Cannabis use may limit HIV tissue reservoirs in ART-treated men
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Key takeaways:
- The odds of tissues harboring HIV DNA and viral DNA copies in those tissues were significantly lower in people who used cannabis.
- Levels of proinflammatory cytokines were also significantly lower.
A postmortem study of men with HIV who were being treated with ART revealed that cannabis use is associated with reduced sizes and inflammatory cytokine expression of subtype C HIV-1 reservoirs.
“[This study was prompted] due to an urgent need to eliminate potential HIV tissue reservoirs in infected and ART-treated individuals to prevent a rebound of HIV when people are off ART, to achieve true HIV cure,” Charles Wood, PhD, cancer crusader professor in the department of Interdisciplinary Oncology and associate director of basic science at the Stanley S. Scott Cancer Center, told Healio.
“Numerous prior attempts [at eliminating latent HIV reservoirs], such as using HDAC inhibitors, have mostly been unsuccessful. Novel approaches need to be developed,” Wood said.
He added that although it is controversial, cannabis has been shown to reduce simian immunodeficiency viral load in infected macaques because of its potential anti-inflammatory effects.
“We have decided that in order to test this directly on humans, we conducted the study through studying autopsy tissues of HIV-infected individuals, either on cannabis users or nonusers,” Wood said.
The researchers systematically collected postmortem brain tissues — including tissue from the frontal lobe, parietal lobe, temporal lobe, occipital lobe, hippocampus, cerebellum, basal ganglia and choroid plexus — as well as peripheral tissues and plasma samples from 20 men with subtype C HIV and with suppressed viral load in Zambia. Ten of these men tested positive for cannabis use.
The researchers then compared viral burden and inflammatory cytokine in tissues among people with HIV and suppressed viral load who used cannabis and those who did not.
Overall, the study demonstrated that the odds of tissues harboring HIV DNA and the viral DNA copies in those tissues were significantly lower in people who used cannabis. Specifically, the data showed that tissues of people using cannabis showed 0.16 times, or sixfold lower odds, of harboring HIV long terminal repeats (LTR) DNA (95% CI, 0.08-0.32) and 0.07 times, or 14-fold lower odds, of harboring all 3 LTR/gag proteins/env proteins DNAs (95% CI, 0.03-0.17).
The researchers also found that the transcription levels of proinflammatory cytokines IL-1 beta and IL-6 in lymphoid and appendix tissues of people using cannabis were also significantly lower, as were messenger RNA levels of IL-1 beta and IL-6 in appendix tissues. The team also analyzed cytokine mRNA levels in tissues and found very low levels of viral DNA and RNA.
Taken together, the researchers wrote that these results indicate that cannabis use is associated with “reduced proinflammatory cytokine expression but did not alter anti-inflammatory cytokine expression in subtype C HIV lymphoid tissue reservoirs that harbored most of proviruses.”
“Cannabis use may have potential positive effects in limiting HIV tissue reservoirs and reduced the number of copies of residual HIV in antiviral treated aviremic individuals,” Wood said. “However, the circulating HIV subtype in Zambia and in sub-Saharan Africa are subtype C HIV, which is different from the most common strains in the West. Thus, further studies need to determine whether this holds true for other HIV subtypes.”
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