Changes Of Immune Function And Expression Of IL-2 And Its Receptor MRNA In Immune Organs Of Probiotics-fed Chicks After IBD Vaccination

To reveal the influence of probiotics on IBD-vaccine and the function of molecular immunoregulatory, cellular and humoral immunity in immune organs of chicks and to provide a scientific and experimental evidence for the development of probiotics, investigations about the dynamic changes of the expression of IL-2 and its receptor mRNA and the proliferative function, the quantity of T and B lymphocytes in thymus, bursa and spleen of chicks were carried out. One-day-old chicks fed with probiotics and then inoculated by IBD-vaccine and following challenged with virulent IBDV were used in this study, and also technology of cell culture, MTT, histochemistry staining and real-time fluorescence quantitative PCR were used. The results were as follows:1)After one-day-old chicks fed with probiotics, the expression of IL-2 and IL-2R mRNA in immune organs was much stronger than that of controls and differed remarkably at 4~7 days and 4~11 days, respectively (P<0.05 or P<0.01); the quantity of TANAE+ cells was much stronger than that of controls and differed remarkably at 4~11 days (P<0.05 or P<0.01); the proliferative function of T-lymphocytes in thymus and spleen increased persistently; the proliferative function of B-lymphocytes in bursa and spleen was much stronger than that of controls and differed remarkably at 4~11 days(P<0.05 or P<0.01). These results indicated that the function of molecular immunoregulatory, cellular and humoral immunity in immune organs of probiotics-fed chicks strengthened remarkably.2)After the application of probiotics combined with IBD-vaccine, the expression of IL-2 and IL-2R mRNA in immune organs, the quantity of TANAE+ cells and the proliferative function of T and B lymphocytes differed remarkably from IBD-vaccinated chicks. The results indicated that the application of probiotics combined with IBD-vaccine could promote the level of cellular and humoral immunity. The cellular and humoral immune responses were enhanced was closely correlated with the enhancement of molecular immunoregulatory function.3)After the challenge of virulent IBDV, the application of probiotics combined with IBD-vaccine, the expression of IL-2 and IL-2R mRNA in immune organs, the quantity of TANAE+ cells and the proliferative function of T and B lymphocytes differed remarkably from IBD-vaccinated chicks. These implied that the protective efficiency of probiotics with IBD vaccine is closely correlated with the level of molecular immunoregulatory function and the situations of cellular immune and humoral immune functions of probiotics-fed and IBD-vaccinated chicks.4)Probiotics II group chicks with Bacillus primarily, the expression of IL-2 and IL-2R mRNA in immune organs, the quantity of TANAE+ cells and the proliferative function of T and B lymphocytes differed remarkably from probiotics I group chicks with Lactobacillus primarily, either individually or with IBD vaccines, collaboratively. These results indicated that the function of molecular immunoregulatory, cellular and humoral immunity in immune organs of probiotics II group chicks with Bacillus primarily was much stronger than that of probiotics I group chicks with Lactobacillus primarily.