Avian Immunobiology Laboratory, Department of Animal and Poultry Sciences, Virginia Tech, 3170 Litton-Reaves, Blacksburg, VA 24061, United States.
Dev Comp Immunol. 2010 Sep;34(9):1021-32. doi: 10.1016/j.dci.2010.05.005. Epub 2010 May 20.
Macrophage migration inhibitory factor (MIF) is recognized as a soluble factor produced by sensitized T lymphocytes and inhibits the random migration of macrophages. Recent studies have revealed a more prominent role for MIF as a multi-functional cytokine mediating both innate and adaptive immune responses. This study describes the cloning and functional characterization of avian MIF in an effort to better understand its role in innate and adaptive immunity, and potential use in poultry health applications. The full-length avian MIF gene was amplified from stimulated chicken lymphocytes and cloned into a prokaryotic expression vector. The confirmed 115 amino acid sequence of avian MIF has 71% identity with human and murine MIF. The bacterially expressed avian recombinant MIF (rChMIF) was purified, followed by endotoxin removal, and then tested by chemotactic assay and quantitative real-time PCR (qRT-PCR). Diff-Quick staining revealed a substantial decrease in migration of macrophages in the presence of 0.01microg/ml rChMIF. qRT-PCR analysis revealed that the presence of rChMIF enhanced levels of IL-1beta and iNOS during PBMCs stimulation with LPS. Additionally, the Con A-stimulated lymphocytes showed enhanced interferon (IFN)-gamma and IL-2 transcripts in the presence of rChMIF. Interestingly, addition of rChMIF to the stimulated PBMCs, in the presence of lymphocytes, showed anti-inflammatory function of rChMIF. To our knowledge, this study represents the first report for the functional characterization of avian MIF, demonstrating the inhibition of macrophage migration, similar to mammalian MIF, and the mediation of inflammatory responses during antigenic stimulation.
巨噬细胞移动抑制因子（MIF）被认为是致敏 T 淋巴细胞产生的一种可溶性因子，可抑制巨噬细胞的随机迁移。最近的研究揭示了 MIF 作为一种多功能细胞因子的更突出作用，可介导先天和适应性免疫反应。本研究描述了禽类 MIF 的克隆和功能特征，以期更好地了解其在先天和适应性免疫中的作用及其在禽类健康应用中的潜在用途。从刺激的鸡淋巴细胞中扩增了全长禽类 MIF 基因，并将其克隆到原核表达载体中。确认的禽类 MIF 115 个氨基酸序列与人源和鼠源 MIF 具有 71%的同源性。经细菌表达的禽类重组 MIF（rChMIF）经纯化、内毒素去除后，通过趋化试验和定量实时 PCR（qRT-PCR）进行测试。Diff-Quick 染色显示，在 0.01μg/ml rChMIF 存在的情况下，巨噬细胞的迁移明显减少。qRT-PCR 分析显示，rChMIF 的存在增强了 PBMCs 与 LPS 刺激时 IL-1β和 iNOS 的水平。此外，rChMIF 存在时，Con A 刺激的淋巴细胞显示出 IFN-γ和 IL-2 转录本的增强。有趣的是，在淋巴细胞存在的情况下，向刺激的 PBMCs 中添加 rChMIF 显示出 rChMIF 的抗炎功能。据我们所知，本研究代表了禽类 MIF 功能特征的首次报道，证明了其抑制巨噬细胞迁移的功能与哺乳动物 MIF 相似，并在抗原刺激期间介导炎症反应。
