Murine Microglia Immunostimulatory CpG-DNA Activates

Bacterial DNA containing motifs of unmethylated CpG dinucleotides (CpG-DNA) triggers innate immune cells through the pattern recognition receptor Toll-like receptor 9 (TLR-9). CpG-DNA possesses potent immunostimulatory effects on macrophages, dendritic cells, and B lymphocytes. Therefore, CpG-DNA contributes to inflammation during the course of bacterial infections. In contrast to other TLR-dependent microbial patterns, CpG-DNA is a strong inductor of IL-12. Thus, it acts as a Th1-polarizing agent that can be utilized as potent vaccine adjuvant. To assess the role of CpG-DNA in immune reactions in the CNS, we analyzed the effects of CpG-DNA on microglial cells in vitro and in vivo. Primary microglial cells as well as microglial cell lines express TLR-9 mRNA. Consequently, CpG-DNA activated microglial cells in vitro and induced TNF- (cid:1) , IL-12p40, IL-12p70, and NO. Furthermore, MHC class II, B7-1, B7-2, and CD40 molecules were up-regulated. In addition, phagocytic activity of microglia was enhanced. After intracerebroventricular injection of CpG-DNA, microglial cells were activated and produced TNF- (cid:1) and IL-12p40 transcripts, as shown by in situ hybridization. These results indicate that microglia is sensitive to CpG-DNA. Thus, bacterial DNA containing CpG motifs could not only play an important role during infections of the CNS, but also might trigger and sustain Th1-dominated immunopathogenic reactions. The Journal of Immunology, 2002, 168: 4854–4863.

[1]  N. Janabi,et al.  Activation of microglia and astrocytes by CpG oligodeoxynucleotides , 2001, Neuroreport.

[2]  N. Kadowaki,et al.  Subsets of Human Dendritic Cell Precursors Express Different Toll-like Receptors and Respond to Different Microbial Antigens , 2001, The Journal of experimental medicine.

[3]  S. Akira,et al.  Toll-like receptors: critical proteins linking innate and acquired immunity , 2001, Nature Immunology.

[4]  S. Akira,et al.  Human TLR9 confers responsiveness to bacterial DNA via species-specific CpG motif recognition , 2001, Proceedings of the National Academy of Sciences of the United States of America.

[5]  P. Ricciardi-Castagnoli,et al.  Developmental plasticity of CNS microglia , 2001, Proceedings of the National Academy of Sciences of the United States of America.

[6]  S. Akira,et al.  The innate immune response to bacterial flagellin is mediated by Toll-like receptor 5 , 2001, Nature.

[7]  G. Reichmann,et al.  Brain Dendritic Cells and Macrophages/Microglia in Central Nervous System Inflammation1 , 2001, The Journal of Immunology.

[8]  J. Schwab,et al.  Transient in vivo activation of rat brain macrophages/microglial cells and astrocytes by immunostimulatory multiple CpG oligonucleotides , 2001, Journal of Neuroimmunology.

[9]  S. Dower,et al.  Regulation of Toll-Like Receptors in Human Monocytes and Dendritic Cells1 , 2001, The Journal of Immunology.

[10]  S. Rivest,et al.  Toll‐like receptor 4: the missing link of the cerebral innate immune response triggered by circulating gram‐negative bacterial cell wall components , 2001, FASEB journal : official publication of the Federation of American Societies for Experimental Biology.

[11]  Z. Kokaia.  In Situ Hybridization Histochemistry , 2000, Current protocols in toxicology.

[12]  S. Akira,et al.  A Toll-like receptor recognizes bacterial DNA , 2000, Nature.

[13]  U. Renner,et al.  Lipopolysaccharide Directly Stimulates the Intrapituitary Interleukin-6 Production by Folliculostellate Cells via Specific Receptors and the p 38 a Mitogen-Activated Protein Kinase / Nuclear Factor-k B Pathway , 2000 .

[14]  M. Netea,et al.  Circulating cytokines as mediators of fever. , 2000, Clinical infectious diseases : an official publication of the Infectious Diseases Society of America.

[15]  S. Akira,et al.  Recognition of CpG DNA is mediated by signaling pathways dependent on the adaptor protein MyD88 , 2000, Current Biology.

[16]  P. Ghezzi,et al.  Lps induces IL-6 in the brain and in serum largely through TNF production. , 2000, Cytokine.

[17]  John T. Chang,et al.  CpG Oligonucleotides Are Potent Adjuvants for the Activation of Autoreactive Encephalitogenic T Cells In Vivo , 2000, The Journal of Immunology.

[18]  K. Mokhtari,et al.  Successful treatment of intracranial gliomas in rat by oligodeoxynucleotides containing CpG motifs. , 2000, Clinical cancer research : an official journal of the American Association for Cancer Research.

[19]  Robert B Sim,et al.  Complement C1q Is Dramatically Up-Regulated in Brain Microglia in Response to Transient Global Cerebral Ischemia1 2 , 2000, The Journal of Immunology.

[20]  A. Krieg,et al.  The role of CpG motifs in innate immunity. , 2000, Current opinion in immunology.

[21]  P. Klenerman,et al.  The effects of DNA containing CpG motif on dendritic cells , 1998, Immunology.

[22]  W. Brown,et al.  Modulation of host immune responses by protozoal DNA. , 1999, Veterinary immunology and immunopathology.

[23]  E. Raz,et al.  Immunostimulatory DNA and applications to allergic disease. , 1999, The Journal of allergy and clinical immunology.

[24]  B. Bloom,et al.  Host defense mechanisms triggered by microbial lipoproteins through toll-like receptors. , 1999, Science.

[25]  R. Fujinami,et al.  Exacerbation of Viral and Autoimmune Animal Models for Multiple Sclerosis by Bacterial DNA , 1999, Brain pathology.

[26]  S. Akira,et al.  Unresponsiveness of MyD88-deficient mice to endotoxin. , 1999, Immunity.

[27]  S. Jander,et al.  The role of microglia and macrophages in the pathophysiology of the CNS , 1999, Progress in Neurobiology.

[28]  G. Koretzky,et al.  Differential regulation of the IL-12 p40 promoter and of p40 secretion by CpG DNA and lipopolysaccharide. , 1999, Journal of immunology.

[29]  M. Prinz,et al.  Murine Microglial Cells Produce and Respond to Interleukin‐18 , 1999, Journal of neurochemistry.

[30]  S. Akira,et al.  Cutting edge: Toll-like receptor 4 (TLR4)-deficient mice are hyporesponsive to lipopolysaccharide: evidence for TLR4 as the Lps gene product. , 1999, Journal of immunology.

[31]  H. Dickensheets,et al.  Inhibition of IL‐4‐inducible gene expression in human monocytes by type I and type II interferons , 1999, Journal of leukocyte biology.

[32]  T. Bártfai,et al.  Fever: Links with an ancient receptor , 1999, Current Biology.

[33]  H. Wagner,et al.  Bacterial CpG DNA activates immune cells to signal infectious danger. , 1999, Advances in immunology.

[34]  P. Ricciardi-Castagnoli,et al.  Defective LPS signaling in C3H/HeJ and C57BL/10ScCr mice: mutations in Tlr4 gene. , 1998, Science.

[35]  H. Mischak,et al.  CpG‐DNA‐specific activation of antigen‐presenting cells requires stress kinase activity and is preceded by non‐specific endocytosis and endosomal maturation , 1998, The EMBO journal.

[36]  T. Wu,et al.  Sequence motifs in adenoviral DNA block immune activation by stimulatory CpG motifs. , 1998, Proceedings of the National Academy of Sciences of the United States of America.

[37]  C. Janeway,et al.  MyD88 is an adaptor protein in the hToll/IL-1 receptor family signaling pathways. , 1998, Molecular cell.

[38]  S. Saccani,et al.  The Human Toll Signaling Pathway: Divergence of Nuclear Factor κB and JNK/SAPK Activation Upstream of Tumor Necrosis Factor Receptor–associated Factor 6 (TRAF6) , 1998, The Journal of experimental medicine.

[39]  K. Heeg,et al.  CpG oligodeoxynucleotides trigger protective and curative Th1 responses in lethal murine leishmaniasis. , 1998, Journal of immunology.

[40]  Manuel Buttini,et al.  Lipopolysaccharide induces expression of tumour necrosis factor alpha in rat brain: inhibition by methylprednisolone and by rolipram , 1997, British journal of pharmacology.

[41]  C. Harding,et al.  CpG Oligodeoxynucleotides Act as Adjuvants that Switch on T Helper 1 (Th1) Immunity , 1997, The Journal of experimental medicine.

[42]  C. Janeway,et al.  Innate Immunity: The Virtues of a Nonclonal System of Recognition , 1997, Cell.

[43]  E. Shevach,et al.  Microbial products induce autoimmune disease by an IL-12-dependent pathway. , 1997, Journal of immunology.

[44]  H. Kimura,et al.  In vivo induction of inducible nitric oxide synthase by microinjection with interferon‐γ and lipopolysaccharide in rat hippocampus , 1996 .

[45]  M. Schäfer,et al.  Follicular dendritic cells, interdigitating cells, and cells of the monocyte-macrophage lineage are the C1q-producing sources in the spleen. Identification of specific cell types by in situ hybridization and immunohistochemical analysis. , 1995, Journal of immunology.

[46]  G. Bishop,et al.  CpG motifs in bacterial DNA trigger direct B-cell activation , 1995, Nature.

[47]  N. Rothwell,et al.  Cytokines and the nervous system I: expression and recognition , 1995, Trends in Neurosciences.

[48]  E. London.  Imaging Drug Action in the Brain , 1992 .

[49]  R. Steinman,et al.  Generation of large numbers of dendritic cells from mouse bone marrow cultures supplemented with granulocyte/macrophage colony-stimulating factor , 1992, The Journal of experimental medicine.

[50]  E. Benveniste.  Inflammatory cytokines within the central nervous system: sources, function, and mechanism of action. , 1992, The American journal of physiology.

[51]  N. Shastri,et al.  Detection of rare antigen-presenting cells by the lacZ T-cell activation assay suggests an expression cloning strategy for T-cell antigens. , 1992, Proceedings of the National Academy of Sciences of the United States of America.

[52]  R. Crooke.  In vitro toxicology and pharmacokinetics of antisense oligonucleotides. , 1991, Anti-cancer drug design.

[53]  V. Perry,et al.  Heterogeneity in the distribution and morphology of microglia in the normal adult mouse brain , 1990, Neuroscience.

[54]  F. Bistoni,et al.  Immortalization of murine microglial cells by a v-raf / v-myc carrying retrovirus , 1990, Journal of Neuroimmunology.

[55]  R. Angerer,et al.  Demonstration of tissue-specific gene expression by in situ hybridization. , 1987, Methods in enzymology.

[56]  K. Frei,et al.  Astrocyte-derived interleukin 3 as a growth factor for microglia cells and peritoneal macrophages. , 1986, Journal of immunology.

[57]  D. Melton,et al.  Efficient in vitro synthesis of biologically active RNA and RNA hybridization probes from plasmids containing a bacteriophage SP6 promoter. , 1984, Nucleic acids research.

[58]  C. Barker,et al.  Immunologically privileged sites. , 1977, Advances in immunology.