Dengue virus infection promotes translocation of high mobility group box 1 protein from the nucleus to the cytosol in dendritic cells, upregulates cytokine production and modulates virus replication.

High mobility group box 1 (HMGB1) protein functions in regulation of transcription, cellular activation and pro-inflammatory responses. However, the potential role of HMGB1 during viral infection has not been investigated. This study attempted to elucidate whether the HMGB1-mediated inflammatory response contributes to the pathogenesis of dengue virus (DENV) infection. Our data showed that HMGB1 was released at low DENV infection levels (m.o.i. of 1) under non-necrotic conditions by human dendritic cells (DCs). When DENV-infected DCs were co-cultured with autologous T cells, there was increased production of HMGB1 by both cell types. HMGB1 regulated tumour necrosis factor alpha, interleukin (IL)-6, IL-8 and alpha interferon secretion in DENV-infected DCs. Additionally, increased HMGB1 production was associated with reduced DENV replication titres in DCs. These results suggest that HMGB1 production influences DENV infection in susceptible hosts.