Figure 3.Effects of different hormones, neurotransmitters or neuropeptides on type 1/pro-inflammatory and type 2/anti-inflammatory cytokine production, the Th1/Th2 balance, and cellularvs. humoral immunity. Note that the systemic Th2-inducing, anti-inflammatory effects of some hormones and neurotransmitters, as depicted here, may not pertain to certain conditions or local responses (see text and Figure 4, below). GCs, E2 and 1,25(OH)2 vitamin D3 do not affect the production of IL-10 by monocytes; yet, lymphocyte-derived IL-10 production is up-regulated by these hormones. *Available evidence suggests that progesterone up-regulate the production of IL-4 by lymphocytes and Th2 cells, without affecting the secretion of IL-10 by these cells; conversely, E2 and 1,25(OH)2 vitamin D3 up-regulate lymphocyte-derived IL-10, but do not affect the production of IL-4. Note that CAs, and probably histamine and adenosine are not able to affect the production of type 2 cytokines by Th2 cells, directly, simply because these cells do not express b2-ARs, and most likely H2 and A2a receptors or because Th2 cells might have less active cAMP/PKA pathway. Indirectly, however, andin vivoconditions, they may potentiate the cytokine production by Th2 cells, since they remove the inhibitory restraints on these cells exerted mainly by IL-12 and IFN-g. Solid lines represent stimulation, while dashed lines inhibition.Abbreviations: Ach, acetylcholine; ADO, adenosine, CAs, catecholamines, CGRP, calcitonin gene-related peptide; GCs, glucocorticoids, E2, estradiol; IL, interleukin; IFN, interferon; NE, norepinephrine; Prog, progesterone; SP, substance P; TNF, tumor necrosis factor; VIP, vasoactive intestinal polypeptide, VitD3, 1,25(OH)2 vitamin D3.