A FQHPSFI peptide selectively binds to LPS-activated alveolar macrophages and inhibits LPS-induced MIP-2 production.
OBJECTIVE
The goal of this study was to identify peptides selectively binding to lipopolysaccharide (LPS)-activated alveolar macrophages (AMs) and to characterize their effects on the production of LPS-induced cytokines.


METHODS
A phage display library was sequentially screened by binding phages to unmanipulated AMs and then to LPS-activated AMs. Individual phage clones were identified by cell-based ELISA. Positive phage clones were characterized by DNA sequencing and bioinformatics analysis. Binding specificity of the selected phage to LPS-activated AMs was tested using immunofluorescent staining. The selected candidate peptide was chemically synthesized to determine whether it could modulate LPS-induced cytokine production in AMs.


RESULTS
Twenty-two out of 40 phage clones selected randomly after four rounds of biopanning bound selectively to LPS-activated AMs, and 12 of them displayed novel peptides. A phage clone displaying FQHPSFI peptide bound effectively to LPS-activated AMs, but not to other cells tested. Furthermore, the synthetic FQHPSFI peptide, but not seven point mutants tested, competitively inhibited the binding of the phage clone to LPS-activated AMs. Importantly, the FQHPSFI peptide significantly inhibited LPS-stimulated microphage inflammatory protein 2 (MIP-2) production in vitro.


CONCLUSIONS
Our data demonstrate that phage display technology is a powerful tool for the identification of bioactive peptides. The identified FQHPSFI peptide may be used for the modulation of LPS-stimulated MIP-2 production in AMs.
Ding
Ning
N
Department of Anesthesiology, Guangzhou First Municipal People's Hospital, Guangzhou Medical College, Guangzhou, China. dingninggy@hotmail.com
Xiao
Hui
H
Wang
Fang
F
Xu
Lixin
L
She
Shouzhang
S
D000595:Amino Acid Sequence; D000818:Animals; D054426:Chemokine CXCL2 / Q000235:genetics / Q000378:metabolism*; D016207:Cytokines / Q000378:metabolism; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology*; D016676:Macrophages, Alveolar / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D008297:Male; D008969:Molecular Sequence Data; D019151:Peptide Library; D010455:Peptides / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
D054426:Chemokine CXCL2; C513296:Cxcl2 protein, rat; D016207:Cytokines; D008070:Lipopolysaccharides; D019151:Peptide Library; D010455:Peptides