Altered beta-adrenoceptor function associated to protein kinase C activation in hyperproliferative T lymphocytes

beta -Adrenoceptor (beta AR) expression and function as well as its modulat ion via intracellular transduction signals, were analyzed on the T cell lym phoma BW5147. Independently to the kinetic of proliferation and relative to the number of receptors displayed in normal T lymphocytes, BW5147 cells di splayed a decreased number of beta AR, uncoupled to adenylate cyclase, but coupled to protein kinase C stimulation. This last effect was impaired by a beta -antagonist and by blockers of the enzymatic pathways involved in T l ymphocyte proliferation, inducing a recovery of beta AR sites. Down-regulat ion of beta AR would implicate the loss of a negative neuroimmune control m echanism for lymphocyte proliferation. The coupling of the remaining sites to a positive signal for cellular activation, would contribute to establish an hyperproliferative state. (C) 2000 Elsevier Science B.V. All rights res erved.