Interactions of surfactant protein A with influenza A viruses: binding and neutralization.
The interaction of pulmonary surfactant protein A (SP-A) with influenza A H1N1 and H3N2 viruses was investigated. SP-A is a sialated C type lectin with affinity for mannose residues. Flow cytometry showed that binding of fluorescein isothiocyanate (FITC)-labeled SP-A to H3N2 virus-infected cells was specific and time- and concentration-dependent. Oligosaccharides did not affect the binding of FITC-SP-A to the infected cells. Preincubation of H1N1 and H3N2 with SP-A resulted in a dose-dependent reduction of the infectivity of the viruses to cells. Removal of the carbohydrate moiety of SP-A by N-glycosidase F or cleavage of its sialic acid residues by neuraminidase prevented the interactions of SP-A with the viruses. It is concluded that SP-A binds to influenza A viruses via its sialic acid residues and, thereby, neutralizes the virus.
Eijkman-Winkler Laboratory for Medical Microbiology, University Hospital Utrecht, Netherlands.
C A
CA
Benne
C A
CA
Kraaijeveld
J A
JA
van Strijp
E
E
Brouwer
M
M
Harmsen
J
J
Verhoef
L M
LM
van Golde
J F
JF
van Iwaarden
D000818:Animals; D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D016650:Fluorescein-5-isothiocyanate; D005470:Fluorometry; D006801:Humans; D007124:Immunoenzyme Techniques; D009980:Influenza A virus / Q000254:growth & development / Q000378:metabolism*; D009844:Oligosaccharides / Q000494:pharmacology; D011485:Protein Binding / Q000187:drug effects; D011510:Proteolipids / Q000378:metabolism* / Q000494:pharmacology*; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants / Q000378:metabolism* / Q000494:pharmacology*; D014779:Virus Replication / Q000187:drug effects
D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D009844:Oligosaccharides; D011510:Proteolipids; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants; D016650:Fluorescein-5-isothiocyanate