Regulation of CXCR/IL-8 in human airway epithelial cells.
BACKGROUND
Severe asthma is characterized by neutrophilic inflammation and high levels of interleukin (IL)-8. Airway epithelial cells play a pivotal role in the pathogenesis and chronicity of asthma. The objective of this work was to determine whether CXC receptors were involved in human small airway epithelial cell (SAEC) activity by incubating them with IL-8; the investigation also included a proteomic approach.


METHODS
IL-6 and intercellular adhesion molecule-1 (ICAM-1) were assessed by ELISA and flow cytometry, respectively. CXCR-1 and CXCR-2 receptor mRNA and protein expressions were analyzed by RT-PCR, immunocytochemistry and flow cytometry. Cells were incubated with different concentrations (0-100 ng/ml) of IL-8. The involvement of both receptors was assessed using specific antibodies.


RESULTS
Only the CXCR-1 receptor was expressed in SAECs. IL-8 (50 ng/ml, 12 h) induced the release of IL-6 and had no effect on ICAM-1. Supernatants analyzed by surface enhanced laser desorption ionization time of flight mass spectrometry (SELDI-TOF MS) showed very weak differences in peptide profiles. Interestingly, 4,820-m/z peptide release was detected in the presence of IL-8 and abolished by CXCR-1 antibody.


CONCLUSIONS
The present study illustrated the fact that IL-8 mediated by CXCR-1 increased IL-6. We also highlight the usefulness of SELDI ProteinChip technology to confirm the potential variation of peptide profile. Moreover, we were able to detect the 4,820-m/z peptide secreted in vitro by human airway epithelial cells induced by IL-8 via CXCR-1 receptor. Determination of the protein secretion profile in response to inflammatory stimuli could be an important therapeutic strategy in severe asthma.
Gras
Delphine
D
Clinique des Maladies Respiratoires, CHU-Montpellier, Montpellier, France.
Tiers
Laurent
L
Vachier
Isabelle
I
de Senneville
Laure Denis
LD
Bourdin
Arnaud
A
Godard
Philippe
P
Lehman
Sylvain
S
Chanez
Pascal
P
D000906:Antibodies / Q000276:immunology / Q000494:pharmacology; D001980:Bronchi / Q000166:cytology / Q000378:metabolism; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D015870:Gene Expression / Q000235:genetics; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism* / Q000494:pharmacology; D008168:Lung / Q000166:cytology*; D010455:Peptides / Q000032:analysis / Q000378:metabolism; D011506:Proteins / Q000032:analysis / Q000378:metabolism; D054387:Receptors, CXCR / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D023062:Receptors, Interleukin-8A / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D023063:Receptors, Interleukin-8B / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D020545:Respiratory Mucosa / Q000166:cytology / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D000906:Antibodies; D015850:Interleukin-6; D016209:Interleukin-8; D010455:Peptides; D011506:Proteins; D054387:Receptors, CXCR; D023062:Receptors, Interleukin-8A; D023063:Receptors, Interleukin-8B; D018799:Intercellular Adhesion Molecule-1