Rubio Pérez, CarlotaTrincado Alonso, Juan Luis, 1987-Marchese, Domenica, 1986-Moutinho, CatiaRuiz, SaraParra Farré, GenísHeyn, HolgerSeoane, Joan2021-05-252021-05-252021Rubio-Perez C, Planas-Rigol E, Trincado JL, Bonfill-Teixidor E, Arias A, Marchese D et al. Immune cell profiling of the cerebrospinal fluid enables the characterization of the brain metastasis microenvironment. Nat Comm. 2021 Mar 8;12(1):1503. DOI: 10.1038/s41467-021-21789-x2041-1723http://hdl.handle.net/10230/47651Brain metastases are the most common tumor of the brain with a dismal prognosis. A fraction of patients with brain metastasis benefit from treatment with immune checkpoint inhibitors (ICI) and the degree and phenotype of the immune cell infiltration has been used to predict response to ICI. However, the anatomical location of brain lesions limits access to tumor material to characterize the immune phenotype. Here, we characterize immune cells present in brain lesions and matched cerebrospinal fluid (CSF) using single-cell RNA sequencing combined with T cell receptor genotyping. Tumor immune infiltration and specifically CD8+ T cell infiltration can be discerned through the analysis of the CSF. Consistently, identical T cell receptor clonotypes are detected in brain lesions and CSF, confirming cell exchange between these compartments. The analysis of immune cells of the CSF can provide a non-invasive alternative to predict the response to ICI, as well as identify the T cell receptor clonotypes present in brain metastasis.application/pdfeng© Carlota Rubio-Perez et al. 2021. This article is licensed under a Creative CommonsAttribution 4.0 International License, which permits use, sharing,adaptation, distribution and reproduction in any medium or format, as long as you giveappropriate credit to the original author(s) and the source, provide a link to the CreativeCommons license, and indicate if changes were made (https://creativecommons.org/licenses/by/4.0/)Sistema nerviós -- CàncerMetàstasiGenèticainfo:eu-repo/semantics/articlehttp://dx.doi.org/10.1038/s41467-021-21789-xinfo:eu-repo/semantics/openAccess