Asthma is a complex disorder characterized by episodic airway obstruction and hyper-responsiveness, sometimes accompanied by airway remodeling. Although the underlying causes of asthma remain poorly understood, one contributing factor is exposure to respiratory pathogens. For example, asthmatics positive for Mycoplasma pneumoniae (M. pneumoniae) infection have demonstrated an improvement in pulmonary function after antibiotic treatment whereas patients that test negative do not, suggesting a causal relationship between M. pneumoniae infection and asthma symptom severity. Although there is a strong clinical correlation between M. pneumoniae infection and a sub-set of asthma cases, until recently, the identification of a virulence factor that might play a role in disease pathogenesis had remained elusive. This situation changed, however, when we discovered a 591 amino acid protein with ADP-ribosyltransferase (ART) activity in M. pneumoniae designated Community Acquired Respiratory Distress Syndrome ToXin (CARDS TX). The experiments outlined in this proposal are designed to uncover the structure and action of CARDS TX using a range of biophysical techniques. Using the well-established tools of single crystal X-ray diffraction, we will determine: 1) the three-dimensional structure of CARDS TX;2) CARDS TX in complex with its NAD"""""""""""""""" co-factor;3) CARDS TX in complex with neutralizing monoclonal antibody Fab fragments;and 4) CARDS TX in complex with recombinant extracellular domains of its cell surface receptor surfactant protein-A (SP-A). A longer term goal is to use these 3-D structures in conjunction with the information coming from Projects 1 and 2 as platforms for the design of CARDS TX inhibitors, which may represent novel therapeutic agents for the treatment of asthma and pulmonary inflammation.
CARDS TX is a virulence protein used by Mycoplasma pneumoniae, the causative agent of asthma, pneumonia, and other inflammatory lung disorders in humans. The experiments outlined in this proposal will reveal the molecular structure of CARDS TX and will illuminate its mode of action. This information will in turn permit the design of novel diagnostic and therapeutic avenues for the treatment of asthma and other pulmonary diseases.
|Sundaram, Aparna; Chen, Chun; Khalifeh-Soltani, Amin et al. (2017) Targeting integrin ?5?1 ameliorates severe airway hyperresponsiveness in experimental asthma. J Clin Invest 127:365-374|
|Benedetto, Roberta; Ousingsawat, Jiraporn; Wanitchakool, Podchanart et al. (2017) Epithelial Chloride Transport by CFTR Requires TMEM16A. Sci Rep 7:12397|
|Steed, Ashley L; Christophi, George P; Kaiko, Gerard E et al. (2017) The microbial metabolite desaminotyrosine protects from influenza through type I interferon. Science 357:498-502|
|Wood, Pamela R; Kampschmidt, Jordan C; Dube, Peter H et al. (2017) Mycoplasma pneumoniae and health outcomes in children with asthma. Ann Allergy Asthma Immunol 119:146-152.e2|
|Maselli, Diego J; Medina, Jorge L; Brooks, Edward G et al. (2017) The Immunopathologic Effects of Mycoplasma Pneumoniae and CARDS Toxin: A Primate Model. Am J Respir Cell Mol Biol :|
|Shen, Haiqian; Gonzalez-Juarbe, Norberto; Blanchette, Krystle et al. (2016) CD8(+) T cells specific to a single Yersinia pseudotuberculosis epitope restrict bacterial replication in the liver but fail to provide sterilizing immunity. Infect Genet Evol 43:289-96|
|Cahill, Katherine N; Raby, Benjamin A; Zhou, Xiaobo et al. (2016) Impaired E Prostanoid2 Expression and Resistance to Prostaglandin E2 in Nasal Polyp Fibroblasts from Subjects with Aspirin-Exacerbated Respiratory Disease. Am J Respir Cell Mol Biol 54:34-40|
|Buchheit, Kathleen M; Cahill, Katherine N; Katz, Howard R et al. (2016) Thymic stromal lymphopoietin controls prostaglandin D2 generation in patients with aspirin-exacerbated respiratory disease. J Allergy Clin Immunol 137:1566-1576.e5|
|Ulm, Ashley; Mayhew, Christopher N; Debley, Jason et al. (2016) Cultivate Primary Nasal Epithelial Cells from Children and Reprogram into Induced Pluripotent Stem Cells. J Vis Exp :|
|Lee-Sarwar, Kathleen; Johns, Christina; Laidlaw, Tanya M et al. (2015) Tolerance of daily low-dose aspirin does not preclude aspirin-exacerbated respiratory disease. J Allergy Clin Immunol Pract 3:449-51|
Showing the most recent 10 out of 39 publications