Melanoma Differentiation-Associated gene 5(MDA5)serves as a pattern recognition receptor(PRR)that identifies pathogen-associated molecular patterns(PAMPs),making it instrumental in antiviral defense.However,its non-ca...Melanoma Differentiation-Associated gene 5(MDA5)serves as a pattern recognition receptor(PRR)that identifies pathogen-associated molecular patterns(PAMPs),making it instrumental in antiviral defense.However,its non-canonical role in adaptive immunity,particularly in regulating B-cell immune functions,is poorly characterized.Here,we demonstrate that MDA5 is critical for the marginal zone(MZ)B-cell differentiation,B-cell receptor(BCR)signal transduction,and cytoskeletal dynamics.We determined that the MDA5-NF-κB-DNM1 axis governs actin polymerization and that this impairment in Mda5 knockout(KO)B cells can be rescued by the treatment with the dynamin1(DNM1)activator Bis-T-23.Furthermore,MDA5 deficiency induces metabolic perturbations in B cells,characterized by a reduced extracellular acidification rate(ECAR)and oxygen consumption rate(OCR),excessive reactive oxygen species(ROS)accumulation,and increased mitochondrial fission.Notably,taurine levels are decreased in Mda5 KO B cells,and in vitro taurine supplementation rescues impaired BCR signaling.Finally,MDA5-deficient mice exhibit a blunted humoral immune response.Overall,this study reveals the key functions and molecular mechanisms of MDA5 in B-cell differentiation,BCR signaling,and the humoral immune response.展开更多
基金supported by the National Natural Science Foundation of China(82371784,32311530061)the National Key Research and Development Program of China(2023YFC2507900,2023YFC2706300)+2 种基金R&D Program of Guangzhou Laboratory(SRPG22-006)State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases(2024ZZ10014)the Hubei Provincial Natural Science Foundation of China(Grant number:2024AFB634).
文摘Melanoma Differentiation-Associated gene 5(MDA5)serves as a pattern recognition receptor(PRR)that identifies pathogen-associated molecular patterns(PAMPs),making it instrumental in antiviral defense.However,its non-canonical role in adaptive immunity,particularly in regulating B-cell immune functions,is poorly characterized.Here,we demonstrate that MDA5 is critical for the marginal zone(MZ)B-cell differentiation,B-cell receptor(BCR)signal transduction,and cytoskeletal dynamics.We determined that the MDA5-NF-κB-DNM1 axis governs actin polymerization and that this impairment in Mda5 knockout(KO)B cells can be rescued by the treatment with the dynamin1(DNM1)activator Bis-T-23.Furthermore,MDA5 deficiency induces metabolic perturbations in B cells,characterized by a reduced extracellular acidification rate(ECAR)and oxygen consumption rate(OCR),excessive reactive oxygen species(ROS)accumulation,and increased mitochondrial fission.Notably,taurine levels are decreased in Mda5 KO B cells,and in vitro taurine supplementation rescues impaired BCR signaling.Finally,MDA5-deficient mice exhibit a blunted humoral immune response.Overall,this study reveals the key functions and molecular mechanisms of MDA5 in B-cell differentiation,BCR signaling,and the humoral immune response.
