Cox Eric, Van der Stede Yves, Verdonck Frank, Snoeck Veerle, Van den Broeck Wim, Goddeeris Bruno
Laboratory of Veterinary Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium.
Vet Immunol Immunopathol. 2002 Sep 10;87(3-4):287-90. doi: 10.1016/s0165-2427(02)00054-5.
The intestinal mucosal immune system can discriminate actively between harmful pathogenic agents and harmless food antigens resulting in different immune responses namely IgA production and oral tolerance, respectively. Recently, a pig model has been developed for studying intestinal mucosal immune responses in which F4 fimbrial antigens of enterotoxigenic Escherichia coli (F4 ETEC) are used as oral antigens. A unique feature of this model is that soluble F4 antigens can be administered to pigs which have a receptor for this fimbriae (F4R(+)) on their small intestinal villous enterocytes and pigs which do not have this receptor (F4R(-)). Oral administration of F4 to the F4R(+) pigs results in an intestinal mucosal immune response that completely protects the pigs against a challenge infection. In F4R(-) pigs such an intestinal mucosal immune response does not occur. However, a priming of the systemic immune system can be seen similar to the priming in pigs fed with the same dose of a food antigen, suggesting that F4 in F4R(-) pigs behaves as a food antigen. The fact that different mucosal immune responses can be induced with soluble F4, makes it an interesting model to study mucosal immune mechanisms in the pig.
肠道黏膜免疫系统能够主动区分有害病原体和无害食物抗原，分别产生不同的免疫反应，即分别产生IgA和形成口服耐受。最近，已开发出一种猪模型用于研究肠道黏膜免疫反应，其中产肠毒素大肠杆菌（F4 ETEC）的F4菌毛抗原被用作口服抗原。该模型的一个独特之处在于，可溶性F4抗原可以给予在其小肠绒毛肠上皮细胞上有这种菌毛受体（F4R(+)）的猪以及没有这种受体（F4R(-)）的猪。给F4R(+)猪口服F4会引发肠道黏膜免疫反应，从而完全保护猪免受感染攻击。在F4R(-)猪中不会发生这种肠道黏膜免疫反应。然而，可以看到其全身免疫系统出现了类似于喂食相同剂量食物抗原的猪所出现的启动现象，这表明F4R(-)猪中的F4表现得像一种食物抗原。可溶性F4能够诱导不同的黏膜免疫反应，这一事实使其成为研究猪黏膜免疫机制的一个有趣模型。
