Hoshino T, Iho S, Kura F
Methods Find Exp Clin Pharmacol. 1986 Mar;8(3):167-73.
This paper deals with the immunosuppressive effects of 1,25-dihydroxy vitamin D3 (1,25(OH)2, D3), a metabolic product which acts in vivo as the active form vitamin D3. Dose and time of exposure-dependent suppressive effects were demonstrated in vitro on PHA blastogenesis of mononuclear cells, IL-2 production of T cells and IL-1 production of macrophages when these human immunocytes were treated with 1,25(OH)2D3. Addition of exogenous IL-1 and IL-2 partially abrogated the suppressive effects of 1,25(OH)2 D3 on IL-2 production and PHA blastogenesis, respectively. Thus, it is suggested that inhibition of PHA blastogenesis results from the reduced production of such growth factors in this IL-1 -IL-2 cascade system. PWM-induced immunoglobulin (Ig) synthesis of B cells was also markedly inhibited by 1,25(OH)2 D3, which was caused not only by direct suppression toward B cells but also by indirect suppression due to reduced helper factor from T cells when these cells were treated with 1,25(OH)2 D3. It is proposed that 1,25(OH)2D3 may act as one of the immunoregulatory factors in vivo, in addition to its well-known action in calcium metabolism.
本文探讨了1,25 - 二羟基维生素D3（1,25(OH)2D3）的免疫抑制作用，它是维生素D3在体内发挥作用的活性代谢产物。当用1,25(OH)2D3处理这些人类免疫细胞时，体外实验证明了其对单核细胞PHA增殖、T细胞IL - 2产生以及巨噬细胞IL - 1产生具有剂量和暴露时间依赖性的抑制作用。分别添加外源性IL - 1和IL - 2可部分消除1,25(OH)2D3对IL - 2产生和PHA增殖的抑制作用。因此，提示在这个IL - 1 - IL - 2级联系统中，PHA增殖的抑制是由于此类生长因子产生减少所致。当用1,25(OH)2D3处理这些细胞时，1,25(OH)2D3对PWM诱导的B细胞免疫球蛋白（Ig）合成也有明显抑制作用，这不仅是由于对B细胞的直接抑制，还由于T细胞辅助因子减少导致的间接抑制。有人提出，1,25(OH)2D3除了在钙代谢中具有众所周知的作用外，在体内可能还作为免疫调节因子之一发挥作用。
