Introduction and Overview

Infections caused by RNA viruses represent some of the most significant diseases of vertebrates in terms of both morbidity and economic impact. In addition to those with stable human reservoirs, RNA viruses are frequently responsible for zoonotic infections. Such infections account for some of the most feared and least understood infectious diseases. West Nile virus is an arthropod-transmitted virus whose natural reservoir is birds; it emerged in around 2000 as an important new cause of significant human neurological disease, including death, in North America. RNA viruses are clearly worthy of careful examination to understand mechanisms of disease pathogenesis, early and late immune responses, and immune evasion, and as such knowledge will help us develop new and more effective methods for controlling their spread or modifying their disease course. This introductory chapter of the book Cellular Signaling and Innate Immune Responses to RNA Virus Infections presents a brief insight into the organization of the book. The book is divided into two major parts. The first part focuses on the structure, interconnectivity, and mechanisms of activation of the pattern recognition receptors (PRRs)-initiated signaling pathways. The second part of this book examines the ways in which the major RNA virus families interact with these signaling pathways. The understanding of the specific pathways that will be gained from a review of the first part will help to place the diverse mechanisms of immune activation and evasion in context. Finally, overarching mechanisms are summarized and the work is tied together with unifying perspectives.