Title: Deciphering Immune Complexity on the Axes of Time and Space: High-Dimensional Profiling for Tissue Microenvironments

Abstract: High-dimensional tissue profiling on the axes of time, cell type, and treatment is necessary to unravel the heterogeneity within systems-wide responses to disease. We are witnessing a renaissance in the development of these methods, which have enabled greater parameterization, accuracy, and throughput than previously achieved for studying systems biology.

We first utilize techniques in spectral cytometry to study the transfection efficiency of T cell targeted LNPs as a function of time and tissue. We packaged reporter gene mRNA into CD3-targeted LNPs and successfully transfected murine T cells in vivo that were capable of migrating to tumors in the presence of immunotherapy. While promising, we discovered a variety of consequences associated with anti-CD3 coating that sparked questions about immune subsets beyond T cells.

These questions prompted us to engineer a 40-color deep immunophenotyping panel for murine lymphoid tissues and tumors. We used this tool to unlock insights into tissue leukocyte composition and immune response mechanisms to combinatorial immunotherapy.

Only after achieving this level of resolution did we fully appreciate how the spatial organization of immune, stromal, and tumor cells could inform their function. To explore this, we harmonized 51-plex CODEX with Visium spatial transcriptomics to deconvolve pancreatic ductal adenocarcinoma microenvironments. These insights culminated in the development of an anti-Claudin-4 peptide PET probe for PDAC imaging in mice, and I conclude this talk with microdosimetry modelling techniques to aid in future theragnostic development for PDAC treatment.

Please contact Madelyn Bernstein for the Zoom link.