Immunologic release of neutrophil chemotactic activity from human lung tissue.

The release of heat-stable neutrophil chemotactic activity (NCA) has been detected after challenge of isolated human lung tissue with anti-IgE. The major NCA released (NCAL) had similar physicochemical properties to the NCA detected in the circulation of asthmatic subjects after bronchial challenge with specific antigen (NCAAG). NCAL and NCAAG (1) had molecular weights of approximately 600,000 daltons as estimated by Sephacryl S-300 gel-filtration chromatography; (2) both eluted from DEAE-Sephacel (pH 7.8) between 0.1 and 0.2 molar NaCl; (3) had isoelectric points of between 6.5 and 6.8 as determined by chromatofocusing on Polybuffer Exchanger 94. In contrast to NCAAG, lung-derived neutrophil chemotactic activity appeared to be more heterogeneous after gel-filtration and anion-exchange chromatography. The release of NCA was complete by 15 min and there was no evidence of further release up to 12 hr. These observations indicate that high-molecular-weight NCA released from human lung tissue has similar properties to NCAAG and would support the view that NCAAG originates from lung tissue after antigen bronchial challenge in asthmatic subjects.