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A review of porcine tonsils in immunity and disease

Published online by Cambridge University Press:  28 February 2007

Dennis C. Horter ,
Kyoung-Jin Yoon  and
Jeffrey J. Zimmerman
Dennis C. Horter
Affiliation:
Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
Kyoung-Jin Yoon
Affiliation:
Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
Jeffrey J. Zimmerman*
Affiliation:
Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
*
*E-mail: jjzimm@iastate.edu
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Abstract

The porcine tonsils are a group of lymphoepithelial tissues located at the common openings of the gastrointestinal and respiratory tracts. The tonsils participate in a variety of functions involving innate, cellular and humoral immunity at the local and systemic levels. Among these immunological functions is the continuous surveillance for the presence of foreign antigens at the openings of the gastrointestinal and respiratory tracts. Within the pig, the movement of lymphocytes, cytokines and chemotactic molecules from the tonsils to other lymphoid organs confers immunity to other portals of pathogen entry and facilitates an efficient and rapid systemic immune response. In spite of the immunological nature of the tonsils, some microorganisms have acquired adaptations that allow them to circumvent the tonsillar immune defenses and utilize the tonsils as a site of entry, replication and colonization. Several bacterial and viral pathogens persist asymptomatically within the tonsils, making identification of asymptomatic carrier animals difficult in disease control and/or pathogen elimination. This paper reviews the current information on the anatomy, immunology and pathobiology of porcine tonsils and discusses the tonsils as a site of pathogen entry, replication and colonization using Salmonella spp., classical swine fever virus and porcine reproductive and respiratory syndrome virus as examples.

Keywords

tonsilsimmunitydiseasepigs
Type
Review Article
Information
Animal Health Research Reviews , Volume 4 , Issue 2 , December 2003 , pp. 143 - 155
Copyright
Copyright © CAB International 2003

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