Cell-dependent chemiluminescence. Modulation of the N-formyl chemotactic peptide (FNLPNTL) mediated oxidative burst in human polymorphonuclear leukocytes (PMNL) by murine monoclonal antibody NMS-1.

Abstract

Binding of purified monoclonal antibody (moAB) IgM NMS-1 to suspended initially spherical living human PMNLs is not associated with the generation of chemiluminescence but was found to enhance the chemiluminescence response to the N-formyl chemotactic peptide FNLPNTL. We investigated quantitatively the kinetics of oxygen metabolite generation by PMNLs stimulated with FNLPNTL +/- moAB NMS-1 using luminol-dependent chemiluminescence as a very sensitive detection system. Chemiluminescence detection allowed the analysis of the time sequence of onset and development of reactive oxygen metabolites following stimulation of PMNLs by FNLPNTL in the presence of moAB NMS-1. The increase of response of PMNLs stimulated with FNLPNTL in the presence of moAB NMS-1 depended on the concentration of the antibody and the sequence of stimulus addition. Stimulation of human PMNLs by 10 nM FNLPNTL induced a rapid burst of chemiluminescence which peaked approximately 5 min after stimulus addition. The subsequent addition of moAB NMS-1 (greater than or equal to 2 micrograms/ml DPBS(+) - 0.1% HSA, 37 degrees C) to FNLPNTL-stimulated PMNLs - after the FNLPNTL-mediated response had already decayed (16-18 min) - without delay induced a second burst of oxygen metabolite generation. The magnitude of this second peak of activation was dose-dependent. Treatment of PMNLs with moAB NMS-1 (greater than or equal to 1 microgram/ml DPBS(+) - 0.1% HSA, 3 min, 37 degrees C) - prior to FNLPNTL (10 nM) stimulation - increased rate and magnitude of the FNLPNTL-mediated response. This response is biphasic with the first peak at the FNLPNTL position and a second, higher peak approximately 16 min after FNLPNTL addition. The magnitude of response was dose-dependent. The latency (lag time) of the response was not changed compared to controls which received no moAB NMS-1 treatment. The observed moAB NMS-1 dependent increase in FNLPNTL-mediated chemiluminescence is transient (50-60 min), persistent activation was not detected.