Abstract

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.

LLU Discipline

Physiology

Department

Basic Sciences

School

School of Medicine

First Advisor

Langridge, William H. R.

Second Advisor

De Leon, Marino

Third Advisor

Figueroa, Johnny

Fourth Advisor

Firek, Anthony

Fifth Advisor

Khan, Salma

Sixth Advisor

Tang, Jiping

Degree Name

Doctor of Philosophy (PhD)

Degree Level

Ph.D.

Year Degree Awarded

2016

Date (Title Page)

6-2016

Language

English

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;

Type

Dissertation

Page Count

181

Digital Format

PDF

Digital Publisher

Loma Linda University Libraries

Usage Rights

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.

Collection

Loma Linda University Electronic Theses and Dissertations

Collection Website

http://scholarsrepository.llu.edu/etd/

Repository

Loma Linda University. Del E. Webb Memorial Library. University Archives