Developing models to investigate how malignant B cells interact with cognate antigen in physiological conditions (360G-Wellcome-215196_Z_19_Z)

Accumulating evidence suggests that antigen-induced B cell receptor (BCR) signalling plays a role in the pathogenesis of Chronic Lymphocytic Leukaemia (CLL). However, how the interaction with specific antigens drives CLL expansion is unclear. With this award, I aim to develop a set of tools to investigate how CLL cells interact with antigen presented in conditions that resemble the tumour micro-environment and, how the interaction with antigen drives expansion of malignant B cells in vivo. To examine how CLL cells interact with antigen at a single cell and single molecule level, I will develop a high-content large-scale imaging approach. To mimic how B cells engage antigen in vivo, I will load antigen on flexible membrane substrates that closely resemble the physical characteristics of follicular dendritic cells (FDCs), from where B cells normally acquire antigen. I will then analyse how efficient CLL cells are at immune synapse formation, BCR signalling and antigen internalisation. To investigate how the interaction with antigen drives CLL expansion in vivo, I will target antigen to the surface of FDCs in mouse lymph nodes and then transfer antigen-specific CLL cells isolated from a CLL mouse model. Subsequently, I will analyse activation and proliferation of transferred CLL cells.