EPILUCAFS

Theoretical Framework
Chronic inflammation caused by smoking is a major hallmark of Lung Cancer (LC), where it drives all stages of tumor development and impinges critically on the tumor microenvironment (TME) and tumor draining lymph nodes (TDLN). The development of immune checkpoint inhibitors (ICI) has advanced our understanding of the critical role of the immune system during tumorigenesis, but patient stratification and treatment success remain a clinical challenge. Psychosocial stress as an important modifier of the immune system may also contribute to poor prognosis in LC. Conceptually, chronic exposure to pro-inflammatory signals evokes epigenetic mechanisms to generate a cellular memory. Spatial sequencing technologies provide access to the startling complexity of cellular subtypes and plasticity in the TME.
Hypotheses
Therefore, we propose to examine how chronic inflammation related to psychosocial stress shapes TME and TDLN. Based on our preliminary data, we aim to study the epigenetic regulation of cancer-associated fibroblasts (CAFs) and their crosstalk with immune cells (notably T cells). We aim to restore immune surveillance with epigenetic drugs targeting specific phenotypes of CAFs and TDLN lymphoid stromal cells (LSCs) as the critical but yet poorly understood regulators of immunosuppression.
Methods
With public and retrospective scRNA-seq data, a single cell atlas will be established inclusive of the heterogeneity and plasticity of TME and TDLN. Along with scATASCseq, the epigenetic landscape of CAF and LSC, characterization of epigenetic regulators, T-cell exhaustion, exclusion, and recruitment of immunosuppressive immune cells will be analyzed using an ex vivo assay with patient material and in vitro and in vivo validation of putative actors with state-of-the-art preclinical models. We will also assess the impact on the DNA methylation of previously identified immunoregulatory genes in CAFs by pyrosequencing under stressed/non-stressed conditions, and their impact on T cell dysfunction. Analysis of the crosstalk with the interferon-gamma pathway will use scRNAseq, multiplex IHC and CyTOF in the murine LC models and the human in vitro models. Finally, we will combine ICI with epidrugs or drugs reverting epigenetic-based immunosuppression in murine LC models and an ex vivo assay in relationship with stress and inflammation to provide a proof-of-concept for restoring ICI susceptibility.
Innovation
The epigenetic landscape of stromal cells under chronic stress and inflammation will identify critical underlying mechanisms for T-cell dysfunction and immune suppression driving bad prognosis in LC. Moreover, we expect to identify novel targets to release immunosuppression and interfere with the deleterious influence of stress on tumor progression.
Researcher Involved
This collaborative network of international experts has developed an ambitious and scope-oriented work plan structured to combine their complementary expertise.