Schematic representation of the experiment. Credit: Pal, V. K. et al.
Researchers have found that hydrogen sulfide gas could be used to suppress replication of latent HIV in specific immune cells isolated from patients1.
Treating the immune cells with the gas reduced the possibility of the latent virus rebounding and causing infection.
The gas treatment could potentially be used in combination with anti-HIV drugs to lock the viruses permanently in a latent stage, say a team of researchers at the Indian Institute of Science in Bangalore.
Hydrogen sulfide modulates inflammatory response, metabolism of specific immune cells and antimicrobial activity in humans. However, its role in HIV infection remains unknown.
The scientists, led by Amit Singh, set out to investigate the relationship between hydrogen sulfide gas and HIV infection by studying specific immune cells containing latent viruses from patients with HIV.
The researchers treated the infected immune cells with a specific agent that reactivated the latent viruses. This depleted levels of hydrogen sulfide gas, resulting in oxidative stress and inflammation which impaired the functions of mitochondria.
Next, they treated the inflamed immune cells with a small molecule that releases hydrogen sulfide gas. This elevated hydrogen sulfide levels in the cells and reduced oxidative stress by activating specific antioxidant genes and pathways. It also restored the functions of mitochondria.
A four-week exposure to a combination of low-concentration hydrogen sulfide and anti-HIV drugs did not produce any toxic effects on the immune cells, says Singh.
