The Immunological Functions of Muramyl Dipeptide Compound Adjuvant on Humoral, Cellular-mediated and Mucosal Immune Responses to PEDV Inactivated Vaccine in Mice.

BACKGROUND: The muramyl dipeptide compound adjuvant, CVC1303, was one new resigned adjuvant to PEDV inactivated vaccine. Exploring the effects of CVC1303 on the immune induction to PEDV vaccine was of vital importance to the clinical application. OBJECTIVES: Here we explored the functions of CVC1303 on the humoral, cellular and mucosal immune response to PEDV vaccine in mice immunization. METHODS: Mice were twice subcutaneously injected with PEDV vaccine including high, medium and low dosages CVC1303, respectively. On 30th day after the second immunization, sera samples were collected from the immunized mice to measure PEDV-specific IgG and IgG subclasses levels, and lymphocytes were isolated to detect T cell subtype and intracellular IL-4 and IL-6 cytokine productions, and the expressions of co-stimulatory molecule on dendritic cells in the immunized mice. Small intestinal and lung washings were collected on 30th and 47th day after the second immunization to measure PEDV-specific IgA levels, and SP immunohistochemical method staining was employed to analyze the deviations of IgA+ positive cells in the small intestinal of the immunized mice. RESULTS: Our investigation proved the strong regulatory roles of CVC1303 on PEDV-specific IgG and IgG1 antibody and cytokines productions, and the significant increased CD3+CD4+T cells subpopulation and expressions of co-stimulatory molecules on dendritic cells in the immunized mice. Moreover, our findings verified the significantly enhanced PEDV-specific IgA antibody titers in small intestinal and lung in the mice immunized with PEDV vaccine and CVC1303. CONCLUSION: Compound adjuvant CVC1303 could effectively improve the PEDV-specific immune responses and mucosal immune, which provided an experimental basis for the further clinical application of new adjuvant CVC1303 and the development of improvement on the mucosal immune response.

Gene expression profiling of hybridoma cells after bursal-derived bioactive factor BP5 treatment.

Bursa of Fabricius is the acknowledged vital humoral immune system for B cell differentiation and antibody production. To study the molecular mechanism underlying the effect of bursal-derived BP5, we used gene microarray to analyze the genomic expression profiling of BP5-treated hybridoma cells. BP5 exhibited an immunomodulatory effect on antibody production in hybridoma cells and induced alterations in the gene expression profiles related to the immune-related biological processes, such as T cell activation and proliferation, B cell activation, B cell-mediated immunity, and cytokines cytokine production involved in immune response. In addition, 26 biological pathways associated with immunomodulatory functions were regulated in BP5-treated hybridoma cells, in which p53 signal pathway played an important role in antitumor. Among these regulated genes, 12 differentially expressed genes were verified by qRT-PCR. The activation of p53 activity by BP5 was further confirmed by p53 luciferase reporter assay and p53 expression. Our data revealed that bursal-derived BP5 could regulate various immune-related cellular processes, including antitumor factor p53 signal pathway, perhaps partially accounting for the reported immunomodulatory roles and novel antiproliferation on tumor cells functions of bursal-derived bioactive factor BP5.