Measles Virus Circumvents the Host Interferon Response by Different Actions of the C and V Proteins

ABSTRACT Measles is an acute febrile infectious disease with high morbidity and mortality. The genome of measles virus (MV), the causative agent, encodes two accessory products, V and C proteins, that play important roles in MV virulence. The V but not the C protein of the IC-B strain (a well-characterized virulent strain of MV) has been shown to block the Jak/Stat signaling pathway and counteract the cellular interferon (IFN) response. We have recently shown that a recombinant IC-B strain that lacks C protein expression replicates poorly in certain cell lines, and its growth defect is related to translational inhibition and strong IFN induction. Here, we show that the V protein of the MV IC-B strain also blocks the IFN induction pathway mediated by the melanoma differentiation-associated gene 5 product, thus actively interfering with the host IFN response at two different steps. On the other hand, the C protein per se possesses no activity to block the IFN induction pathway. Our data indicate that the C protein acts as a regulator of viral RNA synthesis, thereby acting indirectly to suppress IFN induction. Since recombinant MVs with C protein defective in modulating viral RNA synthesis or lacking C protein expression strongly stimulate IFN production, in spite of V protein production, both the C and V proteins must be required for MV to fully circumvent the host IFN response.

Download Full-text

Mutations in the Measles Virus C Protein That Up Regulate Viral RNA Synthesis

Virology ◽

10.1006/viro.2001.0962 ◽

2001 ◽

Vol 285 (1) ◽

pp. 100-109 ◽

Cited By ~ 60

Author(s):

Greta L. Reutter ◽

Case Cortese-Grogan ◽

Julie Wilson ◽

Sue A. Moyer

Keyword(s):

Measles Virus ◽

Rna Synthesis ◽

Viral Rna ◽

C Protein ◽

Virus C

Download Full-text

Protein Kinase PKR Mediates the Apoptosis Induction and Growth Restriction Phenotypes of C Protein-Deficient Measles Virus

Journal of Virology ◽

10.1128/jvi.01669-08 ◽

2008 ◽

Vol 83 (2) ◽

pp. 961-968 ◽

Cited By ~ 56

Author(s):

Ann M. Toth ◽

Patricia Devaux ◽

Roberto Cattaneo ◽

Charles E. Samuel

Keyword(s):

Protein Kinase ◽

Protein Expression ◽

Measles Virus ◽

Growth Restriction ◽

Initiation Factor ◽

Growth Defect ◽

Virus Growth ◽

Α Subunit ◽

C Protein ◽

Initiation Factor 2

ABSTRACT The measles virus (MV) accessory proteins V and C play important roles in MV replication and pathogenesis. Infection with recombinant MV lacking either V or C causes more cell death than infection with the parental vaccine-equivalent virus (MVvac), and C-deficient virus grows poorly relative to the parental virus. Here, we show that a major effector of the C phenotype is the RNA-dependent protein kinase PKR. Using human HeLa cells stably deficient in PKR as a result of RNA interference-mediated knockdown (PKRkd cells), we demonstrated that a reduction in PKR partially rescued the growth defect of C knockout (Cko) virus but had no effect on the growth of either wild-type (WT) or V knockout (Vko) virus. Increased growth of the Cko virus in PKRkd cells correlated with increased viral protein expression, while defective growth and decreased protein expression in PKR-sufficient cells correlated with increased phosphorylation of PKR and the α subunit of eukaryotic initiation factor 2. Furthermore, infection with WT, Vko, or especially Cko virus caused significantly less apoptosis in PKRkd cells than in PKR-sufficient cells. Although apoptosis induced by Cko virus infection in PKR-sufficient cells was blocked by a caspase antagonist, the growth of Cko virus was not restored to the WT level by treatment with this pharmacologic inhibitor. Taken together, these results indicate that PKR plays an important antiviral role during MV infection but that the virus growth restriction by PKR is not dependent upon the induction of apoptosis. Furthermore, the results establish that a principal function of the MV C protein is to antagonize the proapoptotic and antiviral activities of PKR.

Download Full-text

Viral RNA synthesis in measles virus-infected cells

Virology ◽

10.1016/0042-6822(73)90217-1 ◽

1973 ◽

Vol 53 (2) ◽

pp. 379-383 ◽

Cited By ~ 12

Author(s):

Carol Carter ◽

Ann Schluederberg ◽

Francis L. Black

Keyword(s):

Measles Virus ◽

Rna Synthesis ◽

Viral Rna ◽

Infected Cells

Download Full-text

Measles Virus Nonstructural C Protein Modulates Viral RNA Polymerase Activity by Interacting with Host Protein SHCBP1

Journal of Virology ◽

10.1128/jvi.00714-13 ◽

2013 ◽

Vol 87 (17) ◽

pp. 9633-9642 ◽

Cited By ~ 28

Author(s):

M. Ito ◽

M. Iwasaki ◽

M. Takeda ◽

T. Nakamura ◽

Y. Yanagi ◽

...

Keyword(s):

Rna Polymerase ◽

Measles Virus ◽

Polymerase Activity ◽

Viral Rna ◽

Host Protein ◽

C Protein ◽

Rna Polymerase Activity

Download Full-text

The Matrix Protein of Measles Virus Regulates Viral RNA Synthesis and Assembly by Interacting with the Nucleocapsid Protein

Journal of Virology ◽

10.1128/jvi.01056-09 ◽

2009 ◽

Vol 83 (20) ◽

pp. 10374-10383 ◽

Cited By ~ 98

Author(s):

Masaharu Iwasaki ◽

Makoto Takeda ◽

Yuta Shirogane ◽

Yuichiro Nakatsu ◽

Takanori Nakamura ◽

...

Keyword(s):

Plasma Membrane ◽

Mammalian Cells ◽

Measles Virus ◽

Rna Synthesis ◽

Matrix Protein ◽

Viral Rna ◽

M Protein ◽

Ribonucleoprotein Complex ◽

N Protein ◽

The Matrix

ABSTRACT The genome of measles virus (MV) is encapsidated by the nucleocapsid (N) protein and associates with RNA-dependent RNA polymerase to form the ribonucleoprotein complex. The matrix (M) protein is believed to play an important role in MV assembly by linking the ribonucleoprotein complex with envelope glycoproteins. Analyses using a yeast two-hybrid system and coimmunoprecipitation in mammalian cells revealed that the M protein interacts with the N protein and that two leucine residues at the carboxyl terminus of the N protein (L523 and L524) are critical for the interaction. In MV minigenome reporter gene assays, the M protein inhibited viral RNA synthesis only when it was able to interact with the N protein. The N protein colocalized with the M protein at the plasma membrane when the proteins were coexpressed in plasmid-transfected or MV-infected cells. In contrast, the N protein formed small dots in the perinuclear area when it was expressed without the M protein, or it was incapable of interacting with the M protein. Furthermore, a recombinant MV possessing a mutant N protein incapable of interacting with the M protein grew much less efficiently than the parental virus. Since the M protein has an intrinsic ability to associate with the plasma membrane, it may retain the ribonucleoprotein complex at the plasma membrane by binding to the N protein, thereby stopping viral RNA synthesis and promoting viral particle production. Consequently, our results indicate that the M protein regulates MV RNA synthesis and assembly via its interaction with the N protein.

Download Full-text

The C protein of measles virus inhibits the type I interferon response

Virology ◽

10.1016/s0042-6822(03)00537-3 ◽

2003 ◽

Vol 315 (2) ◽

pp. 389-397 ◽

Cited By ~ 106

Author(s):

Jessica A Shaffer ◽

William J Bellini ◽

Paul A Rota

Keyword(s):

Measles Virus ◽

Type I Interferon ◽

Interferon Response ◽

Type I ◽

C Protein

Download Full-text

DDX3 is exploited by Arenaviruses to suppress type I interferons and favor their replication

10.1101/224725 ◽

2017 ◽

Author(s):

María Eugenia Loureiro ◽

Andre Luiz Zorzetto-Fernandes ◽

Sheli Radoshitzky ◽

Xiaoli Chi ◽

Simone Dallari ◽

...

Keyword(s):

Rna Synthesis ◽

Rna Helicase ◽

Emerging Diseases ◽

Viral Rna ◽

World Health ◽

High Morbidity ◽

Late Time ◽

Type I ◽

Proteomic Approach ◽

Infected Cells

ABSTRACTSeveral arenaviruses cause hemorrhagic fever (HF) diseases that are associated with high morbidity and mortality in humans. Accordingly, HF arenaviruses have been listed as top-priority emerging diseases for which countermeasures are urgently needed. Because arenavirus nucleoprotein (NP) plays critical roles in both virus multiplication and immune-evasion, we used an unbiased proteomic approach to identify NP-interacting proteins in human cells. DDX3, a DEAD-box ATP-dependent-RNA-helicase, interacted with NP in both NP-transfected and virus-infected cells. Importantly, DDX3 deficiency compromised the propagation of both Old and New World arenaviruses, including the HF arenaviruses Lassa and Junin viruses. The DDX3 role in promoting arenavirus multiplication correlated with both a previously un-recognized DDX3 contribution to type I interferon suppression in arenavirus infected cells and a positive effect of DDX3 on viral RNA synthesis. Our results uncover novel mechanisms used by arenavirus to exploit the host machinery and subvert immunity, singling out DDX3 as a potential host target for developing new therapies against highly pathogenic arenaviruses.AUTHOR SUMMARYArenaviruses include severe clinical pathogens causing hemorrhagic fevers and have been recently incorporated by the World Health Organization in a list of critical emerging diseases for which additional research and identification of clinical targets is urgently required. A better understanding of how viral proteins interact with host cellular factors to favor arenavirus multiplication can illuminate novel pipelines on therapeutic strategies. Here we demonstrated that the ATP-dependent RNA helicase DDX3 interacted with the arenavirus nucleoprotein, which displays fundamental functions in different steps of the viral-cycle. Our work also revealed an unexpected new biology on the role that DDX3 might play during viral infections. In sharp contrast to previous studies showing DDX3 enhancement of IFN-I induction, we demonstrated that DDX3 suppressed IFN-I production at late time points after arenavirus infection, contributing to a DDX3 pro-viral effect. We also showed that early after infection, DDX3 pro-viral role was IFN-I independent and was mediated by DDX3 facilitation of viral RNA synthesis without affecting RNA translation. Altogether, our study established DDX3 as a critical host interacting partner of the arenavirus nucleoprotein and demonstrated two previously unrecognized DDX3-dependent strategies by which these deadly viruses exploit the host cellular machinery and suppress immunity.

Download Full-text

Attenuation of V- or C-Defective Measles Viruses: Infection Control by the Inflammatory and Interferon Responses of Rhesus Monkeys

Journal of Virology ◽

10.1128/jvi.00169-08 ◽

2008 ◽

Vol 82 (11) ◽

pp. 5359-5367 ◽

Cited By ~ 72

Author(s):

Patricia Devaux ◽

Gregory Hodge ◽

Michael B. McChesney ◽

Roberto Cattaneo

Keyword(s):

Immune Responses ◽

Measles Virus ◽

Mononuclear Cells ◽

Interferon Response ◽

Wild Type Virus ◽

Type Virus ◽

Wild Type ◽

Adaptive Immune Responses ◽

C Protein ◽

Adaptive Immune

ABSTRACT Patients recruited in virus-based cancer clinical trials and immunocompromised individuals in need of vaccination would profit from viral strains with defined attenuation mechanisms. We generated measles virus (MV) strains defective for the expression of either the V protein, a modulator of the innate immune response, or the C protein, which has multiple functions. The virulence of these strains was compared with that of the parental wild-type MV in a natural host, Macaca mulatta. Skin rash, viremia, and the strength of the innate and adaptive immune responses were characterized in groups of six animals. Replication of V- or C-protein-defective viruses was short-lived and reached lower levels in peripheral blood mononuclear cells and lymphatic organs compared to the wild-type virus; none of the mutants reverted to the wild type. The neutralizing antibody titers and MV-specific T-cell responses were equivalent in monkeys infected with the viral strains tested, documenting strong adaptive immune responses. In contrast, the inflammatory response was better controlled by wild-type MV, as revealed by inhibition of interleukin-6 and tumor necrosis factor alpha transcription. The interferon response was also better controlled by the wild-type virus than by the defective viruses. Since V- and C-defective MVs induce strong adaptive immune responses while spreading less efficiently, they may be developed as vaccines for immunocompromised individuals. Moreover, MV unable to interact with single innate immunity proteins may be developed for preferential replication in tumors with specific contexts of vulnerability.

Download Full-text

A Highly Attenuated Measles Virus Vaccine Strain Encodes a Fully Functional C Protein

Journal of Virology ◽

10.1128/jvi.00791-09 ◽

2009 ◽

Vol 83 (22) ◽

pp. 11996-12001 ◽

Cited By ~ 7

Author(s):

Yuichiro Nakatsu ◽

Makoto Takeda ◽

Masaharu Iwasaki ◽

Yusuke Yanagi

Keyword(s):

Vaccine Strain ◽

Measles Virus ◽

Transcription Unit ◽

C Protein ◽

V Protein ◽

P Gene ◽

Its Gene ◽

Overlapping Reading Frames ◽

The Individual ◽

Reading Frames

ABSTRACT The P, V, and C proteins of measles virus are encoded in overlapping reading frames of the P gene, which makes it difficult to analyze the functions of the individual proteins in the context of virus infection. We established a system to analyze the C protein independently from the P and V proteins by placing its gene in an additional transcription unit between the H and L genes. Analyses with this system indicated that a highly attenuated Edmonston lineage vaccine strain encodes a fully functional C protein, and the P and/or V protein is involved in the attenuated phenotype.

Download Full-text