当前位置： SCI文献检索 > EUROPEAN JOURNAL OF IMMUNOLOGY期刊下所有文献 > Surfactant protein A, but not surfactant protein D, is an opsonin for influenza A virus phagocytosis by rat alveolar macrophages.

Surfactant protein A, but not surfactant protein D, is an opsonin for influenza A virus phagocytosis by rat alveolar macrophages.

Abstract：

:Surfactant protein A (SP-A) and surfactant protein D (SP-D) are collectins, and both proteins were shown to interact with influenza A virus and alveolar macrophages. However, it is not known whether SP-A and SP-D can serve as opsonins for the phagocytosis of influenza A virus by alveolar macrophages. In the present study, we investigated the opsonic activities of SP-A and SP-D for phagocytosis of fluorescein isothiocyanate (FITC)-labeled influenza A (H3N2) virus by rat alveolar macrophages using flow cytometry. SP-A enhanced the association of the virus with macrophages in a dose-dependent manner, reaching a maximum at an SP-A concentration of 60 microg/ml. An approximate threefold increase in association of influenza A virus with alveolar macrophages in the presence of SP-A over control incubations which contained no SP-A was observed. Half of the total cell-associated fluorescence could be quenched as demonstrated using the extracellular quenching dye trypan blue. These results indicate that SP-A mediates internalization of FITC-labeled influenza A (H3N2) virus by alveolar macrophages. Removal of the carbohydrate moiety of SP-A by N-glycosidase F treatment or cleavage of its sialic acid residues by neuraminidase abolished the enhancement of the phagocytosis of FITC-labeled influenza A virus by alveolar macrophages. Mannan, a mannose homopolysaccharide known to bind to the carbohydrate-binding domain of SP-A, did not affect the SP-A-mediated phagocytosis of FITC-labeled influenza by alveolar macrophages. In contrast, SP-D neither enhanced the association of FITC-labeled influenza A virus with alveolar macrophages nor affected the opsonic activity of SP-A for FITC-labeled influenza A (H3N2) virus at the SP-D concentrations tested. It is concluded that SP-A acts via its sialic acid residues as an opsonin in the phagocytosis of influenza A virus by alveolar macrophages.

journal_name

Eur J Immunol

journal_title

European journal of immunology

authors

Benne CA,Benaissa-Trouw B,van Strijp JA,Kraaijeveld CA,van Iwaarden JF

doi

10.1002/eji.1830270413

subject

Has Abstract

pub_date

1997-04-01 00:00:00

pages

886-90

issue

eissn

0014-2980

issn

1521-4141

journal_volume

pub_type

杂志文章

在线工具

Surfactant protein A, but not surfactant protein D, is an opsonin for influenza A virus phagocytosis by rat alveolar macrophages.