Kunert Andre, van Brakel Mandy, van Steenbergen-Langeveld Sabine, da Silva Marvin, Coulie Pierre G, Lamers Cor, Sleijfer Stefan, Debets Reno
Laboratory of Tumor Immunology, Department of Medical Oncology, Erasmus MC Cancer Institute, 3015 CN Rotterdam, the Netherlands; and
Laboratory of Tumor Immunology, Department of Medical Oncology, Erasmus MC Cancer Institute, 3015 CN Rotterdam, the Netherlands; and.
J Immunol. 2016 Sep 15;197(6):2541-52. doi: 10.4049/jimmunol.1502024. Epub 2016 Aug 3.
Adoptive T cell therapy has shown significant clinical success for patients with advanced melanoma and other tumors. Further development of T cell therapy requires improved strategies to select effective, yet nonself-reactive, TCRs. In this study, we isolated 10 TCR sequences against four MAGE-C2 (MC2) epitopes from melanoma patients who showed clinical responses following vaccination that were accompanied by significant frequencies of anti-MC2 CD8 T cells in blood and tumor without apparent side effects. We introduced these TCRs into T cells, pretreated tumor cells of different histological origins with the epigenetic drugs azacytidine and valproate, and tested tumor and self-reactivities of these TCRs. Pretreatment of tumor cells upregulated MC2 gene expression and enhanced recognition by T cells. In contrast, a panel of normal cell types did not express MC2 mRNA, and similar pretreatment did not result in recognition by MC2-directed T cells. Interestingly, the expression levels of MC2, but not those of CD80, CD86, or programmed death-ligand 1 or 2, correlated with T cell responsiveness. One of the tested TCRs consistently recognized pretreated MC2(+) cell lines from melanoma, head and neck, bladder, and triple-negative breast cancers but showed no response to MHC-eluted peptides or peptides highly similar to MC2. We conclude that targeting MC2 Ag, combined with epigenetic drug-enhanced antigenicity, allows for significant and tumor-selective T cell responses.
过继性T细胞疗法已在晚期黑色素瘤和其他肿瘤患者中显示出显著的临床成效。T细胞疗法的进一步发展需要改进策略，以选择有效且不具有自身反应性的TCR。在本研究中，我们从黑色素瘤患者中分离出10条针对四种MAGE-C2（MC2）表位的TCR序列，这些患者在接种疫苗后出现临床反应，同时血液和肿瘤中抗MC2 CD8 T细胞频率显著升高且无明显副作用。我们将这些TCR导入T细胞，用表观遗传药物阿扎胞苷和丙戊酸预处理不同组织学来源的肿瘤细胞，并测试这些TCR的肿瘤反应性和自身反应性。肿瘤细胞的预处理上调了MC2基因表达并增强了T细胞的识别。相比之下，一组正常细胞类型不表达MC2 mRNA，类似的预处理也不会导致MC2定向T细胞的识别。有趣的是，MC2的表达水平与T细胞反应性相关，而CD80、CD86、程序性死亡配体1或2的表达水平则不然。所测试的TCR之一始终能识别来自黑色素瘤、头颈癌、膀胱癌和三阴性乳腺癌的预处理MC2(+)细胞系，但对MHC洗脱肽或与MC2高度相似的肽无反应。我们得出结论，靶向MC2抗原并结合表观遗传药物增强的抗原性，可引发显著且具有肿瘤选择性的T细胞反应。
