Blobner Jens, Kilian Michael, Tan Chin Leng, Aslan Katrin, Sanghvi Khwab, Meyer Jochen, Fischer Manuel, Jähne Kristine, Breckwoldt Michael O, Sahm Felix, von Deimling Andreas, Bendszus Martin, Wick Wolfgang, Platten Michael, Green Edward, Bunse Lukas
DKTK Clinical Cooperation Unit Neuroimmunology and Brain Tumor Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
Department of Neurology, Medical Faculty Mannheim, Mannheim Center for Translational Neurosciences (MCTN), Heidelberg University, Heidelberg, Germany.
Neurooncol Adv. 2021 Sep 28;3(1):vdab147. doi: 10.1093/noajnl/vdab147. eCollection 2021 Jan-Dec.
Glioblastomas, the most common primary malignant brain tumors, are considered immunologically cold malignancies due to growth in an immune sanctuary site. While peptide vaccines have shown to generate intra-tumoral antigen-specific T cells, the identification of these tumor-specific T cells is challenging and requires detailed analyses of tumor tissue. Several studies have shown that CNS antigens may be transported via lymphatic drainage to cervical lymph nodes, where antigen-specific T-cell responses can be generated. Therefore, we investigated whether glioma-draining lymph nodes (TDLN) may constitute a reservoir of tumor-reactive T cells.
We addressed our hypothesis by flow cytometric analyses of chicken ovalbumin (OVA)-specific CD8 T cells as well as T-cell receptor beta (TCRβ) next-generation-sequencing (TCRβ-NGS) of T cells from tumor tissue, TDLN, spleen, and inguinal lymph nodes harvested from experimental mouse GL261 glioma models.
Longitudinal dextramer-based assessment of specific CD8 T cells from TDLN did not show tumor model antigen reactivity. Unbiased immunogenomic analysis revealed a low overlap of TCRβ sequences from glioma-infiltrating CD8 T cells between mice. Enrichment scores, calculated by the ratio of productive frequencies of the different TCRβ-CDR3 amino-acid (aa) rearrangements of CD8 T cells derived from tumor, TDLN, inguinal lymph nodes, and spleen demonstrated a higher proportion of tumor-associated TCR in the spleen compared to TDLN.
In experimental glioblastoma, our data did not provide evidence that glioma-draining cervical lymph nodes are a robust reservoir for spontaneous glioma-specific T cells highlighting the requirement for detailed analyses of glioma-infiltrating T cells for the discovery of tumor-specific TCR.
胶质母细胞瘤是最常见的原发性恶性脑肿瘤，由于生长于免疫庇护部位，被认为是免疫冷恶性肿瘤。虽然肽疫苗已显示可产生肿瘤内抗原特异性T细胞，但识别这些肿瘤特异性T细胞具有挑战性，需要对肿瘤组织进行详细分析。多项研究表明，中枢神经系统抗原可能通过淋巴引流转运至颈部淋巴结，在那里可产生抗原特异性T细胞反应。因此，我们研究了胶质瘤引流淋巴结（TDLN）是否可能构成肿瘤反应性T细胞的储存库。
我们通过对鸡卵清蛋白（OVA）特异性CD8 T细胞进行流式细胞术分析，以及对从实验性小鼠GL261胶质瘤模型收获的肿瘤组织、TDLN、脾脏和腹股沟淋巴结中的T细胞进行T细胞受体β（TCRβ）下一代测序（TCRβ-NGS），来验证我们的假设。
基于纵向前体药物的TDLN特异性CD8 T细胞评估未显示肿瘤模型抗原反应性。无偏倚免疫基因组分析显示，小鼠之间胶质瘤浸润性CD8 T细胞的TCRβ序列重叠度较低。通过计算来自肿瘤、TDLN、腹股沟淋巴结和脾脏的CD8 T细胞不同TCRβ-CDR3氨基酸（aa）重排的产生频率之比得出的富集分数表明，与TDLN相比，脾脏中肿瘤相关TCR的比例更高。
在实验性胶质母细胞瘤中，我们的数据未提供证据表明胶质瘤引流颈部淋巴结是自发胶质瘤特异性T细胞的强大储存库，这突出了对胶质瘤浸润性T细胞进行详细分析以发现肿瘤特异性TCR的必要性。
