Search

Mantle cell lymphoma (MCL), a rare and aggressive B cell non-Hodgkin lymphoma, mainly develops in the lymph node (LN) and creates a protective and immunosuppressive niche that facilitates tumor survival, proliferation and chemoresistance. To capture disease heterogeneity and tumor microenvironment (TME) cues, we have developed the first patient-derived MCL spheroids (MCL-PDLS) that recapitulate tumor oncogenic pathways and immune microenvironment in a multiplexed system that allows easy drug screening, including immunotherapies. MCL spheroids, integrated by tumor B cells, monocytes and autologous T cells self-organize in disc-shaped structures, where B and T cells maintain viability and proliferate, and monocytes differentiate into M2-like macrophages. RNA-seq analysis demonstrated that tumor cells recapitulate hallmarks of MCL-LN (proliferation, NF-kB and BCR), with T cells exhibiting an exhaustion profile (PD1, TIM-3 and TIGIT). MCL-PDLS reproduces in vivo responses to ibrutinib and demonstrates that combination of ibrutinib with nivolumab (anti-PD1) may be effective in ibrutinib-resistant cases by engaging an immune response with increased interferon gamma and granzyme B release. In conclusion, MCL-PDLS recapitulates specific MCL-LN features and in vivo responses to ibrutinib, representing a robust tool to study MCL interaction with the immune TME and to perform drug screening in a patient-derived system, advancing towards personalized therapeutic approaches.

Simple Summary Follicular lymphoma is an indolent B cell lymphoproliferative disorder of transformed follicular center B cells, which accounts for 20–30 percent of all non-Hodgkin lymphoma (NHL) cases. Although huge efforts have been made in the last 10 years, this pathology is still considered as incurable, leaving open the discovery and testing of new therapeutic targets requiring relevant preclinical models. Here, we report a realistic 3D model of t (14;18)-positive B-NHL cell culture (ultra-low attachment (ULA)-multicellular aggregates of lymphoma cells (MALC)), which monitored by state-of-the-art 2D and 3D imaging, allows more robust drug testing. Abstract Follicular lymphoma (FL) is an indolent B cell lymphoproliferative disorder of transformed follicular center B cells, which accounts for 20–30 percent of all non-Hodgkin lymphoma (NHL) cases. Great advances have been made to identify the most relevant targets for precision therapy. However, no relevant models for in vitro studies have been developed or characterized in depth. To this purpose, we generated a 3D cell model from t(14;18)-positive B-NHL cell lines cultured in ultra-low attachment 96-well plates. Morphological features and cell growth behavior were evaluated by classical microscopy (2D imaging) and response to treatment with different drugs was evaluated by a high-content analysis system to determine the robustness of the model. We show that the ultra-low attachment (ULA) method allows the development of regular, spherical and viable ULA-multicellular aggregates of lymphoma cells (MALC). However, discrepancies in the results obtained after 2D imaging analyses on drug-treated ULA-MALC prompted us to develop 3D imaging and specific analyses. We show by using light sheet microscopy and specifically developed 3D imaging algorithms that 3D imaging and dedicated analyses are necessary to characterize morphological properties of 3D models and drug effects. This study proposes a new method, but also imaging tools and informatic solutions, developed for FL necessary for future preclinical studies.

Simple Summary Follicular lymphoma is a paradigm of tumors that require the interaction between tumor and microenvironment cells to foster their development from initial steps to progression. Recent large-scale genome studies have uncovered multiple genetic alterations that cooperate with the lymphoma microenvironment to promote cell survival, proliferation and to facilitate tumor evasion from host immune system. Understanding the crosstalk between tumor B-cells and the microenvironment is fundamental to identify vulnerabilities that may offer novel therapeutic targets. This review highlights recent findings showing the effect of common genetic mutations modulating the cell composition and phenotype of the tumor microenvironment and the novel therapeutic perspectives to target these interactions. Abstract Follicular Lymphoma (FL), the most common indolent non-Hodgkin’s B cell lymphoma, is a paradigm of the immune microenvironment’s contribution to disease onset, progression, and heterogeneity. Over the last few years, state-of-the-art technologies, including whole-exome sequencing, single-cell RNA sequencing, and mass cytometry, have precisely dissected the specific cellular phenotypes present in the FL microenvironment network and their role in the disease. In this already complex picture, the presence of recurring mutations, including KMT2D, CREBBP, EZH2, and TNFRSF14, have a prominent contributory role, with some of them finely tuning this exquisite dependence of FL on its microenvironment. This precise characterization of the enemy (FL) and its allies (microenvironment) has paved the way for the development of novel therapies aimed at dismantling this contact network, weakening tumor cell support, and reactivating the host’s immune response against the tumor. In this review, we will describe the main microenvironment actors, together with the current and future therapeutic approaches targeting them.