Retinal pigment epithelium and microglia express the CD5 antigen-like protein, a novel autoantigen in age-related macular degeneration.
Retinal pigment epithelium and microglia express the CD5 antigen-like protein, a novel autoantigen in age-related macular degeneration.
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DOI：
10.1016/j.exer.2016.12.006
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发表时间：
2017-03
影响因子：
3.4
通讯作者：
Giorgianni F
中科院分区：
文献类型：
--
作者：
Iannaccone A;Hollingsworth TJ;Koirala D;New DD;Lenchik NI;Beranova-Giorgianni S;Gerling IC;Radic MZ;Giorgianni F
我们报告了一种新的自身抗原在人类黄斑组织中表达，确定后，初步的Western印迹（WB）为基础的筛选受试者的血清与年龄相关性黄斑变性（AMD）的循环自身抗体（AAbs）识别黄斑抗原。免疫沉淀，2D-凝胶电泳（2D-GE）和液相色谱-串联质谱（LC-MS/MS），直接酶联免疫吸附试验（ELISA），WB，免疫组织化学（IHC），人原代和ARPE-19永生化细胞培养物被用来表征这种新的抗原。AMD中约40 kDa的自身抗原被鉴定为清道夫受体CD 5抗原样蛋白（CD 5L），也称为巨噬细胞凋亡抑制剂（AIM）。免疫组化和WB法检测CD 5L/AIM在人RPE细胞中的定位，免疫组化法检测CD 5L/AIM在视网膜小胶质细胞中的定位。用重组CD 5L/AIM对AMD血清亚组进行的ELISA显示，AMD中的抗CD 5L/AIM反应性比对照血清高近2倍（p=0.000007）。反应性≥0.4与患AMD的几率高18倍相关（χ2=21.42，p=0.00063）。AMD血清中的循环CD 5L/AIM水平也比对照高近2倍（p=0.0052）。RPE和视网膜小胶质细胞中CD 5L/AIM表达的发现增加了这些细胞在视网膜中的已知免疫调节作用。识别CD 5L/AIM的AAbs的发现鉴定了一种可能的新的疾病生物标志物，并表明CD 5L/AIM在AMD原位发病机制中的潜在作用。通过抗CD 5L/AIM AAbs可能有助于AMD的发病机制进行了讨论。特别是，由于已知CD 5L刺激自噬并参与巨噬细胞中的氧化LDL摄取，我们提出抗CD 5L/AIM自身抗体可能在AMD中的玻璃疣生物发生和炎性RPE损伤中发挥作用。患有年龄相关性黄斑变性的受试者的血清表现出针对抗原的自身抗体，在2D凝胶和质谱实验之后，发现该抗原是CD 5样（CD 5L）蛋白，一种已知由巨噬细胞产生的分泌型清道夫受体。免疫组织化学实验表明，这种抗原也在整个细胞质中表达，并且更离散地，在人视网膜色素上皮细胞系的核水平（插图）上表达。共聚焦免疫组织化学显微镜实验还显示，人黄斑神经视网膜组织切片中的CD 5L反应性与已知的小胶质细胞特异性标记物Iba 1的反应性共定位。
We report on a novel autoantigen expressed in human macular tissues, identified following an initial Western blot (WB)-based screening of sera from subjects with age-related macular degeneration (AMD) for circulating auto-antibodies (AAbs) recognizing macular antigens. Immunoprecipitation, 2D-gel electrophoresis (2D-GE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS), direct enzyme-linked immunosorbent assays (ELISA), WBs, immunohistochemistry (IHC), human primary and ARPE-19 immortalized cell cultures were used to characterize this novel antigen. An approximately 40-kDa autoantigen in AMD was identified as the scavenger receptor CD5 antigen-like protein (CD5L), also known as apoptosis inhibitor of macrophage (AIM). CD5L/AIM was localized to human RPE by IHC and WB methods and to retinal microglial cells by IHC. ELISAs with recombinant CD5L/AIM on a subset of AMD sera showed a nearly 2-fold higher anti-CD5L/AIM reactivity in AMD vs. control sera (p=0.000007). Reactivity ≥0.4 was associated with 18-fold higher odds of having AMD (χ2=21.42, p=0.00063). Circulating CD5L/AIM levels were also nearly 2-fold higher in AMD sera compared to controls (p=0.0052). The discovery of CD5L/AIM expression in the RPE and in retinal microglial cells adds to the known immunomodulatory roles of these cells in the retina. The discovery of AAbs recognizing CD5L/AIM identifies a possible novel disease biomarker and suggest a potential role for CD5L/AIM in the pathogenesis of AMD in situ. The possible mechanisms via which anti-CD5L/AIM AAbs may contribute to AMD pathogenesis are discussed. In particular, since CD5L is known to stimulate autophagy and to participate in oxidized LDL uptake in macrophages, we propose that anti-CD5L/AIM auto-antibodies may play a role in drusen biogenesis and inflammatory RPE damage in AMD. Sera of subjects with age-related macular degeneration exhibit auto-antibodies directed against an antigen that, following 2D gel and mass spectrometry experiments, was discovered to be the CD5-like (CD5L) protein, a secreted scavenger receptor known to be produced by macrophages. Immunohistochemical experiments reveal that this antigen is expressed also throughout the cytoplasm and, more discretely, at the nuclear level (inset) by human retinal pigment epithelium cell lines. Confocal immunohistochemical microscopy experiments show also that CD5L reactivity in human macular neuroretinal tissue section colocalizes with reactivity for Iba1, a known microglial specific marker.
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影响因子：
4.4
作者：
Bian, Zong-Mei;Elner, Susan G.;Elner, Victor M.
通讯作者：
Elner, Victor M.
DOI：
10.1073/pnas.222551899
发表时间：
2002-11-12
影响因子：
11.1
作者：
Crabb, JW;Miyagi, M;Hollyfield, JG
通讯作者：
Hollyfield, JG
DOI：
10.1136/bjophthalmol-2011-300344
发表时间：
2011-12
期刊：
The British journal of ophthalmology
影响因子：
--
作者：
Curcio CA;Johnson M;Rudolf M;Huang JD
通讯作者：
Huang JD
DOI：
10.1038/nri3071
发表时间：
2011-10-10
期刊：
Nature reviews. Immunology
影响因子：
--
作者：
通讯作者：
--
DOI：
10.1073/pnas.0601552103
发表时间：
2006-09-05
影响因子：
11.1
作者：
Ebrahem, Quteba;Renganathan, Kutralanathan;Anand-Apte, Bela
通讯作者：
Anand-Apte, Bela