Title: Gut-associated lymphoid tissue
- Witold Lasek
- Review articles
- Polish Gastroenterology
- Start page:
- Final page:
- gut-associated lymphoid tissue, Peyer's patches, secretory IgA (S-IgA)
The mucous membranę covering the digestive tract is in continuous contact with large numbers of environ-mental agents/antigens with either pathogenic potential or no detrimental properties. The GALT (gut-associated lymphoid tissue) represents a system, the function of which is for the most part independent of systemie reactions. It is composed of two compartments: inductive sites, where immune response is initia-ted, and effector sites. The former include highly specialised structures such as Peyer's patches, the ap-pendix and solitary follicles of the gastrointestinal tract while the latter consist of numerous lymphocytes di-spersed throughout the lamina propria and gastrointestinal epithelium. One of the most important defence elements of GALT are secretory IgA (S-IgA) which play a major role in the protection of mucosal surfaces. The defence mechanisms in GALT operate in a highly selective manner: on the one hand they are activated against infeetious agents, while on the other hand they are suppressed when in contact with food antigens and indigenous microflora.