scholarly journals Sendai virus C protein limits NO production in infected RAW264.7 macrophages

2018 ◽  
Vol 24 (7) ◽  
pp. 430-438 ◽  
Author(s):  
Erdenezaya Odkhuu ◽  
Takayuki Komatsu ◽  
Naoki Koide ◽  
Yoshikazu Naiki ◽  
Kenji Takeuchi ◽  
...  
Keyword(s):  
Sendai Virus ◽  
Virus Multiplication ◽  
Inos Expression ◽  
No Production ◽  
Ns1 Protein ◽  
Wild Type ◽  
C Protein ◽  
Raw264.7 Macrophages ◽  
Virus C ◽  
Stat Pathway

To suppress virus multiplication, infected macrophages produce NO. However, it remains unclear how infecting viruses then overcome NO challenge. In the present study, we report the effects of accessory protein C from Sendai virus (SeV), a prototypical paramyxovirus, on NO output. We found that in RAW264.7 murine macrophages, a mutant SeV without C protein (4C(–)) significantly enhanced inducible NO synthase (iNOS) expression and subsequent NO production compared to wild type SeV (wtSeV). SeV 4C(-) infection caused marked production of IFN-β, which is involved in induction of iNOS expression via the JAK-STAT pathway. Addition of anti-IFN-β Ab, however, resulted in only marginal suppression of NO production. In contrast, NF-κB, a primarily important factor for transcription of the iNOS gene, was also activated by 4C(–) infection but not wtSeV infection. Induction of NO production and iNOS expression by 4C(–) was significantly suppressed in cells constitutively expressing influenza virus NS1 protein that can sequester double-stranded (ds)RNA, which triggers activation of signaling pathways leading to activation of NF-κB and IRF3. Therefore, C protein appears to suppress NF-κB activation to inhibit iNOS expression and subsequent NO production, possibly by limiting dsRNA generation in the context of viral infection.

scholarly journals Sendai Virus C Proteins Counteract the Interferon-Mediated Induction of an Antiviral State

1999 ◽  
Vol 73 (8) ◽  
pp. 6559-6565 ◽  
Author(s):  
Dominique Garcin ◽  
Patrizia Latorre ◽  
Daniel Kolakofsky
Keyword(s):  
Sendai Virus ◽  
Antiviral Response ◽  
Single Amino Acid ◽  
Wild Type ◽  
C Protein ◽  
Antiviral State ◽  
Protein Levels ◽  
Vesicular Stomatitis ◽  
C Proteins ◽  
Virus C

ABSTRACT We have studied the relationship between the Sendai virus (SeV) C proteins (a nested set of four proteins initiated at different start codons) and the interferon (IFN)-mediated antiviral response in IFN-competent cells in culture. SeV strains containing wild-type or various mutant C proteins were examined for their ability (i) to induce an antiviral state (i.e., to prevent the growth of vesicular stomatitis virus [VSV] following a period of SeV infection), (ii) to induce the elevation of Stat1 protein levels, and (iii) to prevent IFN added concomitant with the SeV infection from inducing an antiviral state. We find that expression of the wild-type C gene and, specifically, the AUG114-initiated C protein prevents the establishment of an antiviral state: i.e., cells infected with wild-type SeV exhibited little or no increase in Stat1 levels and were permissive for VSV replication, even in the presence of exogenous IFN. In contrast, in cells infected with SeV lacking the AUG114-initiated C protein or containing a single amino acid substitution in the C protein, the level of Stat1 increased and VSV replication was inhibited. The prevention of the cellular IFN-mediated antiviral response appears to be a key determinant of SeV pathogenicity.

MKP-1 switches arginine metabolism from nitric oxide synthase to arginase following endotoxin challenge

2007 ◽  
Vol 293 (2) ◽  
pp. C632-C640 ◽  
Author(s):  
Leif D. Nelin ◽  
Xianxi Wang ◽  
Qun Zhao ◽  
Louis G. Chicoine ◽  
Tamara L. Young ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Peritoneal Macrophages ◽  
Mapk Signaling ◽  
Inos Expression ◽  
No Production ◽  
Wild Type ◽  
Endotoxin Challenge ◽  
Raw264.7 Macrophages ◽  
Urea Production

l-Arginine (l-arg) is metabolized to nitric oxide (NO) by inducible NO synthase (iNOS) or to urea and l-ornithine (l-orn) by arginase. NO is involved in the inflammatory response, whereas arginase is the first step in polyamine and proline synthesis necessary for tissue repair and wound healing. Mitogen-activated protein kinases (MAPK) mediate LPS-induced iNOS expression, and MAPK phosphatase-1 (MKP-1) plays a crucial role in limiting MAPK signaling in macrophages. We hypothesized that MKP-1, by attenuating iNOS expression, acts as a switch changing l-arg metabolism from NO production to l-orn production after endotoxin administration. To test this hypothesis, we performed studies in RAW264.7 macrophages stably transfected with an MKP-1 expression vector in thioglyollate-elicited peritoneal macrophages harvested from wild-type and Mkp-1−/− mice, as well as in vivo in wild-type and Mkp-1−/− mice. We found that overexpression of MKP-1 resulted in lower iNOS expression and NO production but greater urea production in response to LPS. Although deficiency of MKP-1 resulted in greater iNOS expression and NO production and lower urea production in response to LPS, neither the overexpression nor the deficiency of MKP-1 had any substantial effect on the expression of the arginases.

scholarly journals Importance of the Anti-Interferon Capacity of Sendai Virus C Protein for Pathogenicity in Mice

2007 ◽  
Vol 81 (7) ◽  
pp. 3264-3271 ◽  
Author(s):  
Atsushi Kato ◽  
Katsuhiro Kiyotani ◽  
Toru Kubota ◽  
Tetsuya Yoshida ◽  
Masato Tashiro ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Growth Rate ◽  
Innate Immunity ◽  
Sendai Virus ◽  
Wild Type ◽  
C Protein ◽  
Hela Cell Lines ◽  
Final Yield ◽  
Virus C ◽  
Protein Blocks

ABSTRACT The Sendai virus (SeV) C protein blocks signal transduction of interferon (IFN), thereby counteracting the antiviral actions of IFN. Using HeLa cell lines expressing truncated or mutated SeV C proteins, we found that the C-terminal half has anti-IFN capacity, and that K151A, E153A, and R154A substitutions in the C protein eliminated this capacity. Here, we further created the mutant virus SeV Cm*, in which K151A, E153K, and R157L substitutions in the C protein were introduced without changing the amino acid sequence of overlapped P, V, and W proteins. SeV Cm* was found to lack anti-IFN capacity, as expected. While the growth rate and final yield of SeV Cm* were inferior to those of the wild-type SeV in IFN-responsive, STAT1-positive 2fTGH cells, SeV Cm* grew equivalently to the wild-type SeV in IFN-nonresponsive, STAT1-deficient U3A cells. SeV Cm* was thus shown to maintain multiplication capacity, except that it lacked anti-IFN capacity. Intranasally inoculated SeV Cm* could propagate in the lungs of STAT1−/− mice but was cleared from those of STAT1+/+ mice without propagation. It was found that the anti-IFN capacity of the SeV C protein was indispensable for pathogenicity in mice. Conversely, the results show that the innate immunity contributed to elimination of SeV in early stages of infection in the absence of anti-IFN capacity.

Sendai virus C protein physically associates with Stat1

2001 ◽  
Vol 6 (6) ◽  
pp. 545-557 ◽  
Author(s):  
Kenji Takeuchi ◽  
Takayuki Komatsu ◽  
Junko Yokoo ◽  
Atsushi Kato ◽  
Tatsuo Shioda ◽  
...  
Keyword(s):  
Sendai Virus ◽  
C Protein ◽  
Virus C

scholarly journals Proteomics Investigation of the Time Course Responses of RAW264.7 Macrophages to Infections With the Wild-Type and Twin-Arginine Translocation Mutant Strains of Brucella melitensis

2021 ◽  
Vol 11 ◽  
Author(s):  
Xin Yan ◽  
Sen Hu ◽  
Yan Yang ◽  
Da Xu ◽  
Wenxing Liu ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Time Course ◽  
Nitrosative Stress ◽  
Brucella Melitensis ◽  
No Production ◽  
Wild Type ◽  
Twin Arginine Translocation ◽  
Raw264.7 Macrophages ◽  
Mutant Strains ◽  
Related Proteins

Brucella, a notorious intracellular pathogen, causes chronic infections in many mammals, including humans. The twin-arginine translocation (Tat) pathway transports folded proteins across the cytoplasmic membrane; protein substrates translocated by Brucella include ABC transporters, oxidoreductases, and cell envelope biosynthesis proteins. Previously, we showed that a Tat mutant of Brucella melitensis M28 exhibits reduced survival within murine macrophages. In this study, we compared the host responses elicited by wild-type M28 and its Tat-mutant strains ex vivo. We utilized label-free quantitative proteomics to assess proteomic changes in RAW264.7 macrophages after infection with M28 and its Tat mutants. A total of 6085 macrophage proteins were identified with high confidence, and 79, 50, and 99 proteins were differentially produced upon infection with the Tat mutant at 4, 24, and 48 hpi, respectively, relative to the wild-type infection. Gene ontology and KEGG enrichment analysis indicated that immune response-related proteins were enriched among the upregulated proteins. Compared to the wild-type M28 infection, the most upregulated proteins upon Tat-mutant infection included the cytosolic nucleic acid signaling pathway-related proteins IFIH1, DHX58, IFI202, IFI204, and ISG15 and the NF-κB signaling pathway-related proteins PTGS2, CD40, and TRAF1, suggesting that the host increases the production of these proteins in response to Tat mutant infection. Upregulation of some proteins was further verified by a parallel reaction monitoring (PRM) assay. ELISA and qRT-PCR assays indicated that Tat mutant infection significantly induced proinflammatory cytokine (TNF-α and IL-6) and nitric oxide (NO) production. Finally, we showed that the Tat mutant displays higher sensitivity to nitrosative stress than the wild type and that treatment with the NO synthase inhibitor L-NMMA significantly increases the intracellular survival of the Tat mutant, indicating that NO production contributes to restricting Tat mutant survival within macrophages. Collectively, this work improves our understanding of host immune responses to Tat mutants and provides insights into the mechanisms underlying the attenuated virulence of Tat mutants.

scholarly journals Targeting of the Sendai Virus C Protein to the Plasma Membrane via a Peptide-Only Membrane Anchor

2007 ◽  
Vol 81 (7) ◽  
pp. 3187-3197 ◽  
Author(s):  
Jean-Baptiste Marq ◽  
Albert Brini ◽  
Daniel Kolakofsky ◽  
Dominique Garcin
Keyword(s):  
Plasma Membrane ◽  
Sendai Virus ◽  
Intracellular Localization ◽  
Membrane Targeting ◽  
Membrane Anchor ◽  
C Protein ◽  
Cellular Antiviral Response ◽  
Α Helix ◽  
Virus C ◽  
Cellular Compartments

ABSTRACT Several cellular proteins are synthesized in the cytosol on free ribosomes and then associate with membranes due to the presence of short peptide sequences. These membrane-targeting sequences contain sites to which lipid chains are attached, which help direct the protein to a particular membrane domain and anchor it firmly in the bilayer. The intracellular concentration of these proteins in particular cellular compartments, where their interacting partners are also concentrated, is essential to their function. This paper reports that the apparently unmodified N-terminal sequence of the Sendai virus C protein (MPSFL KK IL K L R G RR . . .; letters in italics represent hydrophobic residues; underlined letters represent basic residues, which has a strong propensity to form an amphipathic α-helix in a hydrophobic environment) also function as a membrane targeting signal and membrane anchor. Moreover, the intracellular localization of the C protein at the plasma membrane is essential for inducing the interferon-independent phosphorylation of Stat1 as part of the viral program to prevent the cellular antiviral response.

Sendai virus C protein impairs both phosphorylation and dephosphorylation processes of Stat1

FEBS Letters ◽  
2002 ◽  
Vol 511 (1-3) ◽  
pp. 139-144 ◽  
Author(s):  
Takayuki Komatsu ◽  
Kenji Takeuchi ◽  
Junko Yokoo ◽  
Bin Gotoh
Keyword(s):  
Sendai Virus ◽  
C Protein ◽  
Virus C

scholarly journals Sendai Virus Targets Inflammatory Responses, as Well as the Interferon-Induced Antiviral State, in a Multifaceted Manner

2003 ◽  
Vol 77 (14) ◽  
pp. 7903-7913 ◽  
Author(s):  
Laura Strähle ◽  
Dominique Garcin ◽  
Philippe Le Mercier ◽  
Joerg F. Schlaak ◽  
Daniel Kolakofsky
Keyword(s):  
Immune Responses ◽  
Inflammatory Responses ◽  
Sendai Virus ◽  
Wild Type ◽  
C Protein ◽  
Multifaceted Approach ◽  
V Protein ◽  
Antiviral State ◽  
Adaptive Immune ◽  
Cellular Genes

ABSTRACT We have used cDNA arrays to compare the activation of various cellular genes in response to infection with Sendai viruses (SeV) that contain specific mutations. Three groups of cellular genes activated by mutant SeV infection, but not by wild-type SeV, were identified in this way. While some of these genes are well known interferon (IFN)-stimulated genes, others, such as those for interleukin-6 (IL-6) and IL-8, are not directly induced by IFN. The gene for beta IFN (IFN-β), which is critical for initiating an antiviral response, was also specifically activated in mutant SeV infections. The SeV-induced activation of IFN-β was found to depend on IFN regulatory factor 3, and the activation of all three cellular genes was independent of IFN signaling. Mutations that disrupt four distinct elements in the SeV genome (the leader RNA, two regions of the C protein, and the V protein) all lead to enhanced levels of IFN-β mRNA, and at least three of these viral genes also appear to be involved in preventing activation of IL-8. Our results suggest that SeV targets the inflammatory and adaptive immune responses as well as the IFN-induced intracellular antiviral state by using a multifaceted approach.

scholarly journals Dephosphorylation Failure of Tyrosine-Phosphorylated STAT1 in IFN-Stimulated Sendai Virus C Protein-Expressing Cells

Virology ◽  
2002 ◽  
Vol 293 (2) ◽  
pp. 205-209 ◽  
Author(s):  
Sakura Saito ◽  
Toshio Ogino ◽  
Naoko Miyajima ◽  
Atsushi Kato ◽  
Masayoshi Kohase
Keyword(s):  
Sendai Virus ◽  
C Protein ◽  
Virus C
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