Methamphetamine increases the proportion of SIV-infected microglia/macrophages, alters metabolic pathways, and elevates cell death pathways: a single-cell analysis

Both drugs abuse and HIV infection continue to affect many indiviiduals. Both have untoward effects on the brain, and the two conditions often co-exist. In the brain, macrophages and microglia are infectable by HIV, and these cells are also targets for the effects of drugs of abuse such as the psychostimulant methamphetamine. In order to determine the interaction of HIV and methamphetamine we isolated microglia and macrophages from the brains of SIV-infected rhesus monkeys treated with methamphetamine and from SIV-infected monkeys who did not receive methamphetamine. Cells were subjected to single cell RNA sequencing and results analyzed by statistical and bioinformatic analysis. In the animals treated with methamphetamine, a significantly increased proportion of cells were infected by SIV. In addition, genes encoding functions in cell death pathways were increased, and the brain-derived neurotropic factor pathway was inhibited. The gene expression patterns in infected cells did not cluster separately from uninfected cells, but clusters comprised of cells from methamphetamine-treated animals differed in neuroinflammatory and metabolic pathways from those comprised of cells from untreated animals. Methamphetamine increases CNS infection by SIV and has adverse effects on both infected and uninfected microglia and brain macrophages, highlighting the dual and interacting harms of HIV infection and drug abuse on the brain. Microglia/Macrophages were isolated from the brains of 2 saline-treated (control), and 2 Methamphetamine treated (experimental), SIV-infected rhesus monkeys with encephalitis and cryopreserved. They were subsequently thawed, purified immunomagnetically for CD11b+ and then by flow cytometry for CD11b+ and Live cells, and then captured by the 10xGenomics platform subjected to single cell RNA sequencing