Immunotherapy With Nebulized Pattern Recognition Receptor Agonists Restores Severe Immune Paralysis and Improves Outcomes in Mice With Influenza-Associated Pulmonary Aspergillosis

Authors

Jezreel Pantaleón García
Sebastian Wurster
Nathaniel D Albert
Uddalak Bharadwaj
Keerthi Bhoda
Vikram K Kulkarni
Mbaya Ntita
Paris Rodríguez Carstens
Madeleine Burch-Eapen
Daniela Covarrubias López
Jania Foncerrada Lizaola
Katherine E Larsen
Lauren M Matula
Seyed J Moghaddam
Yongxing Wang
Dimitrios P Kontoyiannis
Scott E Evans

Language

English

Publication Date

5-14-2025

Journal

mBio

DOI

10.1128/mbio.04061-24

PMID

40197039

PMCID

PMC12077147

PubMedCentral® Posted Date

4-8-2025

PubMedCentral® Full Text Version

Post-print

Abstract

Influenza-associated pulmonary aspergillosis (IAPA) is a potentially deadly superinfection in patients with influenza pneumonia, especially those with severe disease, underlying immunosuppression, corticosteroid therapy, or requiring intensive care support. Given the high mortality of IAPA, adjunct immunomodulatory strategies remain a critical unmet need. Previously, the desensitization of pattern recognition pathways has been described as a hallmark of IAPA pathogenesis and a predictor of mortality in IAPA patients. Therefore, we studied the impact of nebulized Toll-like receptor 2/6/9 agonists Pam2 CSK4 (Pam2) and CpG oligodeoxynucleotides (ODNs) on infection outcomes and pulmonary immunopathology in a corticosteroid-immunosuppressed murine IAPA model. Mice with IAPA receiving mock therapy showed rapidly progressing disease and a paralyzed immune response to secondary Aspergillus fumigatus infection. Nebulized Pam2ODN was well tolerated and significantly prolonged event-free survival. Specifically, dual-dose Pam2ODN therapy before and after A. fumigatus infection led to 81% survival and full recovery of all survivors. Additionally, transcriptional analysis of lung tissue homogenates revealed induction of pattern recognition receptor signaling and several key effector cytokine pathways after Pam2ODN therapy. Moreover, transcriptional and flow cytometric analyses suggested increased frequencies of macrophages, natural killer cells, and T cells in the lungs of Pam2ODN-treated mice. Collectively, immunomodulatory treatment with nebulized Pam2ODN strongly improved morbidity and mortality outcomes and alleviated paralyzed antifungal immunity in an otherwise lethal IAPA model. These findings suggest that Pam2ODN might be a promising candidate for locally delivered immunomodulatory therapy to improve outcomes of virus-associated mold infections such as IAPA.

Keywords

Animals, Mice, Pulmonary Aspergillosis, Aspergillus fumigatus, Receptors, Pattern Recognition, Disease Models, Animal, Female, Immunotherapy, Orthomyxoviridae Infections, Oligodeoxyribonucleotides, Lung, Treatment Outcome, Mice, Inbred C57BL, Nebulizers and Vaporizers, pneumonia, influenza, aspergillosis, immunotherapy, immunomodulation, cytokines, macrophages, epithelial pathogenesis, animal models, innate immunity recognition

Published Open-Access

yes

Recommended Citation

Pantaleón García, Jezreel; Wurster, Sebastian; Albert, Nathaniel D; et al., "Immunotherapy With Nebulized Pattern Recognition Receptor Agonists Restores Severe Immune Paralysis and Improves Outcomes in Mice With Influenza-Associated Pulmonary Aspergillosis" (2025). Faculty, Staff and Student Publications. 5622.
https://digitalcommons.library.tmc.edu/uthgsbs_docs/5622