Veterinary Immunology and Immunopathology vol:137 issue:3-4 pages:291-297
In this study gnotobiotic animals were used to see if the F4 fimbrial antigen of F4ac+ Escherichia coli is as immunogenic as in conventional pigs. In addition, the adjuvant effect of beta-1,3/1,6-glucans was analysed for the first time in germ-free domestic animals. Oral F4 immunisation of F4 receptor positive (F4R(+)) piglets was able to induce a systemic and mucosal immune response as conventional pigs, although less pronounced. Nevertheless, an IgA response was observed in Peyer's patches and mesenteric lymph nodes. Moreover, a dose dependent effect was observed. Oral administration of beta-glucans for 5 weeks was not able to enhance this F4-specific immune response. The only effect of the beta-glucan treatment we observed was a significantly higher IL-1 alpha mRNA expression in the spleen. No significant changes in total serum antibody concentrations and in the volume of the ileal Peyer's patches were seen.