OPIATE BINDING-SITES IN THE CELLULAR IMMUNE-SYSTEM - EXPRESSION AND REGULATION

The direct actions of opiates on the mammalian immune system depend on the existence of ligand binding sites either on the surface of the af fected cell or in the interior of the cell. With the cloning of variou s opiate receptors from neuronal tissue, numerous researchers have scr eened leukocyte cDNA libraries for the expression of these receptors w ith some positive results. However, the pattern of expression of neuro nal opiate receptors in the cellular immune system does not completely explain the biological action of opiates there. Several possibilities could account for this non-congruence including differential expressi on of the receptors as determined by such factors as cell population o r prior history of the cells; the existence of sequence modified versi ons of the neuronal receptors such that the amplification methods miss their presence; or the opiates act by a different, non-receptor mecha nism in the cellular immune system. (C) 1998 Elsevier Science B.V.