Iron deficiency, but not underfeeding reduces the secretion of interferon-gamma by mitogen-activated murine spleen cells

Interferon-gamma (IFN-gamma), a cytokine primarily secreted by T and natural killer cells regulates cell-mediated and innate immunity. Iron deficiency, a public health problem in children impairs immune function. To determine whether reduced IFN-gamma contributes to impaired immunity, we measured IFN-gamma in supernatants of activated (2.5 mu g/ml concanavalin A, 50 ng/ml anti-CD3 antibody) spleen cells from control (C), iron-deficient (ID), pair-fed (PF), and iron-replete mice for 3 (R3) and 14 days (R14) (11-12/group). Except for iron content, the low iron (5 ppm) and control (50 ppm) diets had identical composition. Mean indices of iron status after 51 days of feeding were as follows: C = PF approximate to R14 > R3 > ID (p < 0.01). Iron deficiency, but not pairfeeding reduced IFN-gamma concentration in mitogen-treated cells by 30-43% (p < 0.05); iron repletion improved it. Reduced IFN-gamma was not simply due to differences in IL-12 (IFN-gamma inducer), percentage of CD3+ T cells, or impaired cell proliferation because these indices were not always decreased. It was likely due to a defect in T cell activation that leads to IFN-gamma gene expression. IFN-gamma positively correlated with indicators of iron status, body, and thymus weights (r = 0.238-0.472; p < 0.05). Reduced IFN-gamma secretion during iron deficiency may affect response to infections. (C) 2010 Elsevier Ltd. All rights reserved.