Defining the Role of ANKEF1 in Ciliary Function and Host Defense Against Influenza Virus Infection - Project Summary Most influenza cases resolve without complications, but some progress to serious conditions like pneumonia, acute respiratory distress syndrome, or encephalitis. Genetic predispositions, such as inborn errors of immunity, are known factors that contribute to these severe outcomes, yet the underlying mechanisms in otherwise healthy individuals, particularly children, remain unclear. This proposal focuses on ANKEF1, a ciliary protein identified as having a loss-of-function mutation in a child who succumbed to influenza-associated rhombencephalitis—a rare and severe complication characterized by inflammation of the brainstem that can occur in some severe cases of influenza-associated encephalitis (IAE). Our preliminary findings indicate that ANKEF1 is critical for ciliary motility in airway epithelial cells, which is essential for effective mucociliary clearance (MCC). In mouse models, ANKEF1 deficiency leads to impaired MCC, reducing the ability to clear pathogens from the respiratory tract and leading to increased susceptibility to influenza infection, higher morbidity, and greater mortality. We hypothesize that persistent viral presence in the airways due to defective MCC triggers an exaggerated inflammatory response, which elevates the risk of IAE through increased cytokine production and disruption of brain barrier integrity In this proposal, we will leverage novel mouse models, human iPSC-derived airway epithelial cultures, and advanced multi-omics technologies to define how ANKEF1 regulates ciliary function and host defense. Aim 1 will investigate how ANKEF1 deficiency alters ciliary beat frequency, coordination, and motility in the airways and brain, and assess the resulting impact on viral replication and immune responses ex vivo. Aim 2 will characterize disease progression in ANKEF1-deficient mice by measuring viral titers, immune responses, and tissue damage in both the respiratory system and brain. Additionally, we will use single-cell RNA sequencing and spatial transcriptomics to identify key pathways associated with increased disease severity. Aim 3 will elucidate the molecular mechanisms by which ANKEF1 modulates ciliary functions and identify key interactions and regulatory networks that contribute to host defense against IAV infection. This research will provide new insights into the role of ciliary function in airway and brain defenses, potentially revealing therapeutic targets for severe influenza and other respiratory diseases.
