Zika virus may infect, kill human brain stem cells

A Zika virus-laden mosquito bite may infect and kill a type of brain cell, vital for the development of the brain, says a new study conducted in lab grown human cells.

The infected stem cells then become the havens for the viral reproduction and thus result in complete cell death and or disruption of the cell growth, the study said. 

"We are trying to fill the knowledge gap between the infection and potential neurological defects," said first author Hengli Tang, virologist from the Florida State University in the US.

The study is important because it shows the mechanism by which the virus works in certain cells.

And knowing the mechanism of the virus could eventually allow researchers to design strategies to prevent the Zika virus from infecting different types of cells in the brain, the researchers explained.

"What we show is that the Zika virus infects neuronal cells in dish that are counterparts to those that form the cortex during human brain development. We still don't know at all what is happening in the developing foetus,” said one of the researchers Hongjun Song, neuroscientist and stem cell biologist, at the Johns Hopkins University.

These findings may correlate with disrupted brain development, but direct evidence for a link between Zika virus and microcephaly is more likely to come from clinical studies, the researchers noted.

Babies born with microcephaly have underdeveloped brains and may face severe, lifelong developmental disabilities.

For the study, published in the journal Cell Stem Cell, the researchers used human stem cells that were engineered to produce cells similar to those that give rise to the brain's cortex in human embryos. 

As humans are typically infected by the Zika virus carried by mosquitoes, the scientists also grew the virus in mosquitoes to imitate a real-life scenario in which the virus is carried in a mosquito before infecting a human. 

The researchers, then, applied the Zika virus to the lab-grown brain cells and found that the virus infected and spread through a plate of these cells within a span of three days. Also, it killed the cells or disrupted their growth.