scholarly journals The Deoptimization of Rabies Virus Matrix Protein Impacts Viral Transcription and Replication

Viruses ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 4 ◽  
Author(s):  
Jun Luo ◽  
Yue Zhang ◽  
Qiong Zhang ◽  
Yuting Wu ◽  
Boyue Zhang ◽  
...  

Rabies virus (RABV) matrix (M) protein plays several important roles during RABV infection. Although previous studies have assessed the functions of M through gene rearrangements, this interferes with the position of other viral proteins. In this study, we attenuated M expression through deoptimizing its codon usage based on codon pair bias in RABV. This strategy more objectively clarifies the role of M during virus infection. Codon-deoptimized M inhibited RABV replication during the early stages of infection, but enhanced viral titers at later stages. Codon-deoptimized M also inhibited genome synthesis at early stage of infection and increased the RABV transcription rates. Attenuated M through codon deoptimization enhanced RABV glycoprotein expression following RABV infection in neuronal cells, but had no influence on the cell-to-cell spread of RABV. In addition, codon-deoptimized M virus induced higher levels of apoptosis compared to the parental RABV. These results indicate that codon-deoptimized M increases glycoprotein expression, providing a foundation for further investigation of the role of M during RABV infection.

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Fan Jia ◽  
Li Li ◽  
Haizhou Liu ◽  
Pei Lv ◽  
Xiangwei Shi ◽  
...  

AbstractRabies virus (RV) is the most widely used vector for mapping neural circuits. Previous studies have shown that the RV glycoprotein can be a target to improve the retrograde transsynaptic tracing efficiency. However, the current versions still label only a small portion of all presynaptic neurons. Here, we reshuffled the oG sequence, a chimeric glycoprotein, with positive codon pair bias score (CPBS) based on bioinformatic analysis of mouse codon pair bias, generating ooG, a further optimized glycoprotein. Our experimental data reveal that the ooG has a higher expression level than the oG in vivo, which significantly increases the tracing efficiency by up to 12.6 and 62.1-fold compared to oG and B19G, respectively. The new tool can be used for labeling neural circuits Therefore, the approach reported here provides a convenient, efficient and universal strategy to improve protein expression for various application scenarios such as trans-synaptic tracing efficiency, cell engineering, and vaccine and oncolytic virus designs.


2020 ◽  
Vol 94 (9) ◽  
Author(s):  
Zhaochen Luo ◽  
Lei Lv ◽  
Yingying Li ◽  
Baokun Sui ◽  
Qiong Wu ◽  
...  

ABSTRACT Rabies, caused by rabies virus (RABV), is a fatal encephalitis in humans and other mammals, which continues to present a public health threat in most parts of the world. Our previous study demonstrated that Toll-like receptor 7 (TLR7) is essential in the induction of anti-RABV antibodies via the facilitation of germinal center formation. In the present study, we investigated the role of TLR7 in the pathogenicity of RABV in a mouse model. Using isolated plasmacytoid dendritic cells (pDCs), we demonstrated that TLR7 is an innate recognition receptor for RABV. When RABV invaded from the periphery, TLR7 detected viral single-stranded RNA and triggered immune responses that limited the virus’s entry into the central nervous system (CNS). When RABV had invaded the CNS, its detection by TLR7 led to the production of cytokines and chemokines and an increase the permeability of the blood-brain barrier. Consequently, peripheral immune cells, including pDCs, macrophages, neutrophils, and B cells infiltrated the CNS. While this immune response, triggered by TLR7, helped to clear viruses, it also increased neuroinflammation and caused immunopathology in the mouse brain. Our results demonstrate that TLR7 is an innate recognition receptor for RABV, which restricts RABV invasion into the CNS in the early stage of viral infection but also contributes to immunopathology by inducing neuroinflammation. IMPORTANCE Developing targeted treatment for RABV requires understanding the innate immune response to the virus because early virus clearance is essential for preventing the fatality when the infection has progressed to the CNS. Previous studies have revealed that TLR7 is involved in the immune response to RABV. Here, we establish that TLR7 recognizes RABV and facilitates the production of some interferon-stimulated genes. We also demonstrated that when RABV invades into the CNS, TLR7 enhances the production of inflammatory cytokines which contribute to immunopathology in the mouse brain. Taken together, our findings suggest that treatments for RABV must consider the balance between the beneficial and harmful effects of TLR7-triggered immune responses.


2000 ◽  
Vol 74 (21) ◽  
pp. 10212-10216 ◽  
Author(s):  
Hélène Raux ◽  
Anne Flamand ◽  
Danielle Blondel

ABSTRACT The rabies virus P protein is involved in viral transcription and replication but its precise function is not clear. We investigated the role of P (CVS strain) by searching for cellular partners by using a two-hybrid screening of a PC12 cDNA library. We isolated a cDNA encoding a 10-kDa dynein light chain (LC8). LC8 is a component of cytoplasmic dynein involved in the minus end-directed movement of organelles along microtubules. We confirmed that this molecule interacts with P by coimmunoprecipitation in infected cells and in cells transfected with a plasmid encoding P protein. LC8 was also detected in virus particles. Series of deletions from the N- and C-terminal ends of P protein were used to map the LC8-binding domain to the central part of P (residues 138 to 172). These results are relevant to speculate that dynein may be involved in the axonal transport of rabies virus along microtubules through neuron cells.


1999 ◽  
Vol 73 (1) ◽  
pp. 242-250 ◽  
Author(s):  
Teshome Mebatsion ◽  
Frank Weiland ◽  
Karl-Klaus Conzelmann

ABSTRACT To elucidate the functions of rhabdovirus matrix (M) protein, we determined the localization of M in rabies virus (RV) and analyzed the properties of an M-deficient RV mutant. We provide evidence that M completely covers the ribonucleoprotein (RNP) coil and keeps it in a condensed form. As determined by cosedimentation experiments, not only the M-RNP complex but also M alone was found to interact specifically with the glycoprotein G. In contrast, an interaction of G with the nucleoprotein N or M-less RNP was not observed. In the absence of M, infectious particles were mainly cell associated and the yield of cell-free infectious virus was reduced by as much as 500,000-fold, demonstrating the crucial role of M in virus budding. Supernatants from cells infected with the M-deficient RV did not contain the typical bullet-shaped rhabdovirus particles but instead contained long, rod-shaped virions, demonstrating severe impairment of the virus formation process. Complementation with M protein expressed from plasmids rescued rhabdovirus formation. These results demonstrate the pivotal role of M protein in condensing and targeting the RNP to the plasma membrane as well as in incorporation of G protein into budding virions.


2021 ◽  
Vol 102 (10) ◽  
Author(s):  
Caiqian Wang ◽  
Lei Lv ◽  
Qiong Wu ◽  
Zongmei Wang ◽  
Zhaochen Luo ◽  
...  

Rabies is a zoonotic disease caused by the rabies virus (RABV). RABV can lead to fatal encephalitis and is still a serious threat in most parts of the world. Interferon regulatory factor 7 (IRF7) is the main transcriptional regulator of type I IFN, and it is crucial for the induction of IFNα/β and the type I IFN-dependent immune response. In this study, we focused on the role of IRF7 in the pathogenicity and immunogenicity of RABV using an IRF7-/- mouse model. The results showed that the absence of IRF7 made mice more susceptible to RABV, because IRF7 restricted the replication of RABV in the early stage of infection. IRF7 deficiency affected the recruitment of plasmacytoid dendritic cells to the draining lymph nodes (dLNs), reduced the production of type I IFN and expression of IFN-stimulated genes. Furthermore, we found that the ability to produce specific RABV-neutralizing antibody was impaired in IRF7-/- mice. Consistently, IRF7 deficiency affected the recruitment of germinal-centre B cells to dLNs, and the generation of plasma cells and RABV-specific antibody secreting cells. Moreover, the absence of IRF7 downregulated the induction of IFN-γ and reduced type 1 T helper cell (Th1)-dependent antibody production. Collectively, our findings demonstrate that IRF7 promotes humoral immune responses and compromises the pathogenicity of RABV in a mouse model.


2007 ◽  
Vol 82 (5) ◽  
pp. 2330-2338 ◽  
Author(s):  
Rojjanaporn Pulmanausahakul ◽  
Jianwei Li ◽  
Matthias J. Schnell ◽  
Bernhard Dietzschold

ABSTRACT While the glycoprotein (G) of rabies virus (RV) is known to play a predominant role in the pathogenesis of rabies, the function of the RV matrix protein (M) in RV pathogenicity is not completely clear. To further investigate the roles of these proteins in viral pathogenicity, we constructed chimeric recombinant viruses by exchanging the G and M genes of the attenuated SN strain with those of the highly pathogenic SB strain. Infection of mice with these chimeric viruses revealed a significant increase in the pathogenicity of the SN strain bearing the RV G from the pathogenic SB strain. Moreover, the pathogenicity was further increased when both G and M from SB were introduced into SN. Interestingly, the replacement of the G or M gene or both in SN by the corresponding genes of SB was associated with a significant decrease in the rate of viral replication and viral RNA synthesis. In addition, a chimeric SN virus bearing both the M and G genes from SB exhibited more efficient cell-to-cell spread than a chimeric SN virus in which only the G gene was replaced. Together, these data indicate that both G and M play an important role in RV pathogenesis by regulating virus replication and facilitating cell-to-cell spread.


2015 ◽  
Vol 90 (3) ◽  
pp. 1444-1454 ◽  
Author(s):  
Alexander Koehler ◽  
Larissa Kolesnikova ◽  
Ulla Welzel ◽  
Gordian Schudt ◽  
Astrid Herwig ◽  
...  

ABSTRACTMarburg virus (MARV) induces severe hemorrhagic fever in humans and nonhuman primates but only transient nonlethal disease in rodents. However, sequential passages of MARV in rodents boosts infection leading to lethal disease. Guinea pig-adapted MARV contains one mutation in the viral matrix protein VP40 at position 184 (VP40D184N). The contribution of the D184N mutation to the efficacy of replication in a new host is unknown. In the present study, we demonstrated that recombinant MARV containing the D184N mutation in VP40 [rMARVVP40(D184N)] grew to higher titers than wild-type recombinant MARV (rMARVWT) in guinea pig cells. Moreover, rMARVVP40(D184N)displayed higher infectivity in guinea pig cells. Comparative analysis of VP40 functions indicated that neither the interferon (IFN)-antagonistic function nor the membrane binding capabilities of VP40 were affected by the D184N mutation. However, the production of VP40-induced virus-like particles (VLPs) and the recruitment of other viral proteins to the budding site was improved by the D184N mutation in guinea pig cells, which resulted in the higher infectivity of VP40D184N-induced infectious VLPs (iVLPs) compared to that of VP40-induced iVLPs. In addition, the function of VP40 in suppressing viral RNA synthesis was influenced by the D184N mutation specifically in guinea pig cells, thus allowing greater rates of transcription and replication. Our results showed that the improved viral fitness of rMARVVP40(D184N)in guinea pig cells was due to the better viral assembly function of VP40D184Nand its lower inhibitory effect on viral transcription and replication rather than modulation of the VP40-mediated suppression of IFN signaling.IMPORTANCEThe increased virulence achieved by virus passaging in a new host was accompanied by mutations in the viral genome. Analyzing how these mutations affect the functions of viral proteins and the ability of the virus to grow within new host cells helps in the understanding of the molecular mechanisms increasing virulence. Using a reverse genetics approach, we demonstrated that a single mutation in MARV VP40 detected in a guinea pig-adapted MARV provided a replicative advantage of rMARVVP40(D184N)in guinea pig cells. Our studies show that this replicative advantage of rMARV VP40D184Nwas based on the improved functions of VP40 in iVLP assembly and in the regulation of transcription and replication rather than on the ability of VP40 to combat the host innate immunity.


2003 ◽  
Vol 84 (6) ◽  
pp. 1613-1621 ◽  
Author(s):  
Stefan Finke ◽  
Roland Mueller-Waldeck ◽  
Karl-Klaus Conzelmann

2020 ◽  
pp. jbc.RA120.014190
Author(s):  
Xing Liu ◽  
Fang Li ◽  
Jiwen Zhang ◽  
Lulu Wang ◽  
Jinliang Wang ◽  
...  

Rabies virus (RABV) matrix protein (M) plays crucial roles in viral transcription, replication, assembly, and budding; however, its function during the early stage of virus replication remains unknown. Here, we mapped the protein interactome between RABV M and human host factors using a proteomic approach, finding a link to the V-type proton ATPase (V-ATPase) catalytic subunit A (ATP6V1A) which is located in the endosomes where RABV first enters. By downregulating or upregulating ATP6V1A expression in HEK293T cells, we found that ATP6V1A facilitated RABV replication. We further found that ATP6V1A was involved in the dissociation of incoming viral M proteins during viral uncoating. Co-immunoprecipitation demonstrated that M interacted with the full length or middle domain of ATP6V1A, which was dependent on the lysine residue at position 256 and the glutamic acid residue at position 279. RABV growth and uncoating in ATP6V1A-depleted cells was restored by trans-complementation with the full length or interaction domain of ATP6V1A. Moreover, stably overexpressed ATP6V1A enhanced RABV growth in Vero cells which are used for the production of rabies vaccine. Our findings identify a new partner for RABV M proteins and establish a new role of ATP6V1A by promoting virion uncoating during RABV replication.


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