A Novel Function of a CXC-Type Chemokine CXCL14 As a Specific Carrier of CpG DNA into Dendritic Cells for Activating Toll-like Receptor 9-Mediated Adaptive Immunity

Abstract CXCL14 is a primordial CXC-type chemokine that induces migration of immature dendritic cells (DCs), tissue resident macrophages, and natural killer cells. It has been reported that CXCL14 plays multiple roles in tumor suppression, exacerbation of autoimmune arthritis, and induction of obesity-associated insulin resistance. However, underlying molecular mechanisms of these phenomena remain to be elucidated. Although CXCL14 binds to the CXCL12 receptor CXCR4 with high affinity, chemoattractive activity of CXCL14 is much weaker than CXCL12. In this study, we newly discovered that CXCL14 specifically binds to CpG DNA and activates Toll-like receptor 9 (TLR9), thereby inducing inflammatory cytokines such as IL-6, IL-12 p40, and TNFa in mouse bone marrow-derived dendritic cells (BMDCs). Cell surface expression levels of MHC class-II and CD86 in BMDCs were also enhanced by the combination of CpG DNA and CXCL14. In this experimental setting, CXCL14 interacted with certain classes of CpG DNA, but not with RNA ligands for TLR3 and TLR8. In addition, this CpG DNA-cooperative activity was not present in CXCL8 and CXCL12, excluding a nonspecific interaction between CpG DNA and an alkaline chemokine. In BMDCs and inguinal lymph node DCs, intracellular transport of a low concentration of CpG DNA was greatly enhanced by the addition of CXCL14. Confocal microscopical analyses revealed that CpG DNA and CXCL14 mainly co-localized in EEA1+ endosome and LAMP1+ lysosomal compartments where TLR9 is present. Furthermore, we demonstrated that CXCL14 binds to CpG DNA in vitro in the neutral pH condition with high affinity (Kd=9.8 nM). This interaction was completely dissociated in pH 6.0, implying that CpG DNA can be released and passed to TLR9 in the endosome and lysosome. Consistent with our hypothesis, induction of IL-12 p40, MHC class-II, and CD86 by the combination of CpG DNA and CXCL14 was not observed in BMDCs derived from TLR9 knockout (KO) mice. Moreover, after systemic administration of CpG DNA, plasma concentration of IL-12 p40 and frequency of MHC-class II+CD11c+CD8+DCs in spleen were significantly decreased in CXCL14-deficient mice when compared to littermate control mice. Taken together, these results demonstrated that CXCL14 serves as a specific carrier for CpG DNA into conventional DCs for activating TLR9-mediated adaptive immune system. This is also the first demonstration of a DNA sensing function of chemokine. The combination of CXCL14 and CpG DNA would be a promising vaccine adjuvant for enhancing immnunosurveillance against pathogens and malignant cancers. Disclosures Tanegashima: Tokyo Metropolitan Institute of Medical Science: Patents & Royalties. Takahashi:Tokyo Metropolitan Institute of Medical Science: Patents & Royalties. Tsuji:Tokushima University: Patents & Royalties. Shigenaga:Tokushima University: Patents & Royalties. Otaka:Tokushima University: Patents & Royalties.

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Purification and Characterization of MHC Class II Containing Organelles in Mouse Bone-Marrow-Derived Dendritic Cells

Dendritic Cell Protocols ◽

10.1385/1-59259-150-7:413 ◽

2003 ◽

pp. 413-422

Author(s):

Philippe Pierre

Keyword(s):

Bone Marrow ◽

Dendritic Cells ◽

Mhc Class Ii ◽

Class Ii ◽

Mouse Bone Marrow ◽

Purification And Characterization

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In vitro induction of lymph node cell proliferation by mouse bone marrow dendritic cells following stimulation with different Echinococcus multilocularis antigens

Journal of Helminthology ◽

10.1017/s0022149x10000878 ◽

2011 ◽

Vol 85 (2) ◽

pp. 128-137 ◽

Cited By ~ 6

Author(s):

M.C. Margos ◽

D. Grandgirard ◽

S. Leib ◽

Bruno Gottstein

Keyword(s):

Bone Marrow ◽

Dendritic Cells ◽

Lymph Node ◽

Mhc Class Ii ◽

Echinococcus Multilocularis ◽

Class Ii ◽

Striking Difference ◽

Mouse Bone Marrow ◽

Expression Levels ◽

Tnf Α

AbstractThe immune response of mice experimentally infected with Echinococcus multilocularis metacestodes becomes impaired so as to allow parasite survival and proliferation. Our study tackled the question on how different classes of E. multilocularis antigens (crude vesicular fluid (VF); purified proteinic rec-14-3-3; purified carbohydrate Em2(G11)) are involved in the maturation process of bone-marrow-derived dendritic cells (BMDCs) and subsequent exposure to lymph node (LN) cells. In our experiments, we used BMDCs cultivated from either naïve (control) or alveolar echinococcosis (AE)-infected C57BL/6 mice. We then tested surface markers (CD80, CD86, MHC class II) and cytokine expression levels (interleukin (IL)-10, IL-12p40 and tumour necrosis factor (TNF)-α) of non-stimulated BMDCs versus BMDCs stimulated with different Em-antigens or lipopolysaccharide (LPS). While LPS and rec-14-3-3-antigen were able to induce CD80, CD86 and (to a lower extent) MHC class II surface expression, Em2(G11) and, strikingly, also VF-antigen failed to do so. Similarly, LPS and rec-14-3-3 yielded elevated IL-12, TNF-α and IL-10 expression levels, while Em2(G11) and VF-antigen didn't. When naïve BMDCs were loaded with VF-antigen, they induced a strong non-specific proliferation of uncommitted LN cells. For both, BMDCs or LN cells, isolated from AE-infected mice, proliferation was abrogated. The most striking difference, revealed by comparing naïve with AE-BMDCs, was the complete inability of LPS-stimulated AE-BMDCs to activate lymphocytes from any LN cell group. Overall, the presenting activity of BMDCs from AE-infected mice seemed to trigger unresponsiveness in T cells, especially in the case of VF-antigen stimulation, thus contributing to the suppression of clonal expansion during the chronic phase of AE infection.

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Maturation of Dendritic Cells Is Accompanied by Rapid Transcriptional Silencing of Class II Transactivator (Ciita) Expression

Journal of Experimental Medicine ◽

10.1084/jem.194.4.379 ◽

2001 ◽

Vol 194 (4) ◽

pp. 379-392 ◽

Cited By ~ 112

Author(s):

Salomé Landmann ◽

Annick Mühlethaler-Mottet ◽

Luca Bernasconi ◽

Tobias Suter ◽

Jean-Marc Waldburger ◽

...

Keyword(s):

Dendritic Cells ◽

Cell Surface ◽

De Novo ◽

Regulatory Region ◽

Class Ii ◽

Histone Deacetylation ◽

Cell Surface Expression ◽

Interferon Α ◽

Mouse Bone Marrow ◽

Class Ii Transactivator

Cell surface expression of major histocompatibility complex class II (MHCII) molecules is increased during the maturation of dendritic cells (DCs). This enhances their ability to present antigen and activate naive CD4+ T cells. In contrast to increased cell surface MHCII expression, de novo biosynthesis of MHCII mRNA is turned off during DC maturation. We show here that this is due to a remarkably rapid reduction in the synthesis of class II transactivator (CIITA) mRNA and protein. This reduction in CIITA expression occurs in human monocyte-derived DCs and mouse bone marrow–derived DCs, and is triggered by a variety of different maturation stimuli, including lipopolysaccharide, tumor necrosis factor α, CD40 ligand, interferon α, and infection with Salmonella typhimurium or Sendai virus. It is also observed in vivo in splenic DCs in acute myelin oligodendrocyte glycoprotein induced experimental autoimmune encephalitis. The arrest in CIITA expression is the result of a transcriptional inactivation of the MHC2TA gene. This is mediated by a global repression mechanism implicating histone deacetylation over a large domain spanning the entire MHC2TA regulatory region.

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