Identification of Cellular Factors Responsible for the Viral Suppressive Effect of Cannabinoids by a Targeted Transcriptomic Analysis

Background: Recent studies have shown that cannabinoids restrict human immunodeficiency virus type 1 (HIV-1) replication in vitro and in vivo, although the molecular mechanism of inhibition is not known. The traditional approach of studying specific cannabinoid-modulated cellular processes that may restrict viral infection has been demonstrated to be an inconclusive method for revealing the underlying mechanism of viral suppression. To resolve this limitation, we have developed a targeted transcriptomic approach that capitalizes on recent studies of host-HIV-1 genomics and interactomics to identify cannabinoid-responsive cellular factors involved in modulating HIV-1 replication.

Methods: Human T cell lines were treated with a panel of cannabinoids prior to infection with HIV-1. Quantitative PCR was used to identify the target cell/cannabinoid combinations that resulted in decreased HIV-1 replication. The transcriptomes of cannabinoid-treated cells were characterized by RNA-Seq. A panel of focused genes algorithmically compiled from host-HIV-1 genomic and interactomic studies was used to identify differentially expressed genes that interact with HIV-1. An integrated network analysis of the identified genes was utilized to reveal specific host factors that are recruited in HIV-1 replication and affected by cannabinoids.

Results: Among the cell/cannabinoid combinations, Jurkat/CP55,940 and Jurkat/JWH-210 exhibited the most significant viral suppressive effects. Treatment of cells with CP55,940 or JWH-210 resulted in the modulation of 3311 and 1708 genes, respectively; of these, 34 and 11 genes interact with HIV-1. Network analysis based on the abovementioned cannabinoid-modulated HIV-1-associated genes revealed that host transcription and apoptotic processes were affected. Specifically, neurofibromin 2 and heat shock 70 kDa protein 6 genes were identified by the networks and may be involved in the cannabinoid-mediated viral suppressive activity.

Conclusion: We have developed an innovative method capable of negotiating through complex transcriptomic profiles and have successfully identified specific host factors and cellular pathways associated with both cannabinoid signaling and HIV-1 replication. This study serves as the entrée for future characterizations of the underlying mechanisms of cannabinoid-mediated viral suppression.