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The relationship between released soluble FceRI-alpha and its cell surface density on human basophils
BACKGROUND: The IgE-mediated activation of mast cells and basophils results in the secretion of many substances, including the release of FceRI-alpha subunit. This released alpha subunit can bind IgE and it may act as a down-regulator of subsequent IgE-dependent reactions. However, previous studies...
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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Public Library of Science
2021
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7822313/ https://www.ncbi.nlm.nih.gov/pubmed/33481953 http://dx.doi.org/10.1371/journal.pone.0245942 |
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author | MacGlashan, Donald |
author_facet | MacGlashan, Donald |
author_sort | MacGlashan, Donald |
collection | PubMed |
description | BACKGROUND: The IgE-mediated activation of mast cells and basophils results in the secretion of many substances, including the release of FceRI-alpha subunit. This released alpha subunit can bind IgE and it may act as a down-regulator of subsequent IgE-dependent reactions. However, previous studies do not observe loss of the mass of FceRI-alpha associated with the cells, at least not for human basophils. This study was designed to understand the basis for the discordant observations. METHODS: Purified human basophils were stimulated with multiple activating secretagogues and supernatants were examined for histamine and released FceRI-alpha. In addition, cell surface IgE densities (occupied and unoccupied) were measured by flow cytometry and total cellular content of mature and immature FceRI-alpha determined with Western blots. RESULTS: Released FceRI-alpha, on average, represented 7% of the total surface FceRI before the reaction. The molecular weight of the soluble FceRI-alpha was approximately 54 kD, larger than immature subunit and somewhat smaller than surface subunit. In addition, 1) release ceased long before internalized FceRI-alpha was processed, 2) release was insensitive to Bafilomycin A, 3) release was independent of the starting density of FceRI and 4) release occurred more effectively with non-IgE-dependent stimuli, FMLP or C5a. CONCLUSIONS: There appears to be relatively constant amount of nearly mature FceRI-alpha that is susceptible to secretion events induced by any form of stimulation. The amount, on average, represents about 7% of the mature form of FceRI-alpha. |
format | Online Article Text |
id | pubmed-7822313 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-78223132021-01-29 The relationship between released soluble FceRI-alpha and its cell surface density on human basophils MacGlashan, Donald PLoS One Research Article BACKGROUND: The IgE-mediated activation of mast cells and basophils results in the secretion of many substances, including the release of FceRI-alpha subunit. This released alpha subunit can bind IgE and it may act as a down-regulator of subsequent IgE-dependent reactions. However, previous studies do not observe loss of the mass of FceRI-alpha associated with the cells, at least not for human basophils. This study was designed to understand the basis for the discordant observations. METHODS: Purified human basophils were stimulated with multiple activating secretagogues and supernatants were examined for histamine and released FceRI-alpha. In addition, cell surface IgE densities (occupied and unoccupied) were measured by flow cytometry and total cellular content of mature and immature FceRI-alpha determined with Western blots. RESULTS: Released FceRI-alpha, on average, represented 7% of the total surface FceRI before the reaction. The molecular weight of the soluble FceRI-alpha was approximately 54 kD, larger than immature subunit and somewhat smaller than surface subunit. In addition, 1) release ceased long before internalized FceRI-alpha was processed, 2) release was insensitive to Bafilomycin A, 3) release was independent of the starting density of FceRI and 4) release occurred more effectively with non-IgE-dependent stimuli, FMLP or C5a. CONCLUSIONS: There appears to be relatively constant amount of nearly mature FceRI-alpha that is susceptible to secretion events induced by any form of stimulation. The amount, on average, represents about 7% of the mature form of FceRI-alpha. Public Library of Science 2021-01-22 /pmc/articles/PMC7822313/ /pubmed/33481953 http://dx.doi.org/10.1371/journal.pone.0245942 Text en © 2021 Donald MacGlashan Jr. http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
spellingShingle | Research Article MacGlashan, Donald The relationship between released soluble FceRI-alpha and its cell surface density on human basophils |
title | The relationship between released soluble FceRI-alpha and its cell surface density on human basophils |
title_full | The relationship between released soluble FceRI-alpha and its cell surface density on human basophils |
title_fullStr | The relationship between released soluble FceRI-alpha and its cell surface density on human basophils |
title_full_unstemmed | The relationship between released soluble FceRI-alpha and its cell surface density on human basophils |
title_short | The relationship between released soluble FceRI-alpha and its cell surface density on human basophils |
title_sort | relationship between released soluble fceri-alpha and its cell surface density on human basophils |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7822313/ https://www.ncbi.nlm.nih.gov/pubmed/33481953 http://dx.doi.org/10.1371/journal.pone.0245942 |
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