scholarly journals Analysis of the Function of the Lymphocytic Choriomeningitis Virus S Segment Untranslated Region on Growth Capacity In Vitro and on Virulence In Vivo

Viruses ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 896
Author(s):  
Satoshi Taniguchi ◽  
Tomoki Yoshikawa ◽  
Masayuki Shimojima ◽  
Shuetsu Fukushi ◽  
Takeshi Kurosu ◽  
...  
Keyword(s):  
Reverse Genetics ◽  
Vero Cells ◽  
Lymphocytic Choriomeningitis ◽  
Lymphocytic Choriomeningitis Virus ◽  
Genome Replication ◽  
Growth Capacity ◽  
Functional Roles ◽  
Viral Genome Replication

Lymphocytic choriomeningitis virus (LCMV) is a prototypic arenavirus. The function of untranslated regions (UTRs) of the LCMV genome has not been well studied except for the extreme 19 nucleotide residues of both the 5′ and 3′ termini. There are internal UTRs composed of 58 and 41 nucleotide residues in the 5′ and 3′ UTRs, respectively, in the LCMV S segment. Their functional roles have yet to be elucidated. In this study, reverse genetics and minigenome systems were established for LCMV strain WE and the function of these regions were analyzed. It was revealed that nucleotides 20–40 and 20–38 located downstream of the 19 nucleotides in the 5′ and 3′ termini, respectively, were involved in viral genome replication and transcription. Furthermore, it was revealed that the other internal UTRs (nucleotides 41–77 and 39–60 in the 5′ and 3′ termini, respectively) in the S segment were involved in virulence in vivo, even though these regions did not affect viral growth capacity in Vero cells. The introduction of LCMV with mutations in these regions attenuates the virus and may enable the production of LCMV vaccine candidates.

scholarly journals Characterization of the untranslated region of lymphocytic choriomeningitis virus S segment

2019 ◽  
Author(s):  
Satoshi Taniguchi ◽  
Tomoki Yoshikawa ◽  
Masayuki Shimojima ◽  
Shuetsu Fukushi ◽  
Takeshi Kurosu ◽  
...  
Keyword(s):  
Viral Genome ◽  
Lethal Dose ◽  
Lymphocytic Choriomeningitis ◽  
Lymphocytic Choriomeningitis Virus ◽  
Untranslated Regions ◽  
Genome Replication ◽  
Wild Type ◽  
Viral Genome Replication

ABSTRACTLymphocytic choriomeningitis virus (LCMV) is a prototypic arenavirus. The viral genome consists of two RNA segments, L and S. The 5’- and 3’-termini of both L and S segments are highly conserved among arenaviruses. These regions consist of 19 complementary base pairs and are essential for viral genome replication and transcription. In addition to these 19 nucleotides in the 5’- and 3’-termini, there are untranslated regions (UTRs) composed of 58 and 41 nucleotide residues in the 5’ and 3’ UTRs, respectively, in the LCMV S segment. Their functional roles, however, have yet to be elucidated. In this study, a reverse genetics and a minigenome system for the LCMV strain WE were established and used to analyze the function of these regions. The results obtained from these analyses, plus RNA secondary structure prediction, revealed that not only these 19 nucleotides but also the 20th–40th and 20th–38th nucleotides located downstream of the 19 nucleotides in the 5’- and 3’-termini, respectively, are heavily involved in viral genome replication and transcription. Furthermore, the introduction of mutations in these regions depressed viral propagation in vitro and enhanced attenuation in vivo. Conversely, recombinant LCMVs (rLCMVs), which had various deletions in the other UTRs, propagated as well as wild-type LCMV in vitro but were attenuated in vivo. Most mice previously infected with rLCMVs with mutated UTRs, when further infected with a lethal dose of wild-type LCMV, survived. These results suggest that rLCMVs with mutated UTRs could be candidates for an LCMV vaccine.IMPORTANCEThe function of untranslated regions (UTRs) of the arenavirus genome has not well been studied except for the 19 nucleotides of the 5’- and 3’-termini. In this study the function of the UTRs of the LCMV S segment was analyzed. It was found that not only the 19 nucleotides of the 5’- and 3’-termini but also the 20th–40th and 20th–38th nucleotides located downstream of the 19 nucleotides in the 5’- and 3’-termini, respectively, were involved in viral genome replication and transcription. Furthermore, other UTRs in the S segment were involved in virulence in vivo. The introduction of mutations to these regions makes it possible to establish attenuated LCMV and potentially develop LCMV vaccine candidates.

scholarly journals IFN-λ1 Displays Various Levels of Antiviral Activity In Vitro in a Select Panel of RNA Viruses

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1602
Author(s):  
Marina Plotnikova ◽  
Alexey Lozhkov ◽  
Ekaterina Romanovskaya-Romanko ◽  
Irina Baranovskaya ◽  
Mariia Sergeeva ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Rna Viruses ◽  
Antiviral Effect ◽  
Vero Cells ◽  
Genome Replication ◽  
Type I ◽  
Protective Effects ◽  
Cellular Models ◽  
Viral Genome Replication

Type III interferons (lambda IFNs) are a quite new, small family of three closely related cytokines with interferon-like activity. Attention to IFN-λ is mainly focused on direct antiviral activity in which, as with IFN-α, viral genome replication is inhibited without the participation of immune system cells. The heterodimeric receptor for lambda interferons is exposed mainly on epithelial cells, which limits its possible action on other cells, thus reducing the likelihood of developing undesirable side effects compared to type I IFN. In this study, we examined the antiviral potential of exogenous human IFN-λ1 in cellular models of viral infection. To study the protective effects of IFN-λ1, three administration schemes were used: ‘preventive’ (pretreatment); ‘preventive/therapeutic’ (pre/post); and ‘therapeutic’ (post). Three IFN-λ1 concentrations (from 10 to 500 ng/mL) were used. We have shown that human IFN-λ1 restricts SARS-CoV-2 replication in Vero cells with all three treatment schemes. In addition, we have shown a decrease in the viral loads of CHIKV and IVA with the ‘preventive’ and ‘preventive/therapeutic’ regimes. No significant antiviral effect of IFN-λ1 against AdV was detected. Our study highlights the potential for using IFN-λ as a broad-spectrum therapeutic agent against respiratory RNA viruses.

scholarly journals Genomic and biological characterization of aggressive and docile strains of lymphocytic choriomeningitis virus rescued from a plasmid-based reverse-genetics system

2008 ◽  
Vol 89 (6) ◽  
pp. 1421-1433 ◽  
Author(s):  
Minjie Chen ◽  
Shuiyun Lan ◽  
Rong Ou ◽  
Graeme E. Price ◽  
Hong Jiang ◽  
...  
Keyword(s):  
Reverse Genetics ◽  
Molecular Mechanisms ◽  
Lymphocytic Choriomeningitis ◽  
Lymphocytic Choriomeningitis Virus ◽  
Biological Characterization ◽  
Causative Agents ◽  
Cloned Cdna ◽  
Viral Determinants

Arenaviruses include several causative agents of haemorrhagic fever disease in humans. In addition, the prototypic arenavirus lymphocytic choriomeningitis virus (LCMV) is a superb model for the study of virus–host interactions, including the basis of viral persistence and associated diseases. There is little understanding about the molecular mechanisms concerning the regulation and specific role of viral proteins in modulating arenavirus–host cell interactions either associated with an acute or persistent infection, and associated disease. Here, we report the genomic and biological characterization of LCMV strains ‘Docile’ (persistent) and ‘Aggressive’ (not persistent) recovered from cloned cDNA via reverse genetics. Our results confirmed that the cloned viruses accurately recreated the in vivo phenotypes associated with the corresponding natural Docile and Aggressive viral isolates. In addition, we provide evidence that the ability of the Docile strain to persist is determined by the nature of both S and L RNA segments. Thus, our findings provide the foundation for studies aimed at gaining a detailed understanding of viral determinants of LCMV persistence in its natural host, which may aid in the development of vaccines to prevent or treat the diseases caused by arenaviruses in humans.

Subtle differences in CTL cytotoxicity determine susceptibility to hemophagocytic lymphohistiocytosis in mice and humans with Chediak-Higashi syndrome

Blood ◽  
2011 ◽  
Vol 118 (17) ◽  
pp. 4620-4629 ◽  
Author(s):  
Birthe Jessen ◽  
Andrea Maul-Pavicic ◽  
Heike Ufheil ◽  
Thomas Vraetz ◽  
Anselm Enders ◽  
...  
Keyword(s):  
Hemophagocytic Lymphohistiocytosis ◽  
Viral Infections ◽  
Nk Cell ◽  
Lymphocytic Choriomeningitis ◽  
Lymphocytic Choriomeningitis Virus ◽  
Mouse Strains ◽  
Lymphocytic Choriomeningitis Virus Infection ◽  
Chediak Higashi Syndrome

Abstract Perforin-mediated cytotoxicity is important for controlling viral infections, but also for limiting immune reactions. Failure of this cytotoxic pathway leads to hemophagocytic lymphohistiocytosis (HLH), a life-threatening disorder of uncontrolled T-cell and macrophage activation. We studied susceptibility to HLH in 2 mouse strains (souris and beigeJ) and a cohort of patients with partial defects in perforin secretion resulting from different mutations in the LYST gene. Although both strains lacked NK-cell cytotoxicity, only souris mice developed all clinical and histopathologic signs of HLH after infection with lymphocytic choriomeningitis virus. The 2 strains showed subtle differences in CTL cytotoxicity in vitro that had a large impact on virus control in vivo. Whereas beigeJ CTLs eliminated lymphocytic choriomeningitis virus infection, souris CTLs failed to control the virus, which was associated with the development of HLH. In LYST-mutant patients with Chediak-Higashi syndrome, CTL cytotoxicity was reduced in patients with early-onset HLH, whereas it was retained in patients who later or never developed HLH. Thus, the risk of HLH development is set by a threshold that is determined by subtle differences in CTL cytotoxicity. Differences in the cytotoxic capacity of CTLs may be predictive for the risk of Chediak-Higashi syndrome patients to develop HLH.

scholarly journals Post-translational modification of α-dystroglycan is not critical for lymphocytic choriomeningitis virus receptor function in vivo

2008 ◽  
Vol 89 (11) ◽  
pp. 2713-2722 ◽  
Author(s):  
Mauro Imperiali ◽  
Roman Spörri ◽  
Jane Hewitt ◽  
Annette Oxenius
Keyword(s):  
Lymphocytic Choriomeningitis ◽  
Lymphocytic Choriomeningitis Virus ◽  
Cellular Receptor ◽  
Receptor Function ◽  
Post Translational Modification ◽  
Rare Type ◽  
Post Translational Modifications ◽  
Virus Receptor

α-Dystroglycan (α-DG) is a ubiquitously expressed molecule that has been identified as a cellular receptor for lymphocytic choriomeningitis virus (LCMV) and other arenaviruses. Recently, it was demonstrated that LCMV receptor function is critically dependent on post-translational modifications, namely glycosylation. In particular, it was shown that O-mannosylation, a rare type of mammalian O-linked glycosylation, is important in determining the binding of LCMV to its cellular receptor. All studies carried out so far showed a dependence on glycosylation in LCMV receptor function in vitro. This work extended these studies to two in vivo models of α-DG hypoglycosylation. The results confirm earlier findings on the in vitro dependence of carbohydrate modifications in LCMV receptor function. However, experiments in animal models showed that this dependence was only very weak in vivo. It is likely that alternative receptors or alternative entry pathways may account for this attenuated in vivo phenotype.

scholarly journals Slow viral propagation during initial phase of infection leads to viral persistence in mice

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Haifeng C. Xu ◽  
Ruifeng Wang ◽  
Prashant V. Shinde ◽  
Lara Walotka ◽  
Anfei Huang ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Evasion ◽  
Protein Transport ◽  
Adaptive Immune System ◽  
Viral Persistence ◽  
Lymphocytic Choriomeningitis ◽  
Type I ◽  
Viral Propagation

AbstractImmune evasion of pathogens can modify the course of infection and impact viral persistence and pathology. Here, using different strains of the lymphocytic choriomeningitis virus (LCMV) model system, we show that slower propagation results in limited type I interferon (IFN-I) production and viral persistence. Specifically, cells infected with LCMV-Docile exhibited reduced viral replication when compared to LCMV-WE and as a consequence, infection with LCMV-Docile resulted in reduced activation of bone marrow derived dendritic cells (BMDCs) and IFN-I production in vitro in comparison with LCMV-WE. In vivo, we observed a reduction of IFN-I, T cell exhaustion and viral persistence following infection of LCMV-Docile but not LCMV-WE. Mechanistically, block of intracellular protein transport uncovered reduced propagation of LCMV-Docile when compared to LCMV-WE. This reduced propagation was critical in blunting the activation of the innate and adaptive immune system. When mice were simultaneously infected with LCMV-Docile and LCMV-WE, immune function was restored and IFN-I production, T cell effector functions as well as viral loads were similar to that of mice infected with LCMV-WE alone. Taken together, this study suggests that reduced viral propagation can result in immune evasion and viral persistence.

scholarly journals Exosomal S100A4 derived from highly metastatic hepatocellular carcinoma cells promotes metastasis by activating STAT3

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Haoting Sun ◽  
Chaoqun Wang ◽  
Beiyuan Hu ◽  
Xiaomei Gao ◽  
Tiantian Zou ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cancer Progression ◽  
Calcium Binding ◽  
Tumor Metastasis ◽  
Metastatic Potential ◽  
Functional Roles ◽  
Stat3 Phosphorylation ◽  
Hcc Cells

AbstractIntercellular cross-talk plays important roles in cancer progression and metastasis. Yet how these cancer cells interact with each other is still largely unknown. Exosomes released by tumor cells have been proved to be effective cell-to-cell signal mediators. We explored the functional roles of exosomes in metastasis and the potential prognostic values for hepatocellular carcinoma (HCC). Exosomes were extracted from HCC cells of different metastatic potentials. The metastatic effects of exosomes derived from highly metastatic HCC cells (HMH) were evaluated both in vitro and in vivo. Exosomal proteins were identified with iTRAQ mass spectrum and verified in cell lines, xenograft tumor samples, and functional analyses. Exosomes released by HMH significantly enhanced the in vitro invasion and in vivo metastasis of low metastatic HCC cells (LMH). S100 calcium-binding protein A4 (S100A4) was identified as a functional factor in exosomes derived from HMH. S100A4rich exosomes significantly promoted tumor metastasis both in vitro and in vivo compared with S100A4low exosomes or controls. Moreover, exosomal S100A4 could induce expression of osteopontin (OPN), along with other tumor metastasis/stemness-related genes. Exosomal S100A4 activated OPN transcription via STAT3 phosphorylation. HCC patients with high exosomal S100A4 in plasma also had a poorer prognosis. In conclusion, exosomes from HMH could promote the metastatic potential of LMH, and exosomal S100A4 is a key enhancer for HCC metastasis, activating STAT3 phosphorylation and up-regulating OPN expression. This suggested exosomal S100A4 to be a novel prognostic marker and therapeutic target for HCC metastasis.

scholarly journals The Nucleoprotein Is Required for Lymphocytic Choriomeningitis Virus-Based Vaccine Vector Immunogenicity

2015 ◽  
Vol 89 (22) ◽  
pp. 11734-11738 ◽  
Author(s):  
Stephanie Darbre ◽  
Susan Johnson ◽  
Sandra Kallert ◽  
Paul-Henri Lambert ◽  
Claire-Anne Siegrist ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cell ◽  
T Cell Responses ◽  
Lymphocytic Choriomeningitis ◽  
Lymphocytic Choriomeningitis Virus ◽  
Viral Transcription ◽  
Genome Replication ◽  
Recombinant Glycoprotein ◽  
Cell Responses ◽  
Deficient Vector

Recombinant glycoprotein-deficient lymphocytic choriomeningitis virus-based vaccine vectors (rLCMV/ΔGP) are potent CD8+T cell inducers. To investigate the underlying molecular requirements, we generated a nucleoprotein-deficient vector counterpart (rLCMV/ΔNP). NP but not GP is a minimaltrans-acting factor for viral transcription and genome replication. We found that, unlike rLCMV/ΔGP, rLCMV/ΔNP failed to elicit detectable CD8+T cell responses unless NP wastranscomplemented in a transgenic host. Hence, NP-dependent intracellular gene expression is essential for LCMV vector immunogenicity.

scholarly journals Construction of an Excisable Bacterial Artificial Chromosome Containing a Full-Length Infectious Clone of Herpes Simplex Virus Type 1: Viruses Reconstituted from the Clone Exhibit Wild-Type Properties In Vitro and In Vivo

2003 ◽  
Vol 77 (2) ◽  
pp. 1382-1391 ◽  
Author(s):  
Michiko Tanaka ◽  
Hiroyuki Kagawa ◽  
Yuji Yamanashi ◽  
Tetsutaro Sata ◽  
Yasushi Kawaguchi
Keyword(s):  
Vero Cells ◽  
Infectious Molecular Clone ◽  
Wild Type ◽  
Molecular Clone ◽  
Viral Genes ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACT In recent years, several laboratories have reported on the cloning of herpes simplex virus type 1 (HSV-1) genomes as bacterial artificial chromosomes (BACs) in Escherichia coli and on procedures to manipulate these genomes by using the bacterial recombination machinery. However, the HSV-BACs reported so far are either replication incompetent or infectious, with a deletion of one or more viral genes due to the BAC vector insertion. For use as a multipurpose clone in research on HSV-1, we attempted to generate infectious HSV-BACs containing the full genome of HSV-1 without any loss of viral genes. Our results were as follows. (i) E. coli (YEbac102) harboring the full-length HSV-1 genome (pYEbac102) in which a BAC flanked by loxP sites was inserted into the intergenic region between UL3 and UL4 was constructed. (ii) pYEbac102 was an infectious molecular clone, given that its transfection into rabbit skin cells resulted in production of infectious virus (YK304). (iii) The BAC vector sequence was almost perfectly excisable from the genome of the reconstituted virus YK304 by coinfection of Vero cells with YK304 and a recombinant adenovirus, AxCANCre, expressing Cre recombinase. (iv) As far as was examined, the reconstituted viruses from pYEbac102 could not be phenotypically differentiated from wild-type viruses in vitro and in vivo. Thus, the viruses grew as well in Vero cells as did the wild-type virus and exhibited wild-type virulence in mice on intracerebral inoculation. (v) The infectious molecular clone pYEbac102 is in fact useful for mutagenesis of the HSV-1 genome by bacterial genetics, and a recombinant virus carrying amino acid substitutions in both copies of the α0 gene was generated. pYEbac102 will have multiple applications to the rapid generation of genetically engineered HSV-1 recombinants in basic research into HSV-1 and in the development of HSV vectors in human therapy.

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