Mucosal immune system, organization

Lymphocytes (T cells)—a group of white blood cells of crucial importance to the adaptive part of the organism s immune system. There are many kinds of lymphocytes (Th 0, Th c, Th 1, Th 2, Th 17). Cytokines produced by T cells probably play a major role in orchestrating allergic inflammation. TH 1 cells produce IFN-y and IL-2 but not IL-4 or IL-5 after activation. TH2 cells produce mainly IL-4, IL-13, and IL-5 but not IL-2 or IFN-y. TH2 cells characterize human allergic responses and are present at mucosal surfaces during the late but not immediate response to an allergen exposure. 

The discovery of vaccines for smallpox, cholera, and typhoid and the variety of vaccines now available have led to a significant reduction in the mortality and morbidity due to many diseases, with smallpox being the first to have been completely eradicated and poliomyelitis targeted to be the next. At present, the World Health Organization is working toward the complete elimination of poliomyelitis throughout the world [188,189], However, since Jenner discovered the vaccine for smallpox more than two centuries ago [190], only some 50 vaccines have been approved for use, and few additional vaccines have been discovered. Most of those in current use are administered parenterally they can induce only a systemic immune response, not mucosal immunity. Obviously the latter is very important in the prevention and treatment of infectious diseases, be they due to viral, bacterial, or parasitic pathogens that attack via the mucosal surfaces [190],... 

Live Attenuated Organisms. Live attenuated bacteria and viruses have been used not only as vaccines but also as a delivery system that elicits humoral, mucosal, and cellular immune responses against exogenous antigens. Since the success with live attenuated oral vaccines against tuberculosis and polio more than 3 decades ago, a number of live attenuated microorganisms have been used as antigen-delivery systems. Live vaccines are relatively easy and cheap to manufacture, because they do not require purification of... 

Many polysaccharides contain branched structures and are chemically modified by the addition of other molecules. Their monomeric or repeat units are often made up of more than one sugar molecule and, consequently, can be quite complex. They form protective capsules of some of the most virulent microorganisms, capsules that, nevertheless, carry information that activate mammalian defenses the immune, interferon, and properdin systems [9, 136]. They are found as key portions of the exoskeletons of insects and arthropods and cell walls of plants and microbes and perform as reserve foodstuffs and important components of intercellular, mucous secretions, synovial and ocular fluids, and blood serum in many organisms. Food Applications compiles recent data on the food applications of marine polysaccharides from such various sources as fishery products, microorganisms, seaweeds, microalgae, and corals [137, 138]. One of the applications of this biopolymer relates to a method for protecting against diseases induced by Streptococcus pneumoniae infections, which comprises mucosal administration of a S. pneumoniae capsular polysaccharide to a patient in need. 

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