Abstract
Schimke immuno-osseous dysplasia (SIOD) is an autosomal recessive, fatal childhood disorder associated with skeletal dysplasia, renal dysfunction, and T-cell immunodeficiency. This disease is linked to biallelic loss-of-function mutations of the SMARCAL1 gene. Although recurrent infection, due to T-cell deficiency, is a leading cause of morbidity and mortality, the etiology of the T-cell immunodeficiency is unclear. Here, we demonstrate that the T cells of SIOD patients have undetectable levels of protein and mRNA for the IL-7 receptor alpha chain (IL7Rα) and are unresponsive to stimulation with IL-7, indicating a loss of functional receptor. No pathogenic mutations were detected in the exons of IL7R in these patients; however, CpG sites in the IL7R promoter were hypermethylated in SIOD T cells. We propose therefore that the lack of IL7Rα expression, associated with hypermethylation of the IL7R promoter, in T cells and possibly their earlier progenitors, restricts T-cell development in SIOD patients.
Original language | English |
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Pages (from-to) | 355-365 |
Number of pages | 11 |
Journal | Clinical Immunology |
Volume | 161 |
Issue number | 2 |
DOIs | |
State | Published - 1 Dec 2015 |
Externally published | Yes |
Keywords
- CD127
- CpG
- IL7Rα
- Promoter DNA methylation
- SIOD
- T-cell immunodeficiency
All Science Journal Classification (ASJC) codes
- Immunology and Allergy
- Immunology