Type 1 diabetes mellitus is a chronic inflammatory disease in which insulin producing β-cells of the pancreatic islets are killed by autoreactive cells of the immune system in response to a loss of tolerance. Dendritic cells (DC) interact predominantly with naïve T cells to regulate the delicate balance between immunity and tolerance required to maintain immunological homeostasis. In this dissertation, immature human dendritic cells (iDC) were inoculated with a chimeric fusion protein vaccine containing the pancreatic β-cell auto-antigen proinsulin linked to a mucosal adjuvant the cholera toxin B subunit (CTB-INS). Proteomic analysis of vaccine inoculated DCs revealed strong up-regulation of the tryptophan catabolic enzyme indoleamine 2, 3-dioxygenase (IDO1) shown to be directly linked to CTB-INS-induced DC activation and maturation. Treatment of vaccinated DCs with the pharmacological NF-κB inhibitors ACHP or DHMEQ inhibited IDO1 biosynthesis, suggesting a role for NF-κB signaling in CTB-INS vaccine up-regulation of dendritic cell IDO1. Further, blocking the NF-κB-inducing kinase (NIK) phosphorylation of IKK-α dimers and translocation of p52/RelB complexes to the nucleus with anti-NIK siRNA, significantly inhibited IDO1 expression in human DCs. Chromatin immunoprecipitation (ChIP) analysis, showed that RelB-p52 dimers bound dendritic cell NF-κB consensus sequences in the IDO1 promoter region, demonstrating vaccine stimulation of NF-κB non-canonical pathway activation of IDO1 expression in human DCs in vivo. Addition of the Tumor Necrosis Factor Associated Factors (TRAF) TRAF6 and TRAF 2, 3 blocking peptides to vaccinated DCs dramatically reduced the level of IDO1 biosynthesis and stimulated DC suggesting the vaccine may function in the same signaling pathway as TNFR super-family for the up-regulation of IDO1 biosynthesis in vaccinated dendritic cells. Together, these data confirm CTB-INS vaccine activation of the non-canonical NF-κB signaling pathway TNFR receptor family up-regulation of dendritic cell IDO1 biosynthesis permitting vaccine inhibition of DC maturation leading to the suppression of type 1 diabetes development.
School of Medicine
Langridge, William H. R.
De Leon, Marino
Doctor of Philosophy (PhD)
Year Degree Awarded
Date (Title Page)
Library of Congress/MESH Subject Headings
Dendritic Cells; Immunity; Cellular; Cell Differentiation; Diabetes Mellitus; Type 1;
Subject - Local
Immunological Homeostasis; Chimeric Fusion Protein Vaccine; Vaccine inhibitation;
Loma Linda University Libraries
This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.
Mbongue, Jacques Christian, "Mechanism of Chimeric Vaccine Mediated Immune Suppression of Human Dendritic Cells" (2016). Loma Linda University Electronic Theses, Dissertations & Projects. 348.
Loma Linda University Electronic Theses and Dissertations
Loma Linda University. Del E. Webb Memorial Library. University Archives