GSE115203
Viral infection enhances NK cell activation via Type I dependent pathways and can be utilized to enhance influenza-specific monoclonal antibody therapies
NK cells are an essential component for the control of influenza infection, acting to both clear virus-infected cells and release antiviral cytokines. Engagement of the NK cell CD16-receptor by antibody-coated influenza-infected cells results in antibody-dependent cellular cytotoxicity (ADCC). Though NK cell-mediated ADCC is an important mechanism to control influenza, influenza infection itself may act to enhance the potency of NK cell ADCC. To understand if virus-infected cells increase NK cell activation, we co-cultured human PBMCs with influenza-infected human alveolar epithelial (A549) cells and evaluated the capacity of NK cells to mediate ADCC. Pre-incubation of PBMCs with influenza-infected target cells markedly enhanced the functionality of NK cells by ADCC antibodies in response to HA immune-complexes containing intravenous immunoglobulin (IVIG), allogenic target cells, with and without rituximab. Trans-well and supernatant transfer experiments showed that virus released into the supernatant is responsible for the enhanced functionality of NK cells, which is apparent at both the protein and RNA transcriptomic levels.  Furthermore, cytokine multiplex data, RNA sequencing and cytokine blocking/supplementation experiments showed Type I interferons released from PBMCs were the primary mechanism of the influenza-induced increased NK cell functionality and ADCC potency. Importantly, the influenza infection-mediated increase in NK cell mediated anti-influenza ADCC was mimicked by the type I interferon agonist Poly-IC. This suggests a potential mechanism for enhancing monoclonal antibody therapies for influenza. We conclude that influenza-infection induced secretion of type I interferons enhances the ADCC capacity of NK cells and this pathway may potentially be manipulated to improve anti-influenza therapies. Overall design: Three separate donor PBMCs were incubated with either infected A549 cells or uninfected A549 cells for 12 hours. Target cell populations of lymphocytes gated on LIVE/DEAD negative populations or LIVE/DEAD negative CD3-CD56+ NK cells of interest were subsequently sorted from these PBMCs. Transcriptional profiling and differential gene expression was performed using RNA sequencing.