Abstract
Purpose: :
To the study the expression of CD1d by corneal cells, and the potential immuno–regulator role of NKT lymphocytes in vitro and ex vivo in chronic ocular surface inflammation.
Methods: :
We studied in vitro CD1d expression on primary cultures of corneal and conjunctival epithelial cells, kératocytes and on Chang conjunctival cell line in flow cytometry as well as ex vivo from conjunctival epithelial cells collected by impression cytology, from voluntary normal test subjects and in four groups of 8 patients with chronic inflammatory ocular surface diseases (severe ocular burns, chronic allergic conjunctivitis, severe ocular rosacea, and ocular Sjögren). We tested the capacity of the primary cultures of corneal epithelial cells to present α– GalCer to allogenic NKT lymphocytes cell lines in co–cultures, to stimulate them, evaluated lymphocytes proliferation and cytokines production. Cell were studied in their basal state and treated for 24, 48, and 72 hours with lipopolysaccharide (LPS) from Escherichia coli and Influenza Virus serotype A PR8 34.
Results: :
Purity of primary cell lines was checked morphologically and phenotypicaly, and confirmed with immunostaining (KL1anti–pancytokeratin antibody (basic cytokeratins 3, 11 and 12) for corneal epithelial cells, anti–pancytokeratin antibody marking cytokeratins 8, 18 and 19 for conjunctival epithelial cells, anti–vimentin antibody for keratocytes).Ocular surface cells in culture do not express CD1d in a basal state. Stimulation induced the expression of CD1d by lines by corneal epithelial cell lines and by keratocytes but not by primary cultures of conjunctival cells or by the Chang cell line.Stimulation by the LPS and the viral particles on keratocytes gives similar results.IFN–γ in association with LPS increases CD1d expression by corneal epithelial cells. IFN–γ and IL–4 production was observed only when the antigen presenting cells were preincubated with α–GalCer, and is completely inhibited in the presence of the anti–CD1d. antibody.
Conclusions: :
CD1d expression study could become a new routine tool in the near future for studying chronic ocular surface inflammation.
Keywords: anterior segment • immunomodulation/immunoregulation • cornea: tears/tear film/dry eye