Down regulation of beta adrenergic receptor expression on B cells by activation of early signals in alloantigen induced immune response

A GENARO; GA CREMASCHI; G GORELIK; L STERIN-BORDA; E BORDA

NEUROIMMUNOMODULATION.

S. Karger Medical and Scientific Publishers

Lugar: Switzerland; Año: 2000 vol. 8 p. 114 - 121

1021-7401

Previously we described a decrease in beta-adrenergic receptor expression in B lymphocytes as a consequence of in vivo alloimmunization. This decrease correlates with the highest response of alloantibody production by B cells. In the present report we examined the participation of intracellular signals elicited after alloimmune stimulation. We showed that in vitro stimulation of B cells with mitomycin C-treated allogenic cells induced a reduction in the number of beta-adrenoceptors. This downregulation correlated to changes in basal and in isoproterenol-stimulated intracellular cAMP levels. We found that calcium mobilization and protein kinase C activation triggered after direct allogenic stimulation and/or by the action of T cell-soluble factors induced the reduction in beta-adrenoceptor sites. These findings could be of interest to understand the neuroendocrine mechanisms involved in the regulation of B cell activation. Copyright 2000 S. Karger AG, Basel