Cytokine priming of the respiratory burst in human eosinophils is Ca2+ independent and accompanied by induction of tyrosine kinase activity

• Published in: Journal of leukocyte biology Vol. 53; no. 4; pp. 347 - 353
• Main Authors: Bruggen, Tjomme, Kok, Paul T.M., Raaijmakers, Jan A.M., Verhoeven, Arthur J., Kessels, Roger G.C., Lammers, Jan W.J., Koenderman, Leo
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Society for Leukocyte Biology 01.04.1993; Federation of American Societies for Experimental Biology
• Subjects: Biological and medical sciences; Calcium - blood; Cell physiology; Dose-Response Relationship, Drug; Enzyme Induction; Eosinophils - drug effects; Eosinophils - enzymology; Eosinophils - physiology; Fundamental and applied biological sciences. Psychology; GM‐CSF; Granulocyte-Macrophage Colony-Stimulating Factor - pharmacology; human eosinophils; Humans; In Vitro Techniques; Interleukin-3 - pharmacology; Interleukin-5 - pharmacology; interleukin‐3; interleukin‐5; intracellular calcium; Ionomycin - pharmacology; Kinetics; Molecular and cellular biology; Molecular Weight; Oxygen Consumption - drug effects; Phosphoproteins - blood; Phosphoproteins - isolation & purification; Platelet Activating Factor - pharmacology; priming; Protein-Tyrosine Kinases - biosynthesis; Protein-Tyrosine Kinases - blood; Recombinant Proteins - pharmacology; respiratory burst; Signal transduction; tyrosine phosphorylation; Zymosan - pharmacology; Human; Tyrosine; Phosphorylation; Calcium; Cytokine; Eosinophil; Mechanism; Signal transduction; Interleukin 5; Interleukin 3; Respiratory burst; Intracellular; Granulocyte macrophage colony stimulating factor
• ISSN: 0741-5400; 1938-3673
• DOI: 10.1002/jlb.53.4.347

We report that pretreatment of human eosinophils with GM‐CSF, IL‐3, or IL‐5 enhanced the respiratory burst induced by opsonized particles. In order to gain more insight into the intracellular mechanism(s) involved in cytokine priming, the role of [Ca2+], and tyrosine kinases was studied. Optimal priming concentrations of GM‐CSF, IL‐3, and IL‐5 did not induce a rise in [Ca2+]i, and Ca2+‐depleted eosinophils ([Ca2+]i < 20 nM) were still primed after preincubation with these cytokines. GM‐CSF, IL‐3, and IL‐5 induced phosphorylation of two proteins (102 and 122 kd) on tyrosine residues, as deduced from Western blot analysis with an antiphospho‐ tyrosine monoclonal antibody (4G10). This cytokine‐ stimulated tyrosine phosphorylation was not inhibited under Ca2+‐depleted conditions. In conclusion, this study demonstrates that GM‐CSF, IL‐3, and IL‐5 priming of the opsonized particle‐induced respiratory burst in human eosinophils is completely Ca2+ independent. Moreover the tyrosine phosphorylation of a 102‐kd and a 122‐kd protein is Ca2+ independent, suggesting that this event might be involved in cytokine priming.