INTRODUCTION After encountering an antigen,B cells undergo class switch recombination(CSR),which substitutes the Cμgene with Cγ,Cε,or Cαto generate IgG,IgE,and IgA antibodies with the same antigenic specificity bu...INTRODUCTION After encountering an antigen,B cells undergo class switch recombination(CSR),which substitutes the Cμgene with Cγ,Cε,or Cαto generate IgG,IgE,and IgA antibodies with the same antigenic specificity but new effector functions.1 The DNAediting enzyme activation-induced deaminase(AID)is essential for CSR by targeting switch(S)regions preceding Cμ(namely,the Sμdonor region)and the Cγ,Cε,and Cαgenes(namely,the Sγ,ε,αacceptor regions).1 Cis-and trans-controlled DNA double strand beaks are generated during this process.2–6 Recruitment of DNA repair factors that facilitate the end-joining process is a crucial step of class switch recombination.Two pathways are implicated in this end joining.The classical non-homogenous end joining(c-NHEJ)pathway ligates DNA ends with no or little homology.By contrast,the alternative end joining(A-EJ)pathways is used to ligate DNA ends that have microhomology.展开更多
基金This work was supported by ANR(project EpiSwitch-3’RR 2016)N.G.was supported by a grant from Association de Spécialisation et d’Orientation Scientifique(Lebanon)and the municipality of Khiam(Lebanon)H.I.is supported by CORC(FJA/NP 2015-109)and the University of Limoges.
文摘INTRODUCTION After encountering an antigen,B cells undergo class switch recombination(CSR),which substitutes the Cμgene with Cγ,Cε,or Cαto generate IgG,IgE,and IgA antibodies with the same antigenic specificity but new effector functions.1 The DNAediting enzyme activation-induced deaminase(AID)is essential for CSR by targeting switch(S)regions preceding Cμ(namely,the Sμdonor region)and the Cγ,Cε,and Cαgenes(namely,the Sγ,ε,αacceptor regions).1 Cis-and trans-controlled DNA double strand beaks are generated during this process.2–6 Recruitment of DNA repair factors that facilitate the end-joining process is a crucial step of class switch recombination.Two pathways are implicated in this end joining.The classical non-homogenous end joining(c-NHEJ)pathway ligates DNA ends with no or little homology.By contrast,the alternative end joining(A-EJ)pathways is used to ligate DNA ends that have microhomology.
