A Q fever vaccine remains an important public health and national security goal. The objective of this application is to clone the O antigen epitopes from C. burnetii lipopolysaccharide (LPS) expressed on a heterologous LPS lipid A and core or N-linked glycoprotein, and combine this with protective T cellstimulating recombinant proteins in Recombinant Attenuated Salmonella Vaccines (RASV). The vaccine candidates will be characterized for the protective capacity of recombinant antigens that confer strong T-cell responses in vaccine-induced and infection-derived immunity in BL6 and MHC ll-humanized (DR1 or DR4) mice and outbred guinea pigs. We will accomplish the objective by pursuing the following specific aims: (1) Identify and characterize genes required forsubunit LPS O-antigen expression. Protective carbohydrate epitopes on the O-side chain of C. burnetii LPS can be expressed on a heterologous lipid A-core acceptor in Salmonella by cloning essential genes encoding the biosynthetic pathways for O antigen synthesis. Selection for recombinant O antigen carbohydrate synthesis will include phage resistance, LPS-specific antibody reactivity, and direct cloning of predicted genes for O antigen synthesis. (2) Heterologously express O polysaccharide as an N-linked glycoprotein. Protective carbohydrate epitopes on the O-side chain of C. burnetii LPS will be expressed as an N-linked glycoprotein using the transferase (PgIB) and acceptor (AcrA) proteins from Campylobacterjejuni. The coupled O side chain carbohydrates will be purified, and structurally and antigenically characterized. A C. burnetii antigenic protein (Com-1) will be modified with an acceptor motif to replace AcrA and evaluated for the ability to act as an antigenic N-linked carrier protein. (3) Identify and characterize mimetope peptides that antigenically model O-polysaccharide. Combinatorial peptide libraries will be screened for targets that cross react with antibody specific for C. burnetii O polysaccharide. These peptides will be tested for protective antibody responses upon vaccination by recognizing C. burnetii LPS. Candidate peptides will be conjugated to KLH or TT carrier protein and used to stimulate antibody responses in mice. (4) Evaluate the protective capacity of heterologously expressed C. burnetii Oside chain carbohydrates and proteins in mouse and guinea pig challenge models. Live RASV, microvesicles prepared from RASV, and purified recombinant proteins conjugated to heterologous LPS will be compared.
Vaccine development is a primary focus of the RCE system and the WRCE. C. burnetii is an understudied Select Agent in the RCE system, and the WRCE provides important coverage of the agent in meeting the goals outlined by NIH. Support for the development of a relevant animal model (guinea pig aerosol) in the first funding cycle translated into a tool used in this renewal application for vaccine development. Ongoing, separately funded studies to identify T-cell protein epitopes, both CD4 (NIH, RO1 Samuel, PI) and CD8 (PSRCE, Peters PI, Samuel subcontract), will be used to support the ultimate protein partner choices for combination with LPS epitopes.
|Paterson, Andrew S; Raja, Balakrishnan; Garvey, Gavin et al. (2014) Persistent luminescence strontium aluminate nanoparticles as reporters in lateral flow assays. Anal Chem 86:9481-8|
|Santiago, Felix W; Covaleda, Lina M; Sanchez-Aparicio, Maria T et al. (2014) Hijacking of RIG-I signaling proteins into virus-induced cytoplasmic structures correlates with the inhibition of type I interferon responses. J Virol 88:4572-85|
|Pflughoeft, Kathryn J; Swick, Michelle C; Engler, David A et al. (2014) Modulation of the Bacillus anthracis secretome by the immune inhibitor A1 protease. J Bacteriol 196:424-35|
|Lavinder, Jason J; Wine, Yariv; Giesecke, Claudia et al. (2014) Identification and characterization of the constituent human serum antibodies elicited by vaccination. Proc Natl Acad Sci U S A 111:2259-64|
|Valbuena, Gustavo; Halliday, Hailey; Borisevich, Viktoriya et al. (2014) A human lung xenograft mouse model of Nipah virus infection. PLoS Pathog 10:e1004063|
|Nieves, Wildaliz; Petersen, Hailey; Judy, Barbara M et al. (2014) A Burkholderia pseudomallei outer membrane vesicle vaccine provides protection against lethal sepsis. Clin Vaccine Immunol 21:747-54|
|Gardner, Christina L; Hritz, Jozef; Sun, Chengqun et al. (2014) Deliberate attenuation of chikungunya virus by adaptation to heparan sulfate-dependent infectivity: a model for rational arboviral vaccine design. PLoS Negl Trop Dis 8:e2719|
|Litvinov, Julia; Hagström, Anna E V; Lopez, Yubitza et al. (2014) Ultrasensitive immuno-detection using viral nanoparticles with modular assembly using genetically-directed biotinylation. Biotechnol Lett 36:1863-8|
|Caro-Gomez, Erika; Gazi, Michal; Goez, Yenny et al. (2014) Discovery of novel cross-protective Rickettsia prowazekii T-cell antigens using a combined reverse vaccinology and in vivo screening approach. Vaccine 32:4968-76|
|Georgiou, George; Ippolito, Gregory C; Beausang, John et al. (2014) The promise and challenge of high-throughput sequencing of the antibody repertoire. Nat Biotechnol 32:158-68|
Showing the most recent 10 out of 303 publications