ABSTRACT
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.
Subject(s)
Carcinoma, Non-Small-Cell Lung/immunology , Interleukin-10/physiology , Lung Neoplasms/immunology , Adenocarcinoma/immunology , Adenocarcinoma of Lung , Animals , B7-H1 Antigen/analysis , B7-H1 Antigen/physiology , Cell Line, Tumor , Female , Humans , Mice , Mice, Inbred BALB C , Programmed Cell Death 1 Receptor/analysis , Programmed Cell Death 1 Receptor/physiology , Receptors, Interleukin-10/analysis , Tumor EscapeABSTRACT
BACKGROUND: In spite of modern therapies for non-small-cell lung cancer (NSCLC), prognosis for many patients is still poor and survival rates are low. Immunotherapy is the possibility to improve the lung immune response surrounding the tumour. However, this approach requires detailed understanding of the local immune-responses of NSCLC patients. METHODS: We analysed samples from three different regions within the lungs of NSCLC patients, whereas we distinguished between patients suffering from adenocarcinoma and squamous cell carcinoma. Expression of type 1 T helper (Th1)/type 1 cytotoxic (Tc1) factors was assessed by quantitative real-time PCR, western blot analyses or immunohistochemistry. Cytotoxic cell activity of CD8(+) T cells was determined via co-culture with autologous tumour cells and apoptosis assay. RESULTS: We found decreased levels of the transcription factor T-box expressed in T cells (T-bet or Tbx21) and of the downstream activated IFN-γ-dependent pSTAT1α isoform in the lung tumour areas of patients with NSCLC as compared with tumour-free control regions. In these patients, reduced T-bet and pSTAT1α levels were found associated with increased immunosuppressive markers like cytotoxic T lymphocyte-associated protein 4, programmed cell death 1 and with a suppression of the Th1 cell cytokine production and Tc1 cell activity. CONCLUSIONS: These findings confirm a central role of T-bet in targeted immunotherapy for patients with NSCLC.
