He Haiqi, MacKinnon Kathryn M, Genovese Kenneth J, Nerren Jessica R, Swaggerty Christina L, Nisbet David J, Kogut Michael H
Southern Plains Agricultural Research Center, USDA-ARS, 2881 F&B Road, College Station, TX 77845, USA.
Mol Immunol. 2009 Jul;46(11-12):2218-25. doi: 10.1016/j.molimm.2009.04.020. Epub 2009 May 14.
The scavenger receptors (SRs) comprise structurally and functionally divergent groups of cell surface and secreted proteins that play an important role in innate immune defenses. Searching translated chicken genomic databases revealed many proteins homologous to mammalian SRs. SR mediated immune functions (oxidative burst, degranulation, phagocytosis, nitric oxide (NO) production, and cytokine expression) were evaluated in chicken heterophils, peripheral blood mononuclear cells (PBMC), and a chicken macrophage cell line (HD11) using various SR class A and B ligands. Results showed that the SR-A ligands, fucoidan, poly(I) and poly(G), but not SR-B ligands, phosphatidylserine and LDL, stimulated dose-dependent NO production in HD11 cells. However, SR-A ligands failed to induce NO in chicken monocytes. Quantitative RT-PCR indicated that SR ligands differentially regulated the gene expression of cytokines and chemokine in HD11 cells with a strong up-regulation of the cytokines IL-1 beta and IL-6 and the chemokine MIP-1 beta, but had no effect on IL-4, IL-12, IFN-gamma, and IFN-beta. SR-B ligands did not alter expression of these genes. SR-A ligands had no stimulatory effect on functional response in heterophils. However, LDL, a SR-B ligand stimulated oxidative burst in both heterophils and PBMC. Additionally, results indicate that SRs are involved in bacterial binding in macrophages.
清道夫受体（SRs）由结构和功能各异的细胞表面及分泌蛋白组成，在天然免疫防御中发挥重要作用。通过搜索已翻译的鸡基因组数据库发现了许多与哺乳动物SRs同源的蛋白质。使用各种A类和B类SR配体，对鸡异嗜性粒细胞、外周血单核细胞（PBMC）和鸡巨噬细胞系（HD11）中的SR介导的免疫功能（氧化爆发、脱颗粒、吞噬作用、一氧化氮（NO）产生和细胞因子表达）进行了评估。结果表明，SR-A配体，即岩藻依聚糖、聚肌苷酸和聚鸟苷酸，而非SR-B配体磷脂酰丝氨酸和低密度脂蛋白（LDL），在HD11细胞中刺激了剂量依赖性的NO产生。然而，SR-A配体未能在鸡单核细胞中诱导NO产生。定量逆转录聚合酶链反应（RT-PCR）表明，SR配体在HD11细胞中差异调节细胞因子和趋化因子的基因表达，细胞因子白细胞介素-1β（IL-1β）和白细胞介素-6（IL-6）以及趋化因子巨噬细胞炎性蛋白-1β（MIP-1β）强烈上调，但对IL-4、IL-12、干扰素-γ（IFN-γ）和干扰素-β（IFN-β）没有影响。SR-B配体并未改变这些基因的表达。SR-A配体对异嗜性粒细胞的功能反应没有刺激作用。然而，SR-B配体LDL在异嗜性粒细胞和PBMC中均刺激了氧化爆发。此外，结果表明SRs参与巨噬细胞中的细菌结合。
