The role of IL-1beta in the regulation of IL-8 and IL-6 in human corneal epithelial cells during Pseudomonas aeruginosa colonization.
OBJECTIVE
Recent studies have shown that the levels of interleukin (IL)-1beta, IL-6 and IL-8 are associated with the severity of infectious diseases. The purpose of this study was to investigate whether IL-1beta regulates the expression of IL-6 and IL-8 in human corneal epithelial cells during Pseudomonas aeruginosa colonization.


METHODS
Confluent immortalized human corneal epithelial cells were challenged with P. aeruginosa 6294 in the presence of anti-human IL-1beta antibody or matched control antibody. The cells were also challenged with recombinant IL-1beta protein without bacterial colonization. Expression of IL-1beta, IL-6 and IL-8 mRNA and protein was detected by reverse transcription (RT)-PCR and by enzyme-linked immunosorbent assay (ELISA), respectively. IL-1beta localization was determined by immunohistochemistry.


RESULTS
Human corneal epithelial cells expressed low levels of IL-1beta and high levels of IL-6 and IL-8 during P. aeruginosa colonization. Addition of IL-1beta Ab resulted in a significant decrease (P < 0.05) in IL-8 protein expression at 4 h, 8 h and 12 h. Addition of IL-1beta Ab reduced IL-6 protein expression at 8 h and increased IL-6 protein expression at 12 h. Addition of recombinant IL-1beta protein alone strongly stimulated the expression of IL-8 and IL-6. Immunohistochemical staining showed that IL-1beta protein was present both intracellularly and extracellularly in P. aeruginosa colonized cells.


CONCLUSIONS
IL-1beta is able to modulate expression of both IL-6 and IL-8 at transcriptional and post-transcriptional levels in human corneal epithelial cells.
Xue
M L
ML
Cooperative Research Centre For Eye Research and Technology, University of New South Wales, School of Optometry, Sydney, New South Wales, Australia. mxue@crcert.unsw.edu.au
Zhu
H
H
Willcox
M
M
Wakefield
D
D
Lloyd
A
A
Thakur
A
A
D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay; D019573:Epithelium, Corneal / Q000378:metabolism* / Q000382:microbiology*; D005786:Gene Expression Regulation; D006801:Humans; D007124:Immunoenzyme Techniques; D007375:Interleukin-1 / Q000494:pharmacology / Q000502:physiology*; D015850:Interleukin-6 / Q000235:genetics* / Q000378:metabolism; D016209:Interleukin-8 / Q000235:genetics* / Q000378:metabolism; D011550:Pseudomonas aeruginosa / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D011994:Recombinant Proteins / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction
D007375:Interleukin-1; D015850:Interleukin-6; D016209:Interleukin-8; D012333:RNA, Messenger; D011994:Recombinant Proteins