Killing two birds with one stone may be possible for Dengue virus and Zika virus, two pathogens spread by the same mosquito and which come from the same viral family. The new study, a collaboration between Imperial College London and Washington University in St. Louis, displayed the protective effect of human antibodies from Dengue virus patients in mice models of Zika virus.
The same group of scientists first discovered in a past study that antibodies from the blood of people infected with Dengue virus were capable of targeting both Dengue and Zika. In their new study, they put the antibodies to the test.
Mice models of Zika infection were treated with Dengue antibodies. For three weeks, the researchers watched to see what happened to mice treated with those antibodies versus mice given no treatment. Mice given Dengue antibodies were less likely to die and lose weight, and researchers found significantly lower levels of virus in their brain and testes, two areas known to be packed with Zika virus during infection.
In addition to treating mice already infected with Zika virus, antibody treatment was also able to protect unborn mice pups in pregnant mice with the infection. For pregnant mice not treated with antibodies, 90 percent of their babies died. Only 10 percent of treated pregnant mice lost their babies.
"This paper shows for the first time that antibodies we had previously found to be effective against Dengue potently protect against Zika virus in mice and can treat the early stages of infection,” said Gavin Screaton, senior author of the study.
Screaton and his team used modified anti-EDE1 antibodies to prevent antibody-dependent enhancement (ADE), a phenomenon observed by researchers conducting similar studies. During ADE, antibodies successfully recognize and flag Zika virus, but immune cells fail to act on those flags and kill the virus.
What’s next? Researchers hope to make possible a new vaccine based on the Dengue antibodies that are capable of targeting both Dengue virus and Zika virus. Human clinical trials pending, the new vaccine could be the first to effectively target both pathogens.
"This group of antibodies is unique in being able to target Dengue and Zika,” Screaton explained. “The next step is to see whether they are effective in larger animal models, and potentially even humans."
The present study was published in the journal Nature Immunology.
Source: Imperial College London