Role of the peripheral benzodiazepine receptor sites in modulation of the immune response

The benzodiazepine/GABA receptor chloride ionophore complex ("supramolecular complex") is thought to mediate the anti-anxiety effects of benzodiazepines (BZs). Studies indicate that the supramolecular complex may be important in neural regulation of immunity. The objective of this study was to determine if receptors not associated with the supramolecular complex (in the central nervous system) have a role in regulation of immunity. Murine B cells were found to bind the peripheral ligand Ro 5-4864 47% more than T cells. Ro 5-4864 inhibited Con-A-stimulated T cell proliferation by 30%. Natural killer cell activity was also suppressed. These effects were partially blocked by the peripheral antagonist PK 11195 indicating that the suppression observed with Ro 5-4864 was specific and that the peripheral BZ receptor sites on immune cells may have a role in immune modulation.