 Abstract
for the RCE
 Bacillus
anthracis Host
Interactions
 Discovery
of Subunit Vaccine Candidates against
Glanders
 Alphavirus
Vaccines for Biodefense
 Novel
Genetic Tools for Viral Biodefense
 Development
and Evaluation of Human
Brucellosis
Vaccines
 Rapid
Diagnostic Tools for Q Fever
New
Diagnostic Methods for Accute Rickettsial
Infections
Risks
and Interventions for Pandemic Influenza
Development
of Novel Pseudoinfectious Flavivirus Vaccines
Development
of Diagnostic Reagents for the detection
of
Francisella and
Francisella
Infection
Toward
Control of Rift Valley Fever Virus
Replication
Novel
Vaccine Technology for Biodefense
Nucleocapsid-specific
Small Molecule Inhibitors
of
the Bunyaviridae
New
Technologies for Creating Affinity Reagents
New Opportunities Projects
Identification
and Characterization of Novel
Flavivirus
Antivirals
Biosafety
Containment Training Program
Passive
Immunotherapeutics for
Select
Agents
Preclinical
Testing of YF17D/LAS, a Bivalent
Vaccine
for Lassa and
Yellow
Fever |
Bacillus
anthracis Host Interactions
Collaborating
Institution: University of Texas Health Science Center at Houston,
Houston, TX
Principal Investigator: Theresa M. Koehler, Ph.D.
Title of the
Project: Bacillus anthracis–Host Interactions
Co-Investigators:
a) Jimmy D. Ballard Ph.D. – University of Oklahoma Health
Sciences Center, Oklahoma City, OK
b) Steven R. Blanke, Ph.D. – University of Illinois, Urbana,
IL
c) C. Rick Lyons, M.D., Ph.D. – University of New Mexico
Health Sciences Center, Albuquerque, NM
Expected Product: Therapeutic candidates for the treatment of
inhalation anthrax (inhibitors of anthrax spore infection of alveolar
macrophages).
Description: Anthrax disease results from a complex series of
interactions between the invading bacterium, Bacillus anthracis,
and the mammalian host. For inhalation anthrax, infection begins
with entry of spores into the lung. Alveolar macrophages phagocytose
the spores and transport them to lymph nodes of the mediastinum.
Ultimately the metabolically active form of the bacterium disseminates
to the blood and other body tissues, reaching concentrations up
to 108 CFU per ml and secreting the anthrax toxin proteins. In
recent years, research emphases have focused on toxin protein structure
and function. However, anthrax disease, whether acquired naturally
or as the result of intentional dissemination of spores, results
from infection with B. anthracis, not simply acquisition of toxin.
Despite the importance of human infection with B. anthracis, there
is an almost complete lack of knowledge of fundamental cellular
and molecular mechanisms by which the bacterium interacts with
its host. Results of studies proposed here will fill this critical
gap in knowledge and reveal bacterial and host targets for generation
of new therapeutics for anthrax.
We will use an in vitro macrophage model and in vivo murine model
to identify pathogen and host targets important for multiple early
steps in infection. The importance of pathogen and host factors
during early infection will be assessed in both models by modulating
expression of candidate B. anthracis and macrophage targets. In
Aim 1 we will identify and characterize B. anthracis and macrophage
molecular targets important for multiple steps of early infection.
We will establish a detailed model of B. anthracis-macrophage interactions.
A major part of this work will be to characterize the modulation
of both bacterial and macrophage gene expression as a result of
B. anthracis-macrophage interactions, using transcriptional profiling
and proteome analyses. In Aim 2 we will investigate B. anthracis
development in a mouse nasal instillation model for anthrax, focusing
on the pulmonary response. We will test B. anthracis mutants for
attenuation of pathogenesis in the model. B. anthracis germination,
survival, and persistence in the lung will be correlated with lung
histopathology and immune response. We will track development of
B. anthracis in the whole animal using chemiluminescence-based
in vivo imaging technology. Using these assays, we will establish
the spatial and temporal development of a fully virulent B. anthracis
strain and isogenic mutants deleted for genes encoding therapeutic
candidates.
Our long-term objective is to generate new therapeutics to block
interactions of B. anthracis spores with alveolar macrophages.
The most powerful strategy will probably employ a cocktail of inhibitors
targeting multiple steps in the infectious process. Bacterial and
macrophage targets shown experimentally to be important for B.
anthracis–macrophage interactions will be immediately forwarded
to RCE core facilities to be expressed recombinantly and crystallized
for high-resolution structural analysis. The structural data will
be used for structural-based identification of lead-inhibitor templates.
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