Croft Priyakshi Kalita-de, Chittoory Haarika, Nguyen Tam H, Saunus Jodi M, Kim Woo Gyeong, McCart Reed Amy E, Lim Malcolm, De Luca Xavier M, Ferguson Kaltin, Niland Colleen, Mazzieri Roberta, Dolcetti Riccardo, Simpson Peter T, Lakhani Sunil R
UQ Centre for Clinical Research, Faculty of Medicine, University of Queensland, Herston, QLD 4029, Australia.
QIMR Berghofer Medical Research Institute, Herston, QLD 4029, Australia.
Biology (Basel). 2021 May 11;10(5):425. doi: 10.3390/biology10050425.
The heterogeneity of tumor infiltrating lymphocytes (TILs) is not well characterized in brain metastasis. To address this, we performed a targeted analysis of immune-cell subsets in brain metastasis tissues to test immunosuppressive routes involved in brain metastasis. We performed multiplex immunofluorescence (mIF), using commercially available validated antibodies on formalin-fixed paraffin embedded whole sections. We quantitated the subsets of immune-cells utilizing a targeted panel of proteins including PanCK, CD8, CD4, VISTA and IBA-1, and analyzed an average of 15,000 cells per sample. Classifying tumors as either high (>30%) or low (<30%) TILs, we found that increased TILs density correlated with survival. Phenotyping these TILs we found tumors with low TILs had significantly higher expression of the immune-checkpoint molecule VISTA in tumor cells ( < 0.01) as well as in their microenvironment ( < 0.001). Contrastingly, the tumors with high TILs displayed higher levels of microglia, as measured by IBA-1 expression. Low TILs-tumors displayed CD8+ T-cells that co-express VISTA ( < 0.01) significantly more compared to high TILs group, where CD8+cells significantly co-express IBA-11 ( < 0.05). These results were supported by RNA analysis of a publicly available, independent cohort. Our work contributes to a growing understanding of the immune surveillance escape routes active in brain metastasis.
肿瘤浸润淋巴细胞（TILs）的异质性在脑转移瘤中尚未得到充分表征。为了解决这一问题，我们对脑转移瘤组织中的免疫细胞亚群进行了靶向分析，以测试参与脑转移的免疫抑制途径。我们使用市售的经过验证的抗体，对福尔马林固定石蜡包埋的全切片进行多重免疫荧光（mIF）检测。我们利用包括PanCK、CD8、CD4、VISTA和IBA-1在内的一组靶向蛋白对免疫细胞亚群进行定量，每个样本平均分析15000个细胞。将肿瘤分为高（>30%）或低（<30%）TILs，我们发现TILs密度增加与生存率相关。对这些TILs进行表型分析时，我们发现低TILs肿瘤在肿瘤细胞（<0.01）及其微环境（<0.001）中免疫检查点分子VISTA的表达显著更高。相比之下，通过IBA-1表达测量，高TILs肿瘤显示出更高水平的小胶质细胞。与高TILs组相比，低TILs肿瘤中显著更多地显示出共表达VISTA的CD8+T细胞（<0.01），而在高TILs组中，CD8+细胞显著共表达IBA-11（<0.05）。这些结果得到了一个公开可用的独立队列的RNA分析的支持。我们的工作有助于加深对脑转移中活跃的免疫监视逃逸途径的理解。
