LA JOLLA, Calif., Jan. 12 (UPI) -- Scientists at La Jolla Institute for Allergy and Immunology are using T cells to determine how the Zika virus interacts with the body and causes disease.
Researchers set out to understand why Zika persists in certain tissues even after the infection goes away, how the immune system fights the virus and prevents reinfection, and the likelihood of long-term complications.
The study found that CD8+ T cells work to control Zika and prevent it from becoming severe. CD8+ T cells are a group of T cells known to be cytotoxic and kill disease.
"Our study acknowledges the importance of T cells in an environment where most people are focused on antibodies," Sujan Shresta, Ph.D., an associate professor in the Center for Infectious Disease and senior author of the study, said in a press release. "For most diseases a strong antibody response is enough. But with Zika and dengue viruses a phenomenon known as antibody-dependent enhancements is a concern, which makes a strong T cell response really important."
The body's immune system typically creates antibodies based on previous, similar virus exposure to fight off a virus and give lifelong immunity. This is the case for many viruses such as influenza.
However, in dengue, different strains of the virus only provide protection against that specific type of virus. In dengue, pre-existing antibodies can actually increase the severity of a different strain of the virus in a subsequent infection.
Dengue and Zika have a similar makeup, so antibody-dependent enhancement is a concern for researchers in the Zika virus as well.
Shresta and Annie Elong Ngono, Ph.D., postdoctoral researcher and first author of the study, created a new mouse model for Zika that is used to study Zika-specific T cell responses and test vaccines by blocking receptor for interferon 1, or IFNAR, with IFNAR-blocking antibodies making the mice more prone to Zika.
They then analyzed T cells from Zika-infected mice to determine which parts of the virus produced a strong immune response. The results showed that CD8+ T cells are responsive in fighting Zika.
"Being able to track Zika-specific T cells across different model systems provides a valuable tool to better understand sexual and trans-placental transmission and how the virus crosses the blood-brain barrier and reaches other immune-privileged areas such as testes and the eye," Elong Ngono said in a press release.
The study was published in Cell Host & Microbe.