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United States Department of Agriculture

Agricultural Research Service

Title: Immune System

Author
item Eicher, Susan

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: January 26, 2006
Publication Date: N/A

Technical Abstract: The immune system is not a static system. It is now believed that a healthy immune system is one that has been exposed to antigens throughout development, thereby developing an adequate education of self and non-self and immunological memory (Rook and Stanford, 1998; Kabesch and Lauener, 2004). Some aspects of the immune systems are well-conserved among species, but occasionaly pronounced differences can be observed (Pastoret et al., 1998). This discussion will present general immunology, with some references to species specific differences. The primary functions of the immune system are first to prevent pathogen entry and colonization, and secondly to clear on-going infections. Five classes of disease causing organisms are: viruses, bacteria, fungi, protozoa, and helminths (worms). The latter two constitute the discipline of parasitology and the first three are in the discipline of microbiology and the efficiency of the immune response is relative to the disease. The immune system is arbitrarily divided into two systems, innate and adaptive immunity. Some are controlled best by an innate immune response, while others are best controlled by adaptive immunity. Adaptive immunity requires prior exposure to antigen, while innate does not. However, these systems are closely connected, and are derived from the same cell source. The immune system is a complex system, but with a relatively small number of types of cells involved. It begins with basic innate immune responses, these eventually lead to interaction with cells of the adaptive immune system. Through these interactions of cells, cytokines, and proteins, immunity is developed against specific antigens. Finally, memory cells are left that can mount a quick antibody response if the antigen is encountered again.

Last Modified: 7/24/2014
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