Articulatin B chain induced dendritic cells maturation and driven type I T helper cells and cytotoxic T cells activation.

AIMS:Articulatin (AT), purified from the Chinese mistletoe (Viscum articulatum), belongs to the family of type II ribosome-inactivating proteins (RIPs) that contain two subunits, the A and B chains. The B chain of AT is believed to function by means of interacting with the galactose moiety of glycoproteins or glycolipids on the cell membrane and is internalized into cells through endocytosis. In the study, we aim to investigate the immunomodulatory effects of recombinant articulatin B chain (rATB) on mouse bone marrow-derived dendritic cells (BM-DCs). MAIN METHODS:Detection of surface markers expression on BM-DCs by flow cytometry. Analysis of RNA and protein expression by RNAseq and Western blotting assays. Assessment of the adaptive immune responses using an in vivo mouse model. KEY FINDING:Our study presents novel results showing the activation of mouse BM-DCs by rATB, which leads to the induction of CD80, CD86, and MHC II expression as well as primed type I CD4+ T cell differentiation and CD8+ T cell activation. RNAseq and Western blotting assays revealed rATB-induced BM-DC activation to be dependent on the MAPK and NF-κB signaling pathways. In a mouse model, rATB was observed to have adjuvant effects that induced an antigen-specific Th1 immune response. SIGNIFICANCE:Based on in vitro and in vivo assays, this study shows rATB acting as a potential adjuvant that induces BM-DC activation and antigen-specific Th1 related immune response. rATB might have potential applicability in the development of vaccines against pathogens and tumors.