HIV-infected cannabis users have lower circulating CD16 monocytes and IFN-γ-inducible protein 10 levels compared with nonusing HIV patients.
Chronic immune activation and elevated numbers of circulating activated monocytes (CD16) are implicated in HIV-associated neuroinflammation. The objective was to compare the level of circulating CD16 monocytes and IFN-γ-inducible protein 10 (IP-10) between HIV-infected cannabis users (HIVMJ) and noncannabis users (HIVMJ-) and determine whether in-vitro Δ-Tetrahydrocannabinol (THC), a constituent of cannabis, affected CD16 expression as well as IP-10 production by monocytes. The levels of circulating CD16 monocytes and IP-10 from HIVMJ- and HIVMJ donors were examined. In-vitro experimentation using THC was performed on primary leukocytes isolated from HIV-MJ-, HIVMJ- and HIVMJ donors to determine if THC has an impact on CD16 monocyte and IP-10 levels. Flow cytometry was used to measure the number of blood CD16 monocytes and plasma IP-10 from HIVMJ- and HIVMJ donors. Peripheral blood mononuclear cells were isolated from HIV-MJ- and HIV (MJ- and MJ) donors for in-vitro THC and IFNα treatment, and CD16 monocytes and supernatant IP-10 were quantified. HIVMJ donors possessed a lower level of circulating CD16 monocytes and plasma IP-10, compared with HIVMJ- donors. Further, monocytes from HIVMJ donors were unable to induce CD16 expression when treated with in-vitro IFNα, whereas HIV-MJ- and HIVMJ- donors displayed pronounced CD16 induction, suggesting anti-inflammatory effects by cannabis. Lastly, in-vitro THC treatment impaired CD16 monocyte transition to CD16 and monocyte-derived IP-10. Components of cannabis, including THC, may decelerate peripheral monocyte processes that are implicated in HIV-associated neuroinflammation.