Antibody diversification is essential for an effective immune response,with somatic hypermutation(SHM)serving as a key molecular process in this adaptation.Activation-induced cytidine deaminase(AID)initiates SHM by in...Antibody diversification is essential for an effective immune response,with somatic hypermutation(SHM)serving as a key molecular process in this adaptation.Activation-induced cytidine deaminase(AID)initiates SHM by inducing DNA lesions,which are ultimately resolved into point mutations,as well as small insertions and deletions(indels).These mutational outcomes contribute to antibody affinity maturation.The mechanisms responsible for generating point mutations and indels involve the base excision repair(BER)and mismatch repair(MMR)pathways,which are well coordinated to maintain genomic integrity while allowing for beneficial mutations to occur.In this regard,translesion synthesis(TLS)polymerases contribute to the diversity of mutational outcomes in antibody genes by enabling the bypass of DNA lesions.This review summarizes our current understanding of the distinct molecular mechanisms that generate point mutations and indels during SHM.Understanding these mechanisms is critical for elucidating the development of broadly neutralizing antibodies(bnAbs)and autoantibodies,and has implications for vaccine design and therapeutics.展开更多
基金supported by the National Key Research and Development Program of China(2021YFA1301400)the National Natural Science Foundation of China(32370934)the Shanghai Jiao Tong University 2030 Initiative(2030-B23).
文摘Antibody diversification is essential for an effective immune response,with somatic hypermutation(SHM)serving as a key molecular process in this adaptation.Activation-induced cytidine deaminase(AID)initiates SHM by inducing DNA lesions,which are ultimately resolved into point mutations,as well as small insertions and deletions(indels).These mutational outcomes contribute to antibody affinity maturation.The mechanisms responsible for generating point mutations and indels involve the base excision repair(BER)and mismatch repair(MMR)pathways,which are well coordinated to maintain genomic integrity while allowing for beneficial mutations to occur.In this regard,translesion synthesis(TLS)polymerases contribute to the diversity of mutational outcomes in antibody genes by enabling the bypass of DNA lesions.This review summarizes our current understanding of the distinct molecular mechanisms that generate point mutations and indels during SHM.Understanding these mechanisms is critical for elucidating the development of broadly neutralizing antibodies(bnAbs)and autoantibodies,and has implications for vaccine design and therapeutics.
