Characterization of the adenosine receptor profile of HL‐60 promyelocytes during maturation

Abstract

Adenosine has been shown to limit the symptoms of sepsis by inhibiting adhesion and oxidative burst in inflammatory cells after activating one or more adenosine receptors (A1R, A2AR, A2BR, and A3R). The purpose of this study is to characterize the changes in AR expressions profile during maturation and activation of neutrophils and macrophages. HL‐60 promyelocytes are precursor cells that were induced to differentiate into segmented neutrophils after a 5–9‐day incubation with 1.25% dimethyl sulfoxide. Culturing in the presence of 10–7 M 1, 25 dihyroxyvitamin D3 for 4–6 days promoted their maturation into macrophages. Maturation was confirmed by an increase in CD11b and a decrease in CD71 expression on PE‐labeled‐antibody stained cells using a flow cytometer. These cells were further analyzed for the expression of A1R and A3R using FITC‐labeled antibodies. Preliminary results suggest that maturation resulted in a 2‐fold and 4‐fold increase in expression of A1R and A3R receptors, respectively, as compared to HL‐60 cells. This expression pattern was also observed using a confocal microscope. These cells will be further characterized for expression of A1R and A3R receptors following activation using interferon‐gamma; and bacterial lipopolysaccharide. This will provide an in vitro model to study the role of adenosine and adenosine receptor expression changes during inflammation. (Source of support: USP)