Context-Specific Regulation of NFkB Signaling Dynamics in Primary Macrophages

University Of California Los Angeles, Los Angeles CA

Investigators

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Abstract

PROJECT SUMMARY/ABSTRACT Macrophages are ubiquitous tissue-resident cells that are essential for tissue homeostasis and function. Macrophages coordinate the inflammatory response to pathogens, as well as, coordinate tissue repair programs. The diverse and context-specific functions of macrophages are represented in their epigenome. Misregulation of macrophage functions is implicated in autoimmune disorders. Understanding of how context- specific functions of macrophages are regulated by different cytokines is lacking. Elucidating how cytokines regulate macrophage function can inform novel immunotherapeutic approaches for targeting autoimmune diseases. The objective of this application is to examine how conditioning by cytokines, such as IFN? and TNF, regulates macrophage inflammatory responses via NF?B signaling dynamics. NF?B signaling will be measured using time-lapse microscopy in primary macrophages from RelA-mVenus knockin reporter mouse. The epigenomes and transcriptomes of conditioned macrophages will be examined using Histone ChIP-seq, ATAC-seq, and RNA-seq. Specifically, the proposed studies will address how IFN? and TNF regulate the temporal pattern of NF?B nuclear translocation. Preliminary data show that oscillatory NF?B translocations preserve the epigenomic landscape of macrophages, whereas non-oscillatory NF?B nuclear translocations disrupt the cell type-specific epigenomic landscape. Hence, control of NF?B dynamics by IFN? and TNF conditioning may regulate cell-type specific gene expression in macrophages. In Aim 1, I examine how loss of tonic TNF abolishes NF?B oscillations and the consequences on the macrophage epigenome and transcriptome. In Aim 2, I examine how IFN?-priming of macrophages abrogates NF?B oscillations and the consequences on the macrophage epigenome and transcriptome.