title: Modulation of Innate Immune ResponsesviaCovalently Linked TLR Agonists.
abstract: We present the synthesis of novel adjuvants for vaccine development using multivalent scaffolds and bioconjugation chemistry to spatially manipulate Toll-like receptor (TLR) agonists. TLRs are primary receptors for activation of the innate immune system during vaccination. Vaccines that contain a combination of small and macromolecule TLR agonists elicit more directed immune responses and prolong responses against foreign pathogens. In addition, immune activation is enhanced upon stimulation of two distinct TLRs. Here, we synthesized combinations of TLR agonists as spatially defined tri- and di-agonists to understand how specific TLR agonist combinations contribute to the overall immune response. We covalently conjugated three TLR agonists (TLR4, 7, and 9) to a small molecule core to probe the spatial arrangement of the agonists. Treating immune cells with the linked agonists increased activation of the transcription factor NF-κB and enhanced and directed immune related cytokine production and gene expression beyond cells treated with an unconjugated mixture of the same three agonists. The use of TLR signaling inhibitors and knockout studies confirmed that the tri-agonist molecule activated multiple signaling pathways leading to the observed higher activity. To validate that the TLR4, 7, and 9 agonist combination would activate the immune response to a greater extent, we performedin vivostudies using a vaccinia vaccination model. Mice vaccinated with the linked TLR agonists showed an increase in antibody depth and breadth compared to mice vaccinated with the unconjugated mixture. These studies demonstrate how activation of multiple TLRs through chemically and spatially defined organization assists in guiding immune responses, providing the potential to use chemical tools to design and develop more effective vaccines.
authors.affiliation: Department of Chemistry and Department of Medicine, Division of Infectious Diseases, University of California, Irvine , Irvine, California 92697, United States.
authors.forename: Janine K
authors.initials: JK
authors.lastname: Tom
authors.affiliation: Department of Chemistry and Department of Medicine, Division of Infectious Diseases, University of California, Irvine , Irvine, California 92697, United States.
authors.forename: Emmanuel Y
authors.initials: EY
authors.lastname: Dotsey
authors.affiliation: Department of Chemistry and Department of Medicine, Division of Infectious Diseases, University of California, Irvine , Irvine, California 92697, United States.
authors.forename: Hollie Y
authors.initials: HY
authors.lastname: Wong
authors.affiliation: Department of Chemistry and Department of Medicine, Division of Infectious Diseases, University of California, Irvine , Irvine, California 92697, United States.
authors.forename: Lalisa
authors.initials: L
authors.lastname: Stutts
authors.affiliation: Department of Chemistry and Department of Medicine, Division of Infectious Diseases, University of California, Irvine , Irvine, California 92697, United States.
authors.forename: Troy
authors.initials: T
authors.lastname: Moore
authors.affiliation: Department of Chemistry and Department of Medicine, Division of Infectious Diseases, University of California, Irvine , Irvine, California 92697, United States.
authors.forename: D Huw
authors.initials: DH
authors.lastname: Davies
authors.affiliation: Department of Chemistry and Department of Medicine, Division of Infectious Diseases, University of California, Irvine , Irvine, California 92697, United States.
authors.forename: Philip L
authors.initials: PL
authors.lastname: Felgner
authors.affiliation: Department of Chemistry and Department of Medicine, Division of Infectious Diseases, University of California, Irvine , Irvine, California 92697, United States.
authors.forename: Aaron P
authors.initials: AP
authors.lastname: Esser-Kahn