Staphylococcus aureus is one of the most common causes of serious and life-threatening infections in the world. Due to their increasing frequency, increasing drug-resistance, and high morbidity and mortality, a vaccine to prevent S. aureus infections would have an enormous impact on global and US health. We have isolated a gene product, ALS3, that encodes a surface adhesin utilized by the fungus Candida albicans to adhere to human cells. We recently made the exciting discovery that candidal Als3p has striking three dimensional structural homology (>90%) with surface adhesins expressed by S. aureus. Remarkably, our preliminary studies confirm that vaccination of mice with the recombinant N-terminus of Als3p (rAls3p-N) mediates significant cross-kingdom protection against S. aureus, and markedly improves the survival of mice infected with an otherwise fatal inoculum of methicillin-resistant Staphylococcus aureus (MRSA). To date, the precise immunological requisites for host protection against S. aureus infections have been relatively unexplored. Lack of knowledge about requisites for host protection has likely contributed to recent failures of active vaccine strategies targeting S. aureus. We hypothesize that rAls3p-N induces protection against S. aureus by stimulating a coordinated Type 1-Type 2 immune response that optimizes opsonophagocytic activity. To test this hypothesis and to define the general immunological requisites for host protection against S. aureus, we will: 1) determine the impact of rAls3p-N vaccination on murine Type 1/Type 2 immunopolarization during S. aureus infection;2) determine the relative contributions of antibody and cell-mediated immune function to murine host protection against S. aureus;3) elucidate the end-effector mechanisms involved in vaccine-induced protection of mice against S. aureus;and 4) define the breadth of activity of the rAls3p-N vaccine against multiple strains of Staphylococcus and in inbred and outbred mice. Due to the ongoing increase in drug-resistant S. aureus infections, there is a desperate need for a successful active vaccine against this ubiquitous pathogen. The studies proposed will define the requisites for host protection against S. aureus, which is a crucial step in optimizing rAls3p-N vaccine efficacy. The insights into fundamental immunological mechanisms of protection against S. aureus will also be of extreme importance to the development of other vaccine candidates targeting S. aureus in the future.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI072052-04
Application #
7841912
Study Section
Vaccines Against Microbial Diseases (VMD)
Program Officer
Huntley, Clayton C
Project Start
2007-06-15
Project End
2012-05-31
Budget Start
2010-06-01
Budget End
2011-05-31
Support Year
4
Fiscal Year
2010
Total Cost
$361,430
Indirect Cost
Name
La Biomed Research Institute/ Harbor UCLA Medical Center
Department
Type
DUNS #
069926962
City
Torrance
State
CA
Country
United States
Zip Code
90502
Spellberg, Brad; Lipsky, Benjamin A (2012) Systemic antibiotic therapy for chronic osteomyelitis in adults. Clin Infect Dis 54:393-407
Lin, Lin; Ibrahim, Ashraf S; Baquir, Beverlie et al. (2012) Luminescent-activated transfected killer cells to monitor leukocyte trafficking during systemic bacterial and fungal infection. J Infect Dis 205:337-47
Daum, Robert S; Spellberg, Brad (2012) Progress toward a Staphylococcus aureus vaccine. Clin Infect Dis 54:560-7
Lin, Lin; Tan, Brandon; Pantapalangkoor, Paul et al. (2012) Inhibition of LpxC protects mice from resistant Acinetobacter baumannii by modulating inflammation and enhancing phagocytosis. MBio 3:
Luo, Guanpingshen; Lin, Lin; Ibrahim, Ashraf S et al. (2012) Active and passive immunization protects against lethal, extreme drug resistant-Acinetobacter baumannii infection. PLoS One 7:e29446
Spellberg, Brad; Daum, Robert (2012) Development of a vaccine against Staphylococcus aureus. Semin Immunopathol 34:335-48
Spellberg, Brad; Lewis, Roger J; Boucher, Helen W et al. (2011) Design of clinical trials of antibacterial agents for community-acquired bacterial pneumonia. Clin Investig (Lond) 1:19-32
Infectious Diseases Society of America (IDSA); Spellberg, Brad; Blaser, Martin et al. (2011) Combating antimicrobial resistance: policy recommendations to save lives. Clin Infect Dis 52 Suppl 5:S397-428
Spellberg, Brad (2011) The antibiotic crisis: can we reverse 65 years of failed stewardship? Arch Intern Med 171:1080-1
Miller, Loren G; McKinnell, James A; Vollmer, Michael E et al. (2011) Impact of methicillin-resistant Staphylococcus aureus prevalence among S. aureus isolates on surgical site infection risk after coronary artery bypass surgery. Infect Control Hosp Epidemiol 32:342-50

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