Yuzhi Yin1, Yun Bai2, Ana Olivera2, Dean D Metcalfe2. 1. Mast Cell Biology Section, Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Md. Electronic address: yiny@niaid.nih.gov. 2. Mast Cell Biology Section, Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Md.
Abstract
BACKGROUND: CD25+ human mast cells (huMCs) have been reported in patients with monoclonal mast cell diseases and in rare association with inflammation. However, the regulation of CD25 expression on huMCs and the possible biologic consequences remain poorly understood. OBJECTIVE: We sought to identify conditions that would upregulate CD25 expression on huMCs and to explore possible functional implications. METHODS: huMCs were cultured from peripheral blood progenitor cells over 6 to 8 weeks. Expression of CD25 was determined by fluorescence-activated cell sorting and soluble CD25 by ELISA. Signal transducer and activator of transcription 5 (STAT5) phosphorylation induced by IL-2 in huMCs, regulatory T (Treg) cells, or in cocultured huMCs and Treg cells was examined by fluorescence-activated cell sorting. RESULTS: Addition of IL-3 to CD34+ progenitors at the initiation of huMC cultures in the presence of stem cell factor and IL-6 upregulated the expression of CD25 in developing huMCs and resulted in shedding of soluble CD25 into the media. Removal of IL-3 after the first week of culture did not affect subsequent expression of CD25. Furthermore, addition of IL-3 14 days after the initiation of the culture did not induce significant CD25 expression. Treatment with anti-IL-3 antibody or the Janus kinase inhibitor tofacitinib blocked IL-3-induced CD25 upregulation. Binding of IL-2 to CD25+ huMCs did not induce STAT5 phosphorylation. However, coincubation of Treg cells with CD25+ huMCs pretreated with IL-2 was sufficient to result in STAT5 phosphorylation in Treg cells. CONCLUSIONS: IL-3 promotes CD25 expression and shedding by huMCs. Although CD25+ huMCs do not respond to IL-2, they bind IL-2 and may act as a reservoir of IL-2 to then activate lymphocytes.
BACKGROUND: CD25+ human mast cells (huMCs) have been reported in patients with monoclonal mast cell diseases and in rare association with inflammation. However, the regulation of CD25 expression on huMCs and the possible biologic consequences remain poorly understood. OBJECTIVE: We sought to identify conditions that would upregulate CD25 expression on huMCs and to explore possible functional implications. METHODS: huMCs were cultured from peripheral blood progenitor cells over 6 to 8 weeks. Expression of CD25 was determined by fluorescence-activated cell sorting and soluble CD25 by ELISA. Signal transducer and activator of transcription 5 (STAT5) phosphorylation induced by IL-2 in huMCs, regulatory T (Treg) cells, or in cocultured huMCs and Treg cells was examined by fluorescence-activated cell sorting. RESULTS: Addition of IL-3 to CD34+ progenitors at the initiation of huMC cultures in the presence of stem cell factor and IL-6 upregulated the expression of CD25 in developing huMCs and resulted in shedding of soluble CD25 into the media. Removal of IL-3 after the first week of culture did not affect subsequent expression of CD25. Furthermore, addition of IL-3 14 days after the initiation of the culture did not induce significant CD25 expression. Treatment with anti-IL-3 antibody or the Janus kinase inhibitor tofacitinib blocked IL-3-induced CD25 upregulation. Binding of IL-2 to CD25+ huMCs did not induce STAT5 phosphorylation. However, coincubation of Treg cells with CD25+ huMCs pretreated with IL-2 was sufficient to result in STAT5 phosphorylation in Treg cells. CONCLUSIONS: IL-3 promotes CD25 expression and shedding by huMCs. Although CD25+ huMCs do not respond to IL-2, they bind IL-2 and may act as a reservoir of IL-2 to then activate lymphocytes.
Authors: Cem Akin; Linda M Scott; Can N Kocabas; Nataliya Kushnir-Sukhov; Erica Brittain; Pierre Noel; Dean D Metcalfe Journal: Blood Date: 2007-07-16 Impact factor: 22.113
Authors: G-H Schernthaner; A W Hauswirth; M Baghestanian; H Agis; M Ghannadan; C Worda; M-T Krauth; D Printz; G Fritsch; W R Sperr; P Valent Journal: Allergy Date: 2005-10 Impact factor: 13.146
Authors: Christopher P Shelburne; Margaret E McCoy; Roland Piekorz; Veronica V Sexl; Sheila R Gillespie; Daniel P Bailey; Anita Gharse; Paria Mirmonsef; Meredith N Mann; Mohit Kashyap; Harry V Wright; Hey Jin Chong; L Andrew Bouton; Carlos D Ramirez; Chris S Lantz; John J Ryan Journal: Mol Immunol Date: 2002-09 Impact factor: 4.407