Macrophage Phenotypes and Tissue Repair

Project Summary The overall goals of my laboratory over the next 5 years are to better understand the heterogeneity of inflammatory cell function over the course wound healing, focusing on monocytes, macrophages and Natural Killer cells. We plan to address three focus areas using models of normal (non-diabetic), impaired (diabetic) and improved (LIV-treated diabetic) skin wound healing: First, we will elucidate mechanisms that enable inflammatory cell proliferation after entry into the wound. We will identify mechanisms underlying transitions of monocytes from a proliferative state in bone marrow, to a non-proliferative state in blood, and then back to a proliferative state in damaged tissue. We will also investigate mechanisms that regulate Natural Killer cell proliferation in wounds. Second, we will elucidate the role of infiltrating versus resident inflammatory cells in wound healing. We will use lineage tracing techniques to determine roles of infiltrating versus resident macrophages and Natural Killer cells in wound healing. Third, we will elucidate inflammatory cell communication pathways with other wound cells. We will use spatial transcriptomics to refine our current models of monocyte, macrophage and Natural Killer cell communication with other wound cells over space and time and will perform mechanistic testing of these models. To address each of these focus areas, we will use scRNAseq, scATACseq, spatial transcriptomics and downstream analysis to identify pathways involved in the regulation of inflammatory cell heterogeneity These studies will guide mechanistic experiments using available blocking antibodies, transgenic mice and bone marrow transfer. For the most promising candidates, cell-specific transgenic mice will be generated. To determine the degree to which our mouse data relates to human wound healing, we will map our results to published human wound scRNAseq and spatial transcriptomics datasets. The overall vision of our approach is that by identifying novel regulators of monocyte, macrophage and Natural Killer cell function during wound healing, we can develop novel approaches to manipulate inflammation and improve healing of difficult wounds, and in the process, generate a pipeline of candidate therapies to translate into clinical studies.