Lack of detectable defect in DNA double-strand break repair and DNA-dependent protein kinase activity in radiosensitive human severe combined immunodeficiency fibroblasts
✍ Scribed by Nathalie Nicolas; Nicholas J. Finnie; Marina Cavazzana-Calvo; Dora Papadopoulo; Françoise Le Deist; Alain Fischer; Stephen P. Jackson; Jean-Pierre de Villartay
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 503 KB
- Volume
- 26
- Category
- Article
- ISSN
- 0014-2980
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✦ Synopsis
The initial step of the V(D)J recombination occurs through the generation of a DNA double-strand break (dsb). Defects in the DNA-dependent protein kinase complex (DNA-PK) result in an inability to perform either V(D)J recombination or any dsb repair effectively. The human autosomal T-B-severe combined immunodeficiency (SCID) condition is characterized by an absence of both B and T lymphocytes and is accompanied in some patients by an increase in y-ray sensitivity (T-B-RS SCID) comparable to that found in mouse SCID cells. We show here that cells from six patients with T-B-RS SCID had normal DNA-dsb repair kinetics. Furthermore, DNA-PK activity was present in extracts from these human T-B-RS SCID fibroblasts. We therefore conclude that some human T-B-RS SCID disorders are not caused by a defect in an essential DNA-PK component.