The Combination of Type I IFN, TNF-α, and Cell Surface Receptor Engagement with Dendritic Cells Enables NK Cells To Overcome Immune Evasion by Dengue Virus

The dengue virus (DENV) envelope (E) protein mediates virus entry into cells via interaction with a range of cell-surface receptor molecules. Cell-surface glycosaminoglycans (GAGs) have been shown to play an early role in this interaction, and charged oligosaccharides such as heparin bind to the E protein. We have examined this interaction using site-directed mutagenesis of a recombinant form of the putative receptor-binding domain III of the DENV-2E protein expressed as an MBP (maltose-binding protein)-fusion protein. Using an ELISA-based GAG-binding assay, cell-based binding analysis and antiviral-activity assays, we have identified two critical residues, K291 and K295, that are involved in GAG interactions. These studies have also demonstrated differential binding between mosquito and human cells.

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Sequences within the Cytoplasmic Domain of Gp180/Carboxypeptidase D Mediate Localization to the Trans-Golgi Network

Molecular Biology of the Cell ◽

10.1091/mbc.10.1.35 ◽

1999 ◽

Vol 10 (1) ◽

pp. 35-46 ◽

Cited By ~ 37

Author(s):

Francis J. Eng ◽

Oleg Varlamov ◽

Lloyd D. Fricker

Keyword(s):

Cell Surface ◽

Secretory Pathway ◽

Point Mutations ◽

Cell Surface Receptor ◽

Type I ◽

Multiple Sequence ◽

Trans Golgi Network ◽

Duck Hepatitis ◽

Surface Receptor ◽

Golgi Network

Gp180, a duck protein that was proposed to be a cell surface receptor for duck hepatitis B virus, is the homolog of metallocarboxypeptidase D, a mammalian protein thought to function in the trans-Golgi network (TGN) in the processing of proteins that transit the secretory pathway. Both gp180 and mammalian metallocarboxypeptidase D are type I integral membrane proteins that contain a 58-residue cytosolic C-terminal tail that is highly conserved between duck and rat. To investigate the regions of the gp180 tail involved with TGN retention and intracellular trafficking, gp180 and various deletion and point mutations were expressed in the AtT-20 mouse pituitary corticotroph cell line. Full length gp180 is enriched in the TGN and also cycles to the cell surface. Truncation of the C-terminal 56 residues of the cytosolic tail eliminates the enrichment in the TGN and the retrieval from the cell surface. Truncation of 12–43 residues of the tail reduced retention in the TGN and greatly accelerated the turnover of the protein. In contrast, deletion of the C-terminal 45 residues, which truncates a potential YxxL-like sequence (FxxL), reduced the protein turnover and caused accumulation of the protein on the cell surface. A point mutation of the FxxL sequence to AxxL slowed internalization, showing that this element is important for retrieval from the cell surface. Mutation of a pair of casein kinase II sites within an acidic cluster showed that they are also important for trafficking. The present study demonstrates that multiple sequence elements within the cytoplasmic tail of gp180 participate in TGN localization.

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A cell surface receptor complex for collagen type I recognizes the Arg-Gly-Asp sequence.

The Journal of Cell Biology ◽

10.1083/jcb.104.3.585 ◽

1987 ◽

Vol 104 (3) ◽

pp. 585-593 ◽

Cited By ~ 209

Author(s):

S Dedhar ◽

E Ruoslahti ◽

M D Pierschbacher

Keyword(s):

Cell Surface ◽

Type I Collagen ◽

Attachment Site ◽

Cell Surface Receptor ◽

Type I ◽

Receptor Complex ◽

Collagen Binding ◽

Human Osteosarcoma Cells ◽

Surface Receptor ◽

A Cell

To isolate collagen-binding cell surface proteins, detergent extracts of surface-iodinated MG-63 human osteosarcoma cells were chromatographed on affinity matrices of either type I collagen-Sepharose or Sepharose carrying a collagen-like triple-helical peptide. The peptide was designed to be triple helical and to contain the sequence Arg-Gly-Asp, which has been implicated as the cell attachment site of fibronectin, vitronectin, fibrinogen, and von Willebrand factor, and is also present in type I collagen. Three radioactive polypeptides having apparent molecular masses of 250 kD, 70 kD, and 30 kD were distinguishable in that they showed affinity toward the collagen and collagen-like peptide affinity columns, and could be specifically eluted from these columns with a solution of an Arg-Gly-Asp-containing peptide, Gly-Arg-Gly-Asp-Thr-Pro. These collagen-binding polypeptides associated with phosphatidylcholine liposomes, and the resulting liposomes bound specifically to type I collagen or the collagen-like peptide but not to fibronectin or vitronectin or heat-denatured collagen. The binding of these liposomes to type I collagen could be inhibited with the peptide Gly-Arg-Gly-Asp-Thr-Pro and with EDTA, but not with a variant peptide Gly-Arg-Gly-Glu-Ser-Pro. We conclude from these data that these three polypeptides are membrane molecules that behave as a cell surface receptor (or receptor complex) for type I collagen by interacting with it through the Arg-Gly-Asp tripeptide adhesion signal. The lack of binding to denatured collagen suggests that the conformation of the Arg-Gly-Asp sequence is important in the recognition of collagen by the receptor complex.

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Identification of integrin alpha 2 beta 1 as cell surface receptor for the carboxyl-terminal propeptide of type I procollagen.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(17)31918-x ◽

1994 ◽

Vol 269 (33) ◽

pp. 20982-20986

Author(s):

S.A. Weston ◽

D.J. Hulmes ◽

A.P. Mould ◽

R.B. Watson ◽

M.J. Humphries

Keyword(s):

Cell Surface ◽

Cell Surface Receptor ◽

Type I ◽

Type I Procollagen ◽

Surface Receptor ◽

Carboxyl Terminal

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Inhibition of the Type I Interferon Response in Human Dendritic Cells by Dengue Virus Infection Requires a Catalytically Active NS2B3 Complex

Journal of Virology ◽

10.1128/jvi.01051-10 ◽

2010 ◽

Vol 84 (19) ◽

pp. 9760-9774 ◽

Cited By ~ 97

Author(s):

Juan R. Rodriguez-Madoz ◽

Alan Belicha-Villanueva ◽

Dabeiba Bernal-Rubio ◽

Joseph Ashour ◽

Juan Ayllon ◽

...

Keyword(s):

Dendritic Cells ◽

Dengue Virus ◽

Type I Interferon ◽

Poly I:C ◽

Interferon Response ◽

Type I ◽

Type I Ifn ◽

Human Virus ◽

Catalytically Active ◽

Human Dendritic Cells

ABSTRACT Dengue virus (DENV) is the most prevalent arthropod-borne human virus, able to infect and replicate in human dendritic cells (DCs), inducing their activation and the production of proinflammatory cytokines. However, DENV can successfully evade the immune response in order to produce disease in humans. Several mechanisms of immune evasion have been suggested for DENV, most of them involving interference with type I interferon (IFN) signaling. We recently reported that DENV infection of human DCs does not induce type I IFN production by those infected DCs, impairing their ability to prime naive T cells toward Th1 immunity. In this article, we report that DENV also reduces the ability of DCs to produce type I IFN in response to several inducers, such as infection with other viruses or exposure to Toll-like receptor (TLR) ligands, indicating that DENV antagonizes the type I IFN production pathway in human DCs. DENV-infected human DCs showed a reduced type I IFN response to Newcastle disease virus (NDV), Sendai virus (SeV), and Semliki Forest virus (SFV) infection and to the TLR3 agonist poly(I:C). This inhibitory effect is DENV dose dependent, requires DENV replication, and takes place in DENV-infected DCs as early as 2 h after infection. Expressing individual proteins of DENV in the presence of an IFN-α/β production inducer reveals that a catalytically active viral protease complex is required to reduce type I IFN production significantly. These results provide a new mechanism by which DENV evades the immune system in humans.

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A Novel B220+ NK Cell Progenitor Found in the Murine Lung with Potent in Vitro NK Potential Gives Rise to Mature NK Cells with Distinct NK Cell-Surface Receptor Expression

Blood ◽

10.1182/blood.v112.11.4779.4779 ◽

2008 ◽

Vol 112 (11) ◽

pp. 4779-4779

Author(s):

Timotheus You Fu Halim ◽

Fumio Takei

Keyword(s):

Cell Surface ◽

Nk Cells ◽

Nk Cell ◽

Cell Activity ◽

Physiological Role ◽

Receptor Expression ◽

Cell Surface Receptor ◽

Cell Potential ◽

Surface Receptor

Abstract Natural Killer (NK) cells are important effector cells in innate immunity, and play a vital role in antiviral defense, tumor surveillance and modulation of the adaptive immune response. NK cells were originally believed to arise from a lin−NK1.1−CD122+ bone marrow (BM) progenitor. However, recent findings have identified NK progenitors (NKP) and distinct NK differentiation pathways in the thymus, lymph node, spleen and liver. The physiological role of these extra-BM developmental pathways remains to be determined. We hypothesized that these alternative pathways on NK development would have an impact on the generation of the phenotypic heterogeneity observed in cell-surface receptor expression and functional NK cell subsets. Here, we demonstrate the identification of a small population of cells in the lung of C57Bl/6 mice (0.02% of lung leukocytes) that have a lin−NK1.1−CD122+B220+ cell surface phenotype. These cells also show potent in vitro NK cell activity when cultured on OP-9 stromal cells with IL-7, mSCF, Flt3L and IL-15, as well as in vivo NK cell potential upon adoptive transplant into RAG-2−/− IL2Rγ−/− and NOD/SCID IL2Rγ−/− hosts. Mature NK cells (CD3−NK1.1+) derived in vitro from conventional BM NKP and lung B220+ NKP were characterized for cell-surface receptor expression after 16–18 days (figure 1, mean with SEM). Clear differences in activating and inhibitory NK cell-surface marker expression were observed between NK cells derived in vitro from conventional BM NKP and lung B220+ NKP (Ly49D p<0.05, Ly49G2 p<0.05, NKG2A/C/E p<0.05). These findings suggest that B220+ NKP may generate phenotypically and functionally distinct NK cell types. Figure 1: Cell-surface receptor expression on in vitro derived NK cells Figure 1:. Cell-surface receptor expression on in vitro derived NK cells

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