Splenocytes from copper-deficient mice are low responders and weak stimulators in mixed lymphocyte reactions

The effects of chromium and copper supplementation on mitogen-stimulated T cell proliferation in hypercholesterolaemic postmenopausal women

The purpose of this study was to analyse effects of chromium and/or copper supplementation on immune function in hypercholesterolaemic postmenopausal women. A 2 x 2 factorial research design was used and 40 subjects were supplemented with 0.394 g lactose, 200 microg Cr, 3.0 mg Cu, or 200 microg Cr and 3.0 mg Cu/d for 12 weeks. A significant interactive effect of Cr and Cu supplementation on lymphocyte proliferation was observed with ConA 50 microg/ml stimulation. After 12 weeks of supplementation, ConA-stimulated (50 microg/ml) lymphocyte proliferation was significantly lower when Cu was added to the Cr supplementation group. Moreover, ConA-stimulated (100 microg/ml) lymphocyte proliferation was significantly lower in the Cu supplementation group compared to the Cr supplementation group after 12 weeks of supplementation. These results suggest that Cu blocks enhancement of lymphocyte proliferation by Cr supplementation and that Cu supplementation has potential suppressive effects on the immune function in these subjects.

Nutrition and immunity with emphasis on infection and autoimmune disease

Nutrition and nutritional status can have profound effects on immune functions, resistance to infection and autoimmunity in man and other animals. Nutrients enhance or depress immune function depending on the nutrient and level of its intake. Protein-energy malnutrition and vitamin A deficiency are strongly associated with impaired immunity and infectious disease. The essential role vitamin A plays in infection and maintenance of mucosal surfaces has long been known. Recent evidence shows that T-cell subpopulations, cytokines and antibody subclasses are all affected by vitamin A. In animal studies supplementation with vitamin E protects against infection and is linked to stimulatory effects on the immune system. In man vitamin E and other anti-oxidants increase the number of CD4+ cells. Dietary lipids and zinc have a substantial impact on autoimmunity from protective to potentiation of immuno-pathological processes in animals. There is considerable potential to modify human autoimmune disease by manipulation of lipid nutrition. Deficiency of pyridoxine induces atrophy of lymphoid organs, marked reduction in lymphocyte numbers, impairs antibody responses and IL-2 production. Dietary copper is important in the prevention of infection in some animal species and T-cell function is defective under deficiency states due to an inability to produce IL-2. Selenium has been linked to viral infection, enhanced T-cell functions and TNF beta induced increase in natural killer cell activity. Understanding the molecular and cellular immunological mechanisms involved in nutrient-immune interactions will increase our applications for nutrition of the immune system in health and in disease

Paradoxical conditioning of the plasma copper and corticosterone responses to bacterial endotoxin

The cascade of physiologic mechanisms in response to infection, the acute phase response, is recognized as having a major role in host defense. Two such responses are an increase in plasma copper and activation of the hypothalamic-pituitary-adrenal axis, which are consistently reported to occur during bacterial infection. We aimed to determine whether the alterations in plasma copper and corticosterone were conditionable using the conditioned taste aversion paradigm. The regime involved the pairing of a novel-tasting saccharine solution (the conditioned stimulus) with lipopolysaccharide (the unconditioned stimulus). Seven days after the initial pairing of these stimuli (the test day), the saccharine solution was represented. Animals exposed to this condition displayed a significant decrease in plasma copper levels. In addition, these rats experienced a reduction in plasma corticosterone that was time dependent. Paradoxically, the conditioned response of both these variables were in a direction contrary to that reported during bacterial infection. These results suggest that some acute phase responses may condition as a rebound response, or in an opposing trend to that occurring as the initial reaction.

The effect of alcohol consumption on nutritional status during murine AIDS

As alcohol (ETOH) abusers and AIDS patients have nutritional disorders, the influence of chronic ETOH consumption (5% v/v for 10 weeks) on levels of immunomodulatory nutrients (vitamins A and E, Zn, and Cu) in the serum, liver, small intestine, spleen, and thymus was determined during murine AIDS. The hepatic levels of vitamins A and E and Zn in both normal and LP-BM5 retrovirus-infected female C56BL/6 mice fed ETOH were significantly reduced compared to controls, whereas the level of Cu in the liver was not affected. Intestinal levels of vitamin A and Cu were not affected by ETOH, whereas vitamin E and Zn were significantly reduced in both normal mice and those with AIDS fed ETOH. The splenic levels of vitamin A and Zn in the normal mice were significantly reduced by ETOH compared to controls, but vitamin E and Cu were not. All splenic levels of nutrients measured were reduced in ETOH-fed mice with AIDS. The levels of vitamins A and E, Zn, and Cu in the thymus in murine AIDS were also significantly affected by ETOH consumption. The serum levels of vitamins A and E in both normal mice and murine AIDS were significantly decreased by dietary ETOH. These data produced evidence that chronic ETOH can directly aggravate undernutrition initiated by retrovirus infection. Such ETOH-induced malnutrition in AIDS may be a cofactor, accelerating development of AIDS via immunosuppression secondary to nutritional deficiencies.

Interleukin-2 production is altered by copper deficiency

Copper is an essential nutrient for optimal function of the immune system; deficiency results in impairment of both humoral and cell-mediated components. Copper deficiency in rodents results in decreased numbers of CD4+ (helper) and total T cells. This defect has been traced to impaired production of interleukin-2, a cytokine essential for T-cell division and differentiation. Impairment of quiescent cell proliferation is reversed by both in vivo and in vitro copper supplementation.

Suboptimal levels of dietary copper vary immunoresponsiveness in rats

The effects of severe, moderate, and mild copper deficiencies on cellular and humoral immunity were studied. Fifty male Sprague-Dawley rats, 5 wk of age, were fed diets containing 0.5, 2.0, 3.5, or 5.0 micrograms Cu/g for either 4 or 8 wk. Ten of the rats were fed the control diet, but were pair-fed with the 0.5-micrograms/g treatment group. All rats were immunized once with sheep red blood cells. Mean plasma-copper concentration reflected the dietary levels of copper, and ceruloplasmin activity correlated highly to plasma copper. Rats consuming suboptimal levels of copper responded differently to the deficiencies, so copper status varied among those animals. After 8 wk, cell proliferation, when stimulated by phytohemagglutinin, was dependent on the copper status of the animal. Severely deficient rats had consistently lower lymphocyte stimulation indexes for phytohemagglutinin and concanavalin A, but specific antibody response was not reduced. Immunoglobulin G (IgG) concentrations were variable for all rats, and immunoglobulin M (IgM) concentrations were lower for the severely deficient rats. Suboptimal dietary copper may alter immune function in rats, depending on the ensuing effect on copper status.

Biochemical and immunological changes in mice following postweaning copper deficiency

Weanling albino male mice rapidly develop biochemical signs of copper deficiency when fed a purified diet containing 0.5 mg Cu/kg. Plasma ceruloplasmin activity of copper-deficient (-Cu) mice was 5% of that of copper-adequate (+Cu) control mice after only 3 d on the diet. More gradual loss of organ (liver, spleen, and thymus) cytochrome c oxidase activity was observed during the next 4 wk. Body weight was equivalent between +Cu and -Cu mice, but thymus weight dropped faster in -Cu mice than +Cu mice. The number of antibody producing cells to sheep erythrocytes was lower in -Cu mice compared to +Cu mice after 17 d on the diet. Spleen cytochrome oxidase activity of -Cu mice was 50% of that of +Cu mice by 10 d on the diet. Mitogenic response of splenic and thymic lymphocytes to concanavalin A (con A) was not greatly different between +Cu and -Cu mice. Splenocytes from -Cu mice had a 3-fold higher thymidine incorporation rate in the absence of mitogen compared to +Cu mice. The depressed antibody and high mitogenic background responses of -Cu mice were similar to previous work with another strain (C58) of mice that had been started on copper-deficient treatment from birth. However, the normal proliferative response to con A stimulation in postweaning copper deficiency differs from the previous model. Mice of both studies were very copper-deficient as judged by liver copper levels. Timing of the copper-deficient treatment influences the manner in which copper deficiency alters the immune response.

Effects of dietary copper deficiency on male offspring of heterozygous brindled mice

Female C57BL mice heterozygous for the brindled gene were mated to normal males and fed on a purified diet low in copper throughout gestation and lactation with (+Cu) or without (-Cu) Cu-supplemented drinking water. Male offspring of two genotypes (control, +/y and brindled, Mobr/y) were compared when 10-12 d old. Brindled mice from dams on the -Cu treatment were smaller and had lower packed cell volumes than brindled mice from dams on the +Cu treatment. The -Cu brindled mice were smaller than their littermate brothers (+/y) but had equivalent biochemical features consistent with severe Cu deficiency. Compared with control mice from dams on the +Cu treatment, caeruloplasmin (EC 1.16.3.1) activity was lower in offspring of all three other groups including Mobr/y mice who were not anaemic. Iron levels were similar in organs and bone marrow from all four groups of offspring. When dietary Cu is limiting in brindled mice a more severe Cu deficiency ensues. Thus, appropriate Cu nutriture is important to the management of Menkes' disease in humans, a genetic analogue of the brindled mouse.

Advances in the role of minerals in immunobiology

Immunology and our understanding of its various cells, immunoglobulins and lymphokines are recent events that date from the work of Pasteur and Metchnikoff in the late nineteenth century. Experimental evidence has shown the importance of adequate dietary protein and vitamins. The present review examines past and recent experimental evidence for the role of minerals in the functioning of the immune system. Included is in vivo and in vitro information on the macrominerals; calcium and magnesium, the micro-(trace) minerals; iron, zinc, copper, and selenium as they affect various components of the immune system. The effects of gold as either gold-thiomaleate or gold-thioglucose on selenium is also reviewed.