Granja, AitorPerdiguero Jiménez, PedroMartín-Martín, AlbaDíaz-Rosales, PatriciaSoleto, IreneTafalla, Carolina2024-01-302024-01-302019Granja, Aitor G., et al. «Rainbow Trout IgM+ B Cells Preferentially Respond to Thymus-Independent Antigens but Are Activated by CD40L». Frontiers in Immunology, vol. 10, diciembre de 2019, p. 2902. https://doi.org/10.3389/fimmu.2019.02902.10.3389/fimmu.2019.02902https://hdl.handle.net/20.500.14352/96689Funding This work was supported by the European Research Council (ERC Consolidator Grant 2016 725061 TEMUBLYM) and by projects AGL2014-54456-JIN (Spanish Ministry of Economy and Competitiveness, MINECO) and AGL2017-85494-C2-1-R (Spanish Ministry of Science, Innovation and Universities).In the absence of class switch recombination and germinal centers, the mechanisms through which B cells from teleost fish mount extrafollicular immunoglobulin M (IgM) memory responses remains mostly unexplored. In this report, we demonstrate that teleost IgM+ B cells respond to CD40L, a thymus-dependent activation signal, similarly to mammalian B2 cells. However, when stimulated with different types of antigens, fish IgM+ B cells only reach a general activation state in response to antigens cataloged as thymus-independent 1 (TI-1) in mammals, as established through both functional assays and RNA sequencing. Interestingly, fish IgM+ B cells remained completely unresponsive to TI-2 antigens, suggesting that the engagement of innate receptors provided by TI-1 antigens is required for the activation of teleost B cells. Finally, a synergy between CD40L and TI-1 antigens was also demonstrated, further supporting that there is no clear dichotomy between thymus-dependent and TI responses in teleost fishengAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/journal article1664-3224https://doi.org/10.3389/fimmu.2019.02902/fullopen access577.112Teleost fishB cellsIgMExtrafollicular responsesCD40LBioquímica (Biología)31 Ciencias Agrarias2403 Bioquímica