Project Grant F31HL189093

THE ROLE OF ANAEROBIC MICROBIOTA IN SHAPING EARLY CF AIRWAY ECOSYSTEMS - PROJECT SUMMARY BACTERIAL INFECTIONS ARE THE LEADING CAUSE OF MORBIDITY AND MORTALITY IN PEOPLE WITH CYSTIC FIBROSIS (CF). WHILE STAPHYLOCOCCUS AUREUS IS WIDELY RECOGNIZED AS THE FIRST PATHOGEN TO COLONIZE THE LUNGS OF INFANT AND YOUNG CHILDREN WITH CF, CULTURE-INDEPENDENT ANALYSES HAVE REVEALED THAT THE CF AIRWAYS ALSO HARBOR DIVERSE MICROBIOTA THAT WERE NOT PREVIOUSLY APPRECIATED. AMONG THE MOST ABUNDANT AND PREVALENT GENERA DETECTED IN EARLY LIFE INCLUDE STREPTOCOCCUS, FUSOBACTERIUM, VEILLONELLA AND PREVOTELLA, GENERA TRADITIONALLY CONSIDERED TO BE ORAL- ASSOCIATED COMMENSALS. ALTHOUGH OFTEN DISMISSED AS CONTAMINANTS, CULTURE-BASED AND GENOMIC STUDIES OF BRONCHOALVEOLAR LAVAGE FLUID (BALF), SPUTUM, AND EXPLANT LUNG TISSUE CLEARLY DEMONSTRATE THAT THESE ANAEROBES PERSIST AND METABOLICALLY THRIVE WITHIN THE LOWER CF AIRWAYS. DESPITE THE GROWING BODY OF CLINICAL AND EPIDEMIOLOGICAL EVIDENCE THAT EARLY CF MICROBIOTA MAY PLAY BOTH BENEFICIAL AND DETRIMENTAL ROLES, COMPARATIVELY LITTLE IS KNOWN ABOUT (I) ECOLOGICAL FACTORS THAT FACILITATE ANAEROBIC COMMUNITY ASSEMBLY, (II) HOW THE CF AIRWAY ENVIRONMENT SHAPES SPECIFIC TAXONOMIC COMPOSITIONS, AND (III) HOW THESE COMMUNITIES IMPACT THE BEHAVIOR OF CANONICAL PATHOGENS SUCH AS S. AUREUS. THUS, FURTHER INVESTIGATION INTO PRINCIPLES OF MICROBIOTA ASSEMBLY AND PATHOGENIC ROLE(S) OF THESE POLYMICROBIAL COMMUNITIES IS WARRANTED TO UNDERSTAND THEIR CONTRIBUTIONS TO CF PATHOPHYSIOLOGY. THIS PROPOSAL WILL TEST THE CENTRAL HYPOTHESIS THAT KEYSTONE ANAEROBES AND THE CF AIRWAY ENVIRONMENT TOGETHER SHAPE EARLY AIRWAY COMMUNITY COMPOSITION AND PROMOTE S. AUREUS COLONIZATION. AIM 1 WILL IDENTIFY FACTORS THAT STRUCTURE EARLY CF AIRWAY MICROBIOTA AND DETERMINE HOW DISTINCT ANAEROBIC COMMUNITY COMPOSITIONS INFLUENCE S. AUREUS GROWTH AND PATHOGENICITY. A DEFINED MOCK ANAEROBIC COMMUNITY AND INFANT BALF SAMPLES WILL BE USED TO EVALUATE HOW MUCIN GLYCOPROTEIN COMPOSITION AFFECTS ANAEROBE-ANAEROBE INTERACTIONS AND, IN TURN, MODULATES S. AUREUS BEHAVIOR. TO BETTER RECAPITULATE THE CF LUNG, AIM 2 WILL USE PRIMARY HUMAN AIRWAY EPITHELIAL CELLS FROM CF AND NON-CF DONORS TO ASSESS HOW BOTH CFTR DYSFUNCTION AND ALTERED MUCIN COMPOSITION AFFECT ANAEROBE COMMUNITY ASSEMBLY AND S. AUREUS COLONIZATION AT THE EPITHELIAL SURFACE. ALTOGETHER, THE PROPOSED WORK IS INNOVATIVE IN BOTH THE COMBINATION OF TRANSLATIONAL SCIENCE, BACTERIAL GENETICS, ANALYTICAL BIOCHEMISTRY, AND BIOINFORMATICS. THE RESULTS OF THIS WORK WILL ADVANCE OUR UNDERSTANDING OF HOST-COMMENSAL-PATHOGEN INTERACTIONS IN THE CF AIRWAY AND MAY INFORM NEW STRATEGIES TO PROLONG PATHOGEN ACQUISITION AND IMPROVE CLINICAL OUTCOMES.