Spatial landscape of malignant pleural and peritoneal mesothelioma tumor immune microenvironment.

Immunotherapies have demonstrated limited clinical efficacy in malignant mesothelioma treatment. We conducted multiplex immunofluorescence (mIF) analyses on tissue microarrays (n=3) from malignant peritoneal (MPeM, n=25) and pleural (MPM, n=88) mesothelioma patients. Our study aimed to elucidate spatial distributions of key immune cell populations and their association with LAG3, BAP1, NF2, and MTAP, with MTAP serving as a CDKN2A/B surrogate marker. Additionally, we examined the relationship between the spatial distribution of major immune cell types with MM patient prognosis and clinical characteristics. We observed a higher degree of interaction between immune cells and tumor cells in MPM compared to MPeM. Notably, within MPM tumors, we detected a significantly increased interaction between tumor cells and CD8+ T cells in tumors with low BAP1 expression compared to those with high BAP1 expression. To support the broader research community, we have developed The Human Spatial Atlas of Malignant Mesothelioma (https://mesotheliomaspatialatlas.streamlit.app/), containing mIF and hematoxylin and eosin (H&E) images.