Influence Of Humoral Immunity And Expression Of IL-7 MRNA In Local Mucosal Immune Tissues Of Probiotics Chicks Vaccinated With ND Vaccine

In this study, indirect enzymelinked immunosorbent assay(IELISA), immunohistochemistry staining, transmission electron microscope(TEM), and real-time fluorescence quantitative PCR(SYBR Green I) were used to discover the dynamic changes of the content of immunoglobulin(Ig)A, IgM, IgG in local humor——tear, trachea fluid, bile and intestinal fluid; the dynamic changes of the number of IgS+ antibody-producing cells and the expression of IL-7 mRNA in local mucosal tissues——gland of Harder, cecal tonsils, Peyer's patch of duodenum and ileum of probiotics chicks vaccinated with ND vaccine, which were to reveal the changes and mechanism of humoral immunity in local mucosal tissues of probiotics chicks vaccinated with ND vaccine. The results were as follows:1) The content of IgA, IgM, IgG in local humor——tear, trachea fluid, bile and intestinal fluid of probiotics chicks were enhanced compared with those of without probiotics at 7 days (P<0.05 or P<0.01); At 7 days after chicks vaccinated with ND vaccine, the content of IgA, IgM, IgG in above local humor of probiotics group, ND vaccine group and probiotics chicks vaccinated with ND vaccine were enhanced compared with blank controls group (P<0.05 or P<0.01); At the sametime, the content of IgA, IgM, IgG in ND vaccine group and probiotics chicks vaccinated with ND vaccine were increased compared with probiotics chicks (P<0.05 or P<0.01); the content of IgA, IgM, IgG in probiotics chicks vaccinated with ND vaccine were increased compared with ND vaccine group chicks.2) The numbers of IgS+ cells of gland of Harder, cecal tonsils, Peyer's patch of duodenum and ileum of probiotics chicks were enhanced compared with those of without probiotics at 7 days (P<0.05 or P<0.01); At 7～28 days after chicks vaccinated with ND vaccine, the numbers of IgS+ cells in above local mucosal tissue of probiotics group, ND vaccine group and probiotics chicks vaccinated with ND vaccine were enhanced compared with blank controls group (P<0.05 or P<0.01); At the sametime, the number of IgS+ cells in ND vaccine group and probiotics chicks vaccinated with ND vaccine were increased compared with probiotics chicks (P<0.05 or P<0.01); the number of IgS+ cells in probiotics chicks vaccinated with ND vaccine were increased compared with ND vaccine group chicks.3) The expression of IL-7 mRNA in gland of Harder, cecal tonsils, Peyer's patch of duodenum and ileum of probiotics group, ND vaccine group and probiotics chicks vaccinated with ND vaccine were enhanced with different degree compared with blank control chicks (P<0.05 or P<0.01); the detected items of above local mucosal tissue of probiotics chicks vaccinated with ND vaccine were enhanced with different degree compared with chicks alone vaccinated with ND vaccine.4) Tissue ultrastructure examination revealed that the length of microvilli in cecal tonsils, duodenum and ileum of probiotics chicks, the number of mitochondria, mitochondrial cristae, golgi, ribosomal and rough endoplasmic reticulum and smooth endoplasmic reticulum in the cytoplasm of absorption cell were enhanced compared with those of without probiotics; the numbers of B lymphocyte and goblet cells increased, mitochondria, there are large secretory granule in acinus of gland of Hader.5) After the challenge of virulent NDV, the morbidity of chicks of controls was 100% and all chicks died ultimately with typical symptoms of ND. The morbidity in probiotics group, ND vaccine group and probiotics chicks vaccinated with ND vaccine were 60%, 20% and 0%, respectively and there is no death in any of these groups.The results showed that probiotics could promote the growth development of local mucosal tissue, promote the proliferation and differentiation of cells, enhanced the humoral immunity function in respiratory and digestive tract mucosal, could also enhanced the immunological response to ND vaccine. At the same time, both probiotics and ND vaccine could promote the expression of IL-7 mRNA and the resistance against NDV, the coalescent application of probiotics and ND-vaccine showed better effect than each of them.