Abstract
Abstract: :
Purpose: Closed-eye tears contain activated complement and patrolling neutrophils. In dry eyes, a predisposition to infective complications suggests a disruption of normal host defense. We analysed interactions between human ocular surface mucins and peripheral blood neutrophils to assess the role of mucins in the recruitment of immune effector cells. Methods: Mucins were collected from the ocular surface of normal volunteers and dry eye patients.These mucins were then purified by classic techniques. Peripheral blood leucocytes were isolated from healthy volunteers by dextran-Percoll gradients. Leucocytes were then gently injected into 2 x 70mm mucin coated glass channels. Non-adherent cells were collected and analysed by flow cytometry. Results: Leucocytes did not adhere to the glass channels. The characteristics of the non-adherent cell populations were associated with the type of mucin to which they were exposed. In the presence of normal ocular mucins there was a decrease in CD16 positive neutrophils. This did not occur with mucins from mild (Meibomian Gland Disease) or severe (Sjögren’s Syndrome) dry eye disease. The CD11b positive neutrophils seemed not to be affected by mucin presence. The three flow rates, 0.2, 0.4 and 2ml/min, had a small influence on the adherence pattern of CD16 positive neutrophils to normal mucins only. Conclusions: Normal mucins appear to bind leucocytes selectively. In dry eyes this function appears decreased, and may contribute to the predisposition to infections.
Keywords: cornea: surface mucins • cornea: tears/tear film/dry eye • flow cytometry