Article

Cross-reactive memory CD4+ T cells alter the CD8+ T-cell response to heterologous secondary dengue virus infections in mice in a sequence-specific manner.

Center for Infectious Disease and Vaccine Research, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA.
Viral immunology (Impact Factor: 1.45). 07/2009; 22(3):215-9. DOI: 10.1089/vim.2008.0089
Source: PubMed

ABSTRACT

Dengue virus is the causative agent of dengue fever and the more-severe dengue hemorrhagic fever (DHF). Human studies suggest
that the increased risk of DHF during secondary infection is due to immunopathology partially mediated by cross-reactive memory
T cells from the primary infection. To model T cell responses to sequential infections, we immunized mice with different sequences
of dengue virus serotypes and measured the frequency of peptide-specific T cells after infection. The acute response after
heterologous secondary infections was enhanced compared with the acute or memory response after primary infection. Also, the
hierarchy of epitope-specific responses was influenced by the specific sequence of infection. Adoptive-transfer experiments
showed that memory T cells responded preferentially to the secondary infection. These findings demonstrate that cross-reactive
T cells from a primary infection alter the immune response during a heterologous secondary infection.

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