Delta-9-Tetrahydrocannabinol Inhibits the Splenocyte Proliferative Response to Herpes Simplex Virus Type 2

Abstract

The present investigation was undertaken to determine the effect of in vivo Delta-9-tetrahydrocannabinol (Delta-9-THC) treatment on immune responsiveness to secondary exposure to herpes simplex virus type 2 (HSV2) antigens in vitro. A splenocyte proliferative assay, employing HSV2-infected mouse embyro fibroblasts as target cells, was used to measure immune responsiveness. Administration of 50mg/kg or 100mg/kg Delta-9-THC to B6C3F1 mice in concert with HSV2 infection resulted in suppression of the proliferative response to HSV2 cell-surface antigens expressed on virus-infected mouse embryo fibroblasts. Similarly, in vifero treatment of HSV2-infected cells with Delta-9-THC (10 ⁷M to ⁵M) resulted in a dose-dependent suppression of proliferative responsiveness of splenocytes of non-drug-treated HSV2-sensitized mice. These results suggest that Delta-9-THC inhibits immune responsiveness of B6C3F1 mice to homotypic challenge with HSV2. This inhibition may be resultant of drug action on both effector immunocytes and target HSV2 antigen-bearing cells.