Effects of cadmium and zinc on spontaneous and antibody-dependent cell-mediated cytotoxicity

The influence of cadmium and zinc ions on the interferon and tumor necrosis factor production in bovine aorta endothelial cells

The influence of CdCl(2), used at 1, 10 and 100 microM concentration, and ZnCl(2) at 1, 10 and 100 microM concentration on the production of interferon (IFN) and tumor necrosis factor (TNF) in bovine aorta endothelial cells (BAECs) was examined. BAECs were treated with cadmium ions or zinc ions alone or together with cytokine inducers: Newcastle disease virus (NDV) and lipopolysaccharide (LPS). Cadmium ions at 1 and 10 microM concentration, used alone induced a low, but detectable TNF activity in BAECs, and zinc ions at 1, 10 and 100 microM concentration induced both IFN and TNF activity. In contrast to that, cadmium added to BAECs together with the virus or LPS as cytokine inducers significantly inhibited the production of IFN and TNF. Cadmium effect depended on the concentration used, and 1 and 10 microM CdCl(2) partially, but 100 microM cadmium completely inhibited the production of both cytokines. Zinc ions at 1 and 10 microM concentration, which only slightly inhibited the production of both cytokines, did not reconstitute cadmium-depressed IFN and TNF production. These data indicate that cadmium-induced depression of cytokine production in bovine endothelial cells, in response to viral and bacterial stimuli, cannot be reversed by zinc supplementation.

In vitro effects of various metals on natural killer cell activity in cultured human lymphocytes

Heavy metals have been shown to have a differential effects on various aspects of immune response. Recently natural killer cells have been widely investigated due to their purported role in immune surveillance. To ascertain the immunotoxic effects of lead, cadmium, nickel and chromium on natural killer (NK) cell activity in vitro, peripheral blood lymphocytes from normal donors were examined in the presence of different concentrations (10(-5)-10(-8) M) of four selected metal salts (cadmium sulphate, lead nitrate, chromium nitrate and nickel sulphate). NK cell activity was evaluated in a 4-h chromium release assay against K562 target cells. All of the metal salts were found to exert no effect on NK cell function in the human concentration range.

Effect of cadmium body burden on immune response of school children

The effects of cadmium on measures of immune-system function were determined from a health survey of school children in heavily polluted regions of eastern Germany. A representative sample of 842 students, aged 5-14 y, was included in logistic regression analyses in which the relationship between urinary cadmium content and blood immunoglobulin levels was examined. Investigators further evaluated a subsample of 807 students to determine cadmium's effect on the immediate hypersensitivity reactions elicited by skin-prick challenges with 12 common aeroallergens. Several potentially confounding factors were controlled for, after which investigators found that increasing body burdens of cadmium were associated consistently with dose-dependent suppression of immediate hypersensitivity and of immunoglobin G, but not immunoglobulins M, A, or E levels. The immunoglobulin pattern observed in exposed children led investigators to suggest that secondary humoral responses were impaired by cadmium.

Simultaneous effects of lead and cadmium on NK cell activity and some phenotypic parameters

Lead and cadmium are common environmental contaminants that alter the immune response. Natural killer cell (NK) cytotoxicity and phenotypic parameters are crucial immune responses, but little is known about the effects of these metals on these responses. In the present paper, we investigated the simultaneous effects of lead and cadmium on NK cell activity and CD4+, CD20+ cell percentages in the workers and compared the data with control and lead-exposed groups. We conclude that simultaneous exposure to lead and cadmium is not associated with an impairment of either NK cell function of CD4+ cell percentage. On the other hand, CD20+ cell percentage was found higher in lead+cadmium exposed group than controls.

An immunological study on workers occupationally exposed to cadmium

1. To assess the quantitative relation between exposure to airborne cadmium and various markers of immune function, 37 male workers were examined and compared with unexposed controls. 2. Blood cadmium concentrations were significantly higher in the exposed workers than in the unexposed, as was urine cadmium. 3. No differences in the serum immunoglobulin (IgG, IgM and IgA) levels between two populations were observed. There was also no significant correlation between blood cadmium concentrations and serum immunoglobulin levels of both exposed and control groups, It has been found also that while monocyte counts significantly increased, lymphocyte, neutrophil and eosinophil counts remained unchanged.

Primary rat Sertoli and interstitial cells exhibit a differential response to cadmium

Two cell types central to the support of spermatogenesis, the Sertoli cell and the interstitial (Leydig) cell, were isolated from the same cohort of young male rats and challenged with cadmium chloride to compare their susceptibility to the metal. Both cell types were cultured under similar conditions, and similar biochemical endpoints were chosen to minimize experimental variability. These endpoints include the uptake of 109Cd, reduction of the vital tetrazolium dye MTT, incorporation of 3H-leucine, change in heat-stable cadmium binding capacity, and production of lactate. Using these parameters, it was observed that the Sertoli cell cultures were adversely affected in a dose-and time-dependent manner, while the interstitial cell cultures, treated with identical concentrations of CdCl2, were less affected. The 72-hr LC50's for Sertoli cells and interstitial cells were 4.1 and 19.6 microM CdCl2, respectively. Thus, different cell populations within the same tissue may differ markedly in susceptibility to a toxicant. These in vitro data suggest that the Sertoli cell, in relation to the interstitium, is particularly sensitive to cadmium. Because the Sertoli cell provides functional support for the seminiferous epithelium, the differential sensitivity of this cell type may, in part, explain cadmium-induced testicular dysfunction, particularly at doses that leave the vascular epithelium intact.

Role of thiols in human peripheral blood natural killer and killer lymphocyte activities

The thiol reagents, dithiothreitol, diethyldithiocarbamate and reduced glutathione were each found to inhibit Natural Killer and Killer lymphocyte-mediated cytotoxicities. A biphasic aspect to the inhibition with increasing concentration was observed with diethyldithiocarbamate and reduced glutathione. The inhibition observed in response to reduced glutathione, a non-permeant compound, suggests that cell surface thiols may be critical functional groups in the processes of NK and K lymphocyte-mediated cytotoxicities.