Identification of a tumor-reactive T-cell repertoire in the immune infiltrate of patients with resectable pancreatic ductal adenocarcinoma
The devastating prognosis of patients with resectable pancreatic ductal adenocarcinoma (PDA) presents an urgent need for the development of therapeutic strategies targeting disseminated tumor cells. Until now, T-cell therapy has been scarcely pursued in PDA, due to the prevailing view that it represents a poorly immunogenic tumor.We systematically analyzed T-cell infiltrates in tumor biopsies from 127 patients with resectable PDA by means of immunohistochemistry, flow cytometry, T-cell receptor (TCR) deep-sequencing and functional analysis ofProminent T-cell infiltrates, as well as tertiary lymphoid structures harboring proliferating T-cells, were detected in the vast majority of biopsies f…
Investigation of the immune infiltrate of melanoma metastases under immune checkpoint inhibition.
9570 Background: Tumor infiltrating lymphocytes (TIL) play a crucial role in the therapeutic impact of immune checkpoint blockers. Methods: We investigated metastases from 56 melanoma patients before and during treatment with immune checkpoint blockers (i) immunohistochemically, (ii) with TCR repertoire profiling and (iii) analysis of the transcriptome. The patients were treated with ipilimumab (n = 25) or pembrolizumab (n = 23) or ipilimumab/nivolumab (n = 7); half of them had a disease control, the other half progressed as best response to treatment. Results: In contrast to previous reports immunohistochemical analysis of the immune infiltrate revealed no significant difference in the nu…
Immunotherapy in gastrointestinal cancer: Recent results, current studies and future perspectives
The new therapeutic approach of using immune checkpoint inhibitors as anticancer agents is a landmark innovation. Early studies suggest that immune checkpoint inhibition might also be effective in patients with gastrointestinal cancer. To improve the efficacy of immunotherapy, different strategies are currently under evaluation. This review summarises the discussion during the European Organisation for Research and Treatment of Cancer Gastrointestinal Tract Cancer Translational Research Meeting in Mainz in November 2014 and provides an update on the most recent results of immune therapy in gastrointestinal cancers. Knowledge of potential relationships between tumour cells and their microenv…
NKp30 isoforms and NKp30 ligands are predictive biomarkers of response to imatinib mesylate in metastatic GIST patients
International audience; Despite effective targeted therapy acting on KIT and PDGFRA tyrosine kinases, gastrointestinal stromal tumors (GIST) escape treatment by acquiring mutations conveying resistance to imatinib mesylate (IM). Following the identification of NKp30-based immunosurveillance of GIST and the off-target effects of IM on NK cell functions, we investigated the predictive value of NKp30 isoforms and NKp30 soluble ligands in blood for the clinical response to IM. The relative expression and the proportions of NKp30 isoforms markedly impacted both event-free and overall survival, in two independent cohorts of metastatic GIST. Phenotypes based on disbalanced NKp30B/NKp30C ratio (Del…