Using multiplexed ion beam imaging by time-of-flight mass spectrometry, Keren et al. imaged tumors from 41 triple-negative breast cancer patients. Despite significant heterogeneity between and within samples, several patterns emerged: the extent of immune infiltration correlated with tumor vascularization (but not tumor content) and with immune composition; tumors could be cold, mixed, or compartmentalized; PD-1 was largely expressed on CD8+ T cells in mixed tumors and on CD4+ T cells in compartmentalized tumors; distinct spatial patterns emerged of cells (defined by lineage and phenotypic markers) and immunoregulatory proteins.
The immune system is critical in modulating cancer progression, but knowledge of immune composition, phenotype, and interactions with tumor is limited. We used multiplexed ion beam imaging by time-of-flight (MIBI-TOF) to simultaneously quantify in situ expression of 36 proteins covering identity, function, and immune regulation at sub-cellular resolution in 41 triple-negative breast cancer patients. Multi-step processing, including deep-learning-based segmentation, revealed variability in the composition of tumor-immune populations across individuals, reconciled by overall immune infiltration and enriched co-occurrence of immune subpopulations and checkpoint expression. Spatial enrichment analysis showed immune mixed and compartmentalized tumors, coinciding with expression of PD1, PD-L1, and IDO in a cell-type- and location-specific manner. Ordered immune structures along the tumor-immune border were associated with compartmentalization and linked to survival. These data demonstrate organization in the tumor-immune microenvironment that is structured in cellular composition, spatial arrangement, and regulatory-protein expression and provide a framework to apply multiplexed imaging to immune oncology.
Author Info: (1) Department of Pathology, Stanford University, Stanford CA, 94305, USA. (2) Department of Pathology, Stanford University, Stanford CA, 94305, USA. (3) Department of Pathology, S
Author Info: (1) Department of Pathology, Stanford University, Stanford CA, 94305, USA. (2) Department of Pathology, Stanford University, Stanford CA, 94305, USA. (3) Department of Pathology, Stanford University, Stanford CA, 94305, USA. (4) Department of Pathology, Stanford University, Stanford CA, 94305, USA. (5) Department of Pathology, Stanford University, Stanford CA, 94305, USA. (6) Department of Pathology, Stanford University, Stanford CA, 94305, USA. (7) Department of Pathology, Stanford University, Stanford CA, 94305, USA. (8) Department of Pathology, Stanford University, Stanford CA, 94305, USA. (9) Department of Biology, Caltech, Pasadena, CA 91125, USA; Department of Bioengineering, Caltech, Pasadena, CA 91125, USA. (10) Department of Pathology, Stanford University, Stanford CA, 94305, USA. (11) Department of Pathology, Stanford University, Stanford CA, 94305, USA. Electronic address: bendall@stanford.edu. (12) Department of Pathology, Stanford University, Stanford CA, 94305, USA. Electronic address: mangelo0@stanford.edu.
