Our laboratory has recently reported the structure of a Bacillus anthracis species-specific polysaccharide. This polysaccharide (termed HF-PS) has been classified a 'non-classical'secondary cell wall polymer. It is isolated from the cell wall of vegetative cells by treatment with aqueous hydrogen fluoride (HF), and was previously reported to function in anchoring/exporting the S-layer proteins, Sap and EA1, to the cell surface. Our work strongly supports that the HF-PS is structurally specific to B. anthracis strains, is immunogenic in that animals injected with live or dead spores of B. anthracis Sterne (34F2) produce antibodies against HF-PS, and is immunogenically specific with regard to the binding of these antibodies to the HF-PSs of even closely related B. cereus strains. Further, we have shown that sera from Rhesus macaques that survive exposure to B. anthracis spores contain IgG anti-HF-PS antibodies. Preliminary data and results in the literature support that these polysaccharides could be crucial for important functions with regard to the growth and virulence of pathogenic Bacillus species, including B. anthracis. However, to date direct empirical evidence is still missing.
The aims of this proposal are to engineer mutants that are impaired in the biosynthesis of this HF-PS polysaccharide and to characterize the phenotype of these mutants with regard to their growth, sporulation, HF-PS structure, HF-PS interaction with S-layer proteins and various phage endolysins, and to study the effect of each mutation on the virulence in a mouse model. This research will provide us with necessary insight regarding the HF-PS's pathogenic functions, and its usefulness for the development of vaccines, diagnostics and therapeutics.

Public Health Relevance

The bacterium Bacillus anthracis causes anthrax in humans;as a bioterrorism agent the bacteria are a threat to public health. Our laboratory has recently reported a cell wall polysaccharide of a B. anthracis (termed HF- PS) with a structure specific to these bacteria. We will create B. anthracis mutants impaired in the biosynthesis of this cell wall polysaccharide and investigate whether these mutants are impaired in important bacterial growth functions and disease development. This investigation will lay the groundwork for future studies into improved vaccines, diagnostics, and therapeutics, and into new anthrax-related public health practices.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21AI076753-02
Application #
7860446
Study Section
Special Emphasis Panel (ZRG1-IDM-A (90))
Program Officer
Breen, Joseph J
Project Start
2009-06-05
Project End
2012-05-30
Budget Start
2010-06-01
Budget End
2012-05-30
Support Year
2
Fiscal Year
2010
Total Cost
$185,625
Indirect Cost
Name
University of Georgia
Department
Type
Organized Research Units
DUNS #
004315578
City
Athens
State
GA
Country
United States
Zip Code
30602
Russo, Daniela M; Abdian, Patricia L; Posadas, Diana M et al. (2015) Lipopolysaccharide O-chain core region required for cellular cohesion and compaction of in vitro and root biofilms developed by Rhizobium leguminosarum. Appl Environ Microbiol 81:1013-23
Liu, Wenjun; Sakr, Elias; Schaeffer, Philippe et al. (2014) Ribosylhopane, a novel bacterial hopanoid, as precursor of C35 bacteriohopanepolyols in Streptomyces coelicolor A3(2). Chembiochem 15:2156-61
Grover, Harshita Satija; Chu, H Hamlet; Kelly, Felice D et al. (2014) Impact of regulated secretion on antiparasitic CD8 T cell responses. Cell Rep 7:1716-1728
Ganguly, Jhuma; Low, Lieh Y; Kamal, Nazia et al. (2013) The secondary cell wall polysaccharide of Bacillus anthracis provides the specific binding ligand for the C-terminal cell wall-binding domain of two phage endolysins, PlyL and PlyG. Glycobiology 23:820-32
Forsberg, L Scott; Abshire, Teresa G; Friedlander, Arthur et al. (2012) Localization and structural analysis of a conserved pyruvylated epitope in Bacillus anthracis secondary cell wall polysaccharides and characterization of the galactose-deficient wall polysaccharide from avirulent B. anthracis CDC 684. Glycobiology 22:1103-17
Forsberg, L Scott; Choudhury, Biswa; Leoff, Christine et al. (2011) Secondary cell wall polysaccharides from Bacillus cereus strains G9241, 03BB87 and 03BB102 causing fatal pneumonia share similar glycosyl structures with the polysaccharides from Bacillus anthracis. Glycobiology 21:934-48