Open AccessMicroparticle and anti-influenza activity in human respiratory secretion
Author(s) -
Ornpreya Suptawiwat,
Kanyarat Ruangrung,
Chompunuch Boonarkart,
Pilaipan Puthavathana,
Kittipong Maneechotesuwan,
Komgrid Charngkaew,
Nusara Chomanee,
Prasert Auewarakul
Publication year - 2017
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0183717
Subject(s) - bronchoalveolar lavage , respiratory system , influenza a virus , hemagglutination assay , saliva , receptor , biology , immunology , lung , microbiology and biotechnology , virology , virus , medicine , biochemistry , titer , anatomy
Respiratory secretions, such as saliva and bronchoalveolar fluid, contain anti-influenza activity. Multiple soluble factors have been described that exert anti-influenza activity and are believed to be responsible for the anti-influenza activity in respiratory secretions. It was previously shown that a bronchial epithelial cell culture could produce exosome-like particles with anti-influenza activity. Whether such extracellular vesicles in respiratory secretions have anti-influenza activity is unknown. Therefore, we characterized bronchoalveolar lavage fluid and found microparticles, which mostly stained positive for epithelial cell markers and both α2,3- and α2,6-linked sialic acid. Microparticles were purified from bronchoalveolar lavage fluid and shown to exhibit anti-influenza activity by a hemagglutination inhibition (HI) assay and a neutralization (NT) assay. In addition, physical binding between influenza virions and microparticles was demonstrated by electron microscopy. These findings indicate that respiratory microparticles containing viral receptors can exert anti-viral activity by probably trapping viral particles. This innate mechanism may play an important role in the defense against respiratory viruses.