“
“Dengue is a mosquito-borne viral disease selleck of humans,

and animal models that recapitulate human immune responses or dengue pathogenesis are needed to understand the pathogenesis of the disease. We recently described an animal model for dengue virus (DENV) infection using humanized NOD-scid IL2rγnull mice (NSG) engrafted with cord blood haematopoietic stem cells. We sought to further improve this model by co-transplantation of human fetal thymus and liver tissues into NSG (BLT-NSG) mice. Enhanced DENV-specific antibody titres were found in the sera of BLT-NSG mice compared with human cord blood haematopoietic stem cell-engrafted NSG mice. Furthermore, B cells generated during the acute phase and in memory from splenocytes of immunized BLT-NSG mice secreted DENV-specific IgM antibodies with neutralizing activity. Human T cells in engrafted BLT-NSG mice secreted

interferon-γ in response to overlapping DENV peptide pools and HLA-A2 restricted peptides. The BLT-NSG mice will allow assessment of human immune responses to DENV vaccines and the effects of previous immunity on subsequent DENV infections. Dengue virus (DENV) is a mosquito-borne member of Deforolimus mouse the Flavivirus genus and includes four serotypes (DENV-1, DENV-2, DENV-3 and DENV-4). The virus infects approximately 50 million individuals each year, leading to over 500 000 hospitalizations. Infection results in a range of symptoms from mild fever to acute febrile illness (dengue fever). In a small percentage of cases, however, individuals develop a severe capillary leakage syndrome, dengue haemorrhagic fever and dengue shock syndrome, which can be life-threatening.1,2 Studies in humans suggest that dengue haemorrhagic fever and dengue shock syndrome are more likely to occur in individuals experiencing BCKDHB their second DENV infections and in infants born to DENV-immune mothers. Experimental manipulation of in vivo immune responses to DENV is a critical step in exploration of the role of previous immunity in subsequent DENV infection

and testing of candidate vaccines and therapeutics. Progress in understanding the pathogenesis of dengue haemorrhagic fever has come largely from controlled well-designed clinical studies of patients with mild and severe forms of dengue disease in endemic areas.3–10 Most patients who present to hospital live in endemic areas and are experiencing a secondary infection; however, the serotype of the previous DENV infection is difficult to determine. Furthermore, controlled virus challenge studies are not feasible in humans, and it is difficult to assess the contribution of antibodies or T cells to DENV pathogenesis. Immunodeficient mice bearing components of a human immune system (humanized mice) present a novel approach for studying human immune responses to DENV.