A novel metalloproteinase, leukolysin, and development of a standardized immunoassay

Abstract

Rationale Leukolysin is a matrix metalloproteinase that is expressed on the cell surface of eosinophils and mast cells. Leukolysin degrades extracellular matrix components and allows eosinophils and mast cells to infiltrate into bronchial airways and mediate tissue damage. Leukolysin may be an ideal candidate target for the development of asthma drugs. The purpose of this experiment was to measure serum leukolysin and determine its relationship to airway inflammation. Methods A highly sensitive chemiluminescent enzyme immunoassay (ELISA) was developed utilizing guinea pig anti-leukolysin and rabbit anti-leukolysin reagents made in our laboratories. History, spirometry, exhaled breath condensate (EBC) and serum was collected on 31 asthmatic and 10 non-asthmatics volunteers and the serum and EBC leukolysin levels were determined by immunoassay. Results To validate the immunoassay blinded ELISAs were performed on serial standardized dilutions of leukolysin from 200 ng/ml to 0.08 ng/ml. Regression analysis of the standardized dilutions and relative light units (RLU) showed a linear relationship at 1:100 dilution R squared=0.9765. No definite trends in these small sample populations were found. Conclusions A standardized immnunoassay was developed that accurately measures leukolysin. This assay will prove to be valuable in future research for measuring leukolysin in serum and EBC and determining its role in bronchial asthma.