Human MIF cDNA was first cloned from T-lymphocytes, which revealed that the protein consists of 114 amino acid residues. MIF has long been considered to be expressed exclusively in activated T-lymphocytes ; however, a recent report indicated that macrophages are another majorsource of MIF.Various novel biological properties of MIF have been discovered. MIF is the major secretory protein released by anterior pituitary cells in response to lipopolysaccharide stimulation and is considered to play a central role in endotoxemia.During the course of our MIF study, we cloned rat MIF cDNA, and reported its physicochemical properties. We moreover succeeded in the crystallization of both human and rat MIFs, and elucidated the tertiary structure of rat MIF at 2.2 A resolution. Furthermore, we identified the expression of MIF in human skin and cornea, which indicated that expression of MIF was not limited to T lymphocytes and macrophages.