Indian researchers develop nanozymes that can block HIV reactivation
Bengaluru, Apr 1: Researchers at the Indian Institute of Science (IISc) here 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 Thursday.
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.
"The advantage is that the nanozymes are stable inside biological systems and do not mediate any unwanted reactions inside the cells," Mugesh said. "They are also quite easy to prepare in the lab."
There is currently no way to eliminate HIV from a patient's body completely, according to the statement.
Anti-HIV drugs are only successful in suppressing the virus; they fail at eradicating HIV from infected cells. The virus hides inside the hosts 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, it said.
A few years ago, Amit Singh's team developed a biosensor to measure oxidative stress levels in HIV-infected immune cells in real-time, it was stated.
"We found that to come out of latency and reactivate, HIV needs very little oxidative stress," he said.
One way to prevent reactivation is to keep the oxidative stress constantly low, which would "lock" the virus in a permanent state of latency.
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.
Around the same time, Mugesh's group published a study showing that nanowires made of vanadium pentoxide can efficiently mimic the activity of glutathione peroxidase.
Singh's lab, therefore, decided to collaborate with them.
The researchers prepared ultrathin nanosheets of vanadium pentoxide in the lab and treated HIV-infected cells with them.
The sheets were found to reduce hydrogen peroxide just as effectively as the natural enzyme and prevent the virus from reactivating.
"We found that these nanosheets were having some sort of direct effect where the expression of the host genes essential for virus reactivation is reduced," said Shalini Singh, first author and Research Associate at CIDR.
When the team treated immune cells from HIV-infected patients undergoing antiretroviral therapy (ART) with the nanozymes,latency was induced faster and subsequent reactivation was suppressed when therapy was stopped, indicating that combining the two was more effective, she added.
Combining ART with the nanozymes also has other advantages.
Some ART drugs can cause oxidative stress as a side effect, which can damage heart or kidney cells, Amit Singh said.
"Adding a nanozyme like this can help in reducing the side effects caused by such ART drugs." This can improve the quality of life of HIV patients undergoing treatment.
Although the nanozymes were found to be harmless to normal cells in lab tests, Mugesh said further studies are needed to understand if they can have other effects once they are introduced inside the body.
"Where will they go? Which organs will they enter? How long will they stay in the body? We need to look at all these aspects," he added.
Let the Truth be known. If you read VB and like VB, please be a VB Supporter and Help us deliver the Truth to one and all.
Sensex rises nearly 295 pts to close at 2025-high on foreign fund inflows, drop in crude prices
Mumbai, May 5 (PTI): Benchmark BSE Sensex climbed nearly 295 points to close at an over four-month high on Monday following sustained foreign fund inflows and a sharp correction in global crude oil prices.
Rising for the second in a row, the 30-share BSE barometer gained 294.85 points or 0.37 per cent to settle at 80,796.84, marking its highest close in 2025 so far. During the day, it jumped 547.04 points or 0.67 per cent to 81,049.03.
The NSE Nifty rose 114.45 points or 0.47 per cent to 24,461.15, its highest closing level in 2025.
Among Sensex firms, Adani Ports jumped 6.29 per cent amid reports that Gautam Adani's representatives met with US administration officials to seek the dismissal of criminal charges in a bribery probe. All other listed Adani group stocks, including Adani Enterprises, Adani Ports, Adani Power and Adani Green Energy, ended with sharp gains.
Bajaj Finserv, Mahindra & Mahindra, Eternal, Power Grid, ITC, Tata Motors, Asian Paints and Hindustan Unilever were also among Sensex gainers.
Among the laggards, Kotak Mahindra Bank tanked 4.57 per cent after the firm reported a 7.57 per cent decline in consolidated net profit to Rs 4,933 crore for the March quarter of FY25, primarily due to elevated stress in the microlending book.
State Bank of India, Axis Bank, Titan and IndusInd Bank were among the other losers.
State Bank of India dipped over 1 per cent after it reported an 8.34 per cent decline in consolidated net profit to Rs 19,600 crore for the January-March quarter compared to Rs 21,384 crore a year ago, impacted by a decline in net interest margins.
Foreign Institutional Investors (FIIs) bought equities worth Rs 2,769.81 crore on Friday, according to exchange data.
Foreign investors injected Rs 4,223 crore into the country's equity market in April, as they turned net buyers for the first time in three months amid a blend of favourable global cues and robust domestic fundamentals.
The inflow of foreign capital came last month following a back-to-back net outflow of Rs 3,973 crore in March, Rs 34,574 crore in February, and Rs 78,027 crore in January.
"The market has sustained its positive momentum, though the level of optimism has decreased. Continued foreign inflows and record GST collections in April indicate resilience in economic activity, fostering mild hopefulness. A weak dollar and a decline in oil prices have further bolstered FII sentiment.
"However, the market's momentum is moderating, with action shifting from broad-based movements to stock and sector-specific trends based on results," Vinod Nair, Head of Research, Geojit Investments Limited, said.
The BSE midcap gauge jumped 1.45 per cent and smallcap index climbed 1.23 per cent.
Among sectoral indices, services jumped the most 2.99 per cent, followed by oil & gas (1.95 per cent), auto (1.88 per cent), consumer discretionary (1.58 per cent), utilities (1.50 per cent) and energy (1.49 per cent).
Bankex emerged as the only loser.
As many as 2,563 stocks advanced while 1,459 declined and 180 remained unchanged on the BSE.
Markets in South Korea, Japan, China and Hong Kong were closed due to holidays.
European markets were trading on a mixed note.
US markets ended significantly higher on Friday.
Global oil benchmark Brent crude dropped 1.45 per cent to USD 60.40 a barrel.
The 30-share BSE benchmark gauge settled 259.75 points, or 0.32 per cent, higher at 80,501.99 on Friday. The Nifty eked out a marginal gain of 12.50 points, or 0.05 per cent, to settle at 24,346.70.
