Genhong Cheng’s Group Discovered an Immune Molecule that Protects Against Zika Virus Infection
Source:Genhong Cheng
2017-04-28
A molecule naturally produced by the immune system protects mice and monkeys against Zika virus infection, an international team of researchers has found. Administering the molecule, called 25-hydroxycholesterol or 25HC, to pregnant mice reduced Zika virus infection in the fetal brain and protected against Zika-induced microcephaly. The work was supported in part by CAMS Initiative for Innovative Medicine, National Science and Technology Major Project for “Significant New Drugs Innovation and Development”, NSFC (China) and National Institutes of Health (USA).

Previous experiments suggested that 25HC has broad antiviral activity. In the new study, researchers led by Genhong Cheng, Ph.D., of the Center of Systems Medicine, Chinese Academy of Medical Sciences, investigated whether 25HC has a protective effect against Zika virus, for which there is no licensed antiviral drug or vaccine. Their initial cell culture experiments indicated that 25HC can block Zika and related viruses, including dengue and yellow fever viruses, from entering cells.

The researchers next established that 25HC is protective in mouse and monkey models of Zika virus infection. For example, mice treated with 25HC before being infected with Zika virus had lower blood levels of the virus than mice given a placebo. The 25HC-treated mice were more likely to survive the infection, and the surviving mice had no clinical symptoms. Monkeys given 25HC before Zika virus infection had reduced levels of virus in blood and urine and did not develop fever in response to infection.

To determine whether 25HC could protect against Zika-induced microcephaly, the researchers treated pregnant mice with 25HC or placebo before and for five days after embryos were infected with Zika virus. Treatment with 25HC decreased levels of Zika virus in fetal brain tissue and greatly reduced the occurrence and severity of developmental defects, including small fetal brain size. The researchers did not observe any adverse effects on pregnancy or birth related to 25HC treatment in the animals.

The authors conclude that 25HC shows promise as a natural agent that can combat a broad array of viruses, including Zika virus. Additional preclinical research is needed before establishing whether 25HC is protective in humans against Zika virus infection and associated birth defects.

“We urgently need to develop new strategies to treat and prevent Zika virus infection and other emerging viral diseases. Identifying immune system components with broad antiviral activity and elucidating how they work is a promising step in that direction.” ----NIAID Director Anthony S. Fauci, M.D.

ARTICLE: C Li, YQ Deng, S Wang, F Ma et al. 25-Hydroxycholesterol protects host against Zika virus infection and its associated microcephaly in mouse model. Immunity DOI: XXXX (2017).