Human adenosine receptor bearing lymphocytes: Enumeration, characterization, and distribution in peripheral blood lymphocytes

Abstract

Ox red blood cells (Ox-RBC) which were coated with adenosine covalently linked to human serum albumin (HSA) formed rosettes with a minor population of human peripheral blood lymphocytes (PBL) 2 2 Abbreviations used: PBL, peripheral blood lymphocytes; PBS, phosphate-buffered saline, pH 7.2; cAMP, adenosine 3′,5-monophosphate; HSA, human serum albumin; RBC, red blood cells; ADRL, adenosine receptor lymphocytes; EHNA, erythro-9(2-hydroxy-3-nonyl) adenine. . An average of 10.7% of total circulating PBL were capable of forming adenosine-specific rosettes and the majority of these cells (84%) were found in the spontaneous sheep E-rosetting cell population. The lymphocyte receptor was specific for the adenosine moiety in that HSA-coated Ox-RBC alone, or guanosine-HSA-coated Ox-RBC bound less that 2% of total PBL. In addition, the binding of the adenosine-HSA-coated Ox-RBC to the lymphocytes could be competitively inhibited by adenosine-HSA, adenosine, and low levels of theophylline but not by inosine or guanosine. The majority of the lymphocytes forming the adenosine-HSA rosettes appeared as small resting lymphocytes when examined by electron microscopy.