IL-4 regulates chemokine production induced by TNF-alpha in keratocytes and corneal epithelial cells.
BACKGROUND
Eosinophils are thought to play a major role in the pathogenesis of corneal lesions in ocular allergies. The regulation of chemokine production in corneal cells by the Th2 cytokine, interleukin 4 (IL-4), was examined in order to investigate its role in ocular allergies.


METHODS
Pure cultures of human corneal epithelial cells and keratocytes were exposed to tumour necrosis factor alpha (TNF-alpha) and/or IL-4. 24 hours after exposure, culture supernatants were removed and concentrations of IL-8 and RANTES were quantified by ELISA assay.


RESULTS
Simultaneous addition of IL-4 inhibited TNF-alpha induced IL-8 production in both corneal epithelial cells and keratocytes. TNF-alpha and IL-4 synergistically stimulated the production of RANTES in keratocytes.


CONCLUSIONS
Differential regulation of chemokine production from corneal cells by IL-4 may play a role in the selective recruitment of predominantly eosinophils to the ocular surface in ocular allergies.
Takano
Y
Y
Department of Ophthalmology, Tokyo Dental College, Chiba, Japan.
Fukagawa
K
K
Shimmura
S
S
Tsubota
K
K
Oguchi
Y
Y
Saito
H
H
D002478:Cells, Cultured; D018946:Chemokine CCL5 / Q000096:biosynthesis*; D004804:Eosinophils / Q000378:metabolism; D019573:Epithelium, Corneal / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D015847:Interleukin-4 / Q000502:physiology*; D016209:Interleukin-8 / Q000096:biosynthesis*; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology*
D018946:Chemokine CCL5; D016209:Interleukin-8; D014409:Tumor Necrosis Factor-alpha; D015847:Interleukin-4