Funada U, Wada M, Kawata T, Mori K, Tamai H, Isshiki T, Onoda J, Tanaka N, Tadokoro T, Maekawa A
Faculty of Applied Bioscience, Tokyo University of Agriculture, Setagaya-ku, Tokyo 156-8502, Japan.
Int J Vitam Nutr Res. 2001 Jan;71(1):60-5. doi: 10.1024/0300-9831.71.1.60.
To clarify the role of B-12 in the immunological function, serum C3, IgM, IgG, IgE contents, splenocytes expression of CD4, CD8, and CD4 positive intracellular IFN-gamma and IL-4 were examined in B-12-deficient mice, and the effect of the administration of CH3-B-12 was also studied. Serum C3, IgM and IgG contents were lower in B-12-deficient mice than in the control mice. On the other hand, serum IgE content was significantly higher in B-12-deficient mice, and the value in CH3-B-12 administered mice, administered CH3-B-12 to B-12-deficient mice for 48 h before the end of feeding period, showed a tendency to recovery. CD4+CD8- cells and CD4+CD8-/CD4-CD8+ ratio in splenocytes were significantly higher in B-12-deficient mice than in control mice. CD4+IFN-gamma+ cells was significantly lower in B-12-deficient mice than in control mice, and CD4+IL-4+ was significantly higher in B-12-deficient mice than in control mice. These results suggest that B-12-deficiency causes CD4+CD8-T cells shift from the T helper type 1 to the T helper type 2, which participate in the IgE production and elevates CD4+CD8-/CD4-CD8+ ratio. Thus, B-12 plays a role in maintaining the immune function in mice.
为阐明维生素B12在免疫功能中的作用，我们检测了维生素B12缺乏小鼠的血清C3、IgM、IgG、IgE含量，脾细胞中CD4、CD8的表达以及CD4阳性细胞内干扰素-γ和白细胞介素-4的表达，并研究了甲基维生素B12给药的效果。维生素B12缺乏小鼠的血清C3、IgM和IgG含量低于对照小鼠。另一方面，维生素B12缺乏小鼠的血清IgE含量显著更高，在喂食期结束前48小时给维生素B12缺乏小鼠注射甲基维生素B12后，其血清IgE含量有恢复的趋势。维生素B12缺乏小鼠脾细胞中的CD4⁺CD8⁻细胞和CD4⁺CD8⁻/CD4⁻CD8⁺比值显著高于对照小鼠。维生素B12缺乏小鼠的CD4⁺干扰素-γ⁺细胞显著低于对照小鼠，而CD4⁺白细胞介素-4⁺细胞显著高于对照小鼠。这些结果表明，维生素B12缺乏导致CD4⁺CD8⁻T细胞从辅助性T细胞1型向辅助性T细胞2型转变，这参与了IgE的产生并提高了CD4⁺CD8⁻/CD4⁻CD8⁺比值。因此，维生素B12在维持小鼠免疫功能中发挥作用。
