Myosin IIa promotes antibody responses by regulating B cell activation, acquisition of antigen, and proliferation
journal contributionposted on 2020-08-12, 13:30 authored by Robbert Hoogeboom, Elizabeth M Natkanski, Carla R Nowosad, Dessislava Malinova, Rajesh P Menon, Antonio Casal, Pavel Tolar
B cell responses are regulated by antigen acquisition, processing, and presentation to helper T cells. These functions are thought to depend on contractile activity of non-muscle myosin IIa. Here, we show that B cell-specific deletion of the myosin IIa heavy chain reduced the numbers of bone marrow B cell precursors and splenic marginal zone, peritoneal B1b, and germinal center B cells. In addition, myosin IIa-deficient follicular B cells acquired an activated phenotype and were less efficient in chemokinesis and extraction of membrane-presented antigens. Moreover, myosin IIa was indispensable for cytokinesis. Consequently, mice with myosin IIa-deficient B cells harbored reduced serum immunoglobulin levels and did not mount robust antibody responses when immunized. Altogether, these data indicate that myosin IIa is a negative regulator of B cell activation but a positive regulator of antigen acquisition from antigen-presenting cells and that myosin IIa is essential for B cell development, proliferation, and antibody responses.
B cell developmentB cell responseB cell signalingantigen internalizationantigen presentationcytoskeletonnon-muscle myosinAnimalsAntibody FormationAntigensB-LymphocytesBiomarkersBone Marrow CellsCell MembraneCell MovementCell ProliferationCytokinesisEndocytosisLymphocyte ActivationMice, Inbred C57BLNonmuscle Myosin Type IIAPeritoneumReceptors, Antigen, B-CellSolubilitySpleenTolar FC001185FC-ackAS-ack0601 Biochemistry and Cell Biology