Detection of galectin-3 in tear fluid at disease states and immunohistochemical and lectin histochemical analysis in human corneal and conjunctival epithelium

Background/aim-Components of the tear fluid contribute to the biochemical d efence system of the eye. To reveal whether the immune mediator and lipopol ysaccharide binding galectin-3 is present in tears, tear samples were colle cted from eyes in healthy and pathological states. Investigation of express ion of galectin-3 and galectin-3 reactive glycoligands in normal human conj unctival and corneal epithelia was also initiated as a step to understand t he role of galectin-3 in ocular surface pathology. Methods-Immunoblot analysis using either a rabbit polyclonal or a mouse mon oclonal antibody against galectin-3 was employed to detect galectin-3 in te ar fluid. Galectin-3 expression in tissue specimens was detected by immunoc ytochemistry employing A1D6 mouse monoclonal antibody, and galectin-3 react ive glycoligands were visualised by lectin histochemistry using labelled ga lectin-3. Results-Galectin-3 was found only in tears from patients with ocular surfac e disorders. It was expressed in normal corneal and conjunctival epithelia but not in lacrimal glands. Inflammatory leucocytes and goblet cells found in galectin-3 containing tear fluid also expressed galectin-3. Galectin-3 b inding sites were detected on the surface of conjunctival and corneal epith elial cells co-localising with desmoglein. Conclusions-This study revealed expression of galectin-3 in tear fluid obta ined from patients with eye diseases. The role of this endogenous lectin (p roduced by inflammatory as well as epithelial cells) in antimicrobial actio n and inflammation modulation could be expected.