Emerging preclinical evidence challenges the long-standing assumption that Interleukin-1β (IL-1β) uniformly promotes non–small cell lung cancer (NSCLC). We show that, in the context of chemo-immunotherapy, IL-1β enhances anti-tumor immunity by inducing tumor-cell CXCL10 expression and recruiting CD8+ T cells, thereby sensitizing “cold” tumors to treatment. These findings contrast sharply with the failure of multiple CANOPY trials targeting IL-1β, suggesting that blockade may be effective only in prevention or early carcinogenesis. Instead, controlled IL-1β activation, guided by biomarkers and combined with chemotherapy plus PD-1 blockade, may represent a promising strategy to overcome resistance in established NSCLC.

Interleukin (IL)-1β is known to promote lung cancer growth in both humans and mice. However, in the context of the current standard of care, which includes chemotherapy and immune checkpoint inhibitors, IL-1β can overcome resistance.

IL-1β belongs to the IL-1 family and has the particularity to need to be cleaved by caspase-1 to be active. Once processed, IL-1β is secreted and binds to IL-1R1 on target cells, leading to the transcription of specific genes. Within a tumor, IL-1β is produced and secreted by various cell types, such as immune cells, fibroblasts or cancer cells and has pleiotropic effects on immune cells, angiogenesis, cancer cell proliferation, migration and metastasis. Thus, depending on the cancer type, the treatments or the tumor microenvironment (TME), IL-1β has opposite effects on cancer progression, thus raising the question of inducing or inhibiting IL-1β. Here, we will analyze the impact of IL-1β on cancer cells and immune cells of the TME in different types of cancers.

Recent phase II/III clinical trial testing association of VEGF-targeted therapies + immunotherapy

Many non-small cell lung cancer (NSCLC) patients remain unresponsive to the current standard of care, which includes chemotherapy and immune checkpoint inhibitors, like anti-PD-1/PD-L1 antibodies. While interleukin (IL)-1β is known to promote lung cancer growth in humans and mice, we show here that IL-1β administration or overexpression overcomes resistance to classical chemo-immunotherapy (cisplatin/pemetrexed/anti-PD-1) in mouse lung cancer models. The antitumor effects of IL-1β rely on cancer cell-derived CXCL10 which mediates CD8 T cell recruitment at the tumor site. In lung cancer cells, Thioredoxin Interacting Protein (TXNIP) induces mitochondrial DNA (mtDNA) release in the cytosol, activating Absence in Melanoma 2 (AIM2) inflammasome, which subsequently triggers IL-1β and CXCL10 secretion, thereby reversing chemo-immunotherapy resistance. The clinical relevance of our findings is supported by the transcriptomic analysis of patient tumors, showing that high expression of IL1B, IL1R1, AIM2 and/or TXNIP is associated with better response to immunotherapy in NSCLC patients. Additionally, drug screening identifies MEK and MDM2 inhibitors as inducers of TXNIP expression capable of reversing resistance to chemo-immunotherapy. This study highlights a positive role of IL-1β in lung cancer treatment and suggests that enhancing IL-1β production at the tumor site can overcome resistance to chemo-immunotherapy.

A patient with a PD-L1-negative, TMB-low, KEAP1/STK11 co-mutated metastatic non-small cell lung cancer (NSCLC) experienced a multisite radiological progression at 3 months after initiation of chemoimmunotherapy as first-line treatment for metastatic disease. After the radiological progression, while she was not undergoing treatment, the patient had spontaneous lesions shrinkage and further achieved a prolonged complete response. Genomic and transcriptomic data collected at baseline and at the time of pseudoprogression allowed us to biologically characterize this rare response pattern. We observed the presence of a tumor-specific T-cell response against tumor-specific neoantigens (TNAs). Endogenous retroviruses (ERVs) expression following chemoimmunotherapy was also observed, concurrent with biological features of an anti-viral-like innate immune response with type I IFN signaling and production of CXCR3-associated chemokines. This is the first biological characterization of a NSCLC pseudoprogression under chemoimmunotherapy followed by a prolonged complete response in a PD-L1-negative, TMB-low, KEAP1/STK11 co-mutated NSCLC. These clinical and biological data underline that even patients with multiple factors of resistance to immune checkpoint inhibitors could trigger a tumor-specific immune response to tumor neoantigen, leading to complete eradication of the tumor and probably a vaccinal immune response.

PDF file - 46K, Blockade of IL-17 by monoclonal antibody does not exert any cytotoxic effect on mammary tumor cells in vitro.

PDF file - 32K, DHA incorporates into splenic cells in vivo.

Even though the discovery of immune checkpoint inhibitors (ICIs) has revolutionized cancer treatment, a high proportion of patients do not respond. Moreover, some types of cancers are refractory to these treatments. Thus, the need to find predictive biomarkers of efficacy and to evaluate the association with other treatments, such as chemotherapy or radiotherapy, appears to be essential. Because ICIs reactivate or maintain an active status of T cells, one possibility is to combine these treatments with therapies that engage an immune response against tumor cells. Thus, by inducing immunogenic cell death (ICD) of cancer cells, some conventional anticancer treatments induce such immune response and may have an interest to be combined with ICIs. In this review, we explore preclinical studies and clinical trials that evaluate the combination of ICIs with ICD inducers. More than inducing ICD, some of these treatments appear to modulate the tumor microenvironment and more particularly to inhibit immunosuppression, thus improving treatment efficacy.

Flow cytometry gating strategy to identify memory CD4 T cell subpopulations through chemokine receptor expression.

Inflammasomes are intracellular multiproteic complexes involved in the production of inflammatory cytokines, thus playing a major role in inflammation. While their role in inflammatory diseases is well known, the crosstalk between inflammasomes and cancer is more complicated. These complexes and downstream cytokines may be involved in cancer incidence, progression, and response to treatment. However, depending on the context, inflammasomes can have pro- or antitumor effects. Thus, the knowledge of such complexes and their interaction with the tumor microenvironment should be clarified to propose potential therapeutic tools. Several clinical trials targeting inflammasomes or effector cytokines in association with chemotherapy, radiotherapy, and/or immunotherapy are ongoing to prove the relevance of such combination of treatments.

Whole blood of metastatic colorectal cancer patient (mCRC) was sample before (D0) and after chemotherapy (D15) on EDAT-K2 tubes (BD Bioscience) and a complete blood count (CBC) was performed in Clinical Biology Unit (Centre George François Leclerc).

Supplementary Figure 1 from 5-Fluorouracil Selectively Kills Tumor-Associated Myeloid-Derived Suppressor Cells Resulting in Enhanced T Cell–Dependent Antitumor Immunity

Flow cytometry gating strategy to identify MDSC subpopulations and granulocytes (1) through SCC-A, Lin- (=CD3, CD20, CD19 and CD56) CD14, CD15, CD33 and HLA-DR labeling (upper panel). For each selected population with CD14 and CD15 labelling, mMDSC (2) and gMDSC (3) were identified as HLA-DRlow/- and CD33high (lower panel). CD33 labeling for each population gated on CD14 and CD15 expression (1, 2 and 3). Representative histogram (left panel) and MFI for 3 patients (right panel) Pictures correspond to May-Grünwald Giemsa (MGG) staining of granulocytes, mMDSC and gMDSC isolated after cell sorting (upper panel). Quantification of cellular aspect (granulocytic or monocytic) after MGG staining (lower panel) Expression of IL-4Rα (CD124) in MDSC subpopulations and granulocytes. Representative histogram of CD124 expression (left panel) and MFI for 3 patients are shown (right panel).

PBMCs of mCRC patients were stained after PMA/ionomycin/Brefeldin/Monensin stimulation (4 hrs) with anti-CD4, anti-CD45RA, anti-CCR6, anti-CXCR3, anti-IFN-γ and anti-IL-17A antibodies and analyzed by flow cytometry. The expression of IFN-γ and/or IL-17A on memory CD4 (CD45RA- CD4+) Th1 (CCR6- CXCR3+), Th17 (CCR6+ CXCR3-), Th17/Th1 (CCR6+ CXCR3+) and CCR6- CXCR3- cells is depicted.

Supplementary Figure Legend from 5-Fluorouracil Selectively Kills Tumor-Associated Myeloid-Derived Suppressor Cells Resulting in Enhanced T Cell–Dependent Antitumor Immunity

Supplementary Figure 1: THelper gating strategy Flow cytometry gating strategy to identify memory CD4 T cell subpopulations through chemokine receptor expression. Supplementary Figure 2: MDSC gating strategy and IL-4Rα expression analysis. A. Flow cytometry gating strategy to identify MDSC subpopulations through CD33, Lin (=CD3, CD20, CD19 and CD56), HLA-DR, CD14 and CD15 marker expression. Pictures correspond to May-Grünwald Giemsa staining mMDSC and gMDSC isolated after cell sorting. B. As in A, we identify MDSC subpopulations, granulocytes and monocytes and we have analyzed IL-4Rα (CD124) expression in 3 mCRC patients. Supplementary Figure 3: Blood parameters in Healthy Volunteers versus mCRC patients Whole blood of Healthy volunteers and metastatic colorectal cancer patient (mCRC) was sample on EDTA-K2 tubes (BD Bioscience) and a complete blood count (CBC) was performed in Clinical Biology Unit (Centre George François Leclerc). Supplementary Figure 4: IFN-γ and IL-17A secretion by CCR6 and CXCR3 expressing CD4 T cells PBMCs of mCRC patients were stained after PMA/ionomycin/Brefeldin/Monensin stimulation (4 hrs) with anti-CD4, anti-CD45RA, anti-CCR6, anti-CXCR3, anti-IFN-γ and anti-IL-17A antibodies and analyzed by flow cytometry. The expression of IFN-γ and/or IL-17A on memory CD4 (CD45RA- CD4+) Th1 (CCR6- CXCR3+), Th17 (CCR6+ CXCR3-), Th17/Th1 (CCR6+ CXCR3+) and CCR6- CXCR3- cells is depicted. Supplementary Figure 5: Blood parameters in mCRC patients, D0 versus D15 Whole blood of metastatic colorectal cancer patient (mCRC) was sample before (D0) and after chemotherapy (D15) on EDAT-K2 tubes (BD Bioscience) and a complete blood count (CBC) was performed in Clinical Biology Unit (Centre George François Leclerc). Supplementary Figure 6: mRNA relative expression of genes involved in immunosuppression gMDSC and mMDSC were cell sorted from four mCRC patient blood. mRNA were extracted and the expression of Entpd1, Nt5e, Pdl1, Pdl2, Indo, Arg1 and Inos was determined using RT-qPCR. Supplementary Table 1: Patient and Healthy volunteer's characteristics Baseline characteristics (Age, Sex, Tumor origin, K-Ras and B-Raf status, number of metastatic sites, LDH, PA and CEA) of metastatic colorectal cancer patients (mCRC) and healthy volunteers. Supplementary Table 2: Human primer sequences used for RT-qPCR analysis List of primer used for mRNA relative expression in different myeloid subsets.

Abstract Activation of the transcription factor PPARγ by the n-3 fatty acid docosahexaenoic acid (DHA) is implicated in controlling proinflammatory cytokine secretion, but the intracellular signaling pathways engaged by PPARγ are incompletely characterized. Here, we identify the adapter-encoding gene SOCS3 as a critical transcriptional target of PPARγ. SOCS3 promoter binding and gene transactivation by PPARγ was associated with a repression in differentiation of proinflammatory T-helper (TH)17 cells. Accordingly, TH17 cells induced in vitro displayed increased SOCS3 expression and diminished capacity to produce interleukin (IL)-17 following activation of PPARγ by DHA. Furthermore, naïve CD4 T cells derived from mice fed a DHA-enriched diet displayed less capability to differentiate into TH17 cells. In two different mouse models of cancer, DHA prevented tumor outgrowth and angiogenesis in an IL-17–dependent manner. Altogether, our results uncover a novel molecular pathway by which PPARγ-induced SOCS3 expression prevents IL-17–mediated cancer growth. Cancer Res; 73(12); 3578–90. ©2013 AACR.

Abstract Immune-checkpoint inhibitors (ICI), particularly inhibitors of the PD-1/PD-L1 (Programmed Death 1/Programmed Death-Ligand 1) axis, have modified the management of many types of cancer over the last 10 years. However, both intrinsic and acquired resistance are major clinical issues with these therapies, and only a few patients are cured by ICI monotherapy. To overcome resistance, the concept of combining ICIs with other therapies is emerging and supported by many preclinical trials. Besides associations of ICIs with chemotherapy or radiotherapy, now used in clinical practice, some targeted therapies have also been reported to influence immune response of patients against cancer cells, thus showing potential synergy with ICIs. In this review, we describe the preclinical and clinical advances to date in the use of these combination strategies.