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Human peripheral blood eosinophils express functional CD2-subfamily immunoglobulin receptors
S170 Abstracts
J ALLERGY CLIN IMMUNOL FEBRUARY 2004
SUNDAY
582
Human Peripheral Blood Eosinophils Express Functional CD2Subfamily Immunoglobulin Receptors
A. Munitz1, S. Fraenkel1, M. Colonna2, D. Pende3, L. Moretta4,5, F. LeviSchaffer1; 1Department of Pharmacology, Hebrew University of Jerusalem, School of Pharmacy, Jerusalem, ISRAEL, 2Department of Pathology and Immunology, Washington University School of Medicine, St Louis, MO, 3Istituto Nazionale per la Ricerca sul Cancro, Genova, ITALY, 4Dipartimento di Medicina Sperimentale, Universita’ degli Studi di Genova, Genova, ITALY, 5Istituto Giannina Gaslini, Genova, ITALY. RATIONALE: Complex networks of activating and inhibitory signals likely control the immunological/inflammatory responses coordinated by eosinophils. The CD2-subfamily of the Ig-superfamily, expressed mainly on NK and T cell subsets, includes 2B4, CD48, SLAM and NTB-A. CD48 is a high-affinity ligand for 2B4. Activation of 2B4, SLAM and NTB-A causes tyrosine phosphorylation and recruitment of SAP. We have previously shown that eosinophils express functional 2B4. We examined the expression and function of other members of the CD2-subfamily on eosinophils. METHODS: Eosinophils, neutrophils and basophils were purified from peripheral blood (mildly atopics/normal volunteers, MACS). Expression of 2B4, CD48, SLAM, CD2, NTB-A and SAP was assessed by FACS and Western blot. For activation, eosinophils were incubated with either anti2B4, anti-CD48 or anti-NTB-A and with the cross-linker sheep anti-mouse IgG. EPO release was determined by enzymatic-colorimetric assay; IL-4 and IFN-g by ELISA; phosphorylation of ERK 1/2 by Western blot. RESULTS: Eosinophils expressed CD48, 2B4 and NTB-A but not CD2 or SLAM (n=15). Basophils expressed 2B4 and CD48 (n=4). Neutrophils expressed CD48 and CD150 (n=15). Eosinophils but not neutrophils expressed SAP (n=4). Cross-linking of either CD48 or NTB-A caused EPO release (O.D units 1.872 ± 0.402, 0.522 ± 0.047 2B4 vs. 0.294 ± 0.022, 0.357 ± 0.004 isotype respectively, p<0.01, n=5,3,2). Cross-linking of 2B4 induced INF-g release (53.7-502.9pg/ml 2B4 vs. 0-97.5pg/ml isotype, p<0.01, n=11/14), IL-4 release (16.5-67.3pg/ml 2B4 vs. 10.4851.7pg/ml isotype, p<0.05, n=4/7) and phosphorylation of ERK1/2. CONCLUSIONS: The demonstration that eosinophils express biologically active CD2-subfamily receptors suggests a new role for eosinophils in the regulation of the immune response in health and disease. Funding: Aimwell Trust, The Bloom Foundation
J ALLERGY CLIN IMMUNOL FEBRUARY 2004
SUNDAY
582
Human Peripheral Blood Eosinophils Express Functional CD2Subfamily Immunoglobulin Receptors
A. Munitz1, S. Fraenkel1, M. Colonna2, D. Pende3, L. Moretta4,5, F. LeviSchaffer1; 1Department of Pharmacology, Hebrew University of Jerusalem, School of Pharmacy, Jerusalem, ISRAEL, 2Department of Pathology and Immunology, Washington University School of Medicine, St Louis, MO, 3Istituto Nazionale per la Ricerca sul Cancro, Genova, ITALY, 4Dipartimento di Medicina Sperimentale, Universita’ degli Studi di Genova, Genova, ITALY, 5Istituto Giannina Gaslini, Genova, ITALY. RATIONALE: Complex networks of activating and inhibitory signals likely control the immunological/inflammatory responses coordinated by eosinophils. The CD2-subfamily of the Ig-superfamily, expressed mainly on NK and T cell subsets, includes 2B4, CD48, SLAM and NTB-A. CD48 is a high-affinity ligand for 2B4. Activation of 2B4, SLAM and NTB-A causes tyrosine phosphorylation and recruitment of SAP. We have previously shown that eosinophils express functional 2B4. We examined the expression and function of other members of the CD2-subfamily on eosinophils. METHODS: Eosinophils, neutrophils and basophils were purified from peripheral blood (mildly atopics/normal volunteers, MACS). Expression of 2B4, CD48, SLAM, CD2, NTB-A and SAP was assessed by FACS and Western blot. For activation, eosinophils were incubated with either anti2B4, anti-CD48 or anti-NTB-A and with the cross-linker sheep anti-mouse IgG. EPO release was determined by enzymatic-colorimetric assay; IL-4 and IFN-g by ELISA; phosphorylation of ERK 1/2 by Western blot. RESULTS: Eosinophils expressed CD48, 2B4 and NTB-A but not CD2 or SLAM (n=15). Basophils expressed 2B4 and CD48 (n=4). Neutrophils expressed CD48 and CD150 (n=15). Eosinophils but not neutrophils expressed SAP (n=4). Cross-linking of either CD48 or NTB-A caused EPO release (O.D units 1.872 ± 0.402, 0.522 ± 0.047 2B4 vs. 0.294 ± 0.022, 0.357 ± 0.004 isotype respectively, p<0.01, n=5,3,2). Cross-linking of 2B4 induced INF-g release (53.7-502.9pg/ml 2B4 vs. 0-97.5pg/ml isotype, p<0.01, n=11/14), IL-4 release (16.5-67.3pg/ml 2B4 vs. 10.4851.7pg/ml isotype, p<0.05, n=4/7) and phosphorylation of ERK1/2. CONCLUSIONS: The demonstration that eosinophils express biologically active CD2-subfamily receptors suggests a new role for eosinophils in the regulation of the immune response in health and disease. Funding: Aimwell Trust, The Bloom Foundation