Raftlin Is Involved in the Nucleocapture Complex to Induce Poly(I:C)-mediated TLR3 Activation

Watanabe, Ayako; Tatematsu, Megumi; Saeki, Kazuko; Shibata, Sachiko; Shime, Hiroaki; Yoshimura, Akihiko; Obuse, Chikashi; Seya, Tsukasa; Matsumoto, Misako

doi:10.1074/jbc.m110.185793

Cited by 74 publications

(74 citation statements)

References 33 publications

(26 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The features of the TLR3-recognizing PV-RNAs are consistent with our previous results that raftlin mediates poly(I:C) cellular uptake through interaction with the clathrin-AP-2 complex in human myeloid DCs and epithelial cells 35 . In addition, uptake of B/C-type CpG ODNs that share their uptake receptor with poly(I:C) was also mediated by raftlin 33,35 . Given that PV5-induced TLR3 activation in HEK293 cells was inhibited by pre-treatment with the B-type CpG ODN ( Supplementary Fig.…”

Section: Discussionsupporting

confidence: 79%

“…4c). The internalization of PV5 was similar to that of poly(I:C) 35 . Indeed, PV5 activity was inhibited by the pre-treatment of cells with B-type CpG oligodeoxynucleotide (ODN), which shares an uptake receptor with poly(I:C) ( Supplementary Fig.…”

Section: Resultsmentioning

confidence: 51%

“…TLR3 activation by poly(I:C) requires clathrin-mediated internalization of extracellular poly(I:C) 33 . In human myeloid DCs and epithelial cells such as HeLa cells, the cytoplasmic raft protein, raftlin, induces poly(I:C) uptake through interaction with clathrin-AP-2 complex 34,35 . To understand how extracellular PV-RNAs activate endosomal TLR3, we examined the requirement of raftlin in PV-RNA-induced TLR3 activation by gene silencing of raftlin with small interfering RNA (siRNA).…”

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Toll-like receptor 3 recognizes incomplete stem structures in single-stranded viral RNA

et al. 2013

Self Cite

View full text Add to dashboard Cite

Endosomal Toll-like receptor 3 (TLR3) serves as a sensor of viral infection and sterile tissue necrosis. Although TLR3 recognizes double-stranded RNA, little is known about structural features of virus-or host-derived RNAs that activate TLR3 in infection/inflammatory states. Here we demonstrate that poliovirus-derived single-stranded RNA segments harbouring stem structures with bulge/internal loops are potent TLR3 agonists. Functional poliovirus-RNAs are resistant to degradation and efficiently induce interferon-a/b and proinflammatory cytokines in human and mouse cells in a TLR3-dependent manner. The N-and C-terminal doublestranded RNA-binding sites of TLR3 are required for poliovirus-RNA-mediated TLR3 activation. Like polyriboinosinic:polyribocytidylic acid, a synthetic double-stranded RNA, these RNAs are internalized into cells via raftlin-mediated endocytosis and colocalized with TLR3. Raftlin-associated RNA uptake machinery and the TLR3 RNA-sensing system appear to recognize an appropriate topology of multiple RNA duplexes in poliovirus-RNAs. Hence, TLR3 is a sensor of extracellular viral/host RNA with stable stem structures derived from infection or inflammation-damaged cells.

show abstract

Section: Discussionsupporting

confidence: 79%

Section: Resultsmentioning

confidence: 51%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Toll-like receptor 3 recognizes incomplete stem structures in single-stranded viral RNA

et al. 2013

Self Cite

View full text Add to dashboard Cite

show abstract

“…Recently, we have demonstrated that the cytoplasmic protein Raftlin is indispensable for cell entry of extracellular polyinosinic: polycytidylic acid [poly(I:C)], a virus dsRNA analogue, and TLR3-TICAM-1-mediated signaling (18). Raftlin was originally identified as a major raft protein with molecular mass of 63 kDa in B cells that colocalized with BCR in the lipid raft before and after BCR activation (19).…”

mentioning

confidence: 99%

“…Raftlin also localizes to the lipid raft in T cells and modulates BCR and TCR signaling (20). Although Raftlin possesses fatty acylation sites at the N terminus, it predominantly localizes in the cytoplasm in human epithelial cells and monocyte-derived DCs (Mo-DCs) (18,19). Upon poly(I:C) binding to the uptake receptor on the cell surface, Raftlin moves from the cytoplasm to the plasma membrane, where it induces endocytosis of the uptake receptor via interaction with the clathrin-clathrin-associated adaptor protein-2 (AP-2) complex.…”

mentioning

confidence: 99%

Raftlin Controls Lipopolysaccharide-Induced TLR4 Internalization and TICAM-1 Signaling in a Cell Type–Specific Manner

Tatematsu

Yoshida

Morioka

et al. 2016

The Journal of Immunology

Self Cite

View full text Add to dashboard Cite

The clathrin-dependent endocytic pathway is crucial for endosomal TLR3- and TLR4-mediated Toll–IL-1R domain–containing adaptor molecule-1 (TICAM-1) signaling. TLR4 uses a different signaling platform, plasma membrane and endosomes, for activation of TIRAP-MyD88 and TICAM-2–TICAM-1, respectively. LPS-induced endocytosis of TLR4 is mandatory for TICAM-1–mediated signaling including IFN-β production. Several molecules/mechanisms such as CD14, clathrin, and phosphatidylinositol metabolism have been reported to act as inducers of TLR4 translocation. However, the molecular mechanism of spatiotemporal regulation of TLR4 signaling remains unresolved. We have previously shown that Raftlin is essential for clathrin-dependent endocytosis of TLR3 ligand in human epithelial cells and myeloid dendritic cells (DCs). In this article, we demonstrate that Raftlin also mediated LPS-induced TLR4 internalization and TICAM-1 signaling in human monocyte-derived DCs and macrophages (Mo-Mϕs). When Raftlin was knocked down, LPS-induced TLR4-mediated IFN-β promoter activation, but not NF-κB activation, was decreased in HEK293 cells overexpressing TLR4/MD-2 or TLR4/MD-2/CD14. LPS-induced IFN-β production by monocyte-derived DCs and Mo-Mϕs was significantly decreased by knockdown of Raftlin. Upon LPS stimulation, Raftlin moved from the cytoplasm to the plasma membrane in Mo-Mϕs, where it colocalized with TLR4. Raftlin associated with clathrin-associated adaptor protein–2 in resting cells and transiently bound to TLR4 and clathrin at the cell surface in response to LPS. Thus, Raftlin appears to modulate cargo selection as an accessary protein of clathrin-associated adaptor protein–2 in clathrin-mediated endocytosis of TLR3/4 ligands.

show abstract

An Iron Oxide Nanocarrier Loaded with a Pt(IV) Prodrug and Immunostimulatory dsRNA for Combining Complementary Cancer Killing Effects

Hernández-Gil

Cobaleda-Siles

Zabaleta

et al. 2015

Adv Healthcare Materials

View full text Add to dashboard Cite

There is major current interest in harnessing the immune system against cancer and in developing drugs that provide complementary cancer killing mechanisms. Although the recent advent of nanoparticle-based drug delivery systems has improved the efficacy of platinum drugs for chemotherapy, one of the fundamental paradigms in their design and use is evading surveillance by the immune system to enhance anticancer efficacy. However, new studies are showing that chemotherapy can profit from actively targeting stimulation of the immune system and that suitably functionalized nanomaterials might be ideal for overcoming some key challenges in immunotherapy. Pt(IV) prodrug-modified PEGylated phospholipid micelles that encapsulate biocompatible iron oxide nanoparticles (IONPs) as a new delivery system for cisplatin are reported. The Pt(IV)-IONPs are functionalized with polyinosinic-polycytidylic acid (poly (I:C))--a double stranded RNA (dsRNA) analog widely used as an adjuvant in clinical trials of cancer immunotherapy. The Pt(IV)-IONPs and poly (I:C)--Pt(IV)-IONPs enhance by more than an order of magnitude the prodrug cytotoxicity in different tumor cells, while greatly increasing the ability of cisplatin and poly (I:C) to activate dendritic cells--the key cellular players in immunotherapy. The results suggest that these constructs hold promise for targeted chemoimmunotherapy.

show abstract

Raftlin Is Involved in the Nucleocapture Complex to Induce Poly(I:C)-mediated TLR3 Activation

Cited by 74 publications

References 33 publications

Toll-like receptor 3 recognizes incomplete stem structures in single-stranded viral RNA

Toll-like receptor 3 recognizes incomplete stem structures in single-stranded viral RNA

Raftlin Controls Lipopolysaccharide-Induced TLR4 Internalization and TICAM-1 Signaling in a Cell Type–Specific Manner

An Iron Oxide Nanocarrier Loaded with a Pt(IV) Prodrug and Immunostimulatory dsRNA for Combining Complementary Cancer Killing Effects

Contact Info

Product

Resources

About