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1.
Cell ; 186(9): 1877-1894.e27, 2023 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-37116470

RESUMO

Negative-stranded RNA viruses can establish long-term persistent infection in the form of large intracellular inclusions in the human host and cause chronic diseases. Here, we uncover how cellular stress disrupts the metastable host-virus equilibrium in persistent infection and induces viral replication in a culture model of mumps virus. Using a combination of cell biology, whole-cell proteomics, and cryo-electron tomography, we show that persistent viral replication factories are dynamic condensates and identify the largely disordered viral phosphoprotein as a driver of their assembly. Upon stress, increased phosphorylation of the phosphoprotein at its interaction interface with the viral polymerase coincides with the formation of a stable replication complex. By obtaining atomic models for the authentic mumps virus nucleocapsid, we elucidate a concomitant conformational change that exposes the viral genome to its replication machinery. These events constitute a stress-mediated switch within viral condensates that provide an environment to support upregulation of viral replication.


Assuntos
Vírus da Caxumba , Infecção Persistente , Humanos , Vírus da Caxumba/fisiologia , Nucleocapsídeo , Fosfoproteínas/metabolismo , Replicação Viral
2.
J Virol ; 96(19): e0072222, 2022 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-36135364

RESUMO

The nucleolus is the largest structure in the nucleus, and it plays roles in mediating cellular stress responses and regulating cell proliferation, as well as in ribosome biosynthesis. The nucleolus is composed of a variety of nucleolar factors that interact with each other in a complex manner to enable its function. Many viral proteins interact with nucleolar factors as well, affecting cellular morphology and function. Here, to investigate the association between mumps virus (MuV) infection and the nucleolus, we evaluated the necessity of nucleolar factors for MuV proliferation by performing a knockdown of these factors with small interfering (si)RNAs. Our results reveal that suppressing the expression of Treacle, which is required for ribosome biosynthesis, reduced the proliferative potential of MuV. Additionally, the one-step growth kinetics results indicate that Treacle knockdown did not affect the viral RNA and protein synthesis of MuV, but it did impair the production of infectious virus particles. Viral matrix protein (M) was considered a candidate Treacle interaction partner because it functions in the process of particle formation in the viral life cycle and is partially localized in the nucleolus. Our data confirm that MuV M can interact with Treacle and colocalize with it in the nucleolus. Furthermore, we found that viral infection induces relocalization of Treacle in the nucleus. Together, these findings suggest that interaction with Treacle in the nucleolus is important for the M protein to exert its functions late in the MuV life cycle. IMPORTANCE The nucleolus, which is the site of ribosome biosynthesis, is a target organelle for many viruses. It is increasingly evident that viruses can favor their own replication and multiplication by interacting with various nucleolar factors. In this study, we found that the nucleolar protein Treacle, known to function in the transcription and processing of pre-rRNA, is required for the efficient propagation of mumps virus (MuV). Specifically, our data indicate that Treacle is not involved in viral RNA or protein synthesis but is important in the processes leading to viral particle production in MuV infection. Additionally, we determined that MuV matrix protein (M), which functions mainly in viral particle assembly and budding, colocalized and interacted with Treacle. Furthermore, we found that Treacle is distributed throughout the nucleus in MuV-infected cells. Our research shows that the interaction between M and Treacle supports efficient viral growth in the late stage of MuV infection.


Assuntos
Vírus da Caxumba , Proteínas Nucleares , Proteínas da Matriz Viral , Nucléolo Celular/metabolismo , Humanos , Caxumba , Vírus da Caxumba/fisiologia , Proteínas Nucleares/metabolismo , Fosfoproteínas , Precursores de RNA/metabolismo , RNA Viral/metabolismo , Proteínas da Matriz Viral/metabolismo
3.
Viruses ; 13(12)2021 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-34960805

RESUMO

Frequent mumps outbreaks in vaccinated populations and the occurrence of neurological complications (e.g., aseptic meningitis or encephalitis) in patients with mumps indicate the need for the development of more efficient vaccines as well as specific antiviral therapies. RNA viruses are genetically highly heterogeneous populations that exist on the edge of an error threshold, such that additional increases in mutational burden can lead to extinction of the virus population. Deliberate modulation of their natural mutation rate is being exploited as an antiviral strategy and a possibility for rational vaccine design. The aim of this study was to examine the ability of ribavirin, a broad-spectrum antiviral agent, to introduce mutations in the mumps virus (MuV) genome and to investigate if resistance develops during long-term in vitro exposure to ribavirin. An increase in MuV population heterogeneity in the presence of ribavirin has been observed after one passage in cell culture, as well as a bias toward C-to-U and G-to-A transitions, which have previously been defined as ribavirin-related. At higher ribavirin concentration, MuV loses its infectivity during serial passaging and does not recover. At low ribavirin concentration, serial passaging leads to a more significant increase in population diversity and a stronger bias towards ribavirin-related transitions, independently of viral strain or cell culture. In these conditions, the virus retains its initial growth capacity, without development of resistance at a whole-virus population level.


Assuntos
Antivirais/farmacologia , Vírus da Caxumba/efeitos dos fármacos , Ribavirina/farmacologia , Animais , Chlorocebus aethiops , Farmacorresistência Viral , Variação Genética/efeitos dos fármacos , Vírus da Caxumba/genética , Vírus da Caxumba/fisiologia , Mutação , Células Vero , Replicação Viral
4.
Viruses ; 13(12)2021 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-34960819

RESUMO

Recombinant mumps viruses (MuVs) based on established vaccine strains represent attractive vector candidates as they have known track records for high efficacy and the viral genome does not integrate in the host cells. We developed a rescue system based on the consensus sequence of the L-Zagreb vaccine and generated seven different recombinant MuVs by (a) insertion of one or two additional transcription units (ATUs), (b) lengthening of a noncoding region to the extent that the longest noncoding region in MuV genome is created, or (c) replacement of original L-Zagreb sequences with sequences rich in CG and AT dinucleotides. All viruses were successfully rescued and faithfully matched sequences of input plasmids. In primary rescued stocks, low percentages of heterogeneous positions were found (maximum 0.12%) and substitutions were predominantly obtained in minor variants, with maximally four substitutions seen in consensus. ATUs did not accumulate more mutations than the natural MuV genes. Six substitutions characteristic for recombinant viruses generated in our system were defined, as they repetitively occurred during rescue processes. In subsequent passaging of primary rescue stocks in Vero cells, different inconsistencies within quasispecies structures were observed. In order to assure that unwanted mutations did not emerge and accumulate, sub-consensus variability should be closely monitored. As we show for Pro408Leu mutation in L gene and a stop codon in one of ATUs, positively selected variants can rise to frequencies over 85% in only few passages.


Assuntos
Vírus da Caxumba/genética , Animais , Chlorocebus aethiops , Genoma Viral , Vírus da Caxumba/fisiologia , Mutação , Plasmídeos , Recombinação Genética , Células Vero
5.
Viruses ; 13(9)2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34578327

RESUMO

Mumps virus (MuV) is an important human pathogen that causes parotitis, orchitis, oophoritis, meningitis, encephalitis, and sensorineural hearing loss. Although mumps is a vaccine-preventable disease, sporadic outbreaks have occurred worldwide, even in highly vaccinated populations. MuV not only causes systemic infection but also has a unique tropism to glandular tissues and the central nervous system. In general, tropism can be defined by multiple factors in the viral life cycle, including its entry, interaction with host factors, and host-cell immune responses. Although the underlying mechanisms of MuV tropism remain to be fully understood, recent studies on virus-host interactions have provided insights into viral pathogenesis. This review was aimed at summarizing the entry process of MuV by focusing on the glycan receptors, particularly the recently identified receptors with a trisaccharide core motif, and their interactions with the viral attachment proteins. Here, we describe the receptor structures, their distribution in the human body, and the recently identified host factors for MuV and analyze their relationship with MuV tropism.


Assuntos
Interações Hospedeiro-Patógeno , Vírus da Caxumba/fisiologia , Proteínas Virais/metabolismo , Tropismo Viral , Internalização do Vírus , Humanos , Caxumba/virologia , Vírus da Caxumba/patogenicidade , Ligação Proteica , Receptores Virais , Ligação Viral
6.
Front Immunol ; 12: 582946, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33815357

RESUMO

The causative agent of mumps is a single-stranded, non-segmented, negative sense RNA virus belonging to the Paramyxoviridae family. Besides the classic symptom of painfully swollen parotid salivary glands (parotitis) in mumps virus (MuV)-infected men, orchitis is the most common form of extra-salivary gland inflammation. Mumps orchitis frequently occurs in young adult men, and leads to pain and swelling of the testis. The administration of MuV vaccines in children has been proven highly effective in reducing the incidence of mumps. However, a recent global outbreak of mumps and the high rate of orchitis have recently been considered as threats to male fertility. The pathogenesis of mumps orchitis remains largely unclear due to lack of systematic clinical data analysis and animal models studies. The alarming increase in the incidence of mumps orchitis and the high risk of the male fertility have thus become a major health concern. Recent studies have revealed the mechanisms by which MuV-host cells interact and MuV infection induces inflammatory responses in testicular cells. In this mini-review, we highlight advances in our knowledge of the clinical aspects and possible mechanisms of mumps orchitis.


Assuntos
Infertilidade Masculina/imunologia , Vírus da Caxumba/imunologia , Caxumba/imunologia , Orquite/imunologia , Interações Hospedeiro-Patógeno/imunologia , Humanos , Infertilidade Masculina/complicações , Infertilidade Masculina/prevenção & controle , Masculino , Caxumba/complicações , Caxumba/virologia , Vacina contra Caxumba/administração & dosagem , Vacina contra Caxumba/imunologia , Vírus da Caxumba/fisiologia , Orquite/complicações , Orquite/virologia , Fatores de Risco , Vacinação/métodos
7.
Elife ; 102021 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-33871357

RESUMO

In 2016/2017, Washington State experienced a mumps outbreak despite high childhood vaccination rates, with cases more frequently detected among school-aged children and members of the Marshallese community. We sequenced 166 mumps virus genomes collected in Washington and other US states, and traced mumps introductions and transmission within Washington. We uncover that mumps was introduced into Washington approximately 13 times, primarily from Arkansas, sparking multiple co-circulating transmission chains. Although age and vaccination status may have impacted transmission, our data set could not quantify their precise effects. Instead, the outbreak in Washington was overwhelmingly sustained by transmission within the Marshallese community. Our findings underscore the utility of genomic data to clarify epidemiologic factors driving transmission and pinpoint contact networks as critical for mumps transmission. These results imply that contact structures and historic disparities may leave populations at increased risk for respiratory virus disease even when a vaccine is effective and widely used.


Assuntos
Surtos de Doenças , Vírus da Caxumba/fisiologia , Caxumba/epidemiologia , Adolescente , Adulto , Criança , Pré-Escolar , Surtos de Doenças/estatística & dados numéricos , Genoma Viral , Humanos , Lactente , Micronésia/etnologia , Pessoa de Meia-Idade , Caxumba/transmissão , Caxumba/virologia , Vírus da Caxumba/genética , Washington/epidemiologia , Adulto Jovem
8.
Front Immunol ; 12: 580454, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33679733

RESUMO

Numerous types of viruses have been found in human semen, which raises concerns about the sexual transmission of these viruses. The overall effect of semen on viral infection and transmission have yet to be fully investigated. In the present study, we aimed at the effect of seminal plasma (SP) on viral infection by focusing on the mumps viral (MuV) infection of HeLa cells. MuV efficiently infected HeLa cells in vitro. MuV infection was strongly inhibited by the pre-treatment of viruses with SP. SP inhibited MuV infection through the impairment of the virus's attachment to cells. The antiviral activity of SP was resistant to the treatment of SP with boiling water, Proteinase K, RNase A, and DNase I, suggesting that the antiviral factor would not be proteins and nucleic acids. PNGase or PLA2 treatments did not abrogate the antiviral effect of SP against MuV. Further, we showed that the prostatic fluid (PF) showed similar inhibition as SP, whereas the epididymal fluid and seminal vesicle extract did not inhibit MuV infection. Both SP and PF also inhibited MuV infection of other cell types, including another human cervical carcinoma cell line C33a, mouse primary epididymal epithelial cells, and Sertoli cell line 15P1. Moreover, this inhibitory effect was not specific to MuV, as the herpes simplex virus 1, dengue virus 2, and adenovirus 5 infections were also inhibited by SP and PF. Our findings suggest that SP contains a prostate-derived pan-antiviral factor that may limit the sexual transmission of various viruses.


Assuntos
Antivirais/imunologia , Células Epiteliais/imunologia , Vírus da Caxumba/imunologia , Sêmen/imunologia , Vírus/imunologia , Animais , Antivirais/metabolismo , Linhagem Celular Tumoral , Células Cultivadas , Chlorocebus aethiops , Células Epiteliais/metabolismo , Células Epiteliais/virologia , Células HeLa , Interações Hospedeiro-Patógeno/imunologia , Humanos , Masculino , Camundongos Endogâmicos C57BL , Vírus da Caxumba/fisiologia , Sêmen/metabolismo , Sêmen/virologia , Células Vero
9.
J Immunol Methods ; 490: 112957, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33412172

RESUMO

Neutralizing antibodies against mumps and measles virus are considered a correlate of protection against these diseases. Measurement of neutralizing antibodies is mostly performed using plaque reduction neutralization assay or 50% cell culture infective dose (CCID50) neutralization assay, but there are attempts for measuring neutralizing antibodies using enzyme-linked immunosorbent assay (ELISA) which is simpler, but the literature data regarding its convenience are diverse. The role of complement and antibodies in neutralizing capacity of sera is not completely defined. Here, CCID50 neutralization assay and ELISA were used to determine the neutralization capacity against mumps and measles virus in human sera and therapeutic immunoglobulins (IVIGs). Results showed no correlation of neutralization titers obtained by CCID50 neutralization assay and IgG content obtained by ELISA for mumps or measles in human sera. Data showed some neutralization activity against measles virus and quite high against mumps virus of naïve guinea pig serum and that its addition increases neutralization capacity of IVIG and human sera against mumps and measles viruses. Heat inactivation of human sera reduced neutralization capacity against measles to small extent, and substantially against mumps virus. There is a significant impact of complement in measurement of neutralization capacity against mumps virus.


Assuntos
Anticorpos Neutralizantes/sangue , Proteínas do Sistema Complemento/metabolismo , Vírus do Sarampo/fisiologia , Sarampo/imunologia , Vírus da Caxumba/fisiologia , Caxumba/imunologia , Testes de Neutralização/métodos , Adulto , Animais , Ensaio de Imunoadsorção Enzimática , Feminino , Cobaias , Humanos , Masculino , Sarampo/diagnóstico , Pessoa de Meia-Idade , Caxumba/diagnóstico , Adulto Jovem
10.
mSphere ; 5(6)2020 11 18.
Artigo em Inglês | MEDLINE | ID: mdl-33208518

RESUMO

Between 2015 and 2017, routine molecular surveillance in the United States detected multiple mumps viruses (MuVs) with mutations in the small hydrophobic (SH) gene compared to a reference virus of the same genotype. These mutations include an unusual pattern of uracil-to-cytosine hypermutations and other mutations resulting in the generation of premature stop codons or disruption of the canonical stop codon. The mumps virus SH protein may serve as a virulence factor, based on evidence that it inhibits apoptosis and innate immune signaling in vitro and that recombinant viruses that do not express the SH protein are attenuated in an animal model. In this study, mumps viruses bearing variant SH sequences were isolated from contemporary outbreak samples to evaluate the impact of the observed mutations on SH protein function. All isolates with variant SH sequences replicated in interferon-competent cells with no evidence of attenuation. Furthermore, all SH-variant viruses retained the ability to abrogate induction of NF-κB-mediated innate immune signaling in infected cells. Ectopic expression of variant mumps SH genes is consistent with findings from infection experiments, indicating that the observed abrogation of signaling was not mediated by other viral factors that may modulate innate immune signaling. Molecular surveillance is an important public health tool for monitoring the diversity of circulating mumps viruses and can provide insights into determinants of disease. These findings, in turn, will inform studies employing reverse genetics to elucidate the specific mechanisms of MuV pathogenesis and potential impacts of observed sequence variants on infectivity, fitness, and virulence.IMPORTANCE Mumps virus (MuV) outbreaks occur in the United States despite high coverage with measles, mumps, rubella (MMR) vaccine. Routine genotyping of laboratory-confirmed mumps cases has been practiced in the United States since 2006 to enhance mumps surveillance. This study reports the detection of unusual mutations in the small hydrophobic (SH) protein of contemporary laboratory-confirmed mumps cases and is the first to describe the impact of such mutations on SH protein function. These mutations are predicted to profoundly alter the amino acid sequence of the SH protein, which has been shown to antagonize host innate immune responses; however, they were neither associated with defects in virus replication nor attenuated protein function in vitro, consistent with detection in clinical specimens. A better understanding of the forces governing mumps virus sequence diversity and of the functional consequences of mutations in viral proteins is important for maintaining robust capacity for mumps detection and disease control.


Assuntos
Códon de Terminação/genética , Vírus da Caxumba/fisiologia , Mutação , Proteínas Virais/genética , Animais , Humanos , Sarampo/virologia , Virulência , Fatores de Virulência
11.
Biologicals ; 67: 29-37, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32855039

RESUMO

Leningrad-Zagreb strain of mumps vaccine virus was grown on two different cell substrates viz. MRC-5 cells and Vero cells besides its original cell substrate i.e. Chicken Embryo Cells. Homogeneous virus pools prepared from each set of experiments were then lyophilized as per standard in-house protocol. Critical Quality Attributes (CQAs) such as the titer of the bulk vaccine and potency and stability of the lyophilized vaccine were then estimated using the CCID50 method to understand the lyophilization losses and thermal losses respectively in the vaccine. Another CQA viz. the genetic homogeneity of the vaccine was also tested using the single base extension method for identifying the nucleotides present at the three known locations of single nucleotide polymorphism (SNP). Comparison of CQA results across different cell substrates indicated encouraging results for Vero cell grown L-Zagreb virus compared to the MRC-5 cells grown L-Zagreb mumps virus. Significant improvement in productivity was also observed in the dynamic culture conditions compared to the static culture conditions. Progressive work in this research area can lead to development of a cGMP manufacturing process for mumps vaccine with easy scale up potential in future.


Assuntos
Reatores Biológicos , Vacina contra Caxumba/imunologia , Vírus da Caxumba/imunologia , Caxumba/imunologia , Animais , Linhagem Celular , Chlorocebus aethiops , Liofilização/métodos , Humanos , Caxumba/prevenção & controle , Caxumba/virologia , Vacina contra Caxumba/administração & dosagem , Vacina contra Caxumba/normas , Vírus da Caxumba/genética , Vírus da Caxumba/fisiologia , Controle de Qualidade , Vacinação , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/imunologia , Vacinas Atenuadas/normas , Células Vero , Cultura de Vírus/instrumentação , Cultura de Vírus/métodos
12.
Methods Mol Biol ; 2132: 641-652, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32306363

RESUMO

Many viruses utilize cell-surface glycans as receptors for host cell entry. Viral surface glycoproteins specifically interact with glycan motifs, which strongly contributes to viral tropism. Recently, the interactions between host cell glycan receptors and the mumps virus (MuV) hemagglutinin-neuraminidase (MuV-HN) protein were characterized by determining the co-crystal structure of MuV-HN in complex with glycan receptors. Here, we describe protocols for large-scale expression, purification and crystallization of MuV-HN proteins for structural analyses and glycan-binding assays with the overarching goal of investigating glycan-protein interactions.


Assuntos
Proteína HN/química , Proteína HN/metabolismo , Vírus da Caxumba/fisiologia , Caxumba/virologia , Polissacarídeos/metabolismo , Cromatografia de Afinidade , Cromatografia em Gel , Cristalografia por Raios X , Células HEK293 , Proteína HN/isolamento & purificação , Humanos , N-Acetilglucosaminiltransferases/deficiência , Ligação Proteica , Domínios Proteicos , Engenharia de Proteínas , Tropismo Viral , Internalização do Vírus
13.
PLoS One ; 14(7): e0219168, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31276568

RESUMO

In reverse genetic experiments we have isolated recombinant mumps viruses (rMuV) that carry large numbers of mutations clustered in small parts of their genome, which are not caused by biased hyper-mutation. In two separate experiments we obtained such recombinant viruses: one virus had 11 mutations in the V/P region of the genome; the other, which also contained an extra transcription unit encoding green fluorescent protein (EGFP), had 32 mutations in the N gene. These specific sets of mutations have not been observed in naturally occurring MuV isolates. Unusually, the vast majority of the mutations (48/51) were synonymous. On passage in Vero cells and human B-LCL cells, a B lymphocyte-like cell line, these mutations appear stable as no reversion occurred to the original consensus sequence, although mutations in other parts of the genome occurred and changed in frequency during passage. Defective interfering RNAs accumulate in passage in Vero cells but not in B-LCL cells. Interestingly, in all passaged samples the level of variation in the EGFP gene is the same as in the viral genes, though it is unlikely that this gene is under any functionality constraint. What mechanism gave rise to these viruses with clustered mutations and their stability remains an open question, which is likely of interest to a wider field than mumps reverse genetics.


Assuntos
DNA Complementar/genética , Vírus da Caxumba/fisiologia , Mutação , Proteínas Virais/genética , Animais , Linhagem Celular Tumoral , Chlorocebus aethiops , Proteínas de Fluorescência Verde/genética , Humanos , Vírus da Caxumba/genética , Genética Reversa/métodos , Inoculações Seriadas , Células Vero , Replicação Viral
14.
J Virol ; 93(15)2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31118251

RESUMO

Mumps virus (MuV) is an important aerosol-transmitted human pathogen causing epidemic parotitis, meningitis, encephalitis, and deafness. MuV preferentially uses a trisaccharide containing α2,3-linked sialic acid as a receptor. However, given the MuV tropism toward glandular tissues and the central nervous system, an additional glycan motif(s) may also serve as a receptor. Here, we performed a large-scale glycan array screen with MuV hemagglutinin-neuraminidase (MuV-HN) attachment proteins by using 600 types of glycans from The Consortium for Functional Glycomics Protein-Glycan Interaction Core in an effort to find new glycan receptor motif(s). According to the results of the glycan array, we successfully determined the crystal structures of MuV-HN proteins bound to newly identified glycan motifs, sialyl LewisX (SLeX) and the oligosaccharide portion of the GM2 ganglioside (GM2-glycan). Interestingly, the complex structures showed that SLeX and GM2-glycan share the same configuration with the reported trisaccharide motif, 3'-sialyllactose (3'-SL), at the binding site of MuV-HN, while SLeX and GM2-glycan have several unique interactions compared with those of 3'-SL. Thus, MuV-HN protein can allow an additional spatial modification in GM2-glycan and SLeX at the second and third carbohydrates from the nonreducing terminus of the core trisaccharide structure, respectively. Importantly, MuV entry was efficiently inhibited in the presence of 3'-SL, SLeX, or GM2-glycan derivatives, which indicates that these motifs can serve as MuV receptors. The α2,3-sialylated oligosaccharides, such as SLeX and 3'-sialyllactosamine, are broadly expressed in various tissues, and GM2 exists mainly in neural tissues and the adrenal gland. The distribution of these glycan motifs in human tissues/organs may have bearing on MuV tropism.IMPORTANCE Mumps virus (MuV) infection is characterized by parotid gland swelling and can cause pancreatitis, orchitis, meningitis, and encephalitis. MuV-related hearing loss is also a serious complication because it is usually irreversible. MuV outbreaks have been reported in many countries, even in high-vaccine-coverage areas. MuV has tropism toward glandular tissues and the central nervous system. To understand the unique MuV tropism, revealing the mechanism of receptor recognition by MuV is very important. Here, using a large-scale glycan array and X-ray crystallography, we show that MuV recognizes sialyl LewisX and GM2 ganglioside as receptors, in addition to a previously reported MuV receptor, a trisaccharide containing an α2,3-linked sialic acid. The flexible recognition of these glycan receptors by MuV may explain the unique tropism and pathogenesis of MuV. Structures will also provide a template for the development of effective entry inhibitors targeting the receptor-binding site of MuV.


Assuntos
Proteína HN/metabolismo , Antígenos do Grupo Sanguíneo de Lewis/metabolismo , Vírus da Caxumba/fisiologia , Receptores Virais/metabolismo , Ácidos Siálicos/metabolismo , Tropismo Viral , Ligação Viral , Cristalografia por Raios X , Proteína HN/química , Antígenos do Grupo Sanguíneo de Lewis/química , Análise em Microsséries , Ligação Proteica , Conformação Proteica , Ácidos Siálicos/química
15.
Artigo em Inglês | MEDLINE | ID: mdl-30175075

RESUMO

In the complex microenvironment of the human respiratory tract, different kinds of microorganisms may synergistically interact with each other resulting in viral-bacterial co-infections that are often associated with more severe diseases than the respective mono-infections. Human respiratory paramyxoviruses, for example parainfluenza virus type 3 (HPIV3), are common causes of respiratory diseases both in infants and a subset of adults. HPIV3 recognizes sialic acid (SA)-containing receptors on host cells. In contrast to human influenza viruses which have a preference for α2,6-linked sialic acid, HPIV3 preferentially recognize α2,3-linked sialic acids. Group B streptococci (GBS) are colonizers in the human respiratory tract. They contain a capsular polysaccharide with terminal sialic acid residues in an α2,3-linkage. In the present study, we report that HPIV3 can recognize the α2,3-linked sialic acids present on GBS. The interaction was evident not only by the binding of virions to GBS in a co-sedimentation assay, but also in the GBS binding to HPIV3-infected cells. While co-infection by GBS and HPIV3 had a delaying effect on the virus replication, it enhanced GBS adherence to virus-infected cells. To show that other human paramyxoviruses are also able to recognize the capsular sialic acid of GBS we demonstrate that GBS attaches in a sialic acid-dependent way to transfected BHK cells expressing the HN protein of mumps virus (MuV) on their surface. Overall, our results reveal a new type of synergism in the co-infection by respiratory pathogens, which is based on the recognition of α2,3-linked sialic acids. This interaction between human paramyxoviruses and GBS enhances the bacterial adherence to airway cells and thus may result in more severe disease.


Assuntos
Aderência Bacteriana/efeitos dos fármacos , Glicoproteínas/metabolismo , Hepatócitos/microbiologia , Ácido N-Acetilneuramínico/metabolismo , Streptococcus agalactiae/fisiologia , Proteínas Estruturais Virais/metabolismo , Ligação Viral , Linhagem Celular , Coinfecção/microbiologia , Coinfecção/virologia , Hepatócitos/efeitos dos fármacos , Humanos , Interações Microbianas , Vírus da Caxumba/fisiologia , Vírus da Parainfluenza 3 Humana/fisiologia , Ligação Proteica
16.
J Virol ; 92(20)2018 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-30068647

RESUMO

J paramyxovirus (JPV) was first isolated from moribund mice with hemorrhagic lung lesions in Australia in 1972. It is a paramyxovirus classified under the newly proposed genus Jeilongvirus JPV has a genome of 18,954 nucleotides, consisting of eight genes in the order 3'-N-P/V/C-M-F-SH-TM-G-L-5'. JPV causes little cytopathic effect (CPE) in tissue culture cells but severe disease in mice. The small hydrophobic (SH) protein is an integral membrane protein encoded by many paramyxoviruses, such as mumps virus (MuV) and respiratory syncytial virus (RSV). However, the function of SH has not been defined in a suitable animal model. In this work, the functions of SH of JPV, MuV, and RSV have been examined by generating recombinant JPV lacking the SH protein (rJPV-ΔSH) or replacing SH of JPV with MuV SH (rJPV-MuVSH) or RSV SH (rJPV-RSVSH). rJPV-ΔSH, rJPV-MuVSH, and rJPV-RSVSH were viable and had no growth defect in tissue culture cells. However, more tumor necrosis factor alpha (TNF-α) was produced during rJPV-ΔSH infection, confirming the role of SH in inhibiting TNF-α production. rJPV-ΔSH induced more apoptosis in tissue culture cells than rJPV, rJPV-MuVSH, and rJPV-RSVSH, suggesting that SH plays a role in blocking apoptosis. Furthermore, rJPV-ΔSH was attenuated in mice compared to rJPV, rJPV-MuVSH, and rJPV-RSVSH, indicating that the SH protein plays an essential role in virulence. The results indicate that the functions of MuV SH and RSV SH are similar to that of JPV SH even though they have no sequence homology.IMPORTANCE Paramyxoviruses are associated with many devastating diseases in animals and humans. J paramyxovirus (JPV) was isolated from moribund mice in Australia in 1972. Newly isolated viruses, such as Beilong virus (BeiPV) and Tailam virus (TlmPV), have genome structures similar to that of JPV. A new paramyxovirus genus, Jeilongvirus, which contains JPV, BeiPV, and TlmPV, has been proposed. Small hydrophobic (SH) protein is present in many paramyxoviruses. Our present study investigates the role of SH protein of JPV in pathogenesis in its natural host. Understanding the pathogenic mechanism of Jeilongvirus is important to control and prevent potential diseases that may emerge from this group of viruses.


Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Infecções por Paramyxoviridae/patologia , Paramyxoviridae/crescimento & desenvolvimento , Proteínas Oncogênicas de Retroviridae/metabolismo , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Fatores de Virulência/metabolismo , Animais , Linhagem Celular , Chlorocebus aethiops , Modelos Animais de Doenças , Deleção de Genes , Teste de Complementação Genética , Humanos , Camundongos , Viabilidade Microbiana , Vírus da Caxumba/genética , Vírus da Caxumba/fisiologia , Infecções por Paramyxoviridae/virologia , Vírus Sinciciais Respiratórios/genética , Vírus Sinciciais Respiratórios/fisiologia , Proteínas Oncogênicas de Retroviridae/genética , Virulência , Fatores de Virulência/genética
17.
Cancer Invest ; 36(2): 106-117, 2018 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-29485292

RESUMO

Oncolytic measles and mumps viruses (MeV, MuV) have a potential for anti-cancer treatment. We examined the anti-tumor activity of MeV, MuV, and MeV-MuV combination (MM) against human solid malignancies (HSM). MeV, MuV, and MM targeted and significantly killed various cancer cell lines of HSM but not normal cells. MM demonstrated a greater anti-tumor effect and prolonged survival in a human prostate cancer xenograft tumor model compared to MeV and MuV. MeV, MuV, and MM significantly induced the expression of immunogenic cell death markers and enhanced spleen-infiltrating immune cells. In conclusion, MM combination significantly improves the treatment of human solid malignancies.


Assuntos
Efeito Citopatogênico Viral , Vírus do Sarampo/fisiologia , Vírus da Caxumba/fisiologia , Neoplasias/terapia , Terapia Viral Oncolítica/métodos , Animais , Chlorocebus aethiops , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias/patologia , Neoplasias/virologia , Células Tumorais Cultivadas , Células Vero , Ensaios Antitumorais Modelo de Xenoenxerto
19.
Cell Death Dis ; 8(10): e3146, 2017 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-29072682

RESUMO

Mumps virus (MuV) infection usually results in germ cell degeneration in the testis, which is an etiological factor for male infertility. However, the mechanisms by which MuV infection damages male germ cells remain unclear. The present study showed that C-X-C motif chemokine ligand 10 (CXCL10) is produced by mouse Sertoli cells in response to MuV infection, which induces germ cell apoptosis through the activation of caspase-3. CXC chemokine receptor 3 (CXCR3), a functional receptor of CXCL10, is constitutively expressed in male germ cells. Neutralizing antibodies against CXCR3 and an inhibitor of caspase-3 activation significantly inhibited CXCL10-induced male germ cell apoptosis. Furthermore, the tumor necrosis factor-α (TNF-α) upregulated CXCL10 production in Sertoli cells after MuV infection. The knockout of either CXCL10 or TNF-α reduced germ cell apoptosis in the co-cultures of germ cells and Sertoli cells in response to MuV infection. Local injection of MuV into the testes of mice confirmed the involvement of CXCL10 in germ cell apoptosis in vivo. These results provide novel insights into MuV-induced germ cell apoptosis in the testis.


Assuntos
Quimiocina CXCL10/biossíntese , Células Germinativas/metabolismo , Vírus da Caxumba/fisiologia , Caxumba/metabolismo , Células de Sertoli/metabolismo , Animais , Apoptose/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Caxumba/patologia , Caxumba/virologia , Células de Sertoli/virologia
20.
Am J Trop Med Hyg ; 96(5): 1215-1221, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28500809

RESUMO

AbstractMumps, a highly contagious, viral disease continues to spread in India, despite the availability of an effective vaccine. On November 24, 2014, we came across a suspected case of mumps in a 6-year-old boy in a village of Bhusandapur sector in Odisha. We initiated an outbreak investigation using standard techniques outlined by the Centers for Disease Control and Prevention, Atlanta, GA. This uncovered a silent epidemic of 94 case patients (10% of the population) over a period of 16 weeks between August and December 2014, in a single village, which had gone completely unnoticed by the existing health-care system. Since the index case was one of the last case patients of the outbreak, investigation for immediate control was not a priority. Hence, we have used this exercise to describe the outbreak and identify causes that led to its nondetection. Age range of the case patients was between 2 and 40 years; 85 (90.4%) case patients were ≤ 15 years of age and 54 (57.4%) were females. Average duration of illness was 9 days. No child had received the mumps vaccine. The outbreak had led to a community expenditure of 538 USD. The exercise uncovered a number of weak links in the essential public health services within the health-care delivery system in the area.


Assuntos
Busca de Comunicante , Surtos de Doenças , Vírus da Caxumba/fisiologia , Caxumba/epidemiologia , Vigilância em Saúde Pública , Adolescente , Adulto , Criança , Pré-Escolar , Atenção à Saúde , Feminino , Programas Governamentais , Humanos , Índia/epidemiologia , Masculino , Caxumba/diagnóstico , Caxumba/economia , Caxumba/transmissão
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