Figure 9. Intradermal inoculation of SGE induces vascular leak into the skin and exacerbates Dengue disease in a mouse model of infection.
A. Wild-type mice were inoculated intravenously with dextran that was labeled with Alexa Fluor 680. Immediately thereafter, 15 μl SGE or PBS was inoculated intradermally. After 30 min, mice were euthanized, and ears were scanned using the Odyssey CLx Infrared Imaging System (Licor). Representative scan showing fluorescence that leaked with plasma into the skin at sites of intradermal inoculation or corresponding areas in steady-state ears (white circles). B. Mice deficient in the interferon-α/β receptor (Ifnar−/−) were inoculated intradermally with 105 plaque forming units of Dengue virus-2 strain D220 in the absence or presence of enhancing antibodies (5 μg of monoclonal antibody 4G2, targeting Dengue virus E protein) to model antibody-dependent enhancement (ADE). Dengue virus was inoculated alone or after mixing with Ae. aegypti SGE (+SGE). Kaplan-Meier curves showing survival of mice. Data were pooled from three experiments. Statistically significant differences were tested between the presence and absence of SGE using the Log-rank (Mantel-Cox) test and are marked as ** for P < 0.01.