Ex-vivo modeling of the lymph node microenvironment and its impact on drug response in lymphoma

• Applicants: Professor Dr. Sascha Dietrich; Privatdozentin Dr. Antonina Lavrentieva; Dr. Iliyana Pepelanova
• Subject Area: Hematology, Oncology ; Biomaterials
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 464596535

We aim to develop a versatile and scalable ex-vivo drug testing platform to understand the biological complexity of individual B-cell lymphomas, their interaction with the microenvironment and consequences for drug response. To succeed, significant practical and scientific hurdles need to be overcome, constituting the specific aims of our proposal:1) We aim to better understand the cellular composition and substructure of the lymph node (LN) in follicular lymphoma. We have successfully established a well coordinated biobanking procedure for fresh LN biopsies in the routine of our lymphoma clinic. We will take advantage of this unique resource and characterize the cellular complexity of the malignant LN niche. 2-5) Based on the understanding of the cellular composition of the malignant LN niche we will create ex-vivo LN models with a hierarchy of increasing complexity. Our final aim will be to develop a 3D LN co-culture model of LN-derived stroma cells (LNSC), tumor infiltrating T-cells and malignant B-cells to study drug response and pathway activity in malignant B-cells and non-malignant bystander cells. We will systematically and stepwise build such a comprehensive ex-vivo LN model, which includes the following steps: 1st step) the expansion and extensive characterization of LNSCs. 2nd step) The establishment of co-culture conditions for malignant B-cells, tumor infiltrating T-cells and LNSC. In-vivo tumor growth takes place in 3D space that allows and maximizes tumor-tumor and tumor-stroma cell interactions. As a 3rd step) we will therefore develop a 3D co-culture, which facilitates in vivo-like structural organization, oxygen concentrations/gradients and cellular connectivity. To meet the needs of the complex cellular LN composition we will develop hydrogels based on modified gelatin (gelatin methacryloyl, GelMA) as a basic 3D platform, which are characterized by high biocompatibility and design flexibility. The LN structure is complex and well compartmentalized, therefore, we aim to partially resemble the hierarchical LN architecture and introduce spatial resolution by bioprinting different cell types into the hydrogel to mimic the spatial context of the cellular LN composition. Finally, we will systematically compare expression profiles of B- and T-cells after ex-vivo co-culture with those of the same B- and T-cell subsets characterized directly after surgical excision to estimated how well in-vivo conditions can be resembled.6) Finally, we aim to systematically compare drug response patterns between different culture models to understand the impact of each co-culture component and the spatial resolution on ex-vivo tumor cell maintenance and drug response.

• DFG Programme: Research Grants