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Ilhéus virus (ILHV) is a neglected mosquito-borne flavivirus. ILHV infection may lead to Ilhéus fever, an emerging febrile disease like dengue fever with the potential to evolve into a severe neurological disease characterized by meningoencephalitis; no specific treatments are available for this disease. This study assessed the antiviral properties of caffeic acid, an abundant component of plant-based food products that is also compatible with the socioeconomic limitations associated with this neglected infectious disease. The in vitro activity of caffeic acid on ILHV replication was investigated in Vero and A549 cell lines using plaque assays, quantitative RT-PCR, and immunofluorescence assays. We observed that 500 µM caffeic acid was virucidal against ILHV. Molecular docking indicated that caffeic acid might interact with an allosteric binding site on the envelope protein. [ABSTRACT FROM AUTHOR]

Background: Increased levels of inflammatory cytokines are associated with severe dengue evolution, but the source of such hypercytokinemia is elusive. We investigated the contribution of innate lymphocytes, innate lymphoid cells (ILCs), and natural killer (NK) cells in cytokine production in early dengue infection.Methods: Peripheral blood mononuclear cells of individuals with dengue without warning signs (DWS-) and dengue with warning signs and severe dengue (SD) presentation combined (DWS+) were obtained between 2 and 7 days since fever onset and submitted to flow cytometry without specific antigen stimulation to evaluate cytokines in ILC and NK cell subpopulations.Results: ILCs and NK cells were found to be important sources of cytokines during dengue. ILCs of the DWS+/SD group displayed higher production of interferon gamma (IFN-γ) and interleukin (IL) 4/IL-13 when compared to DWS- individuals. On the other hand, NK Eomes+ cells of DWS- patients displayed higher IFN-γ production levels compared with the DWS+/SD group. Interestingly, when NK cells were identified by CD56 expression, DWS+/SD displayed higher frequency of IL-17 production compared with the DWS- group.Conclusions: These results indicate that ILCs and NK cells are important sources of inflammatory cytokines during acute dengue infection and display distinct profiles associated with different clinical forms. [ABSTRACT FROM AUTHOR]