BACKGROUND: Peripheral blood basophils from 10% to 20% of donors fail to degranulate in response to cross-linking the high-affinity IgE receptor FcepsilonRI. The molecular mechanisms underlying the nonreleaser phenotype have not been established. OBJECTIVES: Our aim was to compare the expression of FcepsilonRI-associated protein tyrosine kinases between nonreleaser and releaser basophils. METHODS: With use of Western blotting we investigated Syk and Lyn protein levels in highly purified basophils from 3 anti-IgE nonreleasers and 2 releasers. RESULTS: We identified 3 healthy nonatopic donors whose nonreleaser basophils express FcepsilonRI normally but fail to express protein for the tyrosine kinase Syk, which is implicated in the initiation of FcepsilonRI-mediated secretion. Protein levels for the tyrosine kinase Lyn are somewhat reduced but not absent in nonreleaser basophils. Levels of Lyn and Syk protein are similar in B cells, eosinophils, and neutrophils from releaser and nonreleaser donors. During these studies one nonreleaser "converted" into a releaser with concomitant basophil Syk expression. CONCLUSION: The absence of detectable Syk could explain the nonreleaser phenotype of basophils from some donors.
BACKGROUND: Peripheral blood basophils from 10% to 20% of donors fail to degranulate in response to cross-linking the high-affinity IgE receptor FcepsilonRI. The molecular mechanisms underlying the nonreleaser phenotype have not been established. OBJECTIVES: Our aim was to compare the expression of FcepsilonRI-associated protein tyrosine kinases between nonreleaser and releaser basophils. METHODS: With use of Western blotting we investigated Syk and Lyn protein levels in highly purified basophils from 3 anti-IgE nonreleasers and 2 releasers. RESULTS: We identified 3 healthy nonatopic donors whose nonreleaser basophils express FcepsilonRI normally but fail to express protein for the tyrosine kinase Syk, which is implicated in the initiation of FcepsilonRI-mediated secretion. Protein levels for the tyrosine kinase Lyn are somewhat reduced but not absent in nonreleaser basophils. Levels of Lyn and Syk protein are similar in B cells, eosinophils, and neutrophils from releaser and nonreleaser donors. During these studies one nonreleaser "converted" into a releaser with concomitant basophil Syk expression. CONCLUSION: The absence of detectable Syk could explain the nonreleaser phenotype of basophils from some donors.
Authors: Wei Zhao; Gregorio Gomez; Matthew Macey; Christopher L Kepley; Lawrence B Schwartz Journal: J Clin Immunol Date: 2011-10-19 Impact factor: 8.317
Authors: R Agrawal; J Wisniewski; M D Yu; J L Kennedy; T Platts-Mills; P W Heymann; J A Woodfolk Journal: Clin Exp Allergy Date: 2014-10 Impact factor: 5.018
Authors: Jacqueline M Langdon; John T Schroeder; Becky M Vonakis; Anja P Bieneman; Kristin Chichester; Susan M Macdonald Journal: J Leukoc Biol Date: 2008-07-14 Impact factor: 4.962