In Brazil, research shows that Zika can take over immune system

Researchers from the Federal University of Rio de Janeiro (UFRJ) have sequenced the full-length genome of a Zika virus and found that the Zika virus can block an important part of the host's immune system. This discovery was made by the gene mapping of the virus circulating in the state of Pernambuco, which was sequenced for the first time by researchers from the Oswaldo Cruz Foundation (FIOCRUZ) from Pernambuco in partnership with professionals from the University of Glasgow, from the UK.

The article with the results was published this week in PLOS Neglected Tropical Diseases journal. The gene was sequenced from a sample collected from a patient infected in 2015 at the beginning of the outbreak.

According to FIOCRUZ researcher Rafael França, who is one of those responsible for the research, a small part of the Zika gene can inhibit an important part of the immune system, responsible for fighting viral infections and preventing virus replication: the interferon. "If Zika blocks the production of interferon, the virus will be able to replicate, then it will strengthen the infectious process, and the cell will be even more infected. It will become more aggressive," said França.

This characteristic is found in other viruses from the same family like the dengue virus, but according to the researcher "[Zika] virus has an evolutionary advantage when compared with the dengue virus."

The discovery should help other researchers develop possible therapeutic methods, since they had identified a characteristic that can help combat the virus. "We can interfere with the gene that, because of the virus, blocks the immune system, and try to prevent the virus' effects as a form of therapy," França explained.

Mutant virus

With the mapping, researchers have identified that the Zika virus in Pernambuco is similar to the virus found in Asia, as other researches had already suggested. They also found that the genetic signature is the same as isolated Zika virus from other regions of Brazil.

Despite being similar, the sequenced Zika virus suffered mutations compared with the virus found in Asia. França also said that it is still early to know whether these changes could be related to a greater number of syndrome associated with congenital Zika virus infection, identified in Pernambuco.

"We have not sequenced the full-length genome of Zika from other places. After other researchers sequence the virus and read the genome, we will be able to compare them," he explained.

In the next phase of the research, which has already begun, they will study the evolution of the virus until now, based on other gene mapping from more recent samples.

Translated by Amarílis Anchieta