Screening of mimetic peptides for CD14 binding site with LBP and antiendotoxin activity of mimetic peptide in vivo and in vitro.
OBJECTIVE
The study was aimed at screening out the mimetic peptides from the binding site of lipopolysaccharide binding protein and CD 14, and then observing if the mimetic peptide will inhibit in vitro LPS-induced inflammatory reaction and function as an anti-endotoxin in the model of LPS-induced acute lung injury.


METHODS
Human monocytic cell line (U937) was used in vitro. Thirty three-month-old SD rats were used. Phage display peptide library was adapted to screen mimetic peptide sequences.


METHODS
U937 cells were exposed to treatment with LPS and rhLBP and then were incubated with MP12 at three different concentrations after they were induced and differentiated by PMA. LPS intravenous injection was used to establish a model of rat acute lung injury which was later treated with intravenous injection of MP12.


RESULTS
We successfully obtained the mimetic peptide of lipopolysaccharide-binding protein and CD 14 binding site, the gene sequence of which is FHRWPTWPLPSP (MP12). MP12 can markedly inhibit LPS induced TNF-alpha expression. MP12 can evidently increase PaO(2) of rats with acute lung injury and also increase the survival rate of these rats.


CONCLUSIONS
MP12 (FHRWPTWPLPSP) has the same function as mimetic of lipopolysaccharide-binding protein and CD 14 binding site. The application of MP12, both in vitro and in vivo, confers the biological activity required to antagonise LBP/CD14 and block LPS inflammatory signals, and it can markedly enhance PaO(2) of rats suffering from acute lung injury and also enhance their survival rate.
Xu
Z
Z
Institute of Respiratory Disease, Xinqiao Hospital, Third Military Medical University, Chongqing, China.
Qian
G S
GS
Li
Q
Q
Feng
Q J
QJ
Wu
G M
GM
Li
K L
KL
D000209:Acute-Phase Proteins / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D032701:Biomimetics; D002352:Carrier Proteins / Q000378:metabolism*; D002460:Cell Line; D006801:Humans; D007249:Inflammation / Q000276:immunology / Q000473:pathology; D018950:Lipopolysaccharide Receptors / Q000235:genetics / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000276:immunology / Q000633:toxicity; D008562:Membrane Glycoproteins / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D009000:Monocytes / Q000166:cytology / Q000378:metabolism; D019151:Peptide Library; D010455:Peptides / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D016415:Sequence Alignment; D000099231:Lipopolysaccharide-Binding Protein
D000209:Acute-Phase Proteins; D002352:Carrier Proteins; D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D019151:Peptide Library; D010455:Peptides; D000099231:Lipopolysaccharide-Binding Protein