Project Funding Details

The role of the intercellular crosstalk between innate lymphoid cells (ILCs) and dendritic cells (DCs) in initiating and coordinating anti-tumor immune response has progressively gained relevance, with natural killer (NK) cells representing the ILC prototype for these interactions. Lately, an operative NK-DC axis has even been associated to increased overall survival and responses to anti-PD-1 immunotherapy. Tertiary lymphoid structures (TLS) are ectopic lymphoid neoformations, which, in cancer, correlate with both good prognosis and immunotherapy effectiveness. Although the mechanisms leading to the formation of TLS, as well as the ones responsible for their protective effects, are not fully understood, current literature indicates that different subsets of innate lymphoid cells (ILCs) could be specifically endowed with lymphoid tissue (LT) inducing properties. On the other hand, the role of DCs as LT-organizer cells has been extensively reported. Based on solid preliminary results we hypothesize that: i) intratumoral NK cells, if properly activated, can efficiently recruit DCs; ii) NK/DC bi-directional activation can trigger the neogenesis of TLS and the subsequent activation of both humoral and cellular immune response within the tumor mass; iii) intratumoral group 3 ILCs would participate to TLS formation by releasing high amount of interleukin-22, following interaction with DCs, in the context of tumor microenvironment We aim to better understand the mechanisms underlying both the formation of TLS within non-small-cell lung cancer (NSCLC) tissues and the processes leading to their protective functions, eventually targeting these mechanisms for either proposing novel immunotherapeutic approaches and/or increasing the rate of patients successfully responding to current immunotherapies. WP1: Comprehensive analyses of factors released by human intratumoral NK cells able to recruit DCs; WP2: Identification of the signals necessary for an optimal release of IL-22 by intratumoral ILC-3; WP3: Spatial localization of NK/ILC3/DCs within human NSCLC and associated TLS, also analysing their functional features by Hyperion technology and spatial transcriptomics. Identification of distinct DC subsets, including follicular DCs, and NK/ILCs, close or far from TLS. WP4: For shedding furher light on protective mechanisms of tumoral TLS, we will investigate in human NSCLC (i) the presence of tumor cells coated by antibodies; (ii) frequency of effectors cells able to perform antibody-dependent cell cytotoxicity; (iii) capability to release complement by tumor stroma. WP5: In an in vivo experimental model, we'll harness bacterial outer membrane vesicles (OMV) as a tool to activate both intratumoral NK cells (via expression on OMV surface of molecules targeting NK activating receptors) and DCs (via the intrinsic adjuvant potential of bacterial OMV). Our proposal will identify receptors and soluble molecules pivotal for the formation of TLS through the reciprocal activation of ILCs and DCs. On the basis of these novel findings, we also expect to obtain a new therapeutic tool based on OMV specifically engineered to target ILC/DC axis and trigger its virtuous activating loop. Identifying the processes involved in TLS generation is of paramount relevance for implementing novel therapeutic interventions able to induce TLS in tumor tissues and boost anti-cancer immunity, thus also improving the rates of response to current immunotherapeutics.