Humoral and cell-mediated immunity in mice with genetic deficiencies of prolactin, growth hormone, insulin-like growth factor-I, and thyroid hormone

Prolactin (PRL), growth hormone (GH), insulin-like growth factor-I (IGF-I), and thyroid hormones have been proposed as critical immunoregulatory media tors, and their clinical use is being considered. The precise role played b y each of these hormones in the generation of humoral and cell-mediated imm une responses was assessed in a panel of mice with mutations that result in a selective reduction of PRL, GH, IGF-I, and/or thyroid hormone production . A surprising result, in view of previous studies indicating an immunoregu latory role for these hormones, was that all mice generated normal humoral and cell-mediated immune responses following challenge with T-independent a nd T-dependent antigens and with Listeria monocytogenes. A review of these findings in the context of previous data has resulted in the formulation of a working hypothesis proposing that these hormones act as anabolic and/or stress modulating mediators with effects on most cells, including those of the immune system. When considered in this context, it is possible to recon cile the contradictory data. (C) 2000 Academic Press.