Delineate the effects of cannabidiol on type 1 IFN mediated inflammation during HIV infection

Abstract

Abstract Methods THP-1 and HMC3 cells were exposed to CBD/vehicle with and without stimulation with 2’3'-cGAMP (cGAMP), LPS, or PMA/ionomycin. qPCR was carried out to investigate the expression of interferon stimulatory genes (ISGs). RNA-Seq was performed to investigate gene expression in cGAMP-stimulated THP1 cells treated with vehicle/CBD. Western blot was performed with THP1 cells treated with vehicle/CBD then cGAMP to investigate the change of expression of phosphorylated STING (pSTING) and autophagy markers (LC3B, p62). Lastly, humanized mice (Hu mice) were constructed, infected with HIV-1 for 12 wks then treated with vehicle/CBD for 2 wks. Flow cytometry and qPCR were performed to examine changes in T cell activation and IFN-1 signaling in peripheral blood before and after CBD treatment. Results We observed significant down regulation of ISGs in stimulated, CBD-treated THP-1 and HMC3 cells. RNA-seq and qPCR confirmatory analysis showed that after stimulation IFN-1 genes were down regulated in CBD group compared to vehicle. We observed significantly higher LC3B/p62 and lower pSTING levels in CBD treated, stimulated cells as compared to vehicle treated, stimulated cells. Lastly, we observed a reduction in PD-1, Tim-3 and ISG MX1 expression in HIV-1 infected Hu mice treated with CBD. Conclusion We observed down regulation of ISGs in stimulated CBD treated cells. CBD treatment leads to induction of cellular autophagy, responsible for regulating/degrading pSTING after cGAS-STING pathway activation and lower ISGs as observed in our study. Lastly, we observed reduced ISGs, and decreased activation/exhaustion marker expression on T cells in HIV infected Hu mice after CBD treatment, suggesting the potential of CBD as an immunomodulator. Supported by grants from NIH/NIDA RFA-DA-20-022