Assessing Potential Additivity of Proinflammatory Cytokines and Kifunensine on ADCC Potency 2309647

Abstract Introduction Antibody-dependent cell mediated cytotoxicity, or ADCC, is a process where antibodies coat a target cell, recruiting effector cells to induce target cell death. This process is generally mediated by IgG antibodies and Fcγ receptors, namely FcγRIIIa/CD16a, which is expressed on cytotoxic natural killer cells (CD56dim CD16+). ADCC is targeted for cancer immunotherapy, whereby increasing ADCC potency is expected to improve patient outcome. We explored the impact of cytokine treatment in vitro on ADCC potency using primary natural killer cells, IL-2, IL-15, TNFα, and IL-10. We also evaluated a novel method, altering N-glycan processing, and assessed the interaction of cytokine treatment and N-glycan manipulation on ADCC of primary human NK cells. Methods Primary NK cells were incubated in YTS media supplemented with no cytokines, IL-2, IL-15, TNFα, IL-10, and/or kifunensine. We then evaluated NK cell activity with Raji cells and rituximab to assess cytotoxicity and ADCC potency. Raji cell lysis was determined via flow cytometry. Primary NK cells were also incubated with PHA-L-AF594 to assess how treatments affect NK cell N-glycosylation. Results NK cells treated with kifunensine alone have lower ADCC potency compared to control. NK cells treated with IL-15 and kifunensine increase ADCC potency through kifunensine suppressing the IL-15-dependent increase in natural cytotoxicity. NK cells treated with IL-2 and IL-15 both demonstrated a change in N-glycosylation, which was then subdued when cells were treated with IL-2 + kifunensine and IL-15 + kifunensine. Conclusion IL-15 combined with kifunensine in vitro increased ADCC potency of primary NK cells with minimal impact on NK cell viability. Funding Source U01-AI-148114 from the National Institute of Allergy and Infectious Diseases Topic Categories Innate Immune Responses and Host Defense: Molecular Mechanisms (INM)