Induced Susceptibility of Host Is Associated with an Impaired Antioxidant System Following Infection with Cryptosporidium parvum in Se-Deficient Mice

Background: Susceptibility or resistance to infection with Cryptosporidium parvum (C. parvum) correlates with Selenium (Se) deficiency in response to infection. Both adult Se-adequate and Se-deficient mouse models of cryptosporidiosis were used to study the cell-mediated immune response during the course of C. parvum infection. Methodology/Principal Findings: Blood samples from mouse models were used for Se status. The concentration of MDA, SOD, GPx and CAT in blood has revealed that lower Se level exist in Se-deficient mice. Mesenteric lymph node (MLN) lymphocytes from both mouse models were proliferated after ex vivo re-stimulation with C. parvum sporozoite antigen. The study of the cytokine profiles from the supernatant of proliferated MLN cells revealed that Se-adequate mice produced higher levels of Th1 (IFN-gamma and IL-2) and moderate amounts of Th2 (IL-4) cytokines throughout the course of infection. Whereas, MLN cells from Se-deficient mice produced lower levels of IFN-gamma, IL-2 and IL-4 cytokines. The counts of total white cell and CD3, CD4, CD8 cell in Se-adequate were higher than that in Se-deficient mice. Significance: These results suggest that Cell immunity is affected by Se status after infection with C. parvum from kinetic changes of different white cells and cytokine. In conclusion, induced susceptibility of host is associated with an impaired antioxidant system following infection with C. parvum in C57BL/6 Selenium deficient mice.