Preferential apical infection and spread of human metapneumovirus highlights the importance of inhaled delivery of neutralizing monoclonal antibody to treat established infections

K Karthik Tiruthani (Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill) M Madison P. Card (University of North Carolina at Chapel Hill Marsico Lung Institute, School of Medicine, University of North Carolina at Chapel Hill) W Whitney Wolf (Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill) L Limei Shen (Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill) A Alison Schaefer (University of North Carolina at Chapel Hill/North Carolina State University Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill) M Marshall Fritz (Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill) K Kenichi Okuda (University of North Carolina at Chapel Hill Marsico Lung Institute, School of Medicine, University of North Carolina at Chapel Hill) J Jack R. Harkema (Department of Pharmacology and Toxicology, Michigan State University) J Jarrod J. Mousa (Department of Biomedical Sciences, College of Medicine, Florida State University) R Raymond J. Pickles (University of North Carolina at Chapel Hill Marsico Lung Institute, School of Medicine, University of North Carolina at Chapel Hill) S Samuel K. Lai (Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill)

Abstract

Human metapneumovirus (hMPV) is a frequent cause of acute respiratory infections in infants, the elderly, and the immunocompromised. No vaccines or treatments are currently available beyond supportive care. Building on our previous work with parainfluenza viruses and respiratory syncytial virus, we investigate the pattern of hMPV infection and spread in polarized and well-differentiated cultures of human airway epithelium (WD-HAE). We found productive infection of WD-HAE requires apical inoculation of hMPV, with infectious spread dependent on progeny viruses shedding into mucus secretions overlaying the apical surface of WD-HAE. A potent neutralizing monoclonal antibodies (mAb) against hMPV fusion protein—mAb364 (also termed MPV364)—prevented initial infection by hMPV and halted spread of established hMPV infection when dosed directly to the apical surface of WD-HAE. Conversely, mAb364 delivered to the basal compartment was unable to curb established infections, even at 100-fold greater concentrations. Intranasal delivery of mAb364 to hamsters with established hMPV infections reduced viral titers by ~four logs within 2 d and alleviated key pathological outcomes of hMPV infection. These results are consistent with hMPV infection and continued spread occurring via the apical surface of the respiratory epithelium, and underscore delivery of neutralizing mAbs to the respiratory tract as an effective intervention against established hMPV infections.

Article Details

Volume / Issue Vol. 122, Issue 39
Published September 30, 2025
ISSN 0027-8424
Publisher National Academy of Sciences

Authors (11)

K

Karthik Tiruthani

Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill

M

Madison P. Card

University of North Carolina at Chapel Hill Marsico Lung Institute, School of Medicine, University of North Carolina at Chapel Hill

W

Whitney Wolf

Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill

L

Limei Shen

Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill

A

Alison Schaefer

University of North Carolina at Chapel Hill/North Carolina State University Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill

M

Marshall Fritz

Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill

K

Kenichi Okuda

University of North Carolina at Chapel Hill Marsico Lung Institute, School of Medicine, University of North Carolina at Chapel Hill

J

Jack R. Harkema

Department of Pharmacology and Toxicology, Michigan State University

J

Jarrod J. Mousa

Department of Biomedical Sciences, College of Medicine, Florida State University

R

Raymond J. Pickles

University of North Carolina at Chapel Hill Marsico Lung Institute, School of Medicine, University of North Carolina at Chapel Hill

S

Samuel K. Lai

Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill