CD4⁺ T Cells Are Key to Shaping a Protective Humoral Immunity in Primary Dengue 2 Virus Infection: Implications for...

Area of Science:

• Immunology
• Virology
• Vaccinology

Background:

• Understanding immune responses in dengue virus (DENV) infection is key for vaccine development.
• Differentiating protective from pathogenic immune mechanisms is critical.

Purpose of the Study:

• To investigate the impact of CD4+ T cell depletion on viral control and humoral immunity during primary DENV2 infection.
• To assess changes in B cell activation, antibody specificity, and antibody-dependent enhancement (ADE) potential.

Main Methods:

• Rhesus macaques underwent CD4+ T cell depletion before DENV2 infection.
• Evaluated viral kinetics, B cell responses, antibody characteristics (specificity, cross-reactivity, neutralization), and ADE potential longitudinally.

Main Results:

• CD4+ T cells are essential for early viral clearance and type-specific neutralizing antibody generation.
• Absence of CD4+ T cells led to delayed antibody maturation, increased cross-reactivity (DENV/Zika virus), and heightened ADE potential.
• Elevated anti-NS1 IgG titers persisted for one year post-infection in CD4-depleted animals.

Conclusions:

• CD4+ T cells orchestrate effective, durable, and type-specific antibody responses against DENV.
• Lack of CD4+ T cells results in impaired antibody development and increased ADE risk.
• DENV and Zika virus vaccines should incorporate CD4+ T cell epitopes to ensure high-quality, type-specific immunity and minimize ADE.