RESPIRATORY SYNCYTIAL VIRUS-INDUCED INTERLEUKIN-4 PRODUCTION BY HUMANCONJUNCTIVAL EPITHELIAL-CELLS CONTRIBUTES TO ALLERGY - PRELIMINARY-STUDY

Purpose. We previously reported allergic conjunctivitis was associated with a local pattern of cytokines and identified respiratory syncytia l virus (RSV) in the conjunctival epithelium, in patients with allergi c conjunctivitis. We hypothesized that RSV infected the normal conjunc tival epithelium and produced interleukin-4 (IL-4), causing an allergi c reaction. To determine this event, we studied production of IL-4 by human conjunctival epithelial cells, after infection with RSV. Methods . Conjunctival samples were collected with a special brush and were ch allenged with 5 X 10(6) pfu/ml of live RSV. RSV infection was detected by immunocytochemical study and RT-PCR. HLA-DR antigen was expressed by flow cytometry. IL-4 was assayed by a sandwich ELISA. Results. Immu nocytochemical study and RT-PCR showed that RSV infected the conjuncti val epithelial cells. HLA-DR was demonstrated in the RSV-infected conj unctival epithelial cells. Average concentrations of IL-4 in culture s upernatants in infected cells were 3.8 +/- 1.8, 3.6 +/- 1.1, and 5.4 /- 1.8 pg/ml at 24, 48, and 72 h, respectively. Levels in non-infected cells were 0.33 +/- 0.0, 0.59 +/- 0.69, and 0.4 +/- 0.22 pg/ml, respe ctively (p > 0.001). Conclusion. Findings suggest that the expression of IL-4 is associated with intracellular infection by RSV in conjuncti va. With our former reports, RSV infection in conjunctival epithelial cells can be suggested as one of the possible environmental pathogens of allergic conjunctivitis.