Differential and cooperative effects of TNFalpha, IL-1beta, and IFNgamma on human conjunctival epithelial cell receptor expression and chemokine release.
OBJECTIVE
To gain better understanding of conjunctival epithelial cell responses to proinflammatory cytokines, the individual and combined effects of TNFalpha, IL-1beta, and IFNgamma on chemokine release (IL-8, regulated on activation normal T-cell expressed and secreted [RANTES]) and surface receptor expression (intercellular adhesion molecule [ICAM]-1, and HLA-DR, -DP, and -DQ) were examined.


METHODS
Conjunctival epithelial cells were isolated from cadaveric conjunctival tissues and cultured in 24-well plates until almost confluent. Recombinant cytokines (0.005-50 ng/mL) were added, alone or in various combinations, 24 hours before harvesting of supernates for ELISAs and cells for flow cytometry.


RESULTS
TNFalpha, IL-1beta, and IFNgamma had distinctive individual and combined effects on the parameters tested. Although TNFalpha and IL-1beta had similar and synergistic effects on increasing expression of ICAM-1, IL-1beta was a more potent upregulator of the release of IL-8 than was TNFalpha. Upregulation of IL-8 was additive when IL-1beta was combined with TNFalpha. Neither TNFalpha nor IL-1beta increased expression of HLA. In contrast, IFNgamma was a potent upregulator of both surface receptors (ICAM-1 and HLA) but IFNgamma alone had no effect on mediator release (IL-8 and RANTES). Release of RANTES required two cytokine signals, with IFNgamma and TNFalpha being the most potent combination.


CONCLUSIONS
Knowledge of the differential and combined effects of proinflammatory cytokines on conjunctival epithelial cells allows better understanding of ocular inflammation.
Stahl
James L
JL
Department of Medicine, Clinical Science Center, School of Medicine, University of Wisconsin-Madison, Madison, Wisconsin 53792, USA. jlstahl@medicine.wisc.edu
Cook
Ellen B
EB
Graziano
Frank M
FM
Barney
Neal P
NP
D002469:Cell Separation; D002478:Cells, Cultured; D018946:Chemokine CCL5 / Q000378:metabolism; D018925:Chemokines / Q000378:metabolism*; D003228:Conjunctiva / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D004338:Drug Combinations; D004797:Enzyme-Linked Immunosorbent Assay; D004847:Epithelial Cells / Q000187:drug effects; D005434:Flow Cytometry; D000949:Histocompatibility Antigens Class II / Q000378:metabolism*; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism*; D007371:Interferon-gamma / Q000494:pharmacology*; D007375:Interleukin-1 / Q000494:pharmacology*; D016209:Interleukin-8 / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D015854:Up-Regulation
D018946:Chemokine CCL5; D018925:Chemokines; D004338:Drug Combinations; D000949:Histocompatibility Antigens Class II; D007375:Interleukin-1; D016209:Interleukin-8; D014409:Tumor Necrosis Factor-alpha; D018799:Intercellular Adhesion Molecule-1; D007371:Interferon-gamma