Dietary zinc deficiency and expression of T lymphocyte signal transductionproteins

Impaired immune function in dietary zinc (Zn) deficiency is characterized i n part by reduced lymphocyte numbers (lymphopenia) and depressed cell-media ted (T lymphocyte) immune function, however, the causative mechanisms at th e molecular level have not been elucidated. This paper will focus on the ro le of dietary Zn in T lymphocyte signal transduction, and specifically, the early Zn-dependent steps for phosphorylation and the putative Zn-finger pr oteins or Zn-metalloenzymes that may be part of the molecular mechanism for explaining immune dysfunction in Zn deficiency. One of the major recent fi ndings is that murine splenic T lymphocyte p56(lck) expression is elevated in dietary Zn deficiency and caloric deficiency. Based on the known functio ns of p56(lck), it is proposed that elevated p56(lck) may contribute to alt ered thymocyte maturation, apoptosis, and lymphopenia in dietary Zn deficie ncy and other malnutrition syndromes.