New research indicates that the skin serves as a primary location for immune surveillance against dengue, a mosquito-borne viral disease. This discovery could aid in the creation of more effective dengue vaccines. Dengue affects an estimated 390 million people and causes approximately 20,000 deaths globally each year.
New research indicates that the skin serves as a primary location for immune surveillance against dengue, a mosquito-borne viral disease.
Key Findings
A study conducted by the University of Bristol in collaboration with Duke-NUS Medical School, Singapore, observed that T-cell responses during dengue virus infection are more concentrated in the skin than in the blood. The findings were published in Science Advances.
The research revealed that individuals experiencing milder illness had a greater presence of cytotoxic T cells in their skin and blood compared to those who required hospital admission. These cells, which are responsible for eliminating virus-infected cells, are linked to protective immunity against the disease.
The team examined T cells in the skin and blood of 73 dengue patients and 10 healthy volunteers. During infection, the skin contained a higher number of active T cells, including both CD4+ and CD8+ T cells, than the blood. Skin-based CD8+ T cells displayed characteristics indicating their development into long-lasting 'resident' immune cells that remain in the tissue, providing an initial defense against reinfection.
Individuals who did not require hospitalization showed elevated levels of CD8+ T cells in both their skin and blood, suggesting these cells may offer protection against severe illness. These observations underscore the potential benefit of developing vaccines capable of enhancing these skin-resident T cells to improve dengue protection.
Expert Statement
Dr. Laura Rivino, Associate Professor in Immunology at the University of Bristol and corresponding author, stated the critical need to identify immune responses that protect against infection and severe disease as dengue expands globally. She noted that while dengue infection begins in the skin after a mosquito bite, the immune response at this site is not well understood.
The research identified the skin as an important site of immune surveillance, with T cell responses to dengue virus being concentrated there.
Dr. Rivino concluded that the research identified the skin as an important site of immune surveillance, with T cell responses to dengue virus being concentrated there. These findings carry significant implications for vaccination strategies, suggesting that eliciting dengue-specific skin-resident CD8+ T cells could enhance vaccine effectiveness.
Further Insights
Analysis of T-cell 'fingerprints' provided early evidence that similar T-cell types exist in both the skin and blood. This suggests a potential common origin or movement between these areas. Previous research by the team demonstrated that blood T cells activated during dengue infection express skin-homing receptors, which guide them back to the skin after circulating in the blood to target infected cells. Further research is necessary to fully comprehend these mechanisms, but the study's results could inform future therapies aimed at boosting protective T cells in relevant tissues.