IL-9 Producing Tumor-Infiltrating Lymphocytes and Treg Subsets Drive Immune Escape of Tumor Cells in Non-Small Cell Lung Cancer.

Although lung cancer is the leading cause of cancer deaths worldwide, the mechanisms how lung cancer cells evade the immune system remain incompletely understood. Here, we discovered IL-9-dependent signaling mechanisms that drive immune evasion in non-small cell lung cancer (NSCLC). We found increased IL-9 and IL-21 production by T cells in the tumoral region of the lung of patients with NSCLC, suggesting the presence of Th9 cells in the lung tumor microenvironment. Moreover, we noted IL-9 producing Tregs in NSCLC. IL-9 target cells in NSCLC consisted of IL-9R+ tumor cells and tumor-infiltrating lymphocytes. In two murine experimental models of NSCLC, and in vitro, IL-9 prevented cell death and controlled growth of lung adenocarcinoma cells. Targeted deletion of IL-9 resulted in successful lung tumor rejection in vivo associated with an induction of IL-21 and reduction of Treg cells. Finally, anti-IL-9 antibody immunotherapy resulted in suppression of tumor development even in established experimental NSCLC and was associated with reduced IL-10 production in the lung. In conclusion, our findings indicate that IL-9 drives immune escape of lung tumor cells via effects on tumor cell survival and tumor infiltrating T cells. Thus, strategies blocking IL-9 emerge as a new approach for clinical therapy of lung cancer.

Increased expression of the immunosuppressive interleukin-35 in patients with non-small cell lung cancer.

BACKGROUND: The immunosuppressive role of the cytokine IL-35 in patients with non-small cell lung cancer (NSCLC) is poorly understood. In this study, we analysed the localisation and regulation of IL-35 in the lung of patients with non-small cell lung cancer (NSCLC) to further elucidate the immune-escape of cancer cells in perioperative course of disease. METHODS: Interleukin 35 (IL-35) was measured by ELISA in postoperative serum from 7 patients with NSCLC as well as 8 samples from healthy controls. Immunohistochemistry, FACS analysis, real-time PCR, as well as western blot from samples of the control (CTR), peri-tumoural (PT) and the tumoural (TU) region of the lung derived from patients with NSCLC and 10 controls were performed. RESULTS: Here we found elevated levels of IL-35 in the TU region as well as postoperative serum from patients with lung adenocarcinoma. Consistently, we found an increased expression of IL-35+Foxp-3+ cells, which associated with ARG1 mRNA expression and decreased TNFA in the TU region of the lung of patients with NSCLC as compared to their CTR region. Furthermore, in the CTR region of the lung of patients with NSCLC, CD68+ macrophages were induced and correlated with IL-35+ cells. Finally, IL-35 positively correlated with TTF-1+PD-L1+ cells in the TU region of NSCLC patients. CONCLUSIONS: Induced IL-35+Foxp3+ cell numbers in the TU region of the lung of patients with NSCLC associated with ARG1 mRNA expression and with TTF-1+PD-L1+ cells. In the tumour-free CTR area, IL-35 correlated with CD68+ macrophages. Thus inhibitors to IL-35 would probably succeed in combination with antibodies against immune checkpoints like PD-L1 and PD-1 currently used against NSCLC because they would inhibit immunosuppressive macrophages and T regulatory cells while promoting T cell-mediated anti-tumoural immune responses in the microenvironment as well as the TU region of NSCLC patients.

NFATc1 Promotes Antitumoral Effector Functions and Memory CD8+ T-cell Differentiation during Non-Small Cell Lung Cancer Development.

Nuclear factor of activated T cells 1 (NFATc1) is a transcription factor activated by T-cell receptor (TCR) and Ca2+ signaling that affects T-cell activation and effector function. Upon tumor antigen challenge, TCR and calcium-release-activated channels are induced, promoting NFAT dephosphorylation and translocation into the nucleus. In this study, we report a progressive decrease of NFATc1 in lung tumor tissue and in tumor-infiltrating lymphocytes (TIL) of patients suffering from advanced-stage non-small cell lung cancer (NSCLC). Mice harboring conditionally inactivated NFATc1 in T cells (NFATc1ΔCD4) showed increased lung tumor growth associated with impaired T-cell activation and function. Furthermore, in the absence of NFATc1, reduced IL2 influenced the development of memory CD8+ T cells. We found a reduction of effector memory and CD103+ tissue-resident memory (TRM) T cells in the lung of tumor-bearing NFATc1ΔCD4 mice, underlining an impaired cytotoxic T-cell response and a reduced TRM tissue-homing capacity. In CD4+ICOS+ T cells, programmed cell death 1 (PD-1) was induced in the draining lymph nodes of these mice and associated with lung tumor cell growth. Targeting PD-1 resulted in NFATc1 induction in CD4+ and CD8+ T cells in tumor-bearing mice and was associated with increased antitumor cytotoxic functions. This study reveals a role of NFATc1 in the activation and cytotoxic functions of T cells, in the development of memory CD8+ T-cell subsets, and in the regulation of T-cell exhaustion. These data underline the indispensability of NFATc1 for successful antitumor immune responses in patients with NSCLC.Significance: The multifaceted role of NFATc1 in the activation and function of T cells during lung cancer development makes it a critical participant in antitumor immune responses in patients with NSCLC. Cancer Res; 78(13); 3619-33. ©2018 AACR.

STAT1 deficiency supports PD-1/PD-L1 signaling resulting in dysfunctional TNFα mediated immune responses in a model of NSCLC.

In this study we described that Signal Transducer and Activator of Transcription 1 (STAT1) is a key point regulator of PD-1 in tumour infiltrating lymphocytes and PD-L1 in Tumour associated macrophages (TAM) in NSCLC. In our murine model of adenocarcinoma targeted deletion of Stat1 was found associated with enhanced tumour growth, impaired differentiation into M1-like macrophages from the bone marrow, the accumulation of tumor associated macrophages overexpressing PD-L1 and impaired T cell responses in the tumor microenvironment by affecting TNFα responses. In our human NSCLC patient cohort we found that loss of isoforms STAT1 α and STAT1ß mRNA in the tumoural region of the lung correlates with increased tumor size in NSCLC patients. Therefore, STAT1 isoform regulation could be considered for future therapeutical strategies associated to current immune-checkpoint blockade therapy in NSCLC.

Interleukin-10-regulated tumour tolerance in non-small cell lung cancer.

BACKGROUND: Lung cancer is the most life-threatening cancer type worldwide. Treatment options include surgery, radio- and chemotherapy, as well as the use of immunomodulatory antibodies. Interleukin (IL)-10 is an immunosuppressive cytokine involved in tumour immune escape. METHODS: Immunohistochemistry (IHC) on human lung surgery tissue as well as human tumour cell line cultures, FACS analysis, real-time PCR and experimental lung cancer. RESULTS: Here we discovered a positive correlation between IL-10 and IL-10 receptor (IL-10R) expression in the lung with tumour diameter in patients with lung cancer (non-small cell lung cancer), the most life-threatening cancer type worldwide. IL-10 and IL-10R were found induced in cells surrounding the lung tumour cells, and IL-10R was mainly expressed on the surface of Foxp-3+ T-regulatory lymphocytes infiltrating the tumour of these patients where its expression inversely correlated with programmed cell death 1. These findings were confirmed in translational studies. In a human lung adenocarcinoma cell line, IL-10R was found induced under metabolic restrictions present during tumour growth, whereby IL-10 inhibited PDL1 and tumour cell apoptosis. CONCLUSIONS: These new findings suggest that IL-10 counteracts IFN-γ effects on PD1/PDL1 pathway, resulting in possible resistance of the tumour to anti-PD1/PDL1 immunotherapy.

Enhanced Acid Sphingomyelinase Activity Drives Immune Evasion and Tumor Growth in Non-Small Cell Lung Carcinoma.

The lipid hydrolase enzyme acid sphingomyelinase (ASM) is required for the conversion of the lipid cell membrane component sphingomyelin into ceramide. In cancer cells, ASM-mediated ceramide production is important for apoptosis, cell proliferation, and immune modulation, highlighting ASM as a potential multimodal therapeutic target. In this study, we demonstrate elevated ASM activity in the lung tumor environment and blood serum of patients with non-small cell lung cancer (NSCLC). RNAi-mediated attenuation of SMPD1 in human NSCLC cells rendered them resistant to serum starvation-induced apoptosis. In a murine model of lung adenocarcinoma, ASM deficiency reduced tumor development in a manner associated with significant enhancement of Th1-mediated and cytotoxic T-cell-mediated antitumor immunity. Our findings indicate that targeting ASM in NSCLC can act by tumor cell-intrinsic and -extrinsic mechanisms to suppress tumor cell growth, most notably by enabling an effective antitumor immune response by the host. Cancer Res; 77(21); 5963-76. ©2017 AACR.

FAM13A is associated with non-small cell lung cancer (NSCLC) progression and controls tumor cell proliferation and survival.

Genome-wide association studies (GWAS) associated Family with sequence similarity 13, member A (FAM13A) with non-small cell lung cancer (NSCLC) occurrence. Here, we found increased numbers of FAM13A protein expressing cells in the tumoral region of lung tissues from a cohort of patients with NSCLC. Moreover, FAM13A inversely correlated with CTLA4 but directly correlated with HIF1α levels in the control region of these patients. Consistently, FAM13A RhoGAP was found to be associated with T cell effector molecules like HIF1α and Tbet and was downregulated in immunosuppressive CD4+CD25+Foxp3+CTLA4+ T cells. TGFß, a tumor suppressor factor, as well as siRNA to FAM13A, suppressed both isoforms of FAM13A and inhibited tumor cell proliferation. RNA-Seq analysis confirmed this finding. Moreover, siRNA to FAM13A induced TGFß levels. Finally, in experimental tumor cell migration, FAM13A was induced and TGFß accelerated this process by inducing cell migration, HIF1α, and the FAM13A RhoGAP isoform. Furthermore, siRNA to FAM13A inhibited tumor cell proliferation and induced cell migration without affecting HIF1α. In conclusion, FAM13A is involved in tumor cell proliferation and downstream of TGFß and HIF1α, FAM13A RhoGAP is associated with Th1 gene expression and lung tumor cell migration. These findings identify FAM13A as key regulator of NSCLC growth and progression.