Surface expression of adenosine deaminase in mitogen-stimulated lymphocytes

Abstract

SUMMARYAdenosine deaminase (ADA) expression on the surface of mitogen-stimulated lymphocytes was studied by flow cytometry. The gate for lymphocytes was located by cell size (forward scatter), cytoplasmic complexity (side scatter) and by expression of the markers CD2, CD4, CD8 and CD 19. After mitogenic proliferation two populations appeared, one corresponding to non-stimulated cells, and the other consisting of larger cells which showed relatively high expression of adenosine deaminase on their surface. The increase was similar to that observed for CD71 expression, and paralleled the increase in 3H-thymidine incorporation. There was a correlation between ADA and CD71 expression (r = 0-92 for phytohaemagglutinin (PHA) and 0 97 for pokeweed mitogen (PWM)). These results suggest a role for ecto-adenosine deaminase in lymphocyte proliferation and/or triggering.

Study of the immunological profile towards Mycobacterium bovis antigens in naturally infected cattle

“…Our preliminary studies demonstrated that PPDB‐stimulated PBMC from M. bovis infected cattle exhibited increased cell size (>600 FSC) and granularity concomitant with an up‐regulation of IL‐2R, indicating that these changes are associated with immune cell activation. Similar findings have been reported in in vitro stimulated peripheral blood lymphocytes of rats (28) and humans (29). Consequently, in this study, cells were analyzed for their size (>600 FSC) as well as their surface marker expression in order to determine which cell population was activated after PPDB stimulation.…”

Cytokines regulate membrane adenosine deaminase on human activated lymphocytes

“…Thus, ecto-ADA was detected in Ͼ80% of T cells in some donors (nϭ14), whereas low or null percentages were detected in others (nϭ10). Ecto-ADA expression in lymphocytes analyzed with a pure or FITC-conjugated polyclonal anti-calf ADA Ab, which has been extensively described [6,12,20,27], presented an Ab-( Fig. 3B) and donor-dependent variability (nϭ37; range, 31-79 of ADA ϩ cells).…”

“…We have reported before that on treatment with mitogens or anti-CD3 antibodies, cell surface ADA expression increases [27]. Here, PHA-and anti-CD3-activated lymphocytes were used to study the effect of IL-12 on cell surface ADA expression.…”

Adenosine and Hemodialysis in Humans

“…2,73 In turn, lymphocyte activation causes MCAD activity to increase. 74,75 This can explain the increase in MCADA activity during HD. The low MCADA activity we found before HD may be the result of a tolerance phenomenon.…”