IgE-dependent IL-4 secretion by human basophils. The relationship between cytokine production and histamine release in mixed leukocyte cultures.
IL-4 protein and mRNA have recently been detected in pure basophil cultures after stimulation. It has also been established in mixed leukocyte cultures obtained by elutriation and challenged with anti-IgE that the basophil is the only cell that makes detectable IL-4. We have used cells prepared using Percoll gradients (5 to 30% basophils) to study the relationship between histamine release and IL-4 synthesis. In cultures challenged with anti-IgE after a 15-min pretreatment with IL-3, detectable IL-4 secretion ranged from 40 to 630 pg/10(6) basophils in 18 of 22 donors, with no significant correlation (r = 0.21, p = 0.34) with basophil purity. IL-4 synthesis was dissociated from histamine release, with optimal production consistently occurring at 10 ng/ml anti-IgE, whereas histamine levels peaked at 50 to 100 ng/ml of stimulus. Stimulation with anti-IgE alone was sufficient for IL-4 secretion but protein levels were enhanced two- to threefold in low responders by increasing the calcium concentration to 5 mM with no significant changes in histamine release. The IgE-independent secretagogues, F-met peptide (1 microM) and C5a (25 ng/ml), demonstrated limited ability to generate detectable IL-4, despite promoting vigorous histamine release. Additional studies showed no significant difference between IL-4 secretion in atopic and nonatopic donors. Finally, IL-4 levels generated with specific Ags were comparable to those levels produced in response to anti-IgE. We predict that basophil IL-4 generation will have a proinflammatory effect, but it appears that the signal transduction mechanisms for its synthesis and release differ from those for histamine release and thus may require different methods of pharmacologic control.
Schroeder
J T
JT
Johns Hopkins Asthma and Allergy Center, Baltimore, MD 21224.
MacGlashan
D W
DW
Kagey-Sobotka
A
A
White
J M
JM
Lichtenstein
L M
LM
D001491:Basophils / Q000378:metabolism*; D000001:Calcimycin / Q000494:pharmacology; D002478:Cells, Cultured; D015936:Complement C5a / Q000494:pharmacology; D016207:Cytokines / Q000096:biosynthesis*; D004306:Dose-Response Relationship, Immunologic; D006636:Histamine Release; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology; D007073:Immunoglobulin E / Q000276:immunology*; D066298:In Vitro Techniques; D007377:Interleukin-3 / Q000494:pharmacology; D015847:Interleukin-4 / Q000378:metabolism*; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology
D016207:Cytokines; D007377:Interleukin-3; D015847:Interleukin-4; D007073:Immunoglobulin E; D000001:Calcimycin; D009240:N-Formylmethionine Leucyl-Phenylalanine; D015936:Complement C5a