Chronic obstructive pulmonary disease (COPD) is a chronic debilitating disease that afflicts ~24 million Americans and is a major cause of death and disability globally. Research over the past 2 decades has begun to elucidate the critical role of bacterial colonization and infection, particularly by nontypeable Haemophilus influenzae (NTHI), in the course and pathogenesis of COPD. In an 18-year ongoing prospective study, we have established that a large proportion of adults with COPD show persistent airway colonization by NTHI. Although such colonization was previously thought to be innocuous because of the absence of acute symptoms, it is now clear that such colonization contributes to the airway inflammation and impaired pulmonary function that are hallmarks of COPD. The carefully characterized strains from this long-term study allow us to address key areas where opportunities to develop novel interventions in the course of COPD exist.
In aim 1 the evolutionary dynamics of the NTHI genome from serial isolates that lived in the complex environment of the human airways will be elucidated to identify adaptations that facilitate persistence in the airways in COPD.
In aim 2 the effect of immune selective pressure on candidate vaccine antigens will be elucidated. Vaccine development for NTHI is undergoing exciting new developments with the recent licensing of a vaccine that contains an NTHI antigen and preclinical and clinical development of several additional antigens. Monitoring the effect of persistence in the human respiratory tract in driving sequence changes and their consequences on candidate vaccine antigens is critical to assessing such vaccine candidates.
In aim 3 the frequency of antimicrobial resistance markers and tolerance in NTHI that colonize and infect adults with COPD will be studied to assess the effect of antibiotic use in driving resistance mechanisms. The genomes of bacteria harbor antibiotic resistance markers that are undetected by simply measuring antimicrobial susceptibility and thus allow us to anticipate future antibiotic resistance mechanisms. Antibiotic tolerance, a term that refers to persistence in the face of active antibiotic, will be explored as a mechanism of persistence in COPD. It is now clear that chronic bacterial colonization of the airways is a major contributor to airway inflammation and impaired pulmonary function in COPD. The application of state-of-the-art methods to a unique set of strains and detailed associated data make it possible to explore 3 key areas that are unexplored: 1) mechanisms of persistence, 2) the effect of persistence on vaccine antigens and 3) the role of repeated antibiotic exposure in driving antibiotic resistance and tolerance as mechanisms of persistence. Each of these 3 areas is rich in opportunities to develop novel interventions in the course of COPD.
Persistence of nontypeable Haemophilus influenzae in the lower airways of adults with chronic obstructive pulmonary disease (COPD) causes airway inflammation and impaired pulmonary function. This proposal uses state of the art methods to investigate how NTHI persists and the consequences of its persistence. The results will reveal new ways to eradicate persistent NTHI and have great potential for novel discoveries to prolong and improve the lives of people with COPD.
|Pettigrew, Melinda M; Ahearn, Christian P; Gent, Janneane F et al. (2018) Haemophilus influenzae genome evolution during persistence in the human airways in chronic obstructive pulmonary disease. Proc Natl Acad Sci U S A 115:E3256-E3265|
|Jacobs, David M; Ochs-Balcom, Heather M; Zhao, Jiwei et al. (2018) Lower Airway Bacterial Colonization Patterns and Species-Specific Interactions in Chronic Obstructive Pulmonary Disease. J Clin Microbiol 56:|
|Tsuji, Brian T; Fisher, James; Boadi-Yeboah, Raheal et al. (2018) Azithromycin Pharmacodynamics against Persistent Haemophilus influenzae in Chronic Obstructive Pulmonary Disease. Antimicrob Agents Chemother 62:|
|Gallo, Mary C; Kirkham, Charmaine; Eng, Samantha et al. (2018) Changes in IgA Protease Expression Are Conferred by Changes in Genomes during Persistent Infection by Nontypeable Haemophilus influenzae in Chronic Obstructive Pulmonary Disease. Infect Immun 86:|
|Otsuka, Taketo; Brauer, Aimee L; Kirkham, Charmaine et al. (2017) Antimicrobial activity of antisense peptide-peptide nucleic acid conjugates against non-typeable Haemophilus influenzae in planktonic and biofilm forms. J Antimicrob Chemother 72:137-144|
|Ahearn, Christian P; Gallo, Mary C; Murphy, Timothy F (2017) Insights on persistent airway infection by non-typeable Haemophilus influenzae in chronic obstructive pulmonary disease. Pathog Dis 75:|
|Pettigrew, Melinda M; Alderson, Mark R; Bakaletz, Lauren O et al. (2017) Panel 6: Vaccines. Otolaryngol Head Neck Surg 156:S76-S87|
|Murphy, Timothy F; Kirkham, Charmaine; Gallo, Mary C et al. (2017) Immunoglobulin A Protease Variants Facilitate Intracellular Survival in Epithelial Cells By Nontypeable Haemophilus influenzae That Persist in the Human Respiratory Tract in Chronic Obstructive Pulmonary Disease. J Infect Dis 216:1295-1302|
|Post, Deborah M B; Ketterer, Margaret R; Coffin, Jeremy E et al. (2016) Comparative Analyses of the Lipooligosaccharides from Nontypeable Haemophilus influenzae and Haemophilus haemolyticus Show Differences in Sialic Acid and Phosphorylcholine Modifications. Infect Immun 84:765-74|
|Hu, Fang; Rishishwar, Lavanya; Sivadas, Ambily et al. (2016) Comparative Genomic Analysis of Haemophilus haemolyticus and Nontypeable Haemophilus influenzae and a New Testing Scheme for Their Discrimination. J Clin Microbiol 54:3010-3017|
Showing the most recent 10 out of 79 publications