Focal adhesion pathway inhibition is the central axis of macrophage phenotypic responses to monoclonal antibody therapy in aggressive lymphoma via high-throughput screening and high-content imaging

Abstract

High-grade B-cell lymphoma (HGBCL) frequently arises as a refractory or relapsed state of diffuse large B-cell lymphoma (DLBCL) and is associated with poor outcomes due to multi-drug resistance and hallmark oncogenic translocations. To identify novel therapeutic strategies, we developed a dual high-throughput screening (HTS) and high-content imaging (HCI) macrophage-tumour co-culture platform that quantifies antibody-dependent and antibody-independent cellular phagocytosis (ADCP/AICP) across a 1,241-compound library. Using GFP+ HGBCL cells and mCherry+ macrophages, we validated our methodology through time-resolved phenotypic profiling, Euclidean distance-based analysis, and hit compound prioritisation. Pathway interrogation revealed focal adhesion as a central hub of macrophage phenotypic modulation, highlighting focal adhesion kinase (FAK/PTK2) as a candidate therapeutic target. Pharmacological inhibition with PF-562271 enhanced phagocytic activity, altered macrophage morphology, and synergised with anti-CD20 monoclonal antibodies in vitro and ex vivo. In vivo, Rituximab plus PF-562271 significantly reduced lymphoma burden and prolonged survival in xenograft models. Collectively, our work demonstrates that HTS/HCI-driven phenotypic profiling of tumour-associated macrophages can uncover actionable therapeutic combinations and nominates FAK inhibition as a promising strategy to potentiate antibody immunotherapy in HGBCL.