FENS Seminars – Assoc. Prof. Atay Vural
Assoc. Prof. Atay Vural (Koc University Neurology Department and Translational Medicine Research Institute) will be the next guest of the KHAS Faculty of Engineering and Natural Sciences seminar series with his speech “CD20+ Natural Killer Cells are a Unique, Polyfunctional, Memory-Like Subset That Expands in Inflammatory Conditions” on Friday, November 24 at 2 PM at Cinema-B. The event is open to anyone interested.
Abstract: CD20+ T cells are known as proinflammatory cells that are expanded in multiple sclerosis and contribute to CNS-directed autoimmunity and several other inflammatory disorders. It has been reported that CD20 is transferred to T cells from B cells during antigen presentation via trogocytosis rather than being expressed by T cells per se. Here, we report that a fraction of NK cells also express CD20 on the cell surface, and the ratio of CD20+ NK cells (CD56+CD20+) to all NK cells is increased in the blood and cerebrospinal fluid of people with multiple sclerosis. CD56+CD20+ cells have an active phenotype and secrete more cytokines after stimulation. Moreover, these cells release a higher number of cytotoxic granules and are more efficient killers when incubated with K562 cancer cells. We also identified that CD56+CD20+ cells are expanded in the inflamed tissues and to a lesser extent in the peripheral blood of patients with chronic inflammatory disorders including multiple sclerosis, autoimmune hepatitis, HBV infection, hepatocellular carcinoma, and lung cancer, in proportion with the inflammatory nature of the disorder. CD56+CD20+ cells in the blood are depleted after rituximab infusion and reconstitute before B cells. Analysis of publicly available single-cell RNA sequencing datasets revealed that the CD20-coding gene MS4A1 can be expressed by NK cells and under a particular transcriptional program, starting from the prenatal period. In adults, MS4A1-expressing NK cells are preferentially located in the secondary lymphoid organs and display a primed and memory-like molecular signature. In summary, our study establishes a connection between CD20 expression in NK cells and immune cell memory, akin to B and T cells. The significant clinical relevance of these cells further strengthens the concept that memory NK cells play pivotal roles in the pathogenesis of autoimmune disorders and response to cancer.
About the Speaker: Dr. Atay Vural graduated from the MD-PhD Program at Hacettepe University. His doctoral thesis in neuroscience was on stroke and was published in Nature Medicine. After completing his neurology residency at the same university in 2013, he worked as a neurologist at Adıyaman Besni State Hospital until 2015. Afterward, he worked as a postdoctoral researcher for three years at the Institute of Clinical Neuroimmunology at Ludwig Maximilian University with support from the European Academy of Neurology and the Alexander von Humboldt Foundation. Since 2018, Dr. Vural has been serving as a research group leader and a neurologist at Koç University, İstanbul. His research focuses on several areas including the investigation of cellular immunology and the role of microcirculation in multiple sclerosis; developing diagnostic autoantibody assays such as anti-MOG and anti-NF antibody assays; genetic ataxias, and sensor-based gait and balance analysis in neurological disorders. Dr. Vural’s research projects have been supported by TÜBİTAK, MS International Federation, and the European Union. His work has been published in prestigious journals, including Brain, Neurology Neuroimmunology Neuroinflammation, Multiple Sclerosis Journal, and Movement Disorders. As of 2023, Dr. Vural’s h-index is 17.