Brucella species, members of Category B agents, are highly infectious Gram-negative bacteria that have been identified as potential biological weapons. Brucellosis is naturally transmitted via ingestion of unpasteurized dairy products, manifesting with flu-like systems and, despite antibiotic treatment, can cause a recurring sequelae, evident as undulant fever and arthritis. Brucellae survival within the host is linked to its ability to resist intracellular recognition, thus, allowing them to sequester in various tissues. To date, there are no effective vaccines for humans, but protection is cell-mediated immunity-dependent, particularly, involving TNF-a and IFN-?. Vaccines that can recapitulate such responses should prove effective in resolving Brucella infections. Two putative polyamine-binding proteins, PotD and PotF, when formulated with ISCOMs plus CpG, conferred immune protection equivalent to the live Rev-1 Brucella melitensis vaccine in mice parenterally challenged with virulent B. melitensis 16M strain. This level of protection (>4 log reduction in tissue colonization) has yet to be shown using a subunit vaccine approach. Given the potency of this vaccine formulation, we are uniquely poised to test the efficacy of these vaccines against parenteral and pulmonary B. melitensis, B. abortus, and B. suis challenges. Thus, we hypothesize that an appropriately formulated vaccine composed of PotD and PotF, combined with a suitable adjuvant for human use, will confer protection against parenteral and pulmonary Brucella challenge. Identifying polyamine-binding proteins as vaccine targets could eventually be further adapted for other Category A and B pathogens. To further this effort, studies in Specific Aim 1 will optimize the dosage and route for Brucella vaccines, PotD and PotF, to confer protection against parenteral and pulmonary B. melitensis challenges and develop correlates for protective immunity. Studies in Specific Aim 2 will optimize the dosage for adjuvant when combined with PotD and PotF to confer optimal protection against parenteral and aerosolized B. melitensis, B. abortus, and B. suis challenges. Studies in Specific Aim 3 will test the efficacy of PotD and PotF vaccines in a caprine brucellosis animal model for their ability to confer protection against mucosally challenged goats for B. melitensis colonization and abortion. Studies in Specific Aim 4 will evaluate various safety parameters for GLP- prepared PotD and PotF subunit vaccines. Thus, these studies will show that subunit vaccines, when appropriately delivered, can protect against parenteral and pulmonary Brucella challenges. PROJECT NARRATIVE Brucellosis can be a debilitating disease, requiring extended antibiotic treatment to clear the brucellae;yet, despite treatment, brucellae can still persist. Thus, studies focused on developing a subunit vaccine for brucellosis and validating the protective efficacy of this vaccine formulation in two susceptible animal hosts and against three species of Brucella. The overall goals of this work are to forward the studies for our vaccines and have many of the preclinical studies completed prior to testing in humans.

Public Health Relevance

Brucellosis can be a debilitating disease, requiring extended antibiotic treatment to clear the brucellae;yet, despite treatment, brucellae can still persist. Thus, studies focused on developing a subunit vaccine for brucellosis and validating the protective efficacy of this vaccine formulation in two susceptible animal hosts and against three species of Brucella. The overall goals of this work are to forward the studies for our vaccines and have many of the preclinical studies completed prior to testing in humans.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI093372-04
Application #
8460570
Study Section
Special Emphasis Panel (ZAI1-NLE-M (J1))
Program Officer
Zou, Lanling
Project Start
2011-05-05
Project End
2016-04-30
Budget Start
2013-05-01
Budget End
2014-04-30
Support Year
4
Fiscal Year
2013
Total Cost
$444,037
Indirect Cost
$120,219
Name
University of Florida
Department
Pathology
Type
Schools of Veterinary Medicine
DUNS #
969663814
City
Gainesville
State
FL
Country
United States
Zip Code
32611
Pascual, David W; Suo, Zhiyong; Cao, Ling et al. (2013) Attenuating gene expression (AGE) for vaccine development. Virulence 4:384-90