Evolution of Highly Polymorphic T Cell Populations in Siblings with the Wiskott-Aldrich Syndrome
| Autor: | Jun Y. Park, Eileen Remold-O'Donnell, Maxim I. Lutskiy, Susanna K. Remold |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
Somatic cell
T-Lymphocytes T cell Immunology Population lcsh:Medicine Thymus Gland macromolecular substances Biology Germline 03 medical and health sciences 0302 clinical medicine Germline mutation medicine Humans Allele lcsh:Science education Germ-Line Mutation 030304 developmental biology Genetics Evolutionary Biology 0303 health sciences education.field_of_study Multidisciplinary Siblings lcsh:R Wiskott–Aldrich syndrome protein Genetics and Genomics Hematology Actin cytoskeleton Wiskott-Aldrich Syndrome medicine.anatomical_structure biology.protein lcsh:Q Wiskott-Aldrich Syndrome Protein Research Article 030215 immunology |
| Zdroj: | PLoS ONE, Vol 3, Iss 10, p e3444 (2008) PLoS ONE |
| ISSN: | 1932-6203 |
| DOI: | 10.1371/journal.pone.0003444 |
| Popis: | Population level evolutionary processes can occur within a single organism when the germ line contains a mutation that confers a cost at the level of the cell. Here we describe how multiple compensatory mutations arose through a within-individual evolutionary process in two brothers with the immune deficiency Wiskott-Aldrich Syndrome (WAS). As a result, both brothers have T lymphocyte populations that are highly polymorphic at the locus of the germ line defect, and no single allele achieves fixation. WASP, the gene product affected in this disease, is specific to white blood cells where it is responsible for regulating actin cytoskeleton dynamics in a wide range of cellular responses. The brothers inherited a rare allele predicted to result in truncated WASP lacking the carboxy-terminal VCA domains, the region that directly catalyzes actin filament generation. Although the brothers' T cell populations are highly polymorphic, all share a corrective effect relative to the inherited allele in that they restore the VCA domain. This indicates massive selection against the truncated germ line allele. No single somatic allele becomes fixed in the circulating T cell population of either brother, indicating that a regulated step in maturation of the affected cell lineage is severely compromised by the germ line allele. Based on the finding of multiple somatic mutations, the known maturation pathway for T-lineage cells and the known defects of T cells and precursor thymocytes in mice with truncated WASP, we hypothesize that the presence of truncated WASP (WASP Delta VCA) confers an extreme disadvantage in early developing thymocytes, above and beyond the known cost of absence of full-length WASP, and that the disadvantage likely occurs through dominant negative competition of WASP Delta VCA with N-WASP, a protein that otherwise partially compensates for WASP absence in developing thymocytes. |
| Databáze: | OpenAIRE |
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