Sterile inflammation in Drosophila.

Zeeshan Shaukat,Dawei Liu,Stephen Gregory

doi:10.1155/2015/369286

Abstract

The study of immune responses in Drosophila has already yielded significant results with impacts on our understanding of vertebrate immunity, such as the characterization of the Toll receptor. Several recent papers have focused on the humoral response to damage signals rather than pathogens, particularly damage signals from tumour-like tissues generated by loss of cell polarity or chromosomal instability. Both the triggers that generate this sterile inflammation and the systemic and local effects of it are only just beginning to be characterized in Drosophila. Here we review the molecular mechanisms that are known that give rise to the recruitment of Drosophila phagocytes, called hemocytes, as well as the signals, such as TNFα, that stimulated hemocytes emit at sites of perceived damage. The signalling consequences of inflammation, such as the activation of JNK, and the potential for modifying this response are also discussed.

Highlights

The inflammatory response to infection by pathogens has been intensively studied for many years both in humans and in all the major model organisms
The inflammatory response in Drosophila lacks several features of vertebrate inflammation, such as heat, redness, and extravasation of leucocytes, some signalling pathways regulating the response are conserved and were discovered in Drosophila. In both insects and mammals there is the recruitment of immune cells to the affected site and the release of chemicals and peptides intended to damage pathogens; this is the process we are describing as inflammation
Many damageassociated molecular patterns (DAMPs) are the normal molecules of the cytoplasm or nucleus that become immunogenic when exposed to extracellular environment

Summary

Introduction

The inflammatory response to infection by pathogens has been intensively studied for many years both in humans and in all the major model organisms. The inflammatory response in Drosophila lacks several features of vertebrate inflammation, such as heat, redness, and extravasation of leucocytes, some signalling pathways regulating the response are conserved and were discovered in Drosophila In both insects and mammals there is the recruitment of immune cells to the affected site and the release of chemicals and peptides intended to damage pathogens; this is the process we are describing as inflammation. The inflammatory triggers, are not from a pathogen and must be generated by changes to normal cells that expose altered or mislocalized self-molecules to the immune system to generate a damage signal These signals, known as damageassociated molecular patterns (DAMPs), are currently the subject of intensive research and may include extracellular chromatin, ATP, cytoskeletal molecules, and mitochondrial components [2]. We will examine the types of cellular damage that can give rise to sterile inflammation during larval life in Drosophila and the molecular triggers involved

Sources of Sterile Inflammation Triggers in Drosophila

Effects of the Inflammatory Response

Implications of Sterile Inflammation Control