The serine protease inhibitor camostat inhibits influenza virus replication and cytokine production in primary cultures of human tracheal epithelial cells

• Published in: Pulmonary pharmacology & therapeutics Vol. 33; pp. 66 - 74
• Main Authors: Yamaya, Mutsuo, Shimotai, Yoshitaka, Hatachi, Yukimasa, Lusamba Kalonji, Nadine, Tando, Yukiko, Kitajima, Yasuo, Matsuo, Kaori, Kubo, Hiroshi, Nagatomi, Ryoichi, Hongo, Seiji, Homma, Morio, Nishimura, Hidekazu
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.08.2015
• Subjects: Aged; Airway epithelial cell; Animals; Aprotinin - pharmacology; Camostat; Cell culture; Cells, Cultured; Dogs; Epithelial Cells - drug effects; Epithelial Cells - virology; Female; Gabexate - analogs & derivatives; Gabexate - pharmacology; Humans; Influenza; Influenza A Virus, H1N1 Subtype - isolation & purification; Influenza A Virus, H3N2 Subtype - isolation & purification; Influenza, Human - drug therapy; Influenza, Human - virology; Interleukin; Madin Darby Canine Kidney Cells; Male; Medical Education; Middle Aged; Pulmonary/Respiratory; RNA, Viral - metabolism; Serine protease; Serine Proteinase Inhibitors - pharmacology; Trachea - cytology; Trachea - virology; Virus Replication - drug effects; Cell culture; RT; AEBSF; Interleukin; CLEIA; SARS-CoV; Camostat; TNF; LPS; IFN; DMEM; LDH; DF-12; ANOVA; MDCK; PBS; Airway epithelial cell; TMPRSS; IL; MOI; F-12; USG; PVDF; TCID; PBS-T; SDS-PAGE; MEM; Influenza; KIU; Serine protease; HA; HAT; COPD; ELISA; phosphate buffered saline with Tween ® 20; hemagglutinin; sodium dodecyl sulfate-polyacrylamide gel electrophoresis; 4-(2-aminoethyl)-benzenesulfonyl fluoride; Ultroser G; mixture of Dulbecco's modified Eagle's medium-Ham's F-12 medium; polyvinylidene difluoride; Kallikrein Inhibitor Unit; lactate dehydrogenase; Dulbecco's modified Eagle's medium; severe acute respiratory syndrome coronavirus; human trypsin-like protease; lipopolysaccharide; Eagle's minimum essential medium; room temperature; Ham's F-12 medium; multiplicity of infection; analysis of variance; interferon; chemiluminescent enzyme immunoassay; tumor necrosis factor; phosphate buffered saline; enzyme-linked immunosorbent assay; Madin Darby Canine Kidney; tissue culture infective dose; transmembrane protease serine S1 member; chronic obstructive pulmonary disease
• DOI: 10.1016/j.pupt.2015.07.001
• ISSN: 1094-5539

Serine proteases act through the proteolytic cleavage of the hemagglutinin (HA) of influenza viruses for the entry of influenza virus into cells, resulting in infection. However, the inhibitory effects of serine protease inhibitors on influenza virus infection of human airway epithelial cells, and on their production of inflammatory cytokines are unclear. Primary cultures of human tracheal epithelial cells were treated with four types of serine protease inhibitors, including camostat, and infected with A/Sendai-H/108/2009/(H1N1) pdm09 or A/New York/55/2004(H3N2). Camostat reduced the amounts of influenza viruses in the supernatants and viral RNA in the cells. It reduced the cleavage of an influenza virus precursor protein, HA0, into the subunit HA1. Camostat also reduced the concentrations of the cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-α in the supernatants. Gabexate and aprotinin reduced the viral titers and RNA levels in the cells, and aprotinin reduced the concentrations of TNF-α in the supernatants. The proteases transmembrane protease serine S1 member (TMPRSS) 2 and HAT (human trypsin-like protease: TMPRSS11D), which are known to cleave HA0 and to activate the virus, were detected at the cell membrane and in the cytoplasm. mRNA encoding TMPRSS2, TMPRSS4 and TMPRSS11D was detectable in the cells, and the expression levels were not affected by camostat. These findings suggest that human airway epithelial cells express these serine proteases and that serine protease inhibitors, especially camostat, may reduce influenza viral replication and the resultant production of inflammatory cytokines possibly through inhibition of activities of these proteases.