We found that strawberry extract suppressed immunoglobulin (Ig) E production in vitro and in vivo, and identified glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as one of the IgE suppressor in the extract. We report here the effect of GAPDH on various Ig productions in vitro and in vivo. GAPDH suppressed IgE and enhanced IgA, IgG and IgM productions in ovalbumin (OVA)-stimulated human peripheral blood mononuclear cells. Oral administration of GAPDH at 10 mg/kg/day to OVA-induced allergy model mice tended to decrease total IgE level and increase total IgA and IgG levels in sera, and also decreased OVA-specific IgE and IgG levels. It is known that the increase of total IgA as well as the decrease of total and specific IgE is important for alleviating allergic symptoms. In addition, GAPDH accelerated IgA production and increased some cytokine secretions such as IL-4, TGF-β1 and IFN-γ in the OVA-immunized mice spleen lymphocytes. These cytokines involved in the class-switching, IgA enhancement, and IgE suppression, respectively, supporting above results. Our study suggests a possibility that oral administration of GAPDH may induce the immunomodulation in allergic responses.

我们发现草莓提取物在体外和体内抑制免疫球蛋白 (Ig) E 的产生，并确定甘油醛-3-磷酸脱氢酶 (GAPDH) 是提取物中的 IgE 抑制剂之一。我们在这里报告 GAPDH 对体外和体内各种 Ig 产生的影响。GAPDH 抑制卵清蛋白 (OVA) 刺激的人外周血单核细胞中的 IgE 并增强 IgA、IgG 和 IgM 的产生。对OVA诱导的过敏模型小鼠口服10mg/kg/天的GAPDH往往会降低血清中总IgE水平并增加血清中总IgA和IgG水平，并且还降低OVA特异性IgE和IgG水平。众所周知，总IgA的增加以及总IgE和特异性IgE的减少对于缓解过敏症状很重要。此外，GAPDH 加速了 OVA 免疫小鼠脾淋巴细胞中 IgA 的产生并增加了一些细胞因子的分泌，如 IL-4、TGF-β1 和 IFN-γ。这些细胞因子分别参与类别转换、IgA 增强和 IgE 抑制，支持了上述结果。我们的研究表明口服 GAPDH 可能会诱导过敏反应中的免疫调节。