Background: The Bursa of Fabricius is an acknowledged central humoral immune organ
unique to birds, which provides an ideal research model on the immature B cell development.
Objective: In this article, our motivation is to study the role on sIgM and establish the molecular
basis and functional processes of Bursal Hexapeptide (BHP) in avian immature B cells DT40 cell
Methods: In this article, we detected the expressions of sIgM mRNA with qPCR in DT40 cells with
BHP treatment, and investigated the gene expression profiles of BHP-treated DT40 cells,
employing microarray analyses. Also, to validate the differentially expressed genes, we performed
KEGG pathway and Gene Ontology analysis in the BHP-treated DT40 cells. Finally, we
comparatively analyzed the similar regulated genes and their involved immune functional processes
between DT40 cell and mouse immature B cell line WEHI231 cell with BHP treatment.
Results: Following the proposed framework, we proved that the BHP enhanced the mRNA
expression levels of IgM in DT40 cells, and induced 460 upregulated genes and 460 downregulated
genes in BHP-treated DT40 cells. The pathway analysis showed that the differentially regulated
genes in DT40 cell line with BHP treatment were involved in 12 enrichment pathways, in which
Toll-like receptor signaling pathway was the vital pathways, and cytokine-cytokine receptor
interaction and Jak-STAT signaling pathway were another two important pathways in BHP-treated
DT40 cells. Moreover, BHP induced the immune related biological processes in BHP-treated DT40
cells, including T cell related, cytokine related, lymphocyte related, and innate immune response
GO terms. Finally, the comparatively analysis showed that there were two downregulated genes
GATA3 and IFNG to be found co-existed among the differentially expressed genes in BHP-treated
DT40 cell and WEHI231 cells, which shared some same immune related functional processes in
both cell lines.
Conclusion: After the applying the framework, we proved the inducing roles and the gene
expression profiles of BHP on avian immature B cells, and verified some molecular basis from the
KEGG and GO analysis. These results provided the insight for mechanism on immature B cell
differentiation, and offer the essential direction for the vaccine improvement.