IRES-dependent translation of the long non coding RNA meloe in melanoma cells produces the most immunogenic MELOE antigens.
IRES-dependent translation of the long non coding RNA meloe in melanoma cells produces the most immunogenic MELOE antigens.
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DOI：
10.18632/oncotarget.10923
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发表时间：
2016-09-13
期刊：
影响因子：
--
通讯作者：
Lang F
中科院分区：
文献类型：
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作者：
Charpentier M;Croyal M;Carbonnelle D;Fortun A;Florenceau L;Rabu C;Krempf M;Labarrière N;Lang F
meloe -1和meloe -2是参与T细胞免疫监视的两种高度特异性黑色素瘤抗原，它们是由ires依赖的长“非编码”和多顺反子RNA， meloe的翻译产生的。在本研究中，我们记录了位于meloe 5 '区域的另一个ORF， meloe -3的表达。来自体外翻译实验和双电子载体转染黑色素瘤细胞的数据表明，MELOE-3仅通过经典的帽依赖途径翻译。使用灵敏的串联质谱技术，我们在黑色素瘤细胞和正常黑色素细胞的总裂解物中检测到MELOE-3的存在。这与我们之前在黑色素瘤中观察到的MELOE-1和MELOE-2的限制性表达形成对比。此外，用来自MELOE-1或MELOE-3的重叠肽体外刺激6个健康供体的PBMC，发现与MELOE-1的丰富库相比，MELOE-3特异性T细胞库非常少。MELOE-3较差的免疫原性及其在黑素细胞中的表达与对生理表达蛋白的免疫耐受一致。相反，ires依赖性mele -1的黑色素瘤限制性表达可能解释了其高免疫原性。总之，在MELOE家族中，ires依赖性抗原代表了黑色素瘤免疫治疗的最佳T细胞靶点。
MELOE-1 and MELOE-2, two highly specific melanoma antigens involved in T cell immunosurveillance are produced by IRES-dependent translation of the long « non coding » and polycistronic RNA, meloe. In the present study, we document the expression of an additional ORF, MELOE-3, located in the 5′ region of meloe. Data from in vitro translation experiments and transfection of melanoma cells with bicistronic vectors documented that MELOE-3 is exclusively translated by the classical cap-dependent pathway. Using a sensitive tandem mass spectrometry technique, we detected the presence of MELOE-3 in total lysates of both melanoma cells and normal melanocytes. This contrasts with our previous observation of the melanoma-restricted expression of MELOE-1 and MELOE-2. Furthermore, in vitro stimulation of PBMC from 6 healthy donors with overlapping peptides from MELOE-1 or MELOE-3 revealed a very scarce MELOE-3 specific T cell repertoire as compared to the abundant repertoire observed against MELOE-1. The poor immunogenicity of MELOE-3 and its expression in melanocytes is consistent with an immune tolerance towards a physiologically expressed protein. In contrast, melanoma-restricted expression of IRES-dependent MELOE-1 may explain its high immunogenicity. In conclusion, within the MELOE family, IRES-dependent antigens represent the best T cell targets for immunotherapy of melanoma.