First Author | Van De Wiele CJ | Year | 2002 |
Journal | J Clin Invest | Volume | 110 |
Issue | 3 | Pages | 395-402 |
PubMed ID | 12163459 | Mgi Jnum | J:107216 |
Mgi Id | MGI:3620422 | Doi | 10.1172/JCI15683 |
Citation | Van De Wiele CJ, et al. (2002) Adenosine kinase inhibition promotes survival of fetal adenosine deaminase-deficient thymocytes by blocking dATP accumulation. J Clin Invest 110(3):395-402 |
abstractText | Thymocyte development past the CD4(-)CD8(-) stage is markedly inhibited in adenosine deaminase-deficient (ADA-deficient) murine fetal thymic organ cultures (FTOCs) due to the accumulation of ADA substrates derived from thymocytes failing developmental checkpoints. Such cultures can be rescued by overexpression of Bcl-2, suggesting that apoptosis is an important component of the mechanism by which ADA deficiency impairs thymocyte development. Consistent with this conclusion, ADA-deficient FTOCs were partially rescued by a rearranged T cell receptor beta transgene that permits virtually all thymocytes to pass the beta-selection checkpoint. ADA-deficient cultures were also rescued by the adenosine kinase inhibitor 5'-amino-5'-deoxyadenosine (5'A5'dAdo), indicating that the metabolite responsible for the inhibition of thymocyte development is not adenosine or deoxyadenosine, but a phosphorylated derivative of an ADA substrate. Correction of ADA-deficient FTOCs by 5'A5'dAdo correlated with reduced accumulation of dATP, implicating this compound as the toxic metabolite. In ADA-inhibited FTOCs rescued with a Bcl-2 transgene, however, dATP levels were superelevated, suggesting that cells failing positive and negative selection continued to contribute to the accumulation of ADA substrates. Our data are consistent with dATP-induced mitochondrial cytochrome c release followed by apoptosis as the mechanism by which ADA deficiency leads to reduced thymic T cell production. |