Monoclonal antibodies to adenosine receptor by an auto-anti-idiotypic approach

BALB/c mice were immunized with adenosine 6-aminocaproyl-BSA. Hybridoma cell lines that secreted anti-idiotypic antibodies were identified by their binding to rabbit anti-adenosine antibodies, but not to normal rabbit immunoglobulins. Two such monoclonal antibodies, AA18 and AA21, also inhibited the binding of [3H]adenosine to the rabbit anti-adenosine antibodies. Therefore, both appeared to recognize idiotypic determinants on the rabbit anti-adenosine antibodies. The monoclonal antibodies AA18 and AA21 were established as being directed at adenosine receptors by the following criteria: (1) they bound to both rat and bovine brain membranes, and binding could be inhibited by CHA, an adenosine receptor agonist, (2) they inhibited the binding of [3H]R-PIA, an adenosine receptor agonist, to rat brain membranes; and (3) they inhibited the adenylate cyclase of rat brain membranes. The monoclonal antibodies were used to screen cDNA libraries in lambda gt11