Immune system carbohydrates

Biermann, C. (1988). Hydrolysis and other cleavages of glycosidic linkages in polysaccharides. Advances in Carbohydrate Chemistry and Biochemistry, 46, 251-271. Bland, E. J., Keshavarz, T. Bucke, C. (2004). The influence of small oUgosaccharides on the immune system. Carbohydrate Research, 339,1673-1678. 

Science 200T,21(5512) 2263. (This issue contains a special section entitled Carbohydrates and Glycobiology. It contains articles on the synthesis, structural determination, and functions of sugar-containing molecules and the roles of glycosylation in the immune system). 

A wide diversity of herbal remedies have purported abilities to stimulate defense functions. Complexes of carbohydrate and lignin, which are present in some herbs, modulate enteric immune functions (Kiyohara et al, 2000), and the changes in cytokine secretion (Matsumoto and Yamada, 2000) can trigger systemic responses. The polysaccharides present in other herbal medicines augment production of immunoglobulin (Ig) A by the Peyer s patches in the small intestine (Sakushima et al, 1997 Yu et al, 1998). The responses of the enteric immune system to lectins are variable (Pusztai 1993), and can elicit systemic responses (Lavelle et al, 2000). Other phytochemicals provide protection by inducing detoxification pathways in mucosal cells (Williamson et al, 1998). 

KIYOHARA H, MATSUMOTO T, YAMADA H (2000) Ligniu-carbohydrate complexes intestinal immune system modulating ingredients in kampo (Japanese herbal) medicine, juzen-taiho-to. Planta Med. 66 20-24. 

Some reports even indicate that the conjugation of proteins or peptides with carbohydrates can increase dramatically their activity compared to that of the native state (Susaki et al., 1998). Carbohydrates also can provide a protective effect on modified peptides toward proteolytic digestion (Rudd et al., 1994) or mask recognition of a peptide by the immune system (Harding et al., 1993). The creation of neoglycoproteins thus can affect the activity of peptides and proteins, which are not normally glycosylated in vivo. 

The glycocalyx (carbohydrate-rich outer cell coat) can possibly shield tumour antigens from the immune system. 

Epitope is an antigenic determinant (a part of a molecule to which an antibody binds), which is a biological structure or sequence, such as a protein or carbohydrate, that is recognized by the immune system and to which an antibody binds. 

Physioiogicai There is an extensive literature that deals with the effects ginseng on CNS function, but effects are also seen in neuroendocrine function, carbohydrate and lipid metabolism, the immune system, and cardiovascular function (Gillis 1997). Ginsenosides induce a decrease in heart rate and have biphasic effects on blood pressure, with decreases preceded by a slight increase (Kaku et al. 1975). Ginsenoside Rgl had the most potent effects on blood pressure. Little or no effect is observed on respiration. 

Clearly, further studies will be necessary to sort out the multiple factors involved in the in vivo immune response to C. neoformans carbohydrate-mimetic peptides. Several conclusions may be drawn from the results to date. Peptides that mimic the cryptococcal capsular polysaccharide show specificity, in that each peptide binds with differing affinity to closely related mAbs [140,149]. The pattern of binding to protective and nonprotective mAbs differs between the mimetic peptides and the polysaccharide [140]. Protective efficacy is related to the location of carbohydrate epitopes recognized by these mAbs, within the polysaccharide capsule, but hkely also depends on interactions between mAbs and cellular responses [149]. Peptides have been shown to be functional, immunogenic mimics, but their protective efficacy depends on multiple factors, including the type of Abs elicited and interactions with the cellular immune system. Protective efficacy does not correlate with binding affinity to representative mAbs, but rather depends on the nature of these interactions. 

A major function of the immune system is thought to be destruction of cancer cells. In this case altered cell surface carbohydrates or proteins elicit an antibody response with destruction of the offending cells. 

Biosynthesis of carbohydrates, fatty acids Biosynthesis of membrane lipids, amino acids Nutrition and digestion Immune systems, antigens... 

Polysaccharides and generally carbohydrates represent the main carbon sink in the plant cell. Polysaccharides commonly serve nutritional (e.g., starch) and structural (e.g., cellulose) functions in plants. Some polysaccharides are cytotoxic against certain types of cancer, such as mouse skin cancer, or tumor lines in vitro (e.g., mouse Sarcoma-180). However, most polysaccharides exert their action through stimulation of the immune system (cancer immunotherapy). Plants containing polysaccharides with anticancer properties include the following ... 

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