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Cytokines regulate membrane adenosine deaminase on human activated lymphocytes
Author(s) -
Cordero Oscar J.,
Salgado Francisco J.,
FernándezAlonso Carmen M.,
Herrera Carolina,
Lluis Carmen,
Franco Rafael,
Nogueira Montserrat
Publication year - 2001
Publication title -
journal of leukocyte biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.819
H-Index - 191
eISSN - 1938-3673
pISSN - 0741-5400
DOI - 10.1189/jlb.70.6.920
Subject(s) - adenosine deaminase , biology , microbiology and biotechnology , adenosine , extracellular , cytokine , flow cytometry , t cell , cell , purinergic signalling , lymphocyte , receptor , immune system , immunology , adenosine receptor , biochemistry , agonist
CD26 is a lymphocyte marker that can anchor adenosine deaminase (ADA) on the T cell surface. We found that ADA is regulated by cytokines on the cell surface during T cell activation. By means of flow cytometry, immunofluorescence, and immunoblotting techniques, we found that interleukin (IL)‐2 and IL‐12 up‐regulate ecto‐ADA and CD26 expression. In clear contrast, IL‐4 led to down‐regulation of lymphocyte surface ADA without modifying the level of CD26. Moreover, neither circulating ADA transcription nor mRNA translation was regulated by cytokines. These results, along with absence of total‐ADA modulation, the variable amount of ADA found in purified plasma membranes, and the different effect of Brefeldin A on the surface presence of ADA and CD26 indicated that cytokines regulate the translocation of ADA towards the cell surface through a mechanism not involving CD26. Ecto‐ADA protected activated lymphocytes from the toxic effects of extracellular adenosine. Therefore, this cell surface ADA control might constitute part of the fine immunoregulatory mechanism of adenosine‐mediated signaling through purinergic receptors in leukocytes.