Spatial modes of inflammatory signaling in tissue*

Our immune system detects and responds rapidly to unexpected challenges from invading pathogens. These responses are collective—orchestrated by a variety of cells throughout the body, and the molecules that they use to communicate. They are also nonlinear, using positive feedback to amplify weak signals—crucial to their function, but dangerous to the host. While we have a nearly complete list of the components of this complex system, understanding the molecular and mathematical drivers of its dynamics remains a vast challenge. This difficulty is due partly to the fact that immune responses involve cells and molecules interacting throughout an organism, where observations remain challenging. However, new tools in optical imaging and molecular biology provide unprecedented opportunities to measure tissue-scale collective dynamics, with the goal of extracting quantitative rules governing this behavior. Here, we use some of these tools to characterize spatial patterns of inflammatory gene expression in the tailfin of the zebrafish, via quantitative snapshots. I will discuss the avenues that this opens for investigating collective control of inflammatory responses.