EXPRESSION OF ALPHA-SUBUNIT GENES OF NICOTINIC ACETYLCHOLINE-RECEPTORS IN HUMAN-LYMPHOCYTES

Using immunohistochemistry and in situ hybridisation, we have studied whether alpha-subunits of nicotinic acetylcholine receptors (nAChRs) a re expressed in human lymphocytes. Cells were isolated by differential low speed gradient centrifugation from heparinised venous blood of 10 healthy volunteers. Receptor sites were visualised using the monoclon al antibody WF6 which specifically recognises alpha-isoforms from seve ral species including man. For visualisation of transcripts, digoxigen in-labelled cRNA probes for alpha 4- and alpha 3-subunits were used. I mmunostaining revealed specific binding of WF6 to isolated human lymph oid cells. The antibody was bound to most cells and concentrated prefe rentially in the perinuclear/surface region. The immunoreactivity rese mbled that observed after application of an antibody recognising CD4 s urface proteins which was conducted for comparison. In situ-hybridisat ion revealed that the alpha 4-subunit genes of nAChRs was expressed in lymphocytes of all probands. The alpha 3-subunit was found, with lowe r intensity than alpha 4-transcripts, in eight of the 10 individuals. Control incubations with corresponding sense cRNAs were negative. It i s concluded that human lymphocytes are able to express alpha-subunit g enes of nAChRs.