Immunotherapeutic treatment strategies for glioblastoma (GBM) are under investigation in clinical trials. However, our understanding of the immune phenotype of GBM-infiltrating T cells (tumor-infiltrating lymphocytes; TILs) and changes during disease progression is limited. Deeper insight is urgently needed to therapeutically overcome tumor-induced immune exhaustion. We used flow cytometry and cytokine assays to profile TILs and peripheral blood lymphocytes (PBLs) from patients with GBM, comparing newly diagnosed or recurrent GBM to long-term survivors (LTS) and healthy donors. TCR sequencing was performed on paired samples of newly diagnosed and recurrent GBM. We identified a clear immune signature of exhaustion and clonal restriction in the TILs of patients with GBM. Exhaustion of CD8 TILs was defined by an increased prevalence of PD-1, CD39, Tim-3, CD45RO, HLA-DR marker expression, and exhibition of an effector-/transitional memory differentiation phenotype, whereas KLRG1 and CD57 were underrepresented. Immune signatures were similar in primary and recurrent tumors; however, restricted TCR repertoire clonality and a more activated memory phenotype were observed in TILs from recurrent tumors. Moreover, a reduced cytokine response to PHA stimulation in the blood compartment indicates a dysfunctional peripheral T-cell response in patients with GBM. LTS displayed a distinct profile, with abundant naïve and less exhausted CD8 T cells. TILs and PBLs exhibit contrasting immune profiles, with a distinct exhaustion signature present in TILs. While the exhaustion profiles of primary and recurrent GBM are comparable, TCR sequencing demonstrated a contracted repertoire in recurrent GBM, concomitant with an increased frequency of activated memory T cells in recurrent tumors. .

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

The recruitment and retention of Natural Killer (NK) cells in the liver are thought to play an important role during hepatotropic infections and liver cirrhosis. The aims of this study were to determine differences between liver-derived and peripheral blood-derived NK cells in the context of liver inflammation and cirrhosis. We conducted a prospective dual-center cross-sectional study in patients undergoing liver transplantation or tumor-free liver resections, in which both liver tissue and peripheral blood samples were obtained from each consenting study participants. Intrahepatic lymphocytes and PBMCs were stained, fixed and analyzed by flow cytometry. Our results showed that, within cirrhotic liver samples, intrahepatic NK cells were particularly enriched for CD49a+ NK cells when compared to tumor-free liver resection samples. CD49a+ liver-derived NK cells included populations of cells expressing CD25, CD34 and CXCR3. Moreover, CD49a+CD25+ liver-derived NK cells exhibited high proliferative capacity in vitro in response to low doses of IL-2. Our study identified a specific subset of CD49a+CD25+ NK cells in cirrhotic livers bearing functional features of proliferation.