The accumulation of viscous mucus in the airways is the primary cause of long-term bacterial infections, respiratory failure, and eventually death in cystic fibrosis (CF). The inflammatory response to infections in the airways leads to the pathological release of cytoskeletal proteins, DNA and other polyelectrolytes, which cause the electrostatic assembly of large aggregates stabilized by cationic ligands in CF mucus, and results in the sequestration of endogenous antibacterial polypeptides and contributes to the loss of antimicrobial function. The long-range goal of this proposal is the rational design of therapeutic strategies in the restoration of antimicrobial function in CF, based on a biophysical understanding of electrostatic interactions in CF mucus. The three specific aims of the proposal are: (1) To determine the ionic strength within the airway surface liquid (ASL) expressed on cultured human airway epithelial cell lines with and without a functioning cystic fibrosis transmembrane conductance regulator (CFTR). (2) To characterize quantitatively the structural form and thermodynamic stability of electrostatic complexes of endogenous antibacterial peptides and anionic polyelectrolytes in the ASL under CF physiological conditions, and design biophysical therapeutic strategies to unbind these sequestered antibacterial peptides. (3) To develop, via directed molecular evolution, an anionic DNAzyme which mimics the biofilm suppression action of cationic lactoferrin, but will not be sequestered due to its opposite charge.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Exploratory/Developmental Grants (R21)
Project #
1R21DK068431-01
Application #
6813214
Study Section
Lung Cellular, Molecular, and Immunobiology Study Section (LCMI)
Program Officer
Mckeon, Catherine T
Project Start
2004-08-01
Project End
2006-07-31
Budget Start
2004-08-01
Budget End
2005-07-31
Support Year
1
Fiscal Year
2004
Total Cost
$149,279
Indirect Cost
Name
University of Illinois Urbana-Champaign
Department
Engineering (All Types)
Type
Schools of Engineering
DUNS #
041544081
City
Champaign
State
IL
Country
United States
Zip Code
61820
Yang, Lihua; Gordon, Vernita D; Mishra, Abhijit et al. (2007) Synthetic antimicrobial oligomers induce a composition-dependent topological transition in membranes. J Am Chem Soc 129:12141-7
Guaqueta, Camilo; Sanders, Lori K; Wong, Gerard C L et al. (2006) The effect of salt on self-assembled actin-lysozyme complexes. Biophys J 90:4630-8
Zribi, Olena V; Kyung, Hee; Golestanian, Ramin et al. (2006) Condensation of DNA-actin polyelectrolyte mixtures driven by ions of different valences. Phys Rev E Stat Nonlin Soft Matter Phys 73:031911
Sanders, Lori K; Guaqueta, Camilo; Angelini, Thomas E et al. (2005) Structure and stability of self-assembled actin-lysozyme complexes in salty water. Phys Rev Lett 95:108302