Human corneal epithelial cells synthesize ELR(-)alpha-chemokines in response to proinflammatory mediators.
The purpose of this study was to characterize the synthesis of alpha-chemokines IP-10, MIG, and I-TAC by human corneal epithelial cells (HCE) following exposure to proinflammatory mediators. Supernatants were collected from HCE cultures stimulated with individual or combinations of TNF-alpha, IL-1alpha, and IFN-gamma, and assayed for alpha-chemokines by ELISA. RT-PCR was used to detect IFN-gamma receptor mRNA. Activation of STAT 1 was determined by Western blotting. Stimulation of HCE with either IL-1alpha or TNF-alpha increased IP-10 protein synthesis up to 6-fold, whereas insignificant levels of MIG and I-TAC were induced. The epithelial cells were found to express IFN-gamma receptors constitutively. Exposure to the ligand resulted in STAT 1 phosphorylation and production of nanogram amounts of IP-10, I-TAC, and MIG. When HCE were stimulated with combinations of TNF-alpha and IFN-gamma, or IL-1alpha and IFN-gamma, the levels of IP-10 and I-TAC secreted were > 150-fold higher than that produced following exposure to a single cytokine. In contrast, MIG protein synthesis was not enhanced upon stimulation with cytokine combinations. The abundant production of ELR(-)alpha -chemokines following appropriate stimulation suggests that HCE may play an important role in the recruitment of effector cells such as activated T-lymphocytes to inflamed corneal tissue. The data also indicate that the synthesis of IP-10, I-TAC, and MIG are differentially regulated in HCE.
McInnis
Karla A
KA
Department of Microbiology and Immunology, College of Medicine, University of South Alabama, Mobile, Alabama, USA.
Britain
Andrea
A
Lausch
Robert N
RN
Oakes
John E
JE
D000998:Antiviral Agents / Q000494:pharmacology; D015153:Blotting, Western; D002478:Cells, Cultured; D054357:Chemokine CXCL10; D054371:Chemokine CXCL11; D054370:Chemokine CXCL9; D019743:Chemokines, CXC / Q000096:biosynthesis*; D004797:Enzyme-Linked Immunosorbent Assay; D019573:Epithelium, Corneal / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D018836:Inflammation Mediators / Q000494:pharmacology*; D007371:Interferon-gamma / Q000494:pharmacology; D053582:Interleukin-1alpha / Q000494:pharmacology; D010766:Phosphorylation; D012333:RNA, Messenger / Q000235:genetics; D017471:Receptors, Interferon / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050794:STAT1 Transcription Factor / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D000096743:Interferon gamma Receptor
D000998:Antiviral Agents; D054357:Chemokine CXCL10; D054371:Chemokine CXCL11; D054370:Chemokine CXCL9; D019743:Chemokines, CXC; D018836:Inflammation Mediators; D007371:Interferon-gamma; D053582:Interleukin-1alpha; D012333:RNA, Messenger; D017471:Receptors, Interferon; D050794:STAT1 Transcription Factor; D014409:Tumor Necrosis Factor-alpha; D000096743:Interferon gamma Receptor; C114753:CXCL10 protein, human; C515202:CXCL11 protein, human; C080810:CXCL9 protein, human; C494079:STAT1 protein, human