Pulmonary surfactant is a potential endogenous inhibitor of proteolytic activation of Sendai virus and influenza A virus

FEBS Letters

Kishino, Yasuo²  Kido, Hiroshi¹  Sakai, Kentaro²  Tashiro, Masato³ 

[1] Division of Enzyme Chemistry, Institute for Enzyme Research, Department of Nutrition, School of Medicine, The University of Tokushima, Tokushima 770, Japan;Department of Nutrition, School of Medicine, The University of Tokushima, Tokushima 770, Japan;Department of Virology, Jichi Medical School, Tochigi 329-04, Japan

关键词: Pulmonary surfactant;    Sendai virus;    Influenza A virus;    Tryptase Clara;    HA;    haemagglutinin;    FO;    precursor fusion glycoprotein;    SDS-PAGE;    sodium dodecyl sulfate polyacrylamide gel electrophoresis;    Boc;    N-tert-butoxycarbonyl;    MCA;    4-methyl-coumaryl-7-amide;    PBS;    phosphate buffered saline;    SPF;    specific-pathogen free;    CIU;    cell-infecting unit;    MEM;    minimal essential medium;   

DOI  :  10.1016/0014-5793(93)81549-F

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The pathogenicities of influenza viruses and paramyxoviruses have been proposed to be primarily determined by a host cell protease(s) that activates viral infectivity by proteolytic cleavage of the envelope glycoproteins. We recently isolated a trypsin-type endoprotease, named tryptase Clara, from rat bronchial and bronchiolar epithelial Clara cells, which is secreted into the airway lumen and activates Sendai virus and influenza A virus proteolytically. We report here that surfactant in the bronchial fluid inhibited tryptase Clara specifically, having a K _i value of 0.13 μM, and inhibited the proteolytic activations by tryptase Clara in vitro and in organ cultures of rat lung. Intranasal infection of rats with Sendai virus was shown to stimulate secretion of tryptase Clara without changing the amount of surfactant in the bronchial lumen, resulting in a preferable condition for proteolytic viral activation and multiplication.

【 授权许可】

Unknown