Individual serum samples were used to determine glutamic oxalacetic transaminase (GOT), glutamic pyruvic transaminase (GPT) and C-reactive protein (CRP) levels, using analytical kits as recommended by the supplier (Bioclin, Brazil). Bleeding Integrase inhibitor time was measured at day seven following the fourth vaccine dose by creating a 3 mm incision at the tail tip. Blood droplets were

collected on filter paper every 30 s for the first 3 min, and every 10 s thereafter. Bleeding was considered to be finished when the collected blood spot’s diameter was less than 0.1 mm [22]. Complete blood cell counts were also taken at this time. Whole blood samples were collected in micro tubes containing 0.37 M EDTA. For hematocrit determination, micro capillaries were filled with blood samples, centrifuged at 5000 rpm for 5 min and properly positioned in a packed

cell volume table for hematocrit scoring [52]. Red blood cell (RBC) and white blood cell (WBC) counts were carried out using a Neubauer chamber. Platelet numbers were determined according to the Fonio’s method and neutrophil and lymphocyte differentiation was performed visually using a phase contrast microscope [52], (Eclipse E200 model, Nikon). Statistical analyses were carried out using ANOVA and a subsequent Bonferroni’s Multiple selleckchem Comparison test. For survival and morbidity rates, Mantel–Cox and Gehan–Breslow–Wilcoxon tests were performed. Statistical significance was set as p < 0.05. Both NS1 and LTG33D were produced by recombinant E. coli cells and tested for antigenicity and/or biological activity. The recombinant DENV2 NS1 protein was obtained mainly as

dimers, as demonstrated after sorting in polyacrylamide gels ( Fig. 2A). As demonstrated previously [36], the recombinant NS1 preserved, at least partially, some features of the native virus protein. In addition, the recombinant NS1 retained, at least in part, the antigenicity of the native protein as demonstrated by the reactivity of the recombinant protein unless with a serum sample collected from a DENV2 infected patient ( Fig. 2B). The reactivity of the anti-NS1 serum sample was drastically reduced after heat denaturation of the recombinant protein, which indicates that conformational epitopes of the protein were lost. To demonstrate that the heat-denaturation treatment did not interfered with the binding of protein to the ELISA plates, the protein samples were reacted with a mouse serum raised in mice immunized with a heat-denatured NS1 ( Fig. 2B). In contrast to antibodies raised in the DENV2 infected subject, this serum sample did not show any reduction in the recognition of the heat-denatured NS1 in ELISA, which indicated that denaturation of the recombinant protein did not affect the binding of the protein to the plate. The purified recombinant LTG33D protein encompassed both the A and B subunits, as detected in polyacrylamide gels ( Fig. 2C).