title: Interferon-gamma, Staphylococcus aureus, and lipopolysaccharide/silica enhance interleukin-1 beta production by human corneal cells.
abstract: Cultures derived from human corneo-scleral rims remaining after a central corneal button had been removed for transplantation, revealed two types of cells on light microscopy: One with typical epithelial morphology and the other resembling fibroblasts. Both cell types contained keratin filaments in early passage and were therefore considered epithelial in nature. The fibroblast-like cells were designated fibroblast-like epithelial cells (FLE) while the typical epithelial cells were referred to as E-type. Both E and FLE cells constitutively produced an IL-1-like factor as determined by thymocyte proliferation assay and IL-2 induction in EL-4 lymphoma cells. Moreover, the supernatants from these cells potentiated concanavalin A (Con A)-primed mitochondrial oxidative metabolism in thymocytes, as indicated by the tetrazolium salt reduction assay (MTT) and this effect was significantly neutralized with monoclonal anti-IL-1 beta. The release of biologically active IL-1 beta by the FLE cells is another characteristic (in addition to the presence of keratin) distinguishing these cells from fibroblasts which do not release biologically active IL-1 beta. Using an ELISA, specific for IL-1 beta, there was clear cut evidence for increased production of this cytokine by FLE cells in response to human recombinant gamma-interferon (IFN-gamma), Staphylococcus aureus, and lipopolysaccharide (LPS) in combination with silica (LPS/silica). Time studies with IFN-gamma and LPS/silica demonstrated that enhanced production was time dependent and that IL-1 beta was primarily cell associated. The results indicate that human corneal E- and FLE-type cells can produce and release IL-1 and that FLE cells can be induced by inflammatory mediators to increase production of IL-1 beta.
authors.affiliation: Department of Microbiology, University of South Carolina School of Medicine, Columbia 29208.
authors.forename: N B
authors.initials: NB
authors.lastname: Shams
authors.forename: M M
authors.initials: MM
authors.lastname: Sigel
authors.forename: R M
authors.initials: RM
authors.lastname: Davis
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology; D002469:Cell Separation; D002478:Cells, Cultured; D003315:Cornea / Q000166:cytology* / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D004848:Epithelium / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D007375:Interleukin-1 / Q000096:biosynthesis*; D007633:Keratins / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008213:Lymphocyte Activation / Q000187:drug effects; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D011994:Recombinant Proteins; D012822:Silicon Dioxide / Q000494:pharmacology*; D013211:Staphylococcus aureus; D013950:Thymus Gland / Q000166:cytology
chemical_list: D007375:Interleukin-1; D008070:Lipopolysaccharides; D011994:Recombinant Proteins; D007633:Keratins; D012822:Silicon Dioxide; D007371:Interferon-gamma