Characterization of the mouse peripheral cannabinoid receptor (CB2) Promoter Region

• Published in: The FASEB journal 2007-04, Vol.21 (5), p.A288-A288
• Main Authors: Norrod, Allison G., Puffenbarger, Robyn A
• Format: Article
• Language: English
• ISSN: 0892-6638; 1530-6860
• DOI: 10.1096/fasebj.21.5.A288-b

The primary cannabinoid receptor of the immune system is CB2, and it is found on T cells, macrophages, and B cells. CB2 mRNA expression cycles as cells go through various stages of an immune response, from low in resident cells, to higher levels in responsive cells, and back to low expression in activated macrophages. To characterize the genetic regulation of CB2, we acquired a portion of mouse chromosome four containing exons 1A, 1B, and 2, with exon 2 containing all protein coding information. We are currently scanning this piece of genomic DNA to define possible transcription factor binding sites via in silico searches. To elucidate the activity of the CB2 promoter, we have made various deletion constructs of two putative promoter sites in a luciferase reporter system. In RAW264.7 macrophage‐like cells, a 707‐bp promoter construct upstream of exon 1A had activity of 3‐fold over the negative control, while an 839‐bp promoter construct upstream of exon 1B had activity 18‐fold over the negative control and a 610‐bp promoter construct had activity 15‐fold over the negative control. In addition, we have characterized the 5′‐end of the mouse CB2 mRNA with a modified 5′‐RACE (rapid amplification of cDNA ends) technique using RNA isolated from murine spleen and thymus. Our ultimate goal is to define the promoter elements responsible for CB2 expression in immune cells.