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Molecular evolution of the human immunoglobulin E response: high incidence of shared mutations and clonal relatedness among epsilon VH5 transcripts from three unrelated patients with atopic dermatitis
We have analyzed the nucleotide sequences of 19 epsilon VH5 transcripts derived from in vivo isotype switched peripheral blood B cells of three patients with atopic dermatitis. Comparison with the patients' own germline VH5 gene segments revealed that the epsilon transcripts were derived from b...
Formato: | Texto |
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Lenguaje: | English |
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The Rockefeller University Press
1993
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2190866/ https://www.ncbi.nlm.nih.gov/pubmed/8418213 |
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collection | PubMed |
description | We have analyzed the nucleotide sequences of 19 epsilon VH5 transcripts derived from in vivo isotype switched peripheral blood B cells of three patients with atopic dermatitis. Comparison with the patients' own germline VH5 gene segments revealed that the epsilon transcripts were derived from both functional members of the human VH5 gene family and harbored numerous somatic mutations (range 5-36 per VH5 gene). In two patients, we detected clonally related but diverged transcripts, permitting the construction of a genealogical tree in one patient. We observed a high proportion of shared silent (S) and replacement (R) mutations among epsilon VH5 sequences derived from all three individuals, even among transcripts descending from the two different germline VH5 gene segments. A remarkably high number of these mutations is shared with previously reported VH5 genes encoding antibodies with defined specificities. The shared S mutations, and likely a fraction of the R mutations, appear to mark preferential sites ("hot spots") of somatic hypermutations in human VH5 genes. The distribution of R and S mutations over complementarity determining region and framework regions in the majority of VH regions deviated from that characteristic of antigen-driven immune response. We hypothesize that the V regions of immunoglobulin E-bearing B cells have accumulated "selectively neutral" mutations over extended periods of clonal expansion, resulting in unusual R/S ratios. We propose that the molecular characteristics of the epsilon VH regions in atopic dermatitis may be representative of antigens that recurrently or chronically stimulate the immune system. |
format | Text |
id | pubmed-2190866 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 1993 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-21908662008-04-16 Molecular evolution of the human immunoglobulin E response: high incidence of shared mutations and clonal relatedness among epsilon VH5 transcripts from three unrelated patients with atopic dermatitis J Exp Med Articles We have analyzed the nucleotide sequences of 19 epsilon VH5 transcripts derived from in vivo isotype switched peripheral blood B cells of three patients with atopic dermatitis. Comparison with the patients' own germline VH5 gene segments revealed that the epsilon transcripts were derived from both functional members of the human VH5 gene family and harbored numerous somatic mutations (range 5-36 per VH5 gene). In two patients, we detected clonally related but diverged transcripts, permitting the construction of a genealogical tree in one patient. We observed a high proportion of shared silent (S) and replacement (R) mutations among epsilon VH5 sequences derived from all three individuals, even among transcripts descending from the two different germline VH5 gene segments. A remarkably high number of these mutations is shared with previously reported VH5 genes encoding antibodies with defined specificities. The shared S mutations, and likely a fraction of the R mutations, appear to mark preferential sites ("hot spots") of somatic hypermutations in human VH5 genes. The distribution of R and S mutations over complementarity determining region and framework regions in the majority of VH regions deviated from that characteristic of antigen-driven immune response. We hypothesize that the V regions of immunoglobulin E-bearing B cells have accumulated "selectively neutral" mutations over extended periods of clonal expansion, resulting in unusual R/S ratios. We propose that the molecular characteristics of the epsilon VH regions in atopic dermatitis may be representative of antigens that recurrently or chronically stimulate the immune system. The Rockefeller University Press 1993-01-01 /pmc/articles/PMC2190866/ /pubmed/8418213 Text en This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/). |
spellingShingle | Articles Molecular evolution of the human immunoglobulin E response: high incidence of shared mutations and clonal relatedness among epsilon VH5 transcripts from three unrelated patients with atopic dermatitis |
title | Molecular evolution of the human immunoglobulin E response: high incidence of shared mutations and clonal relatedness among epsilon VH5 transcripts from three unrelated patients with atopic dermatitis |
title_full | Molecular evolution of the human immunoglobulin E response: high incidence of shared mutations and clonal relatedness among epsilon VH5 transcripts from three unrelated patients with atopic dermatitis |
title_fullStr | Molecular evolution of the human immunoglobulin E response: high incidence of shared mutations and clonal relatedness among epsilon VH5 transcripts from three unrelated patients with atopic dermatitis |
title_full_unstemmed | Molecular evolution of the human immunoglobulin E response: high incidence of shared mutations and clonal relatedness among epsilon VH5 transcripts from three unrelated patients with atopic dermatitis |
title_short | Molecular evolution of the human immunoglobulin E response: high incidence of shared mutations and clonal relatedness among epsilon VH5 transcripts from three unrelated patients with atopic dermatitis |
title_sort | molecular evolution of the human immunoglobulin e response: high incidence of shared mutations and clonal relatedness among epsilon vh5 transcripts from three unrelated patients with atopic dermatitis |
topic | Articles |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2190866/ https://www.ncbi.nlm.nih.gov/pubmed/8418213 |