B lymphocytes of xeroderma pigmentosum or Cockayne syndrome patients with inherited defects in nucleotide excision repair are fully capable of somatic hypermutation of immunoglobulin genes - PubMed (original) (raw)

B lymphocytes of xeroderma pigmentosum or Cockayne syndrome patients with inherited defects in nucleotide excision repair are fully capable of somatic hypermutation of immunoglobulin genes

N Kim et al. J Exp Med. 1997.

Abstract

Recent experiments have strongly suggested that the process of somatic mutation is linked to transcription initiation. It was postulated that a mutator factor loads onto the RNA polymerase and, during elongation, causes transcriptional arrest that activates DNA repair, thus occasionally causing errors in the DNA sequence. We report the analysis of the role of one of the known DNA repair systems, nucleotide excision repair (NER), in somatic mutation. Epstein-Barrvirus-transformed B cells from patients with defects in NER (XP-B, XP-D, XP-V, and CS-A) were studied. Their heavy and light chain genes show a high frequency of point mutations in the variable (V), but not in the constant (C) regions. This suggests that these B cells can undergo somatic hypermutation despite significant defects in NER. Thus, it is doubtful that NER is an essential part of the mechanism of somatic hypermutation of Ig genes. As an aside, NER seems also not involved in Ig gene switch recombination.

PubMed Disclaimer

Figures

Figure 1

Figure 1

Sequence alignments of heavy and light chain cDNAs from patients with XP-B, XP-D, XP-V and CS-A. On the top a general map of heavy and light chain genes is shown. The individual maps below show the approximate positions of nucleotide changes compared with germline V genes. Dotted lines represent unsequenced regions. As a control, ∼300 nucleotides of the constant regions of XPD-4, XPD2-1, XPD2-2, XPV-1, XPV-2, XPV-3, CSA-1, CSA-2, and CSA-3 were sequenced; no mutations were found. *These two clones have the same V and J, but different N and D sequences.

Figure 1

Figure 1

Sequence alignments of heavy and light chain cDNAs from patients with XP-B, XP-D, XP-V and CS-A. On the top a general map of heavy and light chain genes is shown. The individual maps below show the approximate positions of nucleotide changes compared with germline V genes. Dotted lines represent unsequenced regions. As a control, ∼300 nucleotides of the constant regions of XPD-4, XPD2-1, XPD2-2, XPV-1, XPV-2, XPV-3, CSA-1, CSA-2, and CSA-3 were sequenced; no mutations were found. *These two clones have the same V and J, but different N and D sequences.

Figure 1

Figure 1

Sequence alignments of heavy and light chain cDNAs from patients with XP-B, XP-D, XP-V and CS-A. On the top a general map of heavy and light chain genes is shown. The individual maps below show the approximate positions of nucleotide changes compared with germline V genes. Dotted lines represent unsequenced regions. As a control, ∼300 nucleotides of the constant regions of XPD-4, XPD2-1, XPD2-2, XPV-1, XPV-2, XPV-3, CSA-1, CSA-2, and CSA-3 were sequenced; no mutations were found. *These two clones have the same V and J, but different N and D sequences.

Figure 1

Figure 1

Sequence alignments of heavy and light chain cDNAs from patients with XP-B, XP-D, XP-V and CS-A. On the top a general map of heavy and light chain genes is shown. The individual maps below show the approximate positions of nucleotide changes compared with germline V genes. Dotted lines represent unsequenced regions. As a control, ∼300 nucleotides of the constant regions of XPD-4, XPD2-1, XPD2-2, XPV-1, XPV-2, XPV-3, CSA-1, CSA-2, and CSA-3 were sequenced; no mutations were found. *These two clones have the same V and J, but different N and D sequences.

Figure 1

Figure 1

Sequence alignments of heavy and light chain cDNAs from patients with XP-B, XP-D, XP-V and CS-A. On the top a general map of heavy and light chain genes is shown. The individual maps below show the approximate positions of nucleotide changes compared with germline V genes. Dotted lines represent unsequenced regions. As a control, ∼300 nucleotides of the constant regions of XPD-4, XPD2-1, XPD2-2, XPV-1, XPV-2, XPV-3, CSA-1, CSA-2, and CSA-3 were sequenced; no mutations were found. *These two clones have the same V and J, but different N and D sequences.

Similar articles

Cited by

References

    1. French D, Laskov R, Scharff M. The role of somatic hypermutation in the generation of antibody diversity. Science (Wash DC) 1989;244:1152–1157. - PubMed
    1. Storb, U., A. Peters, E. Klotz, N. Kim, H.M. Shen, K. Kage, and B. Rogerson. 1997. Somatic hypermutation of immunoglobulin genes is linked to transcription. Curr. Topics Microbiol. Immunol. In press. - PubMed
    1. Storb U, Peters A, Klotz E, Rogerson B, Hackett J. The mechanism of somatic hypermutation studied with transgenic and transfected target genes. Semin Immunol. 1996;8:131–140. - PubMed
    1. Storb U. Molecular mechanism of somatic hypermutation of immunoglobulin genes. Curr Opin Immunol. 1996;8:206–214. - PubMed
    1. Betz A, Milstein C, Gonzalez-Fernandes R, Pannell R, Larson T, Neuberger M. Elements regulating somatic hypermutation of an immunoglobulin K gene: critical role for the intron enhancer/matrix attachment region. Cell. 1994;77:239–248. - PubMed

Publication types

MeSH terms

Substances

LinkOut - more resources