Proximity ligation assay evaluates IDH1R132H presentation in gliomas
Proximity ligation assay evaluates IDH1R132H presentation in gliomas
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DOI：
10.1172/jci77780
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发表时间：
2015-02-01
影响因子：
15.9
通讯作者：
Platten, Michael
中科院分区：
文献类型：
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作者：
Bunse, Lukas;Schumacher, Theresa;Platten, Michael
为使靶向癌症疫苗有效，目标抗原需要由肿瘤基质中的靶细胞或抗原呈递细胞（APC）自然加工并呈递在主要组织相容性复合体（MHC）上。这些特性的存在通常是基于动物模型、体外对抗原过表达的APC的评估，或者对新鲜实体组织进行耗费材料的免疫沉淀分析来假定的。在此，我们评估了一种替代方法的使用，该方法利用邻近连接试验（PLA）来鉴定脑肿瘤患者石蜡包埋组织切片中一种受MHC II类限制的抗原的呈递情况。这种方法需要一种针对所呈递表位的特异性抗体。我们使用了一种特异性结合突变型异柠檬酸脱氢酶1（IDH1(R132H)）表位的抗体，该表位在神经胶质瘤和其他类型的肿瘤中经常表达。原位PLA显示，在IDH1(R132H)突变的神经胶质瘤组织中，IDH1(R132H)表位与MHC II类共定位。此外，PLA证明了含II类表位的黑色素瘤抗原纽约食管1和MHC II类之间的共定位。总体而言，我们的数据表明PLA可能是一种获取抗原是否在原位呈递信息的有用工具，并且该技术有可能指导使用抗原特异性癌症免疫疗法的临床研究。
For a targeted cancer vaccine to be effective, the antigen of interest needs to be naturally processed and presented on MHC by the target cell or an antigen-presenting cell (APC) in the tumor stroma. The presence of these characteristics is often assumed based on animal models, evaluation of antigen-overexpressing APCs in vitro, or assays of material-consuming immune precipitation from fresh solid tissue. Here, we evaluated the use of an alternative approach that uses the proximity ligation assay (PLA) to identify the presentation of an MHC class II-restricted antigen in paraffin-embedded tissue sections from patients with brain tumors. This approach required a specific antibody directed against the epitope that was presented. We used an antibody that specifically binds an epitope of mutated isocitrate dehydrogenase type 1 (IDH1(R132H)), which is frequently expressed in gliomas and other types of tumors. In situ PLA showed that the IDH1(R132H) epitope colocalizes with MHC class II in IDH1(R132H)-mutated glioma tissue. Moreover, PLA demonstrated colocalization between the class II epitope-containing melanoma antigen New York esophageal 1 and MK class II. Collectively, our data suggest that PLA may be a useful tool to acquire information on whether an antigen is presented in situ, and this technique has potential to guide clinical studies that use antigen-specific cancer immunotherapy.