Fig. 6

The influence of nutritional status on a secondary dengue virus (DENV) infection with another serotype. a Six-week-old female C57BL/6 J mice were fed for 8–10 weeks on a control (healthy weight), high-fat (obese), or low-protein (protein-energy malnutrition, PEM) diet and then treated with 1 mg of antibody to block interferon receptor signaling (IFNAR blocking antibody). The next day, mice were infected with DENV2 Puo-218. Values are means ± SD from groups of 8–10 animals from two biological replicates. b Neutralizing antibodies measured by 50% plaque reduction neutralization test (PRNT₅₀) against DENV2 Puo-218 and DENV1 R99142. Values are means ± SD from groups of 8–14 animals. c, d Fifty-five days later, mice were again treated with 1 mg of IFNAR blocking antibody and then infected with DENV1 R99142. c Percent weight loss throughout the study following infection. Statistical comparisons were made to the healthy weight group using a repeated measures mixed-effects model analysis with Dunnett’s correction. Values are means ± SD. d Viremia following infection as determined by plaque assay in Vero cells. For b and d, values are presented as medians with the minimum and maximum of the range and statistical comparisons were made against the healthy weight group using the Kruskal-Wallis test with Dunn’s multiple comparisons test. **p < 0.01. The dotted line represents the limit of detection (LOD); all negative samples were given a value of 0.5 × LOD for statistical purposes