Abstract
Lipopolysaccharide (LPS), a bacterial endotoxin, triggers deleterious systemic inflammatory responses when released into blood circulation, causing organ dysfunction and death. In response to LPS stimulation, CD14 and toll-like receptor (TLR)-4 elicit inflammatory signaling cascades. Although leukocyte integrins (CD11b/CD18 and CD11c/CD18) were reported to bind LPS and induce NF-κB translocation, the evidence on such epitope location remains elusive. The present study aims to delineate the LPS-binding sites on the integrin CD18 antigen and to design peptide(s) as potential prophylactic and/or therapeutic agents to modulate LPS effects in activated Jurkat cells. Epitope mapping analysis using a series of CD18 truncated variants revealed two putative LPS-binding sites within the βA region (216-248 and 266-318 a.a.), which were further confirmed by point mutation studies. Inhibition assay demonstrated that the CD18-βA266-318 peptide could block LPS binding in a dosedependent manner. Our data also indicated that treatment with the CD18-peptide modulated TNF-α mRNA transcription via the NF-κB signaling pathway in LPS-activated Jurkat cells. In conclusion, we have identified two novel LPS-binding sites located at the CD18 βA domain of leukocyte integrin, and the integrin peptide βA266-318 is shown to inhibit LPS binding and subsequent inflammatory events, having therapeutic implications to cure Gram-negative endotoxemia.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 3231-3239 |
| Number of pages | 9 |
| Journal | FASEB Journal |
| Volume | 21 |
| Issue number | 12 |
| DOIs | |
| State | Published - Oct 2007 |
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Keywords
- Endotoxin-neutralizing peptide
- Lipopolysaccharide
- NF-κB
- Prophylaxis
- Sepsis
- TNF-α
ASJC Scopus subject areas
- Agricultural and Biological Sciences (miscellaneous)
- Biochemistry, Genetics and Molecular Biology(all)
- Biochemistry
- Cell Biology
- Medicine(all)
Cite this
Characterization of two novel LPS-binding sites in leukocyte integrin βA domain. / Wong, Kwong Fai; Luk, John M.; Cheng, R. Holland; Klickstein, Lloyd B.; Fan, Sheung Tat.
In: FASEB Journal, Vol. 21, No. 12, 10.2007, p. 3231-3239.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Characterization of two novel LPS-binding sites in leukocyte integrin βA domain
AU - Wong, Kwong Fai
AU - Luk, John M.
AU - Cheng, R. Holland
AU - Klickstein, Lloyd B.
AU - Fan, Sheung Tat
PY - 2007/10
Y1 - 2007/10
N2 - Lipopolysaccharide (LPS), a bacterial endotoxin, triggers deleterious systemic inflammatory responses when released into blood circulation, causing organ dysfunction and death. In response to LPS stimulation, CD14 and toll-like receptor (TLR)-4 elicit inflammatory signaling cascades. Although leukocyte integrins (CD11b/CD18 and CD11c/CD18) were reported to bind LPS and induce NF-κB translocation, the evidence on such epitope location remains elusive. The present study aims to delineate the LPS-binding sites on the integrin CD18 antigen and to design peptide(s) as potential prophylactic and/or therapeutic agents to modulate LPS effects in activated Jurkat cells. Epitope mapping analysis using a series of CD18 truncated variants revealed two putative LPS-binding sites within the βA region (216-248 and 266-318 a.a.), which were further confirmed by point mutation studies. Inhibition assay demonstrated that the CD18-βA266-318 peptide could block LPS binding in a dosedependent manner. Our data also indicated that treatment with the CD18-peptide modulated TNF-α mRNA transcription via the NF-κB signaling pathway in LPS-activated Jurkat cells. In conclusion, we have identified two novel LPS-binding sites located at the CD18 βA domain of leukocyte integrin, and the integrin peptide βA266-318 is shown to inhibit LPS binding and subsequent inflammatory events, having therapeutic implications to cure Gram-negative endotoxemia.
AB - Lipopolysaccharide (LPS), a bacterial endotoxin, triggers deleterious systemic inflammatory responses when released into blood circulation, causing organ dysfunction and death. In response to LPS stimulation, CD14 and toll-like receptor (TLR)-4 elicit inflammatory signaling cascades. Although leukocyte integrins (CD11b/CD18 and CD11c/CD18) were reported to bind LPS and induce NF-κB translocation, the evidence on such epitope location remains elusive. The present study aims to delineate the LPS-binding sites on the integrin CD18 antigen and to design peptide(s) as potential prophylactic and/or therapeutic agents to modulate LPS effects in activated Jurkat cells. Epitope mapping analysis using a series of CD18 truncated variants revealed two putative LPS-binding sites within the βA region (216-248 and 266-318 a.a.), which were further confirmed by point mutation studies. Inhibition assay demonstrated that the CD18-βA266-318 peptide could block LPS binding in a dosedependent manner. Our data also indicated that treatment with the CD18-peptide modulated TNF-α mRNA transcription via the NF-κB signaling pathway in LPS-activated Jurkat cells. In conclusion, we have identified two novel LPS-binding sites located at the CD18 βA domain of leukocyte integrin, and the integrin peptide βA266-318 is shown to inhibit LPS binding and subsequent inflammatory events, having therapeutic implications to cure Gram-negative endotoxemia.
KW - Endotoxin-neutralizing peptide
KW - Lipopolysaccharide
KW - NF-κB
KW - Prophylaxis
KW - Sepsis
KW - TNF-α
UR - http://www.scopus.com/inward/record.url?scp=35248867073&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=35248867073&partnerID=8YFLogxK
U2 - 10.1096/fj.06-7579com
DO - 10.1096/fj.06-7579com
M3 - Article
C2 - 17522381
AN - SCOPUS:35248867073
VL - 21
SP - 3231
EP - 3239
JO - FASEB Journal
JF - FASEB Journal
SN - 0892-6638
IS - 12
ER -