For thousands of years humans have marvelled at how the body is able to protect itself from infectious pathogens. Even the ancient Chinese and Greeks acknowledged the protective effects of the immune system, noting how one is rendered resistant to catching the same disease a second time. The first empirical studies were performed by Edward Jenner, and later Louis Pasteur, who developed vaccines against smallpox and anthrax, respectively. Indeed, vaccination has become such an important aspect of human health it is sometimes easy to forget the central role the immune system plays in affording protection against so many diseases.
The vast majority of medically important pathogens infect their host across a body surface such as the skin, or across a mucosal tissue such as the respiratory tract or intestines, as these sites are the ones exposed to the external environment. Vertebrates have therefore evolved elaborate immune defence mechanisms to protect against infection across mucosal linings and body surfaces. Mucosal immune defence mechanisms are therefore integral to our survival. However, conventional immunology textbooks largely overlook this aspect of the immune system, even though it remains fundamental for the prevention of infectious disease. Many have continued to teach immunology based on knowledge of the central immune system of the blood and spleen, rather than teaching immunology from the perspective of mucosal and body surfaces. After all, these are the places where host–pathogen interactions actually take place. Therefore I have tried to redress this bias by focusing on immunity at mucosal and body surfaces. This book should therefore prove useful for science undergraduates studying immunology, medical students undertaking academic studies, postgraduate students working toward a higher degree and the broad spectrum of professional academic and clinical scientists working in the field of immunology.
