PREFERENTIAL GENERATION OF LEUKOTRIENE-C4 BY HUMAN EOSINOPHILS

  • 1 January 1984
    • journal article
    • research article
    • Vol. 56  (3) , 716-722
Abstract
The leukotriene [LT] generating capacities of ionophore [calcimycin, A23187] stimulated human eosinophils and neutrophils were compared using specific radioimmunoassays for LTB4 and LTC4. Mixed granulocyte preparations (neutrophils and eosinophils) produced both LTB4 and LTC4 in a time-dependent fashion which was maximal at 10 and 15 min, respectively. Following the separation of eosinophils (> 75%) and neutrophils (> 90%) by metrizamide gradients, LTC4 production was predominantly from eosinophils, whereas neutrophils were the principal source of LTB4. The concentrations of LT produced by the eosinophil and neutrophil rich cell preparations were directly proportional to the concentration of ionophore. Following purification of eosinophil derived products by RP-HPLC [reverse-phase high-pressure chromatography] the LTC4 immunoreactivity corresponded to the elution profile of a synthetic LTC4 marker. In 32 atopic subjects (21 bronchial asthmatics and 11 non-asthmatics) the amounts of LTC4 produced by unseparated leukocytes were directly proportional to the percentage of eosinophils in the total cell suspension. Preferential generation of LTB4 by neutrophils was also demonstrated by immunoreactivity of ionophore stimulated supernatants subjects to RP-HPLC, as well as by its characteristic UV absorbance and GC-MS [gas chromatography mass spectroscopy] profile and the ability to promote directional neutrophil locomotion (chemotaxis). These experiments support the concept that eosinophils accumulate in tissues partly as a result of the response to neutrophil derived LTB4, and that these cells contribute to the production of sulfidopeptide leukotrienes with subsequent amplification of the acute allergic response.