Dr. Barbara Lee-Faubert Kaplan

The focus of my research is to understand the mechanism by which cannabinoid compounds suppress T cell function. Plant-derived cannabinoid compounds (i.e., those derived from marijuana) include both psychoactive (such as delta-9-tetrahydrocannabinol) and non-psychoactive (such as cannabinol and cannabidiol) compounds. The ability of these compounds to exhibit psychoactive properties correlates with their binding affinity to one of the cloned cannabinoid receptors, CB1. Despite differences in cannabinoid receptor binding affinity and magnitude of psychoactive properties, many of the plant-derived cannabinoid compounds are immunosuppressive. Indeed, we have shown that the T cell growth factor interleukin-2 is sensitive to suppression by these compounds. The mechanism by which cannabinoids suppress interleukin-2 is at the level of transcription and is mediated, in part, through suppression of several transcription factors, including AP-1, NFAT and NF-kB. Importantly, the direct T cell suppression does not involve either one of the two known cannabinoid receptors (CB1 or CB2). Currently, I am assessing the ability of one non-psychoactive, plant-derived compund, cannabidiol, to suppress T cell function in two different in vivo models.