Serum thymulin in human zinc deficiency.

Abstract

The activity of thymulin (a thymic hormone) is dependent on the presence of zinc in the molecule. We assayed serum thymulin activity in three models of mildly zinc-deficient (ZD) human subjects before and after zinc supplementation: (a) two human volunteers in whom a specific and mild zinc deficiency was induced by dietary means; (b) six mildly ZD adult sickle cell anemia (SCA) subjects; and (c) six mildly ZD adult non-SCA subjects. Their plasma zinc levels were normal and they showed no overt clinical manifestations of zinc deficiency. The diagnosis of mild zinc deficiency was based on the assay of zinc in lymphocytes, granulocytes, and platelets. Serum thymulin activity was decreased as a result of mild zinc deficiency and was corrected by in vivo and in vitro zinc supplementation, suggesting that this parameter was a sensitive indicator of zinc deficiency in humans. An increase in T101-, sIg-cells, decrease in T4+/T8+ ratio, and decreased IL 2 activity were observed in the experimental human model during the zinc depletion phase, all of which were corrected after repletion with zinc. Similar changes in lymphocyte subpopulation, correctable with zinc supplementation, were also observed in mildly ZD SCA subjects. Inasmuch as thymulin is known to induce intra-and extrathymic T cell differentiation, our studies provide a possible mechanism for the role of zinc on T cell functions.

Severe dermatitis with loss of epidermal Langerhans cells in human and mouse zinc deficiency

“…Indeed, several studies using animal models of Zn deficiency have confirmed that decreased levels of Zn induce thymic atrophy, lymphopenia, and compromised cell-and antibody-mediated immune responses (14,15). Zn deficiency affects many aspects of immune function, including a shift of the Th cell response to a Th2 predominance, reduced antibody formation, reduced killing activity by NK cells and lower levels of phagocytosis and intracellular killing in granulocytes, monocytes, and macrophages (14)(15)(16)(17)(18). Zn also influences the production of chemokines and proinflammatory cytokines like TNF-α, IL-1β, and IL-6 (19)(20)(21)(22).…”

Considerations for determining ‘optimal nutrition’ for copper, zinc, manganese and molybdenum

“…Thymulin is a Zn-dependent immunomodulatory peptide secreted by thymic epithelial cells. Serum thymulin activity is decreased in mild Zn deficiency associated with either dietary Zn restriction or sickle-cell anaemia (Prasad et al 1988). Thymulin activity was increased following Zn supplementation of the subjects and by in vitro addition of Zn to samples from mildly-Zn-deficient subjects.…”

What Caused the Epidemic ofPneumocystisPneumonia in European Premature Infants in the Mid-20th Century?

“…29,30 Fatal Pneumocystis pneumonias occur in humans with severe defects in CD4 ϩ and CD8 ϩ T cells. [31][32][33] T-cell deficiencies are commonly due to congenital or genetic defects, 34 protein/energy malnutrition, 35,36 zinc deficiency, [37][38][39][40][41][42] and human immunodeficiency virus (HIV) 3,[43][44][45][46][47] and in some patients with human T-cell leukemia virus type 1, also known as human T-cell lymphotropic virus type 1 (HTLV-1). 48,49 Such T-cell deficiencies also lead to other infections.…”

“…53 Consequently, zinc deficiency could have interfered with the development and function of T cell in the recipient infants. [37][38][39][40][41][42] However, certain aspects of zinc deficiency are less consistent with that possibility. (1) Zinc-deficient infants have poor growth.…”