Surface protein CD20 serves as the critical target of immunotherapy in various B-cell malignancies for decades, however its biological function and regulation remain largely elusive. Better understanding of CD20 function may help to design improved rational therapies to prevent development of resistance. Using CRISPR/Cas9 technique, we have abrogated CD20 expression in five different malignant B-cell lines. We show that CD20 deletion has no effect upon B-cell receptor signaling or calcium flux. Also B-cell survival and proliferation is unaffected in the absence of CD20. On the contrary, we found a strong defect in actin cytoskeleton polymerization and, consequently, defective cell adhesion and migration in response to homeostatic chemokines SDF1α, CCL19 and CCL21. Mechanistically, we could identify a reduction in chemokine-triggered PYK2 activation, a calcium-activated signaling protein involved in activation of MAP kinases and cytoskeleton regulation. These cellular defects in consequence result in a severely disturbed homing of B cells in vivo.

Central European Institute of Technology Masaryk University Brno Czech Republic

Department of Experimental Biology Faculty of Science Masaryk University Brno Czech Republic

Department of Immunology Medical University of Warsaw Warsaw Poland

Department of Internal Medicine Hematology and Oncology Medical Faculty of Masaryk University and University Hospital Brno Brno Czech Republic

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Towards a Better Characterisation of Leukemic Cells in Chronic Lymphocytic Leukaemia: Cell-Size Heterogeneity Reflects Their Activation Status and Migratory Abilities

Super-enhancer-based identification of a BATF3/IL-2R-module reveals vulnerabilities in anaplastic large cell lymphoma

Current State of CAR T-Cell Therapy in Chronic Lymphocytic Leukemia

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10.6084/m9.figshare.11441016, 10.6084/m9.figshare.11441073