Chapter 24 - Immunophysiology of the avian immune system

Abstract

Our knowledge of the avian immune system and the avian immune response to disease and vaccination still lags behind that of better studied biomedical model systems, such as the human and mouse, progress has been dramatic. Thanks to the chicken genome sequence, we now have far greater understanding of the genes and molecules available to the avian immune response and, therefore, access to the tools required to enable us to understand the biology of that response in far greater detail than previously. In broad terms, the immune systems and responses of mammals and birds are similar. Both mount innate and adaptive immune responses, and the bird’s adaptive immune responses include both cell-mediated and humoral immune responses, leading to immunological memory. However, when one looks at the organs, cells, and molecules of the immune response in birds, one begins to understand that mammals and birds achieve the same overall responses often in quite different ways and, in many respects (but not all), the avian immune response is different. It would be very difficult to summarize all aspects of the avian immune system in this chapter. Instead, we will concentrate on the basic anatomy of the organs of the avian immune response, as well as a description of the major cell types and major areas where the cells and molecules of the immune response differ from those of mammals—in some cases, being unique to avians.