Modulation of IL-8 and RANTES release in human conjunctival epithelial cells: primary cells and cell line compared and contrasted.
OBJECTIVE
Recent research indicates that epithelial cells of the ocular surface can contribute to the allergic reaction by the release of inflammatory and/or chemotactic mediators. In this study, the role of two inflammatory mediators, previously identified in the tear film of ocular allergy subjects, TNF-alpha and IFN-gamma, were evaluated for their effect on the release of two chemotactic mediators, IL-8 and RANTES, from cultured human conjunctival epithelial cells.


METHODS
Human conjunctival epithelial cells (primary cells or HC0597 cell line) were grown to confluence and stimulated with various concentrations of TNF-alpha, IFN-gamma, or a combination of both. Supernatants were collected at 6, 24, and 48 hours and stored frozen for subsequent ELISA analyses of RANTES and IL-8.


RESULTS
RANTES and IL-8 release from HC0597 cells was stimulated in a dose- and time-dependent manner following treatment with TNF-alpha. However, only RANTES release was modulated by IFN-gamma treatment. Treatment of HC0597 cells with both TNF-alpha and IFN-gamma resulted in a synergistic increase in the release of RANTES. This synergistic effect was confirmed using primary cultures of human conjunctival epithelial cells.


CONCLUSIONS
Stimulation of conjunctival epithelium with proinflammatory mediators, TNF-alpha and/or IFN-gamma, generated the release of the chemotactic factors IL-8 and RANTES, which could act to prolong inflammation. These two chemokines may prolong inflammation by recruiting eosinophils to the ocular surface. This is the first study to compare chemokine release in a cell line and primary cells; similar chemokine release after mediator stimulation was demonstrated, indicating that the two cell types are phenotypically similar.
Smit
Eefke E
EE
Department of Opthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, Texas 77555-1106, USA.
Sra
Sharon K
SK
Grabowski
Laura R
LR
Ward
Sherry L
SL
Trocme
Stefan D
SD
D002478:Cells, Cultured; D018946:Chemokine CCL5 / Q000378:metabolism*; D003228:Conjunctiva / Q000187:drug effects / Q000378:metabolism*; D004357:Drug Synergism; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D016209:Interleukin-8 / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D018946:Chemokine CCL5; D016209:Interleukin-8; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma