Metabolites from apoptotic thymocytes inhibit thymopoiesis in adenosine deaminase-deficient fetal thymic organ cultures.

Published

Journal Article

Murine fetal thymic organ culture was used to investigate the mechanism by which adenosine deaminase (ADA) deficiency causes T-cell immunodeficiency. C57BL/6 fetal thymuses treated with the specific ADA inhibitor 2'-deoxycoformycin exhibited features of the human disease, including accumulation of dATP and inhibition of S-adenosylhomocysteine hydrolase enzyme activity. Although T-cell receptor (TCR) Vbeta gene rearrangements and pre-TCR-alpha expression were normal in ADA-deficient cultures, the production of alphabeta TCR(+) thymocytes was inhibited by 95%, and differentiation was blocked beginning at the time of beta selection. In contrast, the production of gammadelta TCR(+) thymocytes was unaffected. Similar results were obtained using fetal thymuses from ADA gene-targeted mice. Differentiation and proliferation were preserved by the introduction of a bcl-2 transgene or disruption of the gene encoding apoptotic protease activating factor-1. The pan-caspase inhibitor carbobenzoxy-Val-Ala-Asp-fluoromethyl ketone also significantly lessened the effects of ADA deficiency and prevented the accumulation of dATP. Thus, ADA substrates accumulate and disrupt thymocyte development in ADA deficiency. These substrates derive from thymocytes that undergo apoptosis as a consequence of failing to pass developmental checkpoints, such as beta selection.

Full Text

Duke Authors

Cited Authors

  • Thompson, LF; Van de Wiele, CJ; Laurent, AB; Hooker, SW; Vaughn, JG; Jiang, H; Khare, K; Kellems, RE; Blackburn, MR; Hershfield, MS; Resta, R

Published Date

  • November 2000

Published In

Volume / Issue

  • 106 / 9

Start / End Page

  • 1149 - 1157

PubMed ID

  • 11067867

Pubmed Central ID

  • 11067867

International Standard Serial Number (ISSN)

  • 0021-9738

Digital Object Identifier (DOI)

  • 10.1172/JCI9944

Language

  • eng

Conference Location

  • United States