Frequency of Dengue Virus-Specific T Cells is related to Infection Outcome in Endemic Settings

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Presentation Time: 11:30 AM - 12:45 PM
Poster Board Number: B157
Abstract ID: 4644

Presenting Author:
Daniela Weiskopf , Research Assistant Professo at La Jolla Inst. for Immunol.

Abstract:

Annually, the four serotypes of dengue virus (DENV 1-4) cause around 400 million infections, of which ~25% present with clinical symptoms. While infection and re-infection are common in endemic areas, the influce of pre-existing T cell memory on subsequent disease outcome is not well understood. To investigate this we collected samples from a pediatric cohort study in dengue-endemic Managua, Nicaragua. We characterized T cell responses in a group of 71 healthy children who had previously exposed to DENV, and who, within one year after sample collection, had a subsequent DENV infection that was either symptomatic (n=25) vs. inapparent (n=46, absence of clinical disease). Thus, our study was designed to investigate the impact of pre-existing DENV-specific T cell responses on the clinical outcomes of subsequent DENV infection. We assessed DENV-specific T cell responses using activation-induced marker assays (AIM). Children who had experienced only one prior DENV infection displayed heterogeneous DENV-specific CD4⁺ and CD8⁺ T cell frequencies. In contrast, children who had experienced two or more DENV infections showed significantly higher frequencies of DENV-specific CD4⁺ and CD8⁺ T cells that were associated with inapparent outcome in the subsequent DENV infection. Taken together, these findings demonstrate the protective role of DENV-specific T cells during DENV infection and constitute an advancement toward identifying protective correlates against dengue disease.