Pseudomonas aeruginosa?induced corneal keratitis is a sight-threatening disease. The rising antibiotic resistance among the Pseudomonas isolates makes treatment of this disease challenging, justifying the need for alternative therapeutic modalities. We propose to explore the concept that exposure of ocular surfaces to commensal strains or perturbations of commensal ecosystems alters the bactericidal capability of neutrophils against P. aeruginosa, thereby determining the threshold for susceptibility to infection.
Specific Aim 1. Define the impact of ocular exposure to commensal strains on susceptibility to P. aeruginosa-induced keratitis. We demonstrated that there was a measurable and significant impact of ocular exposure to commensal organisms that strengthens the immune responses to P. aeruginosa-induced keratitis. In this aim, we will colonize conjunctival mucosal surfaces with different commensal organisms and evaluate the consequences of colonization on P. aeruginosa-induced keratitis.
Specific Aim 2. Define the impact of gut microbiota on neutrophil bactericidal activities at baseline and during P. aeruginosa-induced keratitis. Reduction of gut microbiota has a pronounced impact on susceptibility to keratitis, signifying the existence of a mechanism operating along a ?gut-eye? axis. In this aim we will identify gut commensal communities that regulate neutrophil bactericidal properties against P. aeruginosa. We will utilize selective antibiotic-based reduction of commensal organisms and colonization of germ free mice with different commensal communities to evaluate how gut commensals affect neutrophil bactericidal properties and, thereby, cause susceptibility to keratitis. We will leverage our experience in quantitative transcriptomic and proteomic analysis to gain insights into microbiota-driven granulocyte maturation and examine the mechanisms thereof.
Specific Aim 3. Evaluate the impact of MIF deficiency on commensal presence and development of keratitis. MIF deficiency confers resistance to P. aeruginosa-induced keratitis and, excitingly, commensal communities in MIF-deficient mice are more diverse than those of MIF-sufficient mice. We will explore how these alterations in commensal presence affect resistance to infection by decreasing commensal abundance either locally or in the gut through selective antibiotic treatments.

Public Health Relevance

Bacterial keratitis is a sight-threatening complication of contact lens wear and eye trauma and Pseudomonas aeruginosa is among the most frequently isolated pathogens from corneal ulcers. Our long- term objective is to provide the ophthalmic community with novel therapeutic modalities to control or prevent infection. This application evaluates the impact of different commensal species or communities on promoting resistance to keratitis and the mechanisms responsible for protection.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY022054-07
Application #
9544948
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Mckie, George Ann
Project Start
2012-08-01
Project End
2021-07-31
Budget Start
2018-08-01
Budget End
2019-07-31
Support Year
7
Fiscal Year
2018
Total Cost
Indirect Cost
Name
Brigham and Women's Hospital
Department
Type
DUNS #
030811269
City
Boston
State
MA
Country
United States
Zip Code
Kugadas, Abirami; Wright, Quentin; Geddes-McAlister, Jennifer et al. (2017) Role of Microbiota in Strengthening Ocular Mucosal Barrier Function Through Secretory IgA. Invest Ophthalmol Vis Sci 58:4593-4600
St Leger, Anthony J; Desai, Jigar V; Drummond, Rebecca A et al. (2017) An Ocular Commensal Protects against Corneal Infection by Driving an Interleukin-17 Response from Mucosal ?? T Cells. Immunity 47:148-158.e5
Pandya, Hardik J; Kanakasabapathy, Manoj Kumar; Verma, Saloni et al. (2017) Label-free electrical sensing of bacteria in eye wash samples: A step towards point-of-care detection of pathogens in patients with infectious keratitis. Biosens Bioelectron 91:32-39
Christiansen, Stig Hill; Murphy, Ronan A; Juul-Madsen, Kristian et al. (2017) The Immunomodulatory Drug Glatiramer Acetate is Also an Effective Antimicrobial Agent that Kills Gram-negative Bacteria. Sci Rep 7:15653
Roux, Damien; Weatherholt, Molly; Clark, Bradley et al. (2017) Immune Recognition of the Epidemic Cystic Fibrosis Pathogen Burkholderia dolosa. Infect Immun 85:
Kugadas, Abirami; Gadjeva, Mihaela (2016) Impact of Microbiome on Ocular Health. Ocul Surf 14:342-9
Gauguet, Stefanie; D'Ortona, Samantha; Ahnger-Pier, Kathryn et al. (2015) Intestinal Microbiota of Mice Influences Resistance to Staphylococcus aureus Pneumonia. Infect Immun 83:4003-14
Chen, Li; Zhou, Xia; Fan, Lucy X et al. (2015) Macrophage migration inhibitory factor promotes cyst growth in polycystic kidney disease. J Clin Invest 125:2399-412
Terzulli, Marielle; Contreras-Ruiz, Laura; Ruiz, Laura Contreras et al. (2015) TSP-1 Deficiency Alters Ocular Microbiota: Implications for Sjögren's Syndrome Pathogenesis. J Ocul Pharmacol Ther 31:413-8
Shan, Qiang; Dwyer, Markryan; Rahman, Samir et al. (2014) Distinct susceptibilities of corneal Pseudomonas aeruginosa clinical isolates to neutrophil extracellular trap-mediated immunity. Infect Immun 82:4135-43

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