Search

Despite idelalisib approval in relapsed follicular lymphoma (FL), a complete characterization of the immunomodulatory consequences of phosphatidylinositol 3-kinase δ (PI3Kδ) inhibition, biomarkers of response, and potential combinatorial therapies in FL remain to be established. Using ex vivo cocultures of FL patient biopsies and follicular dendritic cells (FDCs) to mimic the germinal center (n = 42), we uncovered that PI3Kδ inhibition interferes with FDC-induced genes related to angiogenesis, extracellular matrix formation, and transendothelial migration in a subset of FL samples, defining an 18-gene signature fingerprint of idelalisib sensitivity. A common hallmark of idelalisib found in all FL cases was its interference with the CD40/CD40L pathway and induced proliferation, together with the downregulation of proteins crucial for B–T-cell synapses, leading to an inefficient cross talk between FL cells and the supportive T-follicular helper cells (TFH). Moreover, idelalisib downmodulates the chemokine CCL22, hampering the recruitment of TFH and immunosupressive T-regulatory cells to the FL niche, leading to a less supportive and tolerogenic immune microenvironment. Finally, using BH3 profiling, we uncovered that FL–FDC and FL–macrophage cocultures augment tumor addiction to BCL-XL and MCL-1 or BFL-1, respectively, limiting the cytotoxic activity of the BCL-2 inhibitor venetoclax. Idelalisib restored FL dependence on BCL-2 and venetoclax activity. In summary, idelalisib exhibits a patient-dependent activity toward angiogenesis and lymphoma dissemination. In all FL cases, idelalisib exerts a general reshaping of the FL immune microenvironment and restores dependence on BCL-2, predisposing FL to cell death, providing a mechanistic rationale for investigating the combination of PI3Kδ inhibitors and venetoclax in clinical trials.

Relapsed or refractory diffuse large B-cell lymphoma (DLBCL) cases have a poor outcome. Here we analysed clinico-biological features in 373 DLBCL patients homogeneously treated with rituximab, cyclophosphamide, doxorubicin, vincristine and prednisolone (R-CHOP), in order to identify variables associated with early failure to treatment (EF), defined as primary refractoriness or relapse within 12 months from diagnosis. In addition to clinical features, mutational status of 106 genes was studied by targeted next-generation sequencing in 111 cases, copy number alterations in 87, and gene expression profile (GEP) in 39. Ninety-seven cases (26%) were identified as EF and showed significantly shorter overall survival (OS). Patients with B symptoms, advanced stage, high levels of serum lactate dehydrogenase (LDH) or beta 2-microglobulin, low lymphocyte/monocyte ratio and higher Revised International Prognostic Index (R-IPI) scores, as well as those with BCL2 rearrangements more frequently showed EF, with R-IPI being the most important in logistic regression. Mutations in NOTCH2, gains in 5p15 center dot 33 (TERT), 12q13 (CDK2), 12q14 center dot 1 (CDK4) and 12q15 (MDM2) showed predictive importance for EF independently from R-IPI. GEP studies showed that EF cases were significantly enriched in sets related to cell cycle regulation and inflammatory response, while cases in response showed over-representation of gene sets related to extra-cellular matrix and tumour microenvironment.

Microenvironment contributes to follicular lymphoma (FL) pathogenesis and impacts survival with macrophages playing a controversial role. In the present study, using FL primary samples and HK follicular dendritic cells (FDC) to mimic the germinal center, together with mouse models, we have analyzed the three-way crosstalk of FL-FDC-macrophages and derived therapeutic opportunities. Ex vivo primary FL-FDC co-cultures (n = 19) and in vivo mouse co-xenografts demonstrated that FL-FDC crosstalk favors tumor growth and, via the secretion of CCL2 and CSF-1, promotes monocyte recruitment, differentiation, and polarization towards an M2-like protumoral phenotype. Moreover, FL-M2 co-cultures displayed enhanced angiogenesis, dissemination, and immunosuppression. Analysis of the CSF-1/CSF-1R pathway uncovered that CSF-1 was significantly higher in serum from grade 3A FL patients, and that high CSF-1R expression in FL biopsies correlated with grade 3A, reduced overall survival and risk of transformation. Furthermore, CSF-1R inhibition with pexidartinib (PLX3397) preferentially affected M2-macrophage viability and polarization program disrupting FL-M2 positive crosstalk. In vivo CSF1-R inhibition caused M2 reduction and repolarization towards M1 macrophages and antitumor effect cooperating with anti-CD20 rituximab. In summary, these results support the role of macrophages in FL pathogenesis and indicate that CSF-1R may be a relevant prognostic factor and a novel therapeutic target cooperating with anti-CD20 immunotherapy. Grants that contributed to this work included: Gilead Sciences Research Funded Agreement, Spanish Ministry of Economy and Competitiveness & European Regional Development Fund (ERDF) “Una manera de hacer Europa” for SAF2014/57708R and SAF2017/ 88275R to PP-G and MCC, RTI2018-094584-B-I00 to DC, CIBERONC (CB16/12/00334 and CB16/12/00225), and finally Generalitat de Catalunya support for AGAUR 2017SGR1009 to DC

This study was supported by the Ministerio de Economía y Competitividad, Grant n. SAF2015-67633-R ,and PI16/00420 which are part of Plan Nacional de I+D+I and are co-financed by the European Regional Development Fund (FEDER-“Una manera de hacer Europa”) and the CERCA program from Generalitat Catalunya. European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement n. 306240; Generalitat de Catalunya Suport Grups de Recerca AGAUR 2017-SGR1009, and Departament de Salut (SLT002-16-00350), Instituto de Salud Carlos III (ISCIII) International Cancer Genome Consortium for Chronic Lymphocytic Leukemia (ICGC-CLL Genome Project), and project PM15/00007, which is part of Plan Nacional de I+D+I and are co-financed by FEDER. NG is a recipient of a predoctoral fellowship from Agaur and EC is an Academia Researcher of the "Institució Catalana de Recerca i Estudis Avançats" (ICREA) of the Generalitat de Catalunya., Giménez, N., Martínez-Trillos, A., Montraveta, A., Lopez-Guerra, M., Rosich, L., Nadeu, F., Valero, J.G., Aymerich, M., Magnano, L., Rozman, M., Matutes, E., Delgado, J., Baumann, T., Gine, E., González, M., Alcoceba, M., Terol, M.J., Navarro, B., Colado, E., Payer, A.R., Puente, X.S., López-Otín, C., Lopez-Guillermo, A., Campo, E., Colomer, D., Villamor, N.