Biomedical subjects

Liang Nong

Publications and source records attributed to Liang Nong.

3 recordsLinked to original sources

PubMed2004

Cannabinoid receptors and T helper cells.

We have reported that injection of marijuana cannabinoids, such as Delta(9)-tetrahydrocannabinol (THC), into mice, followed by infection with Legionella pneumophila (Lp), suppresses the development of cell-mediated immunity T helper 1 (Th1) activity. These effects are accompanied by suppression of interleukin (IL)-12 and interferon (IFN) gamma production and enhancement of IL-4 production suggesting THC-induced T helper cell biasing. In the current report, other T helper cell biasing mechanisms were studied. Mice were injected with THC followed 18 h later by a challenge infection with Lp. Two-hour post-infection, spleens were removed and analyzed for mRNA to either IL-12Rbeta2 or GATA3 gene products. The results showed that THC suppressed IL-12Rbeta2 but increased GATA3. Receptor antagonists for CB1 (SR141716A, SR1) and CB2 (SR144528, SR2) were also injected to analyze the involvement of cannabinoid receptors. It was determined that SR1 attenuated the THC suppression of IL-12Rbeta2, while SR2 attenuated the increase in GATA3 mRNA. These results suggest that THC suppresses Th1 biasing activity such as IL-12Rbeta2 by a CB1 mediated mechanism and enhances the Th2 biasing activity, GATA3, by a CB2 mechanism. This dichotomy of receptor involvement might result from differential expression and/or signaling function of CB1 and CB2 on Th1 and Th2 cells.

Animals↗

PubMed2003

The cannabinoid system and immune modulation.

Studies on the effects of marijuana smoking have evolved into the discovery and description of the endocannabinoid system. To date, this system is composed of two receptors, CB1 and CB2, and endogenous ligands including anandamide, 2-arachidonoyl glycerol, and others. CB1 receptors and ligands are found in the brain as well as immune and other peripheral tissues. Conversely, CB2 receptors and ligands are found primarily in the periphery, especially in immune cells. Cannabinoid receptors are G protein-coupled receptors, and they have been linked to signaling pathways and gene activities in common with this receptor family. In addition, cannabinoids have been shown to modulate a variety of immune cell functions in humans and animals and more recently, have been shown to modulate T helper cell development, chemotaxis, and tumor development. Many of these drug effects occur through cannabinoid receptor signaling mechanisms and the modulation of cytokines and other gene products. It appears the immunocannabinoid system is involved in regulating the brain-immune axis and might be exploited in future therapies for chronic diseases and immune deficiency.

Animals↗

PubMed2002

Altered cannabinoid receptor mRNA expression in peripheral blood mononuclear cells from marijuana smokers.

We studied, using RT-PCR, the relative expression of cannabinoid receptor (CBR) mRNA in peripheral blood mononuclear cells (PBMC) from different donor groups. Cells from normal donors expressed a CB2 mRNA level threefold higher than CB1 across all age, gender or ethnicity groups, and amplicons were of the same size in all donors. However, cells from marijuana users expressed higher levels of CBR mRNA, but with a preserved CB1/CB2 ratio of 1:3. CBR gene products were also studied following short-term mitogen activation in vitro. CB1 expression decreased following mitogen stimulation when compared to the time-matched medium only cells while the expression of CB2 mRNA remained unchanged. These studies suggest that marijuana smoking and immune activation can alter the basal levels of CB1 and CB2 in PBMCs.

Adult↗