Dengue non-structural
protein (NS1) is an important diagnostic marker during the acute phase of
infection. Because NS1 is partially conserved across the flaviviruses, a highly specific DENV
NS-1 diagnostic test is needed to differentiate
dengue infection from Zika virus (
ZIKV) infection. In this study, we characterized three newly isolated
antibodies against NS1 (A2, D6 and D8) from a
dengue-infected patient and a previously published human anti-NS1 antibody (Den3). All four
antibodies recognized multimeric forms of NS1 from different serotypes. A2 bound to NS1 from DENV-1, -2, and -3, D6 bound to NS1 from DENV-1, -2, and -4, and D8 and Den3 interacted with NS1 from all four
dengue serotypes. Using a competition ELISA, we found that A2 and D6 bound to overlapping
epitopes on NS1 whereas D8 recognized an
epitope distinct from A2 and D6. In addition, we developed a capture ELISA that specifically detected NS1 from dengue viruses, but not ZIKV, using Den3 as the capture antibody and D8 as the detecting antibody. This assay detected NS1 from all the tested dengue virus strains and
dengue-infected patients. In conclusion, we established a
dengue-specific capture ELISA using human
antibodies against NS1. This assay has the potential to be developed as a point-of-care diagnostic tool.