Cross-Reactivity and Expansion of Dengue-Specific T cells During Acute Primary and Secondary Infections in Humans

Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA 01655, USA.
Scientific Reports (Impact Factor: 5.58). 08/2011; 1:51. DOI: 10.1038/srep00051
Source: PubMed


Serotype-cross-reactive memory T cells responding to secondary dengue virus (DENV) infection are thought to contribute to disease. However, epitope-specific T cell responses have not been thoroughly compared between subjects with primary versus secondary DENV infection. We studied CD8(+) T cells specific for the HLA-A*1101-restricted NS3(133) epitope in a cohort of A11(+) DENV-infected patients throughout acute illness and convalescence. We compared the expansion, serotype-cross-reactivity, and activation of these cells in PBMC from patients experiencing primary or secondary infection and mild or severe disease by flow cytometry. Our results show expansion and activation of DENV-specific CD8(+) T cells during acute infection, which are predominantly serotype-cross-reactive regardless of DENV infection history. These data confirm marked T cell activation and serotype-cross-reactivity during the febrile phase of dengue; however, A11-NS3(133)-specific responses did not correlate with prior antigenic exposure or current disease severity.

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Available from: Siripen Kalayanarooj
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    • "Despite extensive studies, the pathogenesis of DHF cannot be fully attributed to the ADE. Activation of dengue virus-specific T cells and dengue virus-infected monocytes may result in increased capillary permeability in patients with DHF [49,50]. Recently, cytokines related to dominant Th2 reaction have been related to the pathogenesis of DHF [44,48,51,52]. "
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    ABSTRACT: Background Appropriate induction of the early Th1 cytokine IL-12 is a critical defense directed against viral infection. We have previously shown that different viruses elicited either IL-12 or IFNα dependent Th1 reactions. Using dengue-2 virus, we sought to explore how dengue-2 induced IL-12 or IFNα expression by monocytic and its derived dendritic cells. Methods We employed human monocytic cell line, THP-1, to investigate whether differentiation of monocytic cells is involved in the switch between IFNα and IL-12 induction. Flow cytometry, RT-PCR and ELISA were respectively used to determine cell differentiation, IL-12 and IFNα mRNA expression and protein production. Results THP-1, expressing CD123, which is a plasmacytoid dendritic cell marker, but not CD14, CD11b or CD11c revealed IFNα mRNA expression while stimulated by dengue-2. In contrast, PMA-induced THP-1 differentiation toward monocytic cells expressed CD11b+, and CD14+, but not CD123, and revealed exclusively IL-12 expression while stimulated by dengue-2. Further studies showed that CD123+ expressing THP-1 cells elicited higher IFNα expression in dose and time dependent induction after infection, and PMA-induced monocytic differentiation of THP-1 cells revealed IL-12 expression. Antibody-dependent enhancement of DEN-2 infection significantly suppressed the DEN-2 induced IL-12 p40 expression in monocytic differentiated THP-1 cells. Conclusions Clarification and modulation of the early Th1 reaction in different monocytic cells may change or prevent complication from dengue infection.
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    No preview · Article · Dec 2012 · Critical Reviews in Immunology
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