GS Paper - 3 Diseases

Researchers at the Indian Institute of Science (IISc) have developed artificial enzymes that they said can successfully block reactivation and replication of the Human Immunodeficiency Virus (HIV) in the host's immune cells. Made from vanadium pentoxide nanosheets, these "nanozymes" work by mimicking a natural enzyme called glutathione peroxidase that helps reduce oxidative stress levels in the host's cells, which is required to keep the virus in check, an IISc statement said on 1 April 2021.

What

  1. The study, published in 'EMBO Molecular Medicine, was led by Amit Singh, Associate Professor and Wellcome Trust-DBT India Alliance Senior Fellow at the Department of Microbiology & Cell Biology and Centre for Infectious Diseases Research (CIDR), and Govindasamy Mugesh, Professor at the Department of Inorganic and Physical Chemistry.
  2. The advantage is that the nanozymes are stable inside biological systems and do not mediate any unwanted reactions inside the cells. They are also quite easy to prepare in the lab. There is currently no way to eliminate HIV from a patient's body completely.
  3. Anti-HIV drugs are only successful in suppressing the virus; they fail at eradicating HIV from infected cells. The virus hides inside the host's immune cells in a "latent" state and stably maintains its reservoir. When the levels of toxic molecules such as hydrogen peroxide increase in the host's cells, leading to a state of increased oxidative stress, the virus gets "reactivated" - it emerges from hiding and begins replicating again.
  4. A few years ago, Amit Singh's team developed a biosensor to measure oxidative stress levels in HIV-infected immune cells in real-time. They found that to come out of latency and reactivate, HIV needs very little oxidative stress. One way to prevent reactivation is to keep the oxidative stress constantly low, which would "lock" the virus in a permanent state of latency.
  5. Enzymes such as glutathione peroxidase are essential for this process; they convert toxic hydrogen peroxide to water and oxygen. However, inducing the host cells to produce more quantities of these enzymes could disrupt the tightly regulated cellular redox machinery.