Immune system function deficiency effects

Zinc plays a number of important roles in the body and deficiency results in serious adverse effects. Recommended daily intake is 12 to 15 mg. Zinc is very common in the environment and readily available in many foods, including grains, nuts, legumes, meats, seafood, and dairy products. Numerous enzymes require zinc, as do proteins that regulate gene expression. Zinc plays a role in the immune system and is also important in the development and function of the nervous system. 

Early studies demonstrated a role for CRH in augmenting function of immune cells, such as natural killer cells (Carr et al 1990). The localization and the synthesis of CRH in the immune system and in immune cells were initially suggested by finding mRNA for CRH in leukocytes (Stephanou et al., 1990) and significant concentrations of CRH in areas of inflammation (KaraUs et al., 1991). This suggested CRH was produced locally that is, in the periphery in areas of inflammation, probably in part by immune cells. Further studies supported these ideas. In Lew/N rats, which are deficient in hypothalamic CRH responses to inflammatory stimuli, there are high levels of CRH in inflamed joints (Crofford et al., 1992). These data suggested that CRH plays the role of an autocrine or paracrine inflammatory factor. The obvious paradox is that CRH plays a powerful antiinflammatory role as the primary CNS activator of the HPA axis, yet in local peripheral sites it has just the opposite effect. Thus, CRH expression and function with respect to inflammation is site specific. 

The development, maintenance, and optimal functioning of the immune system are dependent on balanced and adequate nutrition. However, either a deficiency or an excess of a number of nutrients can have adverse effects. The nutrients with the most pronounced effects in humans include amount and type of dietary fatty acids (FAs), protein energy malnutrition, vitamins A, B6, B12, C, and E, and minerals including zinc, copper, selenium, and iron. Multiple rather than single nutrient deficiencies... 

Immunomodulators are drugs that directly modify a specific immune function or have a net positive or negative effect on the activity of the immune system. The potential uses of immunodulators in clinical medicine include the reconstitution of immune deficiency (e.g. the treatment of AIDS) and the suppression of normal or excessive immune function (e.g. the treatment of graft rejection or autoimmune disease). 

Vitamin E and selenium have roles in the immune system and protect against heavy metal toxicity. Other mutual functions and effects of deficiency in farm animals are discussed in the section on vitamin E (see pp. 81-86). 

This nucleoside appears to control the immune system in vitro both by interacting extracellularly with A1 and A2 membrane receptors and also intracellularly by inhibiting transmethylation and by acting on a P-site. Although adenosine is not the only endogenous modulator of the immune function, the above cited effects and the observation of patients with ADA deficiency suggest that this nucleoside may well have a significant role in the control of human inflammatory and immune reactions. 

---