The influence of pollen proteases on human conjunctival cells

Abstract

Purpose During pollen‐seasons allergy‐like symptoms can also be observed in proven non allergy sufferers. Pollen proteases are thought to be responsible for consecutive conjunctival irritation. We investigated the influence of a well known aggressive pollen species, birch pollen (Betula pendula) on human conjunctival cell cultures. This study is an approach to SNAC (seasonal non allergic conjunctivitis) syndrome. Methods Human cultivated conjunctival cells, so called CHANG‐cells, were incubated with extracts of birch pollen. Zymography was carried out in order to investigate the proteolytic activity of the pollen. Cytomorphological changes were analysed using the CASY1 Cell Counter. Via MTS‐assay the cell viability was quantified. The viability of the cells, which were incubated with pollen extract, was compared to the viability of the control cells and the results were statistically evaluated. Results Depending on the pollen extract concentration and the incubation period, the treatment of CHANG‐cells with pollen extract of birch induced a highly significant decrease of the cell viability. Conclusion Cell damage by pollen proteases is an approach to explain conjunctival irritation in proven non‐allergic persons during the pollen season. A reason why not all persons are affected by the SNAC syndrome at the same extent, could be differences in the concentrations of antiproteases present on the ocular surface.