B cells and dengue: A cat-and-mouse game.

Area of Science:

• Immunology
• Virology
• Infectious Diseases

Background:

• Dengue virus (DENV) poses a significant global health threat, causing millions of infections annually.
• Sequential infections with different DENV serotypes increase the risk of severe dengue (dengue hemorrhagic fever and dengue shock syndrome).
• Understanding the immune response to repeated dengue infections is crucial for developing effective vaccines and therapeutics.

Purpose of the Study:

• To investigate the characteristics of antibodies generated after repeated dengue virus infections.
• To determine if these antibodies exhibit broad neutralizing activity against multiple DENV serotypes.
• To assess the protective potential of these broadly neutralizing antibodies against severe dengue disease.

Main Methods:

• Analysis of antibody repertoires from individuals with a history of multiple dengue infections.
• In vitro neutralization assays using pseudotyped viruses and live DENV serotypes.
• Epitope mapping to identify conserved regions targeted by neutralizing antibodies.
• Passive transfer experiments in animal models to evaluate protection against DENV challenge.

Main Results:

• Repeated dengue infections consistently elicited antibodies with broad neutralizing activity against all four DENV serotypes.
• A subset of these antibodies targeted conserved epitopes across DENV serotypes, contributing to their broad neutralization.
• Antibodies demonstrating higher neutralizing titers in vitro conferred significant protection against viremia and severe pathology in challenged animal models.
• The magnitude and breadth of the antibody response correlated with protection against severe disease manifestations.

Conclusions:

• Sequential dengue infections can induce a potent and broadly neutralizing antibody response.
• These broadly neutralizing antibodies represent a promising target for vaccine development aimed at preventing severe dengue.
• Further research into the mechanisms and specific targets of these antibodies may lead to novel therapeutic strategies against dengue virus.