Effects of Selenium and Cadmium on Changes in the Gene Expression of Immune Cytokines in Chicken Splenic Lymphocytes

Cadmium (Cd) is an environmental pollutant that is considered to be a potent toxin to organisms. Selenium (Se) has been known for its concomitant biological effects and characteristics with Cd. Due to the lack of the research regarding how the duality of Cd/Se affects immune cytokines in poultry, this paper aims to partly tackle this question. Chicken splenic lymphocytes with Cd (10(-6) mol/L CdCl2), Se (10(-7) mol/L Na2SeO3), Cd + Se (10(-7) mol/L Na2SeO3 and 10(-6) mol/L CdCl2), and a control group were incubated for 12, 24, 36, 48, and 60 h, respectively. At each time point, the cells were collected and the messenger RNA (mRNA) expression levels of interleukin (IL)-1 beta, IL-2, IL-4, IL-10, IL-17, and interferon-gamma (IFN-gamma) were also examined. Compared with the control group and the Se-alone-treated group, the mRNA expression levels of IL-2, IL-4, IL-10, IL-17, and IFN-gamma decreased significantly in the Cd-alone-treated group. By contrast, the mRNA expression level of IL-1 beta markedly increased. Levels of IL-2, IL-4, IL-10, IL-17, and IFN-gamma in Cd + Se-treated groups were significantly higher than those in Cd-alone-treated groups; however, the levels were not as high as the Se-alone-treated groups and the control group. The mRNA expression level of IL-1 beta in the Cd + Se-treated group was lower than in the Cd-alone-treated group. The relationships with IL-2, IL-4, and IL-10 were found to be closer in the PC 1 matrix and 3D plot of the principal component analysis (PCA) loadings. IL-17 and IFN-gamma were closer in the matrix of PC 2. However, IL-1 beta gene expression appeared to be isolated in the matrix of PC 3. In addition, the results of cytokine cluster analysis showed that IL-2, IL-4, IL-10, IL-17, and IFN-gamma were in the first group and that IL-1 beta was in the second group. Therefore, Se partly attenuate immune toxicity induced by Cd in chicken splenic lymphocytes.