Benjamin Manchester, University of Guelph

Benjamin Manchester (University of Guelph), Elena Campbell (University of Guelph), Yanlong Pei (University of Guelph), Shayan Sharif (University of Guelph), Jennifer Gommerman (University of Toronto), Sarah Wootton (University of Guelph)

Fighting & Responding

Strategies to establish sustained mucosal immunity are urgently needed to combat chronic Pseudomonas aeruginosa infections in cystic fibrosis patients, in which recurrent colonization and sustained airway inflammation are key contributors to disease burden and mortality. Our goal is to develop an adeno associated virus (AAV)–based platform capable of supporting long term in vivo expression and secretion of protective secretory IgA (SIgA) at mucosal surfaces. As the principal antibody isotype at mucosal sites, SIgA plays a critical role in immune exclusion of pathogens, but its polymeric structure presents significant obstacles for recombinant expression. To overcome this challenge, we engineered a series of AAV vector genomes expressing human IgA1, human IgA2 and murine IgA heavy chains with Kappa light chains. In addition, we integrated various J chain configurations into the genome constructs to evaluate their impact on SIgA assembly efficiency and transcytosis. To assess these genome designs, we employed precision-cut mouse lung slices (PCLS) and muscle slices as ex vivo models to study transduction, antibody expression, and secretion efficiencies. Our preliminary findings indicate that AAV-transduced lung slices secrete IgA with a higher efficiency then muscle slices suggesting that lung tissue could be optimal for SIgA secretion. Across constructs, we expect to observe similar intracellular IgA expression with differences in secretion efficiency depending on both the IgA isotype and genome configuration. This work will advance the development of a durable SIgA based immunoprophylactic platform aimed at preventing chronic P. aeruginosa infections in susceptible patient populations.