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716 Lymphoma-Derived IL-10 Is a Key Immunomodulatory Factor at the Tumor Microenvironment of Activated B-Cell Diffuse Large B-Cell Lymphoma and Influences In Vivo Responses to ImmunotherapyClinically Relevant Abstract

Program: Oral and Poster Abstracts
Type: Oral
Session: 603. Lymphoid Oncogenesis: Basic: Epigenetic, Immune-Related, and Signaling Mechanisms of Lymphomagenesis
Hematology Disease Topics & Pathways:
Biological therapies, Fundamental Science, Research, Lymphomas, non-Hodgkin lymphoma, Diseases, immune mechanism, Immunotherapy, Therapies, Lymphoid Malignancies, Biological Processes, pathogenesis
Monday, December 11, 2023: 10:45 AM

Marcos Garcia-Lacarte, PhD1,2*, Sara C Grijalba1,2*, Francisco J Novo, MD PhD1,2*, Adrián Arnaiz-Leché1,2*, Javier Melchor, PhD1,3*, Marién Pascual, PhD3*, Enrique Goñi2,4*, Sandra Morales-Sánchez5*, María A Burrell, PhD5*, Oscar Blanco, MD PhD6*, Iñigo Clemente-Larramendi1*, Jose A Martinez-Climent, MD PhD2,3,7, Noelia Casares, PhD2,8*, Juan J Lasarte, PhD2,8*, Pablo Sarobe, PhD2,8,9*, Miguel Canales2,10* and Sergio Roa, PhD1,2,7*

1Department of Biochemistry and Genetics, University of Navarra, Pamplona, Spain
2Navarra Institute for Health Research (IdiSNA), Pamplona, Spain
3Hemato-Oncology Program, Cima Universidad de Navarra, Pamplona, Spain
4Computational Biology Program, Cima Universidad de Navarra, Pamplona, Spain
5Department of Pathology, Anatomy and Physiology, University of Navarra, Pamplona, Spain
6Institute of Biomedical Research of Salamanca (IBSAL), Department of Pathology, University of Salamanca, Salamanca, Spain
7Instituto de Salud Carlos III, Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Madrid, Spain
8Immunology and Immunotherapy Program, Cima Universidad de Navarra, Pamplona, Spain
9Instituto de Salud Carlos III, Centro de Investigación Biomédica en Red de Enfermedades hepáticas y digestivas (CIBERehd), Madrid, Spain
10Clínica Universidad de Navarra Cancer Center (CCUN), Pamplona, Spain

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of aggressive non-Hodgkin’s lymphoma with ~40% of patients experiencing refractory or relapsed disease to R-CHOP immunochemotherapy. These higher risk patients often exhibit gene expression profiles that resemble a late germinal center-derived activated B-cell (ABC) phenotype, where diverse specific mutations in genes along BCR and TLR signaling pathways converge into constitutive activation of the NF-κB pathway. Identification of factors that contribute to the survival of malignant ABC-DLBCL cells is crucial for designing specific interventions. In this setting, previous in vitro studies in DLBCL cell lines have evidenced that IL-10 is a direct target of NF-κB signaling that sustains lymphoma cell survival by an auto-stimulatory loop via STAT3 signaling. However, the action of IL-10 could be more complex within the lymphoma microenvironment, as IL-10 can have both stimulatory and inhibitory effects depending on the cellular source of IL-10, the timing of its secretion, and the type of immune cells that receives signals via IL-10 receptor (IL-10R). To explore in vivo the relevance of lymphoma-derived IL-10, we have generated a novel quintuple transgenic mouse model that we call pBIC10, after crossing our previous ABC-DLBCL-like pBIC mice carrying constitutive NF-κB signaling (Pascual et al., Blood 2019) to mice with a floxed Il10 gene for conditional knock-out of IL-10 specifically in malignant ABC-DLBCL cells. As expected, increased intracellular IL-10 signaling was detected in primary murine DLBCL cells from pBIC mice but not in IL-10 deficient pBIC10 mice, which promoted lymphoma cell survival ex vivo as revealed by perturbation studies of the IL-10/JAK1/STAT3 autocrine loop with blocking monoclonal antibodies or selected inhibitors. However, in vivo genetic deletion of lymphoma-derived IL-10 did not offer improved overall survival but, on the contrary, notably accelerated DLBCL progression in pBIC10 mice (Figure 1A, left). A comprehensive integration of multiparametric flow cytometry and transcriptomic analyses using bulk and single-cell RNA-seq of lymphoma cells and the tumor microenvironment coupled with BCR- and TCR-seq, identified lymphoma-derived IL-10 as a key immunomodulator of the DLBCL microenvironment, including unexpected protective paracrine functions in the progression of DLBCL. By comparing IL-10-proficient (pBIC) and -deficient (pBIC10) murine DLBCL models, we observed a multifaceted role of IL-10 produced by DLBCL cells, enabling immune-effector processes (facilitating immune chemotaxis, antigen presentation, and IFNγ responses) that yielded higher percentages of long-lived stem-like CD8+TCF-1+PD-1lo/int T cells and dendritic cells, while restraining PD-1/LAG3-driven T-cell exhaustion and reducing immunosuppression by CD4+CD25+FOXP3+ regulatory T (Treg) cells. Thus, depletion of lymphoma-derived IL-10 decreased T-cell cytotoxicity and increased Treg-driven immunosuppression, which collectively accelerated lymphoma development. Consequently, T-cell targeted immune-checkpoint therapy (with anti-PD-1 antibodies) was effective only in IL-10-proficient DLBCL but not in IL-10-deficient pBIC10 mice (Figure 1A, right). Further comparative studies between pBIC and pBIC10 mice showed that tumor vascularization and expression of B-cell calcium channels, which have been previously associated with sensitivity to rituximab, were counteracted by lymphoma-derived IL-10. Accordingly, anti-CD20-based targeting of lymphoma cells (with rituximab surrogate antibodies) showed best in vivo responses in IL-10-deficient DLBCL mice with respect to pBIC mice (Figure 1A, right). Consistent with this preclinical data, analyses of transcriptional IL-10-associated hallmarks to stratify DLBCL patients (Schmitz et al., NEJM 2018) identified better clinical responses to R-CHOP in patients with pBIC10-like DLBCL phenotype (Figure 1B). Collectively, our study provides new functional and mechanistic insights into the role of lymphoma-derived IL-10 in the pathogenesis of DLBCL and the restraint of an immunosuppressed tumor microenvironment, which holds predictive potential as a biomarker for immunotherapy responses in DLBCL.

Disclosures: Martinez-Climent: Priothera: Research Funding; Roche-Genentech: Research Funding; Janssen: Research Funding; BMS-Celgene: Research Funding; Palleon: Research Funding; AstraZeneca: Research Funding. Canales: Takeda: Consultancy; Roche: Consultancy; BMS: Consultancy; Incyte: Speakers Bureau; Janssen: Consultancy; Karyopharm: Consultancy; Kite: Consultancy; Kyowa: Consultancy; Lilly: Consultancy; Kite: Speakers Bureau; Beigene: Consultancy; Janssen: Speakers Bureau; Incyte: Consultancy; Kyowa: Speakers Bureau; Roche: Speakers Bureau; Takeda: Speakers Bureau. Roa: Roche-Genentech: Research Funding.

*signifies non-member of ASH