PT  - JOURNAL ARTICLE
AU  - Masahiro Koshiba
AU  - Diane L. Rosin
AU  - Nobuhide Hayashi
AU  - Joel Linden
AU  - Michail V. Sitkovsky
TI  - Patterns of A<sub>2A</sub> Extracellular Adenosine Receptor Expression in Different Functional Subsets of Human Peripheral T Cells. Flow Cytometry Studies with Anti-A<sub>2A</sub> Receptor Monoclonal Antibodies
DP  - 1999 Mar 01
TA  - Molecular Pharmacology
PG  - 614--624
VI  - 55
IP  - 3
4099  - http://molpharm.aspetjournals.org/content/55/3/614.short
4100  - http://molpharm.aspetjournals.org/content/55/3/614.full
SO  - Mol Pharmacol1999 Mar 01; 55
AB  - Signaling through A2A adenosine receptors (A2AR) regulates T lymphocyte expansion and modulates T cell receptor (TCR)-mediated effector functions in vitro. To understand the role of A2ARs in the regulation of immune response, we investigated the expression levels of this receptor in different functional lymphocyte subsets. Monoclonal anti-A2AR antibody was used to develop a flow cytometric assay to quantify the expression A2ARs on lymphocytes. We report that detectable levels of expression of A2ARs are much higher among T cells than B cells. More CD4+ than CD8+ T cells express A2ARs, but activation of T cells increases A2AR expression, predominantly in CD8+ T cells. No significant differences were found in the proportion of A2AR+ cells between CD8low and CD8high T cells or between TCR/CD3low and TCR/CD3high T cells. Studies of T helper cell subsets (TH1 and TH2) reveal that lymphokine-producing cells are much more likely to express A2ARs than are cells that do not produce lymphokines. These results suggest that A2ARs are variably expressed on T cell subsets and may regulate cytokine production in activated T lymphocytes. U.S. Government