Refining the Spatial Organization of Dendritic Cells and Macrophages in the Tumor Microenvironment

Solid tumors are composed not only of tumor cells but also of a variety of other cell types, including stromal and immune cells. Initially overlooked, immune cells have now become a critical focus, especially with the advent of immunotherapy. In many cancers, the presence of cytotoxic CD8+ T cells within the tumor is often associated with better prognosis. Mononuclear phagocytes (MNPs), including dendritic cells (DCs) and monocytes/macrophages (MoMacs), are key regulators of the anti-tumor T cell response and are present in most solid tumors. However, their precise spatial organization and functional states within the tumor microenvironment (TME) remain incompletely understood. To address this, we have undertaken a project integrating multiple high-resolution technologies, including single-cell RNA sequencing (scRNA-seq), spatial transcriptomics (Visium HD, Merscope, Xenium), and spatial proteomics (MACSIMA), to provide a comprehensive mapping of DC and macrophage populations in various tumor types. These cutting-edge approaches enable us to decipher the spatial relationships between immune cells, stromal components, and tumor cells, shedding light on how DCs and macrophages contribute to tumor progression and immune responses.