Journal of Antivirals & Antiretrovirals
Open Access
ISSN: 1948-5964
+44 1300 500008
ISSN: 1948-5964
+44 1300 500008
Nishith Nagabhushana, Jeffrey Currier, Zhaodong Liang, Jessica Roman, Maya Williams, Peifang Sun and Brian J Morrison
Naval Medical Research Center, USA
Walter Reed Army Institute of Research, USA
Posters & Accepted Abstracts: J Antivir Antiretrovir
Dengue virus (DENV) infection and/or vaccination leads to several host immune responses, one of which is antibody-dependent cell-mediated cytotoxicity (ADCC). We aim to develop and standardize assays to assess serum ADCC activity using CEMNKR-DC-SIGN cells as targets and normal human PBMCs as effectors. DENV infected CEM-NKR-DC-SIGN cells when treated with a dengue immune and a control na�¯ve serum followed by a secondary antibody, PE-labelled goat anti-human IgG Fc, indicated DENV Ag expression on the surface of target cells at both 3- and 24-hours. The degranulation experiment was done by co-incubating effectors and opsonized targets for 2 hours and consequently staining the cultures with an antibody cocktail (APC-CD56, PerCPCD3, FITC-CD107a, and PE-CD16). The expression of CD107a on CD3-CD56+ suggested a significant increase in degranulation of NK cells against target cells infected for 24-hours but not 3 hours. For all four serotypes, suggesting a possible increase in expression of different viral antigens on the cell surface at 24-hour. ADCC assay was applied to evaluate ADCC titers for serum samples from a tetravalent Dengue virus live attenuated virus (TDENV-LAV/LAV) vaccine study, whose neutralizing antibody (Nab) titers are known. It was found that the titer of ADCC-mediating Abs is not correlated with the titer of NAbs following receipt of TDENV vaccination in DENV-na�¯ve individuals. Subjects with high ADCC titers, but low Nab titers suggest that they could be protected against DENV through ADCC. Hence, we are working towards further optimizing the assay for future application for clinical research and vaccine development.