Dietary zinc deficiency and protein-energy malnutrition decrease in vitro murine T-lymphocyte cell cyle progression

Abstract

In two separate experiments, 35 female C56BL/6 adult mice were randomly assigned to 5 treatment groups (Zn deficient & low protein (ZnDF&LP), Zn deficient (ZnDF), low protein (LP), energy restricted (ER), and control (CTRL)) and fed for 4 weeks. Body weights and spleen weights of all four deficient groups were significantly lower than CTRL in both experiments. However, only the LP group had splenocyte counts significantly lower than CTRL. ZnDF&LP, ZnDF and LP groups had significantly lower serum Zn concentrations than CTRL. In Experiment 1, it was shown that the CD4+/CD8+ ratio of T-lymphocytes was unaltered by dietary deficiencies of zinc and protein. However, the ZnDF&LP group had a decreased percentage of CD4+ cells (23.3%) compared to the CTRL, and there was evidence that all four deficient groups may have increased numbers of immature "double-negative" T-lymphocytes compared to the CTRL group. Cell cycle analysis in Experiment 2 revealed that all deficient groups had a lower percentage of ConA-stimulated cells in S phase (15.8%-18.9%) in the presence of 2-mercaptoethanol compared to CTRL (25.7%). ZnDF&LP, ZnDF and LP groups had a higher percentage of cells in the resting (G$\sb0)$ phase of the cell cycle (78.8%-80.0%) compared to CTRL (70.4%). (Abstract shortened by UMI.)