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

GENARO A.M.; CREMASCHI GA; GORELIK GJ; STERIN-BORDA L; BORDA E

NEUROIMMUNOMODULATION.

KARGER

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.