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Induction of somatic hypermutation in immunoglobulin genes is dependent on DNA polymerase iota


Somatic hypermutation of immunoglobulin genes is a unique, targeted, adaptive process. While B cells are engaged in germinal centres in T-dependent responses, single base substitutions are introduced in the expressed V h/V l genes to allow the selection of mutants with a higher affinity for the immunizing antigen. Almost every possible DNA transaction has been proposed to explain this process, but each of these models includes an error-prone DNA synthesis step that introduces the mutations1,2. The Y family of DNA polymerases3—pol η, pol ι, pol κ and rev1—are specialized for copying DNA lesions and have high rates of error when copying a normal DNA template4,5. By performing gene inactivation in a Burkitt's lymphoma cell line inducible for hypermutation, we show here that somatic hypermutation is dependent on DNA polymerase iota.

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Figure 1: Inactivation of the gene encoding pol ι in the BL2 cell line and restoration of protein expression by transfection with pol-ι cDNA.
Figure 2: No increase in pol-ι and AID protein is observed during induction of SHM.


  1. Gearhart, P. J. & Wood, R. D. Emerging links between hypermutation of antibody genes and DNA polymerases. Nature Rev. Immunol. 1, 187–192 (2001)

    CAS  Article  Google Scholar 

  2. Weill, J.-C. et al. Ig gene hypermutation: a mechanism is due. Adv. Immunol. 80, 183–202 (2002)

    CAS  Article  Google Scholar 

  3. Ohmori, H. et al. The Y-family of DNA polymerases. Mol. Cell 8, 7–8 (2001)

    CAS  Article  Google Scholar 

  4. Friedberg, E. C., Wagner, R. & Radman, M. Specialized DNA polymerases, cellular survival, and the genesis of mutations. Science 296, 1627–1630 (2002)

    ADS  CAS  Article  Google Scholar 

  5. Goodman, M. F. Error-prone repair DNA polymerases in prokaryotes and eukaryotes. Annu. Rev. Biochem. 71, 17–50 (2002)

    CAS  Article  Google Scholar 

  6. Sale, J. E. & Neuberger, M. S. TdT-accessible breaks are scattered over the immunoglobulin V domain in a constitutively hypermutating B cell line. Immunity 9, 859–869 (1998)

    CAS  Article  Google Scholar 

  7. Denepoux, S. et al. Induction of somatic mutation in a human B cell line in vitro. Immunity 6, 35–46 (1997)

    CAS  Article  Google Scholar 

  8. Zan, H. et al. Induction of Ig somatic hypermutation and class switching in a human monoclonal IgM+IgD+ B cell line in vitro: definition of the requirements and modalities of hypermutation. J. Immunol. 162, 3437–3447 (1999)

    CAS  PubMed Central  Google Scholar 

  9. Faili, A. et al. AID-dependent somatic hypermutation occurs as a DNA single strand event in the BL2 cell line. Nature Immunol. 3, 815–821 (2002)

    CAS  Article  Google Scholar 

  10. Muramatsu, M. et al. Class switch recombination and hypermutation require activation-induced cytidine deaminase (AID), a potential RNA editing enzyme. Cell 102, 553–563 (2000)

    CAS  Article  Google Scholar 

  11. Revy, P. et al. Activation-induced cytidine deaminase (AID) deficiency causes the autosomal recessive form of the Hyper-IgM syndrome (HIGM2). Cell 102, 565–575 (2000)

    CAS  Article  Google Scholar 

  12. Tissier, A., McDonald, J. P., Frank, E. G. & Woodgate, R. Pol iota, a remarkably error-prone human DNA polymerase. Genes Dev. 14, 1642–1650 (2000)

    CAS  PubMed Central  Google Scholar 

  13. Frank, E. G. et al. Altered nucleotide misinsertion fidelity associated with pol iota-dependent replication at the end of a DNA template. EMBO J. 20, 2914–2922 (2001)

    CAS  Article  Google Scholar 

  14. McDonald, J. P. et al. Novel human and mouse homologs of Saccharomyces cerevisiae DNA polymerase η. Genomics 60, 20–30 (1999)

    CAS  Article  Google Scholar 

  15. Poltoratsky, V. et al. Expression of error-prone polymerases in BL2 cells activated for Ig somatic hypermutation. Proc. Natl Acad. Sci. USA 98, 7976–7981 (2001)

    ADS  CAS  Article  Google Scholar 

  16. Zhang, W. et al. Clonal instability of V region hypermutation in the Ramos Burkitt's lymphoma cell line. Int. Immunol. 13, 975–984 (2001)

    CAS  Article  Google Scholar 

  17. Bebenek, K. et al. 5′-Deoxyribose phosphate lyase activity of human DNA polymerase iota in vitro. Science 291, 2156–2159 (2001)

    ADS  CAS  Article  Google Scholar 

  18. Petersen-Mahrt, S. K., Harris, R. S. & Neuberger, M. S. AID mutates E. coli suggesting a DNA deamination mechanism for antibody diversification. Nature 418, 99–103 (2002)

    ADS  CAS  Article  Google Scholar 

  19. Papavasiliou, F. N. & Schatz, D. G. The activation-induced deaminase functions in a postcleavage step of the somatic hypermutation process. J. Exp. Med. 195, 993–998 (2002)

    Article  Google Scholar 

  20. Zeng, X. et al. DNA polymerase eta is an A-T mutator in somatic hypermutation of immunoglobulin variable genes. Nature Immunol. 2, 537–541 (2001)

    CAS  Article  Google Scholar 

  21. Rogozin, I. B., Pavlov, Y. I., Bebenek, K., Matsuda, T. & Kunkel, T. A. Somatic mutation hotspots correlate with DNA polymerase eta error spectrum. Nature Immunol. 2, 530–536 (2001)

    CAS  Article  Google Scholar 

  22. Pavlov, Y. I. et al. Correlation of somatic hypermutation specificity and A-T base pair substitution errors by DNA polymerase η during copying of a mouse immunoglobulin κ light chain transgene. Proc. Natl Acad. Sci. USA 99, 9954–9959 (2002)

    ADS  CAS  Article  Google Scholar 

  23. Dörner, T., Foster, S. J., Brezinschek, H.-P. & Lipsky, P. E. Analysis of the targeting of the hypermutational machinery and the impact of subsequent selection on the distribution of nucleotides changes in human VhDhJ rearrangements. Immunol. Rev. 162, 161–171 (1998)

    Article  Google Scholar 

  24. Bachl, J. & Wabl, M. An immunoglobulin mutator that targets G.C base pairs. Proc. Natl Acad. Sci. USA 93, 851–855 (1996)

    ADS  CAS  Article  Google Scholar 

  25. Zan, H. et al. The translesion DNA polymerase zeta plays a major role in Ig and bcl-6 somatic hypermutation. Immunity 14, 643–653 (2001)

    CAS  Article  Google Scholar 

  26. Diaz, M., Verkoczy, L. K., Flajnik, M. F. & Klinman, N. R. Decreased frequency of somatic hypermutation and impaired affinity maturation but intact germinal center formation in mice expressing antisense RNA to DNA polymerase zeta. J. Immunol. 167, 327–335 (2001)

    CAS  Article  Google Scholar 

  27. Johnson, R. E., Washington, M. T., Haracska, L., Prakash, S. & Prakash, L. Eukaryotic polymerases iota and zeta act sequentially to bypass DNA lesions. Nature 406, 1015–1019 (2000)

    ADS  CAS  Article  Google Scholar 

  28. Mittrucker, H. W., Muller-Fleckenstein, I., Fleckenstein, B. & Fleischer, B. Herpes virus saimiri-transformed human T lymphocytes: normal functional phenotype and preserved T cell receptor signalling. Int. Immunol. 5, 985–990 (1993)

    CAS  Article  Google Scholar 

  29. de Wind, N., Dekker, M., Berns, A., Radman, M. & te Riele, H. Inactivation of the mouse Msh2 gene results in mismatch repair deficiency, methylation tolerance, hyperrecombination, and predisposition to cancer. Cell 82, 321–330 (1995)

    CAS  Article  Google Scholar 

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We thank B. Fleckenstein for the CB15 cell line; H. Mossafa for the cytogenetic analysis of pol-ι-null clones; R. Woodgate for pol-ι -specific reagents; M. Radman for critically editing the manuscript. This work was supported by the Fondation Princesse Grace de Monaco and the Ligue Nationale Française contre le Cancer (Equipe labellisée). A.F. and S.A. have been supported during part of this work by the Fondation de France (Fondation contre la Leucémie). C.-A.R. and J.-C.W. share senior authorship.

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Correspondence to Jean-Claude Weill.

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Faili, A., Aoufouchi, S., Flatter, E. et al. Induction of somatic hypermutation in immunoglobulin genes is dependent on DNA polymerase iota. Nature 419, 944–947 (2002).

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