Identification and characterization of an alternatively spliced isoform of mouse Langerin/CD207
Identification and characterization of an alternatively spliced isoform of mouse Langerin/CD207
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DOI：
10.1111/j.0022-202x.2004.22718.x
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发表时间：
2004-07-01
影响因子：
6.5
通讯作者：
Udey, MC
中科院分区：
文献类型：
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作者：
Riedl, E;Tada, Y;Udey, MC
人类朗格蛋白(CD207)是一种新的朗格汉斯细胞(LC)限制性C型凝集素，可能参与抗原的识别和摄取，最近被鉴定为小鼠同源物。在本研究中，我们通过差减克隆和快速扩增cDNAEnds(RACE)的方法从小鼠胚胎皮肤来源的树突状细胞(FSDDC)中分离到小鼠朗格林基因。通过RT-PCR在FSDDC和表皮LC的RNA中检测到一个缺失胞外Neck结构域的小鼠Langerin选择性剪接变异体(DeltaE3Langerin)。在体外培养的FSDDC和表皮LC中均表达全长和DeltaE3Langerin mRNA，但组织表达并不局限于皮肤。用编码表位标记的Langerin和DeltaE3Langerin的cDNA转染成纤维细胞，可以检测到小鼠Langerin蛋白的异构体。重组DeltaE3Langerin蛋白在转基因成纤维细胞中定位于含转铁蛋白的区段。全长小鼠Langerin结合甘露聚糖，而DeltaE3Langerin和缺少Neck结构域的可溶性细菌重组Langerin蛋白没有。转染鼠Langerin基因的成纤维细胞含有典型的Birbeck颗粒(BG)和核小管，而DeltaE3Langerin基因不能诱导成纤维细胞形成BG和核小管。发育调节的Langerin异构体的表达提供了一种调节Langerin参与抗原摄取和处理的机制。
The mouse homologue of human Langerin (CD207), a novel Langerhans cells (LC)-restricted C-type lectin that likely participates in antigen recognition and uptake, has been recently identified. In this study, we isolated the mouse Langerin cDNA from murine fetal skin-derived dendritic cells (FSDDC) by subtractive cloning and rapid amplification of cDNA ends (RACE). An alternatively spliced variant of mouse Langerin that lacked the extracellular neck domain (DeltaE3Langerin) was detected in RNA derived from FSDDC and epidermal LC by RT-PCR. In vitro-generated FSDDC and epidermal LC expressed both full-length and DeltaE3Langerin mRNA, but tissue expression was not restricted to skin. Mouse Langerin protein isoforms were readily detected in fibroblasts transfected with cDNAs encoding epitope-tagged Langerin and DeltaE3Langerin. Recombinant DeltaE3Langerin protein localized with transferrin-containing compartments in transfected fibroblasts. Full-length mouse Langerin-bound mannan, whereas DeltaE3Langerin and soluble bacterial recombinant Langerin protein lacking the neck domain did not. Fibroblasts transfected with mouse Langerin cDNA contained typical Birbeck granules (BG) and cored tubules, whereas DeltaE3Langerin cDNA did not induce BG or cored tubule formation in transfected fibroblasts. Developmentally regulated expression of Langerin isoforms provides a mechanism by which Langerin involvement in antigen uptake and processing could be regulated.