Purchase this article with an account.
SK Sra, LR Grabowski, SD Trocme; TNF-alpha and IFN-gamma Stimulate IL-6 and GM-CSF Release From Primary Conjunctival Epithelial Cells . Invest. Ophthalmol. Vis. Sci. 2002;43(13):2260.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: Proinflammatory cytokines that may stimulate the ocular surface epithelium, have been identified in tears of ocular allergy patients. This study explores the effects of TNF-α and IFN-γ on IL-6 and GM-CSF release from a conjunctival epithelium. Methods: Human conjunctival tissue was obtained from the S.E. Texas Lions Eye Bank (Galveston, TX) and placed in Ca2+ and Mg2+ free DPBS containing 0.25% pronase and 0.25% trypsin (Sigma, St. Louis, MO) for 1 hour at 37ºC. Epithelial cells were grown to 90% confluence in T-25 culture flasks and were stimulated with TNF-α 400 U/mL, IFN-γ (50, 100, and 500 U/mL), or a combination of TNF-α and IFN-γ dissolved in KBM (Keratinocyte Basal Medium). At 48 hrs, supernatants were collected and stored at -80ºC until assayed. Commercial ELISA (R&D Systems, Minneapolis, MN) analysis was used to detect IL-6 and GM-CSF concentration in the supernatants. Spontaneous release was subtracted. Results: IL-6 and GM-CSF were released in a dose dependent fashion after stimulation with IFN-γ. The maximal release of IL-6 was 547.85 pg/mL (SD ±53.58), while the maximal release for GM-CSF was 15.53 pg/mL (SD ± 8.86). Stimulation of TNF-α 400 U/mL released 176.35 pg/mL (SD±18.52) of GM-CSF and 1075.56 pg/mL (SD±9.28 ) of IL-6. The combination of TNF-α 400 U/mL with the three different concentrations of IFN-γ (50,100, and 500 U/mL) were additive and not synergistic for both IL-6 and GM-CSF. Conclusion: Both IL-6 and GM-CSF were released in a dose dependent fashion after (TNF-α and IFN-γ) stimulation; no synergistic responses were noted. IL-6, in addition to its effects on lymphocytes, also functions as a growth factor which can stimulate epithelial wound healing. Release of GM-CSF may affect the survival and activation of eosinophils in tears. The relative proportion of IL-6 and GM-CSF in tears may influence mechanisms of epithelial repair and injury in inflammatory conditions such as ocular allergy.
This PDF is available to Subscribers Only