Authors: Kate Lovesey, Future Science Group
Researchers at Rush University Medical Center (IL, USA) recently published research in PLOS Pathogens, revealing the spread of HIV to peripheral organs via astrocytes, a type of brain cell, This was observed even when patients were undergoing combination antiretroviral therapy (cART), the standard treatment for HIV.
When an individual contracts HIV, the virus attacks the body’s immune system by infecting CD4 positive (CD4+) T cells. CART suppresses the HIV infection by preventing the HIV virus from destroying CD4+ T cells, allowing the body’s immune system to create an immune response and prevent the progression to AIDs.
However, individuals undergoing cART treatment have been reported to experience HIV-associated neurocognitive disorders, such as thinking and memory problems. This is believed to be due to astrocytes within the brain, which support communication between brain cells and maintain the blood-brain barrier, being infected with the HIV within 8 days of infection.
Lena Al-Harthi (Rush University Medical Center) and her research team transplanted HIV-infected or noninfected human astrocytes into the brains of immunodeficient mice, with the aim to understand whether HIV can move from the brain to peripheral organs.
The results demonstrated that the HIV virus was able to spread from transplanted HIV-infected astrocytes to CD4+ T cells in the brain, which then migrated and spread the infection to peripheral organs such as the spleen and lymph nodes. This was also apparent at lower levels when mice were undergoing cART. The interruption of cART resulted in a rebound of the HIV infection, as shown by the detection of HIV DNA/RNA in the spleen.
This research highlights the significant consequences of current HIV treatments and stresses the need for treatments to effectively target and eliminate reservoirs of HIV replication and reinfection.
“This study demonstrates the critical role of the brain as a reservoir of HIV that is capable of re-infecting the peripheral organs with the virus,” commented Jeymohan Joseph (National Institute of Mental Health, USA). “The findings suggest that in order to eradicate HIV from the body, cure strategies must address the role of the central nervous system.”
May Wong (National Institute of Neurological Disorders and Stroke, USA) explained: “HIV remains a major global public health concern, affecting 30–40 million people across the globe. To help patients, we need to fully understand how HIV affects the brain and other tissue-based reservoirs. Though additional studies that replicate these findings are needed, this study brings us another step closer towards that understanding.”
Sources: Lutgen V, Narasipura SD, Barbian H J et al. HIV infects astrocytes in vivo and egresses from the brain to the periphery. PLOS Pathogens (2020); www.eurekalert.org/emb_releases/2020-06/niom-bcc060820.php