Function of IgA immune complex in externally secreted fluids and its application

BALB/c小鼠分为两组；e组只饲喂蛋清蛋白，m组只饲喂牛奶蛋白作为饲粮蛋白质来源。从每组母亲获得的母乳中都发现了各自膳食蛋白质和IgA的免疫复合物。用自己的母乳喂养的婴儿接种卵清蛋白/明矾后，口服卵清蛋白诱导与实验性Th2肠道炎症相关的腹泻。e型婴儿的腹泻明显得到抑制。与此同时，e -婴儿静脉注射卵清蛋白后，血清抗卵清蛋白及卵黏液样IgGI和IgE水平较低，脾脏细胞IL-4合成受到抑制，过敏性死亡发生率较低。因此，喂养相关蛋白质的母亲通过母乳喂养获得了对膳食蛋白质的免疫耐受，从而预防了过敏性疾病，可能是通过分泌到母乳中的膳食蛋白质和slgAs的免疫复合物。

BALB/c mice were divided into two groups;E-group fed only egg white proteins and M-group fed only cow's milk proteins as a dietary protein source. Immune complexes of respective dietary proteins and IgA were found in the breast milk obtained from each group of mother. After immunizing infants fed their own mother's milk with ovalbumin/alum, diarrhea associated with experimental Th2 intestinal inflammation was induced by oral administration of ovalbumin. The diarrhea was dramatically suppressed in E-infants. Concomitantly, low level of serum anti ovalbumin and ovomucoid IgGI and IgE, suppression of IL-4 synthesis by spleen cells, and low incidence of anaphylactic death after intravenous injection of ovalbumin were observed preferentially in E-infants. Thus, immune tolerance and then prevention of allergic disorder against dietary proteins was acquired via breastfeeding by mothers fed the relevant proteins, probably through the immune complexes of dietary proteins and slgAs secreted into breast milk.