Vitamin cellular immunity

The immunological disorders of Indian childhood cirrhosis and of tropical splenomegaly syndrome, where there are disturbances of the immunoglobulin synthesis as well as defects of cellular immune responses, may be the results of a combination of infections and perhaps certain types of unusual autoimmune phenomena—or even to vitamin deficiencies. 

Undemutrition during fetal and early life impacts upon the development of the immune organs and appears to diminish cellular immunity and increase the risk of atopic disorders during childhood (Langley-Evans and Carrington 2006). The references confirm that many food components have a beneficial impact on various elements of the immune system. Proteins, some fats, vitamins (A, B6, E, and folic acid), macro- and microelements (zinc, iron, selenium, and copper), and certain bacteria (probiotic bacteria), for example, have a considerable effect on the immune system. 

Vitamin A-deficient experimental animals fail to grow adults are blind and sterile, with testicular degeneration in males and keratinization of the uterine epithelium in females. Although deficient female animals wUl conceive, and the fetuses will implant, formation of the placenta is impaired and the fetuses are resorbed. Epithelia in general are hyperplastic and keratinized, and there is impaired cellular immunity with increased susceptibility to infection. Both retinol and retinoic acid are required for gestation in the rat in deficient animals, retinoic acid alone will not prevent fetal resorption after about day 10 of gestation (WeUik and DeLuca, 1995 WeUik et al., 1997). 

Imazeki, I. et al. (2006) Immunomodulating effect of vitamin Dj derivatives on type-1 cellular immunity. Biomedical Research, 27, 1-9. 

Anderson, R., Smit, M. J., Joone, G. K., and Van Staden, D. M., 1990, Vitamin C and cellular immune functions Protection against hypochlorous acid-mediated inactivation of glyceraldehyde-3-phosphate dehydrogenase and ATP generation in human leucocyte immunostimulation, Ann. N.Y. Acad. Sci. 587 34-48. 

Vitamin E appears to act as an immunosuppressant due to its ability to suppress both humoral and cellular immune responses. Tocopherol supplementation significantly enhances lymphocyte proliferation, interleukin-2 production, and delayed-type hypersensitivity skin response and decreases prostaglandin E2 production by inhibiting cyclooxygenase activity. There appears to be compelling evidence that intervention with dietary antioxidants, such as vitamin E, may help maintain the well-preserved... 

The above scientific information on rice bran phytochemicals indicates that a multitude of mechanisms are operating at the cellular level to bring about specific health effects. Several health benefits of rice bran appear to be the result of the synergistic function of the many phytochemicals, antioxidants, vitamins and minerals which operates through a specific immune response. Their role in the biochemical mechanisms at the cellular level which result in major health effects is shown in Fig. 17.1. A short overview summarizing the effect of the various phytochemicals on major health issues such as cancer, immune function, cardiovascular disease, diabetes, altered liver function and gastrointestinal and colon disease will be given below. 

Vitamin A is essential for proper functioning of the retina, for the integrity of epithelial tissue, for growth and bone development and for reproduction. For vision the active vitamin appears to be retinal as the chromophore of both rods and cones is 11-cis-retinal which, in combination with the protein opsin, forms the photoreceptor rhodopsin. Retinoic acid is the active form associated with growth, differentiation, and transformation. Both all-trans and 9-cis retinoic acid act as a steroid hormone to affect cellular differentiation, especially for morphogenesis, reproduction and for immune responses. At... 

Maggini, S., Wintergerst, E. S., Beveridge, S., and Hornig, D. H. (2007). Selected vitamins and trace elements support immune function by strengthening epithelial barriers and cellular and humoral immune responses. Br. ]. Nutr. 98(Suppl 1), S29-S35. 

While most of these treatments are on a very shaky scientific footing, desperate people still try them. History has shown that when scientific medicine leaves a vacuum, a host of alternative practitioners will rush in to fill it. These people claim to have the answers that have somehow eluded mainstream researchers. Such as the benefits of the Harmony Token, a colored disk you wear around your neck its manufacturer claims that it resupplies minerals, vitamins, and amino acids with the color that has been stripped away by exposure to electromagnetic radiation. Our bodies, apparently, do not recognize these colorless substances and, as a consequence, our immune systems are weakened. The Harmony Token utilizes 2,800 colors to rebuild and repair the body at the cellular level and allows victims of rheumatoid arthritis to resume normal lives. Testimonials proclaim the disk s astonishing powers it improves gas mileage and reduces car emissions it makes racehorses run faster it cures migraines. It also makes me wonder about people s sanity. 

The influence produced on the immune system by vitamins, macro- and microelements may result from the fact that many of these compounds function as activators of enzymes, mediators of immunological reactions, and compounds responsible for the transfer of information between cells. Deficiency of these nutrients can weaken the humoral and cellular response and, in many cases, the nonspecific response of the immune system. The following vitamins are believed to produce particular influence on the immune system A, B6, C, D, and E (Brock 1996, Mukhopadhyay et al. 2000, Pfahl and Chytil 1996, Semba 1998, Zhao et al. 1994) (Table 2.2.4). 

Manolagas SC, Prowedini DM, and Tsoukas GD (1985) Interactions of 1,25-dihydroxy-vitamin D3 and the immune system. Molecular and Cellular Endocrinology 42,113-22. 

In its second role, in the regulation of cellular differentiation, vitamin A is involved in the formation and protection of epithelial tissues and mucous membranes. In this way it has particular importance in growth, reproduction and immune response. Vitamin A is important in the resistance to disease and promotion of healing through its effect on the immune system and epithelial integrity. In addition, it acts, along with vitamins E and C and 3-carotene, as a scavenger of free radicals (see Box 5.2, p. 83). 

Vitamin Bi, also called thiamine, is required for all tissues and high concentrations are found in skeletal muscle, heart, liver, kidneys and brain. Thiamine diphosphate (TDP) is the active form and it serves as a cofactor for several enzymes involved in carbohydrate catabolism. These enzymes are also important in the biosynthesis of many cellular constituents, including neurotransmitters, and for the production of reducing equivalents used in oxidant stress defenses (Ba 2008). Thiamine is considered an anti-stress vitamin because it strengthens the immune system and improves the body s ability to withstand stress conditions (Haas 1988). 

For peripheral blood mononuclear cells, which are components of the immune system (B cells, T cells and granulocytes), saturable kinetics of riboflavin uptake were proved (Km = 955 nM). Absorption was reduced by the addition of, among others, lumichrome and dinitrophenol. The transport was temperature dependent and sodium independent. During proliferation of these cells, uptake of the vitamin increased four times, although the transporter affinity and their number per cells remained unchanged. This suggested that accumulation of riboflavin in the cells is associated with variable cellular volume (osmolarity of environment) (Zempleni and Mock 2000) (Tables 36.1-36.4). 

The active form of vitamin D, 1,25 dihydroxy-vitamin D (l,25(OH)2D), binds to the vitamin D receptor (VDR), which is expressed in most cells. l,25(OH)2D functions as a steroid hormone, usually by heterodimerization with the retinoid X receptor, binding to vitamin-D response elements (VDRE) located in promoter regions. It induces the expression of target genes involved in many cellular responses, including the immune responses. 

The current leading hypothesis is that nuclear RAR and RXR play a direct role in this process. The retinoid receptors can be activated by physicochemical binding of free retinoic acid to RAR and RXR. Alternatively, covalent forms, such as retinoyl derivatives of RAR and RXR, might also exist. Interestingly, retinyl and retinoyl p-glucuronide stimulate the differentiations of HL-60 cells well without evident conversion to retinol and retinoic acid, respectively. Retinoic acid has also been implicated as a morphogen in embryonic development (18). The adverse effects of vitamin A deficiency on reproduction, growth, and the immune response, in all likelihood, are an expression of perturbations in the process of cellular differentiation. 

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