This application addresses the compelling need to develop new and improved vaccine adjuvants for stimulating protective immunity at mucosal surfaces. The proposal involves a consortium arrangement between the University of Louisville, the University at Buffalo, and the Hauptman-Woodward Institute, and brings together complementary and integrated expertise in vaccine adjuvant research, structural and molecular biology, and induction of mucosal immunity. Studies by this group have succeeded to dissociate useful adjuvant properties from the toxicity of LT-IIb, an AB5-type heat-labile enterotoxin of Escherichia coli. Specifically, the recombinantly expressed B pentameric subunit of LT-IIb (LT-IIb-B5) not only lacks enterotoxicity but, strikingly, can activate the Toll-like receptor (TLR)-2/TLR1 signaling complex and stimulate antibody responses to co-administered vaccine proteins. Proof-of-concept preliminary studies have shown that certain engineered point-substitution mutations in the active region of LT-IIb-B5 enhance its ability to interact with TLR2 and TLR1. The overall objective of this application is to better characterize the physical and functional interaction of LT-IIb-B5 with the TLR2/TLR1 heterodimer, engineer improved versions of LT-IIb-B5 in terms of TLR2/TLR1-mediated adjuvanticity, and develop potential adjuvants through studies in preclinical models of vaccination against oral infection. This will be accomplished through appropriate and innovative molecular biological, structural, and immunological studies outlined in the following four specific aims: 1) To rationally engineer enhanced TLR2-interactive versions of LT-IIb-B5. 2) To structurally characterize the LT-IIb- B5-TLR2/TLR1 interaction using small-angle X-ray scattering (SAXS). 3) To evaluate the engineered LT-IIb-B5 mutants for in vitro TLR2/TLR1-dependent immunostimulatory activities. 4) To determine the ability of LT-IIb-B5 and improved engineered versions thereof to induce protective immunity in vivo. The generated data will form the basis for the long-term goal which is to establish LT-IIb-B5 and improved engineered derivatives as effective adjuvants in vaccine formulations against pathogens which colonize or invade via oral, respiratory, or urogenital mucosal surfaces.

Public Health Relevance

The objective of this application is to rationally engineer novel Toll-like receptor-dependent mucosal adjuvants. These constructs will be evaluated for their capacity to stimulate protective immunity using appropriate preclinical mouse models. The focus of this proposal is on a novel vaccine against periodontitis, an oral inflammatory disease with an impact on systemic health, although the developed mucosal adjuvants can also be used in vaccine formulations against pathogens which colonize or invade via oral, respiratory, or urogenital mucosal surfaces. This work is timely and important given the paucity of safe and effective vaccine adjuvants and the tremendous health impact of infectious diseases.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Research Project (R01)
Project #
5R01DE017138-11
Application #
8693614
Study Section
Oral, Dental and Craniofacial Sciences Study Section (ODCS)
Program Officer
Melillo, Amanda A
Project Start
2006-02-01
Project End
2015-08-31
Budget Start
2014-09-01
Budget End
2015-08-31
Support Year
11
Fiscal Year
2014
Total Cost
Indirect Cost
Name
University of Pennsylvania
Department
Microbiology/Immun/Virology
Type
Schools of Dentistry/Oral Hygn
DUNS #
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
Hajishengallis, George; Lambris, John D (2016) More than complementing Tolls: complement-Toll-like receptor synergy and crosstalk in innate immunity and inflammation. Immunol Rev 274:233-244
Maekawa, Tomoki; Briones, Ruel A; Resuello, Ranillo R G et al. (2016) Inhibition of pre-existing natural periodontitis in non-human primates by a locally administered peptide inhibitor of complement C3. J Clin Periodontol 43:238-49
Hajishengallis, George; Hajishengallis, Evlambia; Kajikawa, Tetsuhiro et al. (2016) Complement inhibition in pre-clinical models of periodontitis and prospects for clinical application. Semin Immunol 28:285-91
Olsen, Ingar; Hajishengallis, George (2016) Major neutrophil functions subverted by Porphyromonas gingivalis. J Oral Microbiol 8:30936
Hajishengallis, George; Lamont, Richard J (2016) Dancing with the Stars: How Choreographed Bacterial Interactions Dictate Nososymbiocity and Give Rise to Keystone Pathogens, Accessory Pathogens, and Pathobionts. Trends Microbiol 24:477-89
Mastellos, D C; Ricklin, D; Hajishengallis, E et al. (2016) Complement therapeutics in inflammatory diseases: promising drug candidates for C3-targeted intervention. Mol Oral Microbiol 31:3-17
Hajishengallis, George; Moutsopoulos, Niki M; Hajishengallis, Evlambia et al. (2016) Immune and regulatory functions of neutrophils in inflammatory bone loss. Semin Immunol 28:146-58
Lamont, Richard J; Hajishengallis, George (2015) Polymicrobial synergy and dysbiosis in inflammatory disease. Trends Mol Med 21:172-83
Hu, John C; Greene, Christopher J; King-Lyons, Natalie D et al. (2015) The Divergent CD8+ T Cell Adjuvant Properties of LT-IIb and LT-IIc, Two Type II Heat-Labile Enterotoxins, Are Conferred by Their Ganglioside-Binding B Subunits. PLoS One 10:e0142942
Hajishengallis, George; Chavakis, Triantafyllos; Hajishengallis, Evlambia et al. (2015) Neutrophil homeostasis and inflammation: novel paradigms from studying periodontitis. J Leukoc Biol 98:539-48

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