From Pixels to Insights: Unveiling Spatial Immune Associations of Immunotherapy Response in Non-Small Cell Lung Cancer using Multiplexed Tissue Imaging

Abstract

Insights into the spatial localisation of immune cells within tumours are key to understand the intercellular communications that dictate clinical outcomes. We applied a tiered approach to characterise the spatial organization and interactions in NSCLC tissues from thirty-five patients that subsequently received PD-1 axis immunotherapy (ICI therapy). Our analysis indicates that regulatory T cells are enriched in non-responding patients. Proximity interactions between Tregs and both monocytes(p=0.009) and CD8+ T cells(p=0.009) were frequently found in non-responding patients, while macrophages were more frequently located in proximity to antigen presenting HLADR+ tumour cells(p=0.01) within responding patients. Spatial compartmentalization of tissues into cellular neighbourhoods indicates that both macrophages(p=0.003) and effector CD4+ T cells(p=0.01) in mixed tumour neighbourhoods, and CD8+ T cells(p=0.03) in HLADR+ tumour neighbourhoods are positively associated with clinical response to ICI therapy. Evaluation of the inferred regulatory functions between immune cells relative to their tumour proximity by a SpatialScore metric suggests that macrophages may exhibit an immunosuppressive phenotype against both CD4+ and CD8+ T cells, and that this association scores more highly in ICI refractory patients. These spatial patterns are associated with overall survival in addition to ICI response and may indicate features relevant for the functional understanding of the tumour microenvironment.