CHEMOTACTIC ACTIVITY OF TEARS AND BACTERIA ISOLATED DURING ADVERSE RESPONSES

Inflammatory processes are characterized by the dynamic influx of leuk ocytes. This leukocyte recruitment and activation is thought to be ini tiated by chemical signals including chemotactic factors. This study w as designed to investigate the chemotactic activity in different tear types and bacteria isolated during adverse responses to contact lens w ear. Chemotactic activity was determined by quantitating in vitro neut rophil migration using a microchemotaxis chamber. Results demonstrated that tears collected immediately after 8 hours sleep (P < 0.001) and tears collected during adverse responses (P < 0.001) showed significan tly higher chemotactic activity compared to reflex tears. Specific neu tralizing antibodies to IL-8, LTB4 and C5a were added to closed eye an d adverse response tears. Pre-incubation of closed eye tears with anti bodies to IL-8 showed a significant reduction in chemotactic activity (P < 0.0001), whereas a significant reduction of PMN migration in adve rse response tears was observed after pre-treatment with antibodies to LTB, (P < 0.0001). However no difference in chemotactic activity was observed after incubation with antibody to C5a or irrelevant antibody. Dot blots demonstrated that closed eye tears contained approximately 150 ng ml(-1) IL-8 and adverse response tears contained 2 ng ml(-1) IL -8. Most Gram negative bacteria isolated from contact lenses caused di rected migration of PMNs. Addition of neutralizing antibody to LPS sig nificantly abrogated the chemotactic activity of bacterial cells (P < 0.001). Our findings provide evidence that IL-8 during eye closure, an d bacterial chemotactic substances and LTB, during contact lens induce d adverse responses, are responsible for the recruitment of PMNs. (C) 1998 Academic Press Limited.