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CpG motifs: the active ingredient in bacterial extracts?

Abstract

The use of bacteria and bacterial extracts for immunotherapy has a checkered past. Recent developments in immunology reveal that these nonspecific immune activators actually work by triggering specific receptors that are expressed by subsets of immune cells. Identification of these receptors and the molecular signaling pathways that they activate has enabled a new era of specific targeted immunotherapy using chemically synthesized mimics of pathogen molecules.

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Figure 1: CpG cellular mechanism of action.

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References

  1. Coley, W.B. The treatment of malignant tumors by repeated inoculations of erysipelas: with a report of ten original cases. Am. J. Med. Sci. 105, 487–511 (1893).

    Article  Google Scholar 

  2. Wiemann, B. & Starnes, C.O. Coley's toxins, tumor necrosis factor and cancer research: a historical perspective. Pharmacol. Ther. 64, 529–564 (1994).

    Article  CAS  PubMed  Google Scholar 

  3. Zuany-Amorim, C. et al. Suppression of airway eosinophilia by killed Mycobacterium vaccae–induced allergen-specific regulatory T cells. Nat. Med. 8, 625–629 (2002).

    Article  CAS  PubMed  Google Scholar 

  4. Janeway, C.A. Jr. & Medzhitov, R. Innate immune recognition. Annu. Rev. Immunol. 20, 197–216 (2002).

    Article  CAS  PubMed  Google Scholar 

  5. Ahmad-Nejad, P. et al. Bacterial CpG-DNA and lipopolysaccharides activate Toll-like receptors at distinct cellular compartments. Eur. J. Immunol. 32, 1958–1968 (2002).

    Article  CAS  PubMed  Google Scholar 

  6. Hemmi, H. et al. A Toll-like receptor recognizes bacterial DNA. Nature 408, 740–745 (2000).

    Article  CAS  PubMed  Google Scholar 

  7. Hornung, V. et al. Quantitative expression of toll-like receptor 1-10 mRNA in cellular subsets of human peripheral blood mononuclear cells and sensitivity to CpG oligodeoxynucleotides. J. Immunol. 168, 4531–4537 (2002).

    Article  CAS  PubMed  Google Scholar 

  8. Krug, A. et al. Toll-like receptor expression reveals CpG DNA as a unique microbial stimulus for plasmacytoid dendritic cells which synergizes with CD40 ligand to induce high amounts of IL-12. Eur. J Immunol. 31, 3026–3037 (2001).

    Article  CAS  PubMed  Google Scholar 

  9. Kadowaki, N. et al. Subsets of human dendritic cell precursors express different toll-like receptors and respond to different microbial antigens. J Exp. Med. 194, 863–870 (2001).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  10. Bauer, S. et al. Human TLR9 confers responsiveness to bacterial DNA via species-specific CpG motif recognition. Proc. Natl. Acad. Sci. USA 98, 9237–9242 (2001).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  11. Ahonen, C.L. et al. Dendritic cell maturation and subsequent enhanced T-cell stimulation induced with the novel synthetic immune response modifier R-848. Cell Immunol. 197, 62–72 (1999).

    Article  CAS  PubMed  Google Scholar 

  12. Vasilakos, J.P. et al. Adjuvant activities of immune response modifier R-848: comparison with CpG ODN. Cell Immunol. 204, 64–74 (2000).

    Article  CAS  PubMed  Google Scholar 

  13. Ito, T. et al. Interferon-alpha and interleukin-12 are induced differentially by Toll- like receptor 7 ligands in human blood dendritic cell subsets. J. Exp. Med. 195, 1507–1512 (2002).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  14. Jurk, M. et al. Human TLR7 or TLR8 independently confer responsiveness to the antiviral compound R-848. Nat. Immunol. 3, 499 (2002).

    Article  CAS  PubMed  Google Scholar 

  15. Biron, C.A., Nguyen, K.B. & Pien, G.C. Innate immune responses to LCMV infections: natural killer cells and cytokines. Curr. Top. Microbiol. Immunol. 263, 7–27 (2002).

    CAS  PubMed  Google Scholar 

  16. Yamamoto, M. et al. Essential role for TIRAP in activation of the signalling cascade shared by TLR2 and TLR4. Nature 420, 324–329 (2002).

    Article  CAS  PubMed  Google Scholar 

  17. Horng, T., Barton, G.M., Flavell, R.A. & Medzhitov, R. The adaptor molecule TIRAP provides signalling specificity for Toll- like receptors. Nature 420, 329–333 (2002).

    Article  CAS  PubMed  Google Scholar 

  18. Yamamoto, M et al.Cutting edge: a novel Toll/IL-1 receptor domain–containing adapter that preferentially activates the IFN-beta promoter in the Toll-like receptor signalling. J. Immuno. 169, 6668–6672 (2002).

  19. Tokunaga, T., Yamamoto, T. & Yamamoto, S. How BCG led to the discovery of immunostimulatory DNA. Jpn. J. Infect. Dis. 52, 1–11 (1999).

    CAS  PubMed  Google Scholar 

  20. Brown, W.C., Estes, D.M., Chantler, S.E., Kegerreis, K.A. & Suarez, C.E. DNA and a CpG oligonucleotide derived from Babesia bovis are mitogenic for bovine B cells. Infect. Immun. 66, 5423–5432 (1998).

    CAS  PubMed  PubMed Central  Google Scholar 

  21. Ronaghy, A. et al. Immunostimulatory DNA sequences influence the course of adjuvant arthritis. J. Immunol. 168, 51–56 (2002).

    Article  CAS  PubMed  Google Scholar 

  22. Krieg, A.M. et al. CpG motifs in bacterial DNA trigger direct B-cell activation. Nature 374, 546–549 (1995).

    Article  CAS  PubMed  Google Scholar 

  23. Krieg, A.M. CpG motifs in bacterial DNA and their immune effects. Annu. Rev. Immunol. 20, 709–760 (2002).

    Article  CAS  PubMed  Google Scholar 

  24. Krug, A. et al. Identification of CpG oligonucleotide sequences with high induction of IFN-alpha/beta in plasmacytoid dendritic cells. Eur. J. Immunol. 31, 2154–2163 (2001).

    Article  CAS  PubMed  Google Scholar 

  25. Wild, J., Grusby, M.J., Schirmbeck, R. & Reimann, J. Priming MHC-I-restricted cytotoxic T lymphocyte responses to exogenous hepatitis B surface antigen is CD4+ T cell dependent. J. Immunol. 163, 1880–1887 (1999).

    CAS  PubMed  Google Scholar 

  26. Sparwasser, T., Vabulas, R.M., Villmow, B., Lipford, G.B. & Wagner, H. CpG-DNA activates dendritic cells in vivo: T helper cell-independent cytotoxic T cell responses to soluble proteins. Eur. J Immunol. 30, 3591–3597 (2000).

    Article  CAS  PubMed  Google Scholar 

  27. Klinman, D.M., Verthelyi, D., Takeshita, F. & Ishii, K.J. Immune recognition of foreign DNA: a cure for bioterrorism? Immunity. 11, 123–129 (1999).

    Article  CAS  PubMed  Google Scholar 

  28. Sethi, S., Lipford, G., Wagner, H. & Kretzschmar, H. Postexposure prophylaxis against prion disease with a stimulator of innate immunity. Lancet 360, 229–230 (2002).

    Article  PubMed  Google Scholar 

  29. Kline, J.N. et al. Modulation of airway inflammation by CpG oligodeoxynucleotides in a murine model of asthma. J. Immunol. 160, 2555–2559 (1998).

    CAS  PubMed  Google Scholar 

  30. Jain, V.V. et al. CpG-oligodeoxynucleotides inhibit airway remodeling in a murine model of chronic asthma. J. Allergy Clin. Immunol. 110, 867–872 (2002).

    Article  CAS  PubMed  Google Scholar 

  31. Creticos, P.S. et al. Immunotherapy with immunostimulatory oligonucleotides linked to purified ragweed Amb-α1 allergen: effects on antibody production, nasal allergen provocation, and ragweed seasonal rhinitis. J. Allergy Clin. Immunol. 109, 742–743 (2002).

    Google Scholar 

  32. Kim, S.K. et al. Comparison of the effect of different immunological adjuvants on the antibody and T-cell response to immunization with MUC1-KLH and GD3-KLH conjugate cancer vaccines. Vaccine 18, 597–603 (1999).

    Article  CAS  PubMed  Google Scholar 

  33. Chu, R.S., Targoni, O.S., Krieg, A.M., Lehmann, P.V. & Harding, C.V. CpG oligodeoxynucleotides act as adjuvants that switch on T helper 1 (Th1) immunity. J. Exp. Med. 186, 1623–1631 (1997).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  34. Davis, H.L. Use of CpG DNA for enhancing specific immune responses. Curr. Top. Microbiol. Immunol. 247, 171–183 (2000).

    CAS  PubMed  Google Scholar 

  35. Heckelsmiller, K. et al. Peritumoral CpG DNA elicits a coordinated response of CD8 T cells and innate effectors to cure established tumors in a murine colon carcinoma model. J. Immunol. 169, 3892–3899 (2002).

    Article  CAS  PubMed  Google Scholar 

  36. Ballas, Z.K. et al. Divergent therapeutic and immunologic effects of oligodeoxynucleotides with distinct CpG motifs. J. Immunol. 167, 4878–4886 (2001).

    Article  CAS  PubMed  Google Scholar 

  37. Kawarada, Y. et al. NK- and CD8(+) T cell-mediated eradication of established tumors by peritumoral injection of CpG-containing oligodeoxynucleotides. J. Immunol. 167, 5247–5253 (2001).

    Article  CAS  PubMed  Google Scholar 

  38. Carpentier, A.F., Xie, J., Mokhtari, K. & Delattre, J.Y. Successful treatment of intracranial gliomas in rat by oligodeoxynucleotides containing CpG motifs. Clin. Cancer Res. 6, 2469–2473 (2000).

    CAS  PubMed  Google Scholar 

  39. Davila, E. & Celis, E. Repeated administration of cytosine-phosphorothiolated guanine- containing oligonucleotides together with peptide/protein immunization results in enhanced CTL responses with anti-tumor activity. J. Immunol. 165, 539–547 (2000).

    Article  CAS  PubMed  Google Scholar 

  40. Davis, H.L. et al. CpG DNA overcomes hyporesponsiveness to hepatitis B vaccine in orangutans. Vaccine 18, 1920–1924 (2000).

    Article  CAS  PubMed  Google Scholar 

  41. Jones, T.R. et al. Synthetic oligodeoxynucleotides containing CpG motifs enhance immunogenicity of a peptide malaria vaccine in Aotus monkeys. Vaccine 17, 3065–3071 (1999).

    Article  CAS  PubMed  Google Scholar 

  42. Roman, M. et al. Immunostimulatory DNA sequences function as T helper-1-promoting adjuvants. Nat. Med. 3, 849–854 (1997).

    Article  CAS  PubMed  Google Scholar 

  43. Lipford, G.B. et al. CpG-containing synthetic oligonucleotides promote B and cytotoxic T cell responses to protein antigen: a new class of vaccine adjuvants. Eur. J. Immunol. 27, 2340–2344 (1997).

    Article  CAS  PubMed  Google Scholar 

  44. Weiner, G.J., Liu, H.M., Wooldridge, J.E., Dahle, C.E. & Krieg, A.M. Immunostimulatory oligodeoxynucleotides containing the CpG motif are effective as immune adjuvants in tumor antigen immunization. Proc. Natl. Acad. Sci. USA 94, 10833–10837 (1997).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  45. Zwaveling, S. et al. Established human papillomavirus type 16-expressing tumors are effectively eradicated following vaccination with long peptides. J. Immunol. 169, 350–358 (2002).

    Article  CAS  PubMed  Google Scholar 

  46. Stern, B.V., Boehm, B.O. & Tary-Lehmann, M. Vaccination with tumor peptide in CpG adjuvant protects via IFN-gamma- dependent CD4 cell immunity. J. Immunol. 168, 6099–6105 (2002).

    Article  CAS  PubMed  Google Scholar 

  47. Egeter, O., Mocikat, R., Ghoreschi, K., Dieckmann, A. & Rocken, M. Eradication of disseminated lymphomas with CpG-DNA activated T helper type 1 cells from nontransgenic mice. Cancer Res. 60, 1515–1520 (2000).

    CAS  PubMed  Google Scholar 

  48. Miconnet, I. et al. CpG are efficient adjuvants for specific CTL induction against tumor antigen-derived peptide. J. Immunol. 168, 1212–1218 (2002).

    Article  CAS  PubMed  Google Scholar 

  49. Blazar, B.R., Krieg, A.M. & Taylor, P.A. Synthetic unmethylated cytosine-phosphate-guanosine oligodeoxynucleotides are potent stimulators of antileukemia responses in naive and bone marrow transplant recipients. Blood 98, 1217–1225 (2001).

    Article  CAS  PubMed  Google Scholar 

  50. Heckelsmiller, K. et al. Combined dendritic cell- and CpG oligonucleotide-based immune therapy cures large murine tumors that resist chemotherapy. Eur. J Immunol. 32, 3235–3245 (2002).

    Article  CAS  PubMed  Google Scholar 

  51. Liu, H.M. et al. Immunostimulatory CpG oligodeoxynucleotides enhance the immune response to vaccine strategies involving granulocyte-macrophage colony- stimulating factor. Blood 92, 3730–3736 (1998).

    CAS  PubMed  Google Scholar 

  52. Sandler, A.D. et al. CpG oligonucleotides enhance the tumor antigen-specific immune response of a granulocyte macrophage colony-stimulating factor-based vaccine strategy in neuroblastoma. Cancer Res. 63, 394–399 (2003).

    CAS  PubMed  Google Scholar 

  53. Sfondrini, L. et al. Prevention of spontaneous mammary adenocarcinoma in HER-2/neu transgenic mice by foreign DNA. FASEB J. 16, 1749–1754 (2002).

    Article  CAS  PubMed  Google Scholar 

  54. Smith, J.B. & Wickstrom, E. Antisense c-myc and immunostimulatory oligonucleotide inhibition of tumorigenesis in a murine B-cell lymphoma transplant model. J. Natl. Cancer Inst. 90, 1146–1154 (1998).

    Article  CAS  PubMed  Google Scholar 

  55. Grossmann, M.E., Davila, E. & Celis, E. Avoiding tolerance against prostatic antigens with subdominant peptide epitopes. J. Immunother. 24, 237–241 (2001).

    Article  CAS  PubMed  Google Scholar 

  56. Hartmann, G. et al. Delineation of a CpG phosphorothioate oligodeoxynucleotide for activating primate immune responses in vitro and in vivo. J. Immunol. 164, 1617–1624 (2000).

    Article  CAS  PubMed  Google Scholar 

  57. Krieg, A.M. From A to Z on CpG. Trends Immunol. 23, 64–65 (2002).

    Article  CAS  PubMed  Google Scholar 

  58. Thoelen, S. et al. Safety and immunogenicity of a hepatitis B vaccine formulated with a novel adjuvant system. Vaccine 16, 708–714 (1998).

    Article  CAS  PubMed  Google Scholar 

  59. Ambrosch, F. et al. A hepatitis B vaccine formulated with a novel adjuvant system. Vaccine 18, 2095–2101 (2000).

    Article  CAS  PubMed  Google Scholar 

  60. van Ojik,, H. et al. Phase I/II study with CpG 7909 as adjuvant to vaccination with MAGE-3 protein in patients with MAGE-3 positive tumors. Ann.Oncol. 13, 157 (2003).

    Google Scholar 

  61. Martin, P. et al. Characterization of a new subpopulation of mouse CD8alpha+ B220+ dendritic cells endowed with type 1 interferon production capacity and tolerogenic potential. Blood 100, 383–390 (2002).

    Article  CAS  PubMed  Google Scholar 

  62. Kuwana, M., Kaburaki, J., Wright, T.M., Kawakami, Y. & Ikeda, Y. Induction of antigen-specific human CD4(+) T cell anergy by peripheral blood DC2 precursors. Eur. J. Immunol. 31, 2547–2557 (2001).

    Article  CAS  PubMed  Google Scholar 

  63. Ferguson, T.A. et al. Uptake of apoptotic antigen-coupled cells by lymphoid dendritic cells and cross-priming of CD8(+) T cells produce active immune unresponsiveness. J. Immunol. 168, 5589–5595 (2002).

    Article  CAS  PubMed  Google Scholar 

  64. Leadbetter, E.A. et al. Chromatin-IgG complexes activate B cells by dual engagement of IgM and Toll-like receptors. Nature 416, 603–607 (2002).

    Article  CAS  PubMed  Google Scholar 

  65. Goeckeritz, B.E. et al. Multivalent cross-linking of membrane Ig sensitizes murine B cells to a broader spectrum of CpG-containing oligodeoxynucleotide motifs, including their methylated counterparts, for stimulation of proliferation and Ig secretion. Int. Immunol. 11, 1693–1700 (1999).

    Article  CAS  PubMed  Google Scholar 

  66. Wang, Y. & Krieg, A.M. Synergy between CpG- or non-CpG DNA and specific antigen for B cell activation. Int. Immunol. 15, 223–231 (2003).

    Article  CAS  PubMed  Google Scholar 

  67. Krieg, A.M. A role for Toll in autoimmunity. Nat. Immunol. 3, 423–424 (2002).

    Article  CAS  PubMed  Google Scholar 

  68. Mor, G. et al. Do DNA vaccines induce autoimmune disease? Hum. Gene Ther. 8, 293–300 (1997).

    Article  CAS  PubMed  Google Scholar 

  69. Yi, A.K. et al. CpG motifs in bacterial DNA activate leukocytes through the pH-dependent generation of reactive oxygen species. J. Immunol. 160, 4755–4761 (1998).

    CAS  PubMed  Google Scholar 

  70. Macfarlane, D.E. & Manzel, L. Antagonism of immunostimulatory CpG-oligodeoxynucleotides by quinacrine, chloroquine, and structurally related compounds. J. Immunol. 160, 1122–1131 (1998).

    CAS  PubMed  Google Scholar 

  71. Hacker, H. et al. CpG-DNA-specific activation of antigen-presenting cells requires stress kinase activity and is preceded by non-specific endocytosis and endosomal maturation. EMBO J. 17, 6230–6240 (1998).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  72. Krieg, A.M. et al. Sequence motifs in adenoviral DNA block immune activation by stimulatory CpG motifs. Proc. Natl. Acad. Sci. USA 95, 12631–12636 (1998).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  73. Lenert, P., Stunz, L.L., Yi, A.K., Krieg, A.M. & Ashman, R.F. CpG Stimulation of primary mouse B cells is blocked by inhibitory oligodeoxyribonucleotides at a site proximal to NF-kB activation. Antisense Nucleic Acid Drug Dev. 11, 247–256 (2001).

    Article  CAS  PubMed  Google Scholar 

  74. Stacey, K.J. et al. The molecular basis for the lack of immunostimulatory activity of vertebrate DNA. J. Immunol. 170, 3614–3620 (2003).

    Article  CAS  PubMed  Google Scholar 

  75. Zeuner, R.A. et al. Reduction of CpG–induced arthritis by suppressive oligodeoxynucleotides. Arthritis Rheum. 46, 2219–2224 (2002).

    Article  CAS  PubMed  Google Scholar 

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Krieg, A. CpG motifs: the active ingredient in bacterial extracts?. Nat Med 9, 831–835 (2003). https://doi.org/10.1038/nm0703-831

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