ABSTRACT
BACKGROUND: Bursa of Fabricius plays the vital functions on B cell development and antibody production in poultry. The bursal-derived peptide plays the essential roles on avian immature B cell development. OBJECTIVES: Here we explored the functions of the recently reported bursal nonapeptide (BP9) on the antibody production and the molecular basis of BP9 on avian immature B cell. METHODS: Chicken were twice immunized with Avian Influenza Virus (AIV) inactivated vaccine plus with BP9 at three dosages, respectively. On two weeks after the second immunization, sera samples were collected from all experimental groups to measure AIV-specific Agglutination Inhibition (HI) antibody titers. Also, on 7th day after the second immunization, spleen lymphocytes were isolated from the immunized chicken to detect the lymphocyte viabilities. DT40 cells were treated with BP9 from 0.02 to 2 µg/mL for 4 and 20h to detect sIgM mRNA levels, and total RNAs from BP9-treated DT40 cells were collected to investigate the gene expression profiles of DT40 cells, and to analyze the enriched pathways and functional biological processes. Finally, nine gene expressions were validated with quantitative PCR (qPCR). RESULTS: Our investigation proved the strong regulatory roles of BP9 on AIV-specific HI antibody titers and lymphocyte viabilities. BP9 promoted sIgM mRNA levels in DT40 cells, and upregulated 598 gene expressions and downregulated 395 gene expressions in DT40 cells with 0.2µg/mL BP9 treatment. Moreover, our findings verified the significantly enriched six pathways and various the biological functional processes of BP9 on avian immature B cell. Also, we found eight signaling pathways in the enriched biological processes of BP9-treated DT40 cells, and the expressions of nine selected genes with qPCR were identical to that of microarray data. CONCLUSION: BP9 promoted the antibody production in the 21-old-day chicken immunization, and stimulated the sIgM expression in DT40 cells. Furthermore, we analyzed the gene expression profile and immune-related biological processes of DT40 cells treated with BP9, which provided some new insights into the mechanism on immature B cell development, and provided important references for adjuvant development on vaccine improvement and clinical application.
Subject(s)
Bursa of Fabricius/chemistry , Influenza Vaccines/immunology , Influenza in Birds/prevention & control , Oligopeptides/immunology , Precursor Cells, B-Lymphoid/immunology , Adjuvants, Immunologic/pharmacology , Animals , Antibody Formation , Cell Differentiation , Cell Line , Cell Proliferation , Chickens , Humans , Immunization , Immunoglobulin M/metabolism , Influenza in Birds/immunology , Influenza in Birds/virology , Oligopeptides/chemistry , Precursor Cells, B-Lymphoid/cytology , Precursor Cells, B-Lymphoid/drug effects , Vaccines, Inactivated/immunologyABSTRACT
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.
Subject(s)
Antineoplastic Agents/pharmacology , Hybridomas/drug effects , Peptides/pharmacology , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Cell Proliferation/drug effects , Cells, Cultured , Chlorocebus aethiops , Drug Screening Assays, Antitumor , Gene Expression Profiling , HeLa Cells , Humans , Hybridomas/cytology , Hybridomas/metabolism , MCF-7 Cells , Mice , Mice, Inbred BALB C , Peptides/chemical synthesis , Peptides/chemistry , Reverse Transcriptase Polymerase Chain Reaction , Signal Transduction/drug effects , Signal Transduction/genetics , Structure-Activity Relationship , Tumor Suppressor Protein p53/genetics , Vero CellsABSTRACT
The bursa of Fabricius (BF) is the central humoral immune organ unique to birds. Here, we isolated a novel bursal pentapeptide I (BPP-I), LGPGP, from BF. BPP-I could play inhibition effect on MCF-7 but not on CEF or Vero cell proliferation in vitro, and enhance antitumor factor p53 protein expression. Also, BPP-I stimulated antibody production in a dose-dependent manner in hybridoma cell. Furthermore, BPP-I could induce various immune responses in mice immunization experiments, including increase antibody production and cytokines IL-4 and IFN-γ level, and induce T-cell immunophenotyping. These results suggest that BPP-I is a potential immunomodulator of antitumor and immunity. The study could provide some novel insights on the probable candidate reagent for the antitumor and immune improvement.
