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1.
Microbes Infect ; 22(2): 80-85, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32087334

RESUMO

At the end of December 2019, a novel coronavirus, 2019-nCoV, caused an outbreak of pneumonia spreading from Wuhan, Hubei province, to the whole country of China, which has posed great threats to public health and attracted enormous attention around the world. To date, there are no clinically approved vaccines or antiviral drugs available for these human coronavirus infections. Intensive research on the novel emerging human infectious coronaviruses is urgently needed to elucidate their route of transmission and pathogenic mechanisms, and to identify potential drug targets, which would promote the development of effective preventive and therapeutic countermeasures. Herein, we describe the epidemic and etiological characteristics of 2019-nCoV, discuss its essential biological features, including tropism and receptor usage, summarize approaches for disease prevention and treatment, and speculate on the transmission route of 2019-nCoV.


Assuntos
Betacoronavirus/patogenicidade , Doenças Transmissíveis Emergentes/epidemiologia , Infecções por Coronavirus/epidemiologia , Pneumonia Viral/epidemiologia , Antivirais/uso terapêutico , Betacoronavirus/genética , China/epidemiologia , Doenças Transmissíveis Emergentes/virologia , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/terapia , Infecções por Coronavirus/transmissão , Epidemias , Genoma Viral , Humanos , Filogenia , Pneumonia Viral/prevenção & controle , Pneumonia Viral/terapia , Pneumonia Viral/transmissão , Receptores Virais , Tropismo Viral
2.
PLoS Pathog ; 15(12): e1008183, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31790513

RESUMO

Crimean-Congo hemorrhagic fever virus (CCHFV, order Bunyavirales, family Nairoviridae, genus Orthonairovirus) is the tick-borne etiological agent of Crimean-Congo hemorrhagic fever (CCHF) in humans. Animals are generally susceptible to CCHFV infection but refractory to disease. Small animal models are limited to interferon-deficient mice, that develop acute fatal disease following infection. Here, using a ZsGreen1- (ZsG) expressing reporter virus (CCHFV/ZsG), we examine tissue tropism and dissemination of virus in interferon-α/ß receptor knock-out (Ifnar-/-) mice. We demonstrate that CCHFV/ZsG retains in vivo pathogenicity comparable to wild-type virus. Interestingly, despite high levels of viral RNA in all organs assessed, 2 distribution patterns of infection were observed by both fluorescence and immunohistochemistry (IHC), corresponding to the permissiveness of organ tissues. To further investigate viral dissemination and to temporally define cellular targets of CCHFV in vivo, mice were serially euthanized at different stages of disease. Flow cytometry was used to characterize CCHFV-associated alterations in hematopoietic cell populations and to classify infected cells in the blood, lymph node, spleen, and liver. ZsG signal indicated that mononuclear phagocytic cells in the lymphatic tissues were early targets of infection; in late-stage infection, overall, the highest levels of signal were detected in the liver, and ZsG was found in both antigen-presenting and lymphocyte cell populations.


Assuntos
Vírus da Febre Hemorrágica da Crimeia-Congo , Febre Hemorrágica da Crimeia/urina , Sistema Fagocitário Mononuclear/virologia , Tropismo Viral/fisiologia , Animais , Feminino , Masculino , Camundongos , Camundongos Knockout , Receptor de Interferon alfa e beta/deficiência
3.
PLoS Negl Trop Dis ; 13(12): e0007985, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31887138

RESUMO

INTRODUCTION: Dengue is the most important mosquito-borne diseases worldwide but was considered scarce in West-Central Africa. During the last decade, dengue outbreaks have increasingly been reported in urban foci in this region suggesting major epidemiological changes. However, in Central Africa where both vectors, Aedes aegypti and Aedes albopictus are well established, the role of each species in dengue transmission remains poorly investigated. METHODOLOGY/PRINCIPAL FINDINGS: Field-collected strains of Ae. aegypti and Ae. albopictus from different ecological settings in Central Africa were experimentally challenged with dengue 2 virus (DENV-2). Mosquitoes were analysed at 14- and 21-days post-infection. Analysis provide evidence that both Ae. aegypti and Ae. albopictus in Central Africa were able to transmit dengue virus with Ae. aegypti exhibiting a higher transmission rate. Unexpectedly, two Ae. aegypti populations from Bénoué and Maroua, in northern Cameroon, were not able to transmit DENV-2. CONCLUSIONS/SIGNIFICANCE: We conclude that both Ae. aegypti and Ae. albopictus are susceptible to DENV-2 and may intervene as active dengue vectors. These findings highlight the urgent need to plan a vector surveillance program and control methods against dengue vectors in Central Africa in order to prevent future outbreaks.


Assuntos
Aedes/crescimento & desenvolvimento , Aedes/virologia , Vírus da Dengue/crescimento & desenvolvimento , Dengue/epidemiologia , Dengue/transmissão , Transmissão de Doença Infecciosa , Tropismo Viral , África Central/epidemiologia , Animais , Feminino , Humanos , Mosquitos Vetores/crescimento & desenvolvimento , Mosquitos Vetores/virologia , Medição de Risco
4.
PLoS Pathog ; 15(10): e1008057, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31671153

RESUMO

Human astroviruses (HAstV) are understudied positive-strand RNA viruses that cause gastroenteritis mostly in children and the elderly. Three clades of astroviruses, classic, MLB-type and VA-type have been reported in humans. One limitation towards a better understanding of these viruses has been the lack of a physiologically relevant cell culture model that supports growth of all clades of HAstV. Herein, we demonstrate infection of HAstV strains belonging to all three clades in epithelium-only human intestinal enteroids (HIE) isolated from biopsy-derived intestinal crypts. A detailed investigation of infection of VA1, a member of the non-canonical HAstV-VA/HMO clade, showed robust replication in HIE derived from different patients and from different intestinal regions independent of the cellular differentiation status. Flow cytometry and immunofluorescence analysis revealed that VA1 infects several cell types, including intestinal progenitor cells and mature enterocytes, in HIE cultures. RNA profiling of VA1-infected HIE uncovered that the host response to infection is dominated by interferon (IFN)-mediated innate immune responses. A comparison of the antiviral host response in non-transformed HIE and transformed human colon carcinoma Caco-2 cells highlighted significant differences between these cells, including an increased magnitude of the response in HIE. Additional studies confirmed the sensitivity of VA1 to exogenous IFNs, and indicated that the endogenous IFN response of HIE to curtail the growth of strains from all three clades. Genotypic variation in the permissiveness of different HIE lines to HAstV could be overcome by pharmacologic inhibition of JAK/STAT signaling. Collectively, our data identify HIE as a universal infection model for HAstV and an improved model of the intestinal epithelium to investigate enteric virus-host interactions.


Assuntos
Infecções por Astroviridae/imunologia , Infecções por Astroviridae/veterinária , Mucosa Intestinal/imunologia , Intestino Delgado/imunologia , Mamastrovirus/fisiologia , Tropismo Viral/genética , Animais , Células CACO-2 , Linhagem Celular , Enterócitos/virologia , Gastroenterite/virologia , Humanos , Imunidade Inata/imunologia , Interferons/imunologia , Mucosa Intestinal/citologia , Mucosa Intestinal/virologia , Intestino Delgado/citologia , Intestino Delgado/virologia , Mamastrovirus/genética , Mamastrovirus/imunologia , Células Vero , Tropismo Viral/imunologia
5.
Virol J ; 16(1): 112, 2019 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-31488178

RESUMO

BACKGROUND: Reverse genetics systems enable the manipulation of viral genomes and therefore serve as robust reverse genetic tools to study RNA viruses. A DNA-launched rescue system initiates the transcription of viral genomic cDNA from eukaryotic promoter in transfected cells, generating homogenous RNA transcripts in vitro and thus enhancing virus rescue efficiency. As one of the hazardous pathogens to ducklings, the current knowledge of the pathogenesis of duck astrovirus type 1 (DAstV-1) is limited. The construction of a DNA-launched rescue system can help to accelerate the study of the virus pathogenesis. However, there is no report of such a system for DAstV-1. METHODS: In this study, a DNA-launched infectious clone of DAstV-1 was constructed from a cDNA plasmid, which contains a viral cDNA sequence flanked by hammerhead ribozyme (HamRz) and a hepatitis delta virus ribozyme (HdvRz) sequence at both terminals of the viral genome. A silent nucleotide mutation creating a Bgl II site in the ORF2 gene was made to distinguish the rescued virus (rDAstV-1) from the parental virus (pDAstV-1). Immunofluorescence assay (IFA) and western blot were conducted for rescued virus identification in duck embryo fibroblast (DEF) cells pre-treated with trypsin. The growth characteristics of rDAstV-1 and pDAstV-1 in DEF cells and the tissue tropism in 2-day-old ducklings of rDAstV-1 and pDAstV-1 were determined. RESULTS: The infectious DAstV-1 was successfully rescued from baby hamster kidney (BHK-21) cells and could propagate in DEF cells pre-treated with 1 µg/ml trypsin. Upon infection of DEF cells pre-treated with trypsin, DAstV-1 mRNA copies were identified after serial passaging, and the result showed that rDAstV-1 and pDAstV-1 shared similar replication kinetics. Animal experiment showed that the rDAstV-1 had an extensive tissue tropism, and the virus was capable of invading both the central and the peripheral immune organs in infected ducklings. CONCLUSIONS: An improved DNA-launched reverse genetics system for DAstV-1 was firstly constructed. Infectious virus recovered from BHK-21 cells could propagate in DEF cells pre-treated with trypsin. This is the first report of the successful in vitro cultivation of DAstV-1. We believe this valuable experimental system will contribute to the further study of DAstV-1 genome function and pathogenesis.


Assuntos
Infecções por Astroviridae/veterinária , Avastrovirus/genética , Avastrovirus/isolamento & purificação , Patos/virologia , Genética Reversa/métodos , Cultura de Vírus/métodos , Animais , Infecções por Astroviridae/virologia , Avastrovirus/crescimento & desenvolvimento , Linhagem Celular , Clonagem Molecular , DNA Complementar/genética , Genoma Viral , Plasmídeos , RNA Viral/genética , Transfecção , Tropismo Viral , Vírion/genética
6.
Int J Mol Sci ; 20(16)2019 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-31398860

RESUMO

Human cytomegalovirus (HCMV) is an opportunistic pathogen causing disease mainly in immunocompromised patients or after congenital infection. HCMV infection of the respiratory tract leads to pneumonitis in the immunocompromised host, which is often associated with a bad clinical course. The related mouse cytomegalovirus (MCMV) likewise exhibits a distinct tropism for the lung and thus provides an elegant model to study host-pathogen interaction. Accordingly, fundamental features of cytomegalovirus (CMV) pneumonitis have been discovered in mice that correlate with clinical data obtained from humans. Recent studies have provided insight into MCMV cell tropism and localized inflammation after infection of the respiratory tract. Accordingly, the nodular inflammatory focus (NIF) has been identified as the anatomical correlate of immune control in lungs. Several hematopoietic cells involved in antiviral immunity reside in NIFs and their key effector molecules have been deciphered. Here, we review what has been learned from the mouse model with focus on the microanatomy of infection sites and antiviral immunity in MCMV pneumonitis.


Assuntos
Infecções por Citomegalovirus/imunologia , Infecções por Citomegalovirus/virologia , Citomegalovirus/fisiologia , Pneumonia Viral/imunologia , Pneumonia Viral/virologia , Animais , Modelos Animais de Doenças , Suscetibilidade a Doenças , Interações Hospedeiro-Patógeno/imunologia , Humanos , Imunidade , Tropismo Viral
7.
Gene Ther ; 26(9): 386-398, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31308478

RESUMO

Recombinant adeno-associated virus (rAAV) has been widely used for gene delivery in animal models and successfully applied in clinical trials for treating inherited retinal disease. Although subretinal delivery of AAVs can effectively transduce photoreceptors and/or retinal pigmental epithelium (RPE), cells most affected by inherited retinal diseases, the procedure is invasive and complicated, and only delivers the gene to a limited retinal area. AAVs can also be delivered intravitreally to the retina, a much less invasive nonsurgical procedure. However, intravitreal administration of non-modified AAV serotypes tends to transduce only ganglion cells and inner nuclear layer cells. To date, most non-modified AAV serotypes that have been identified are incapable of efficiently transducing photoreceptors and/or RPE when delivered intravitreally. In this study, we investigate the retinal tropism of AAVrh10 vector administered by intravitreal injection to mouse, rat, and rabbit eyes. Our results demonstrate that AAVrh10 is capable of transducing not only inner retinal cells, but also outer retinal cells in all three species, though the transduction efficiency in rabbit was low. In addition, AAVrh10 preferentially transduced outer retinal cells in mouse models of retinal disease. Therefore, AAVrh10 vector could be a useful candidate to intravitreally deliver genes to photoreceptor and RPE cells.


Assuntos
Dependovirus/genética , Retina , Transdução Genética/métodos , Animais , Citomegalovirus/genética , Dependovirus/fisiologia , Vetores Genéticos , Proteínas de Fluorescência Verde/genética , Injeções Intravítreas , Masculino , Camundongos , Células Fotorreceptoras/virologia , Coelhos , Ratos , Ratos Sprague-Dawley , Retina/efeitos dos fármacos , Retina/virologia , Doenças Retinianas/terapia , Tropismo Viral
8.
Emerg Microbes Infect ; 8(1): 1076-1085, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31339457

RESUMO

Enterovirus A71 (EV-A71) is one of the main causative agents of hand-foot-and-mouth disease and is occasionally associated with severe neurological complications. EV-A71 pathophysiology is poorly understood due to the lack of small animal models that robustly support viral replication in relevant organs/tissues. Here, we show that adult severe combined immune-deficient (SCID) mice can serve as an EV-A71 infection model to study neurotropic determinants and viral tropism. Mice inoculated intraperitoneally with an EV-A71 clinical isolate had an initial infection of the lung compartment, followed by neuroinvasion and infection of (motor)neurons, resulting in slowly progressing paralysis of the limbs. We identified a substitution (V135I) in the capsid protein VP2 as a key requirement for neurotropism. This substitution was also present in a mouse-adapted variant, obtained by passaging the clinical isolate in the brain of one-day-old mice, and induced exclusive neuropathology and rapid paralysis, confirming its role in neurotropism. Finally, we showed that this residue enhances the capacity of EV-A71 to use mouse PSGL1 for viral entry. Our data reveal that EV-A71 initially disseminates to the lung and identify viral and host determinants that define the neurotropic character of EV-A71, pointing to a hitherto understudied role of PSGL1 in EV-A71 tropism and neuropathology.


Assuntos
Proteínas do Capsídeo/genética , Enterovirus Humano A/fisiologia , Infecções por Enterovirus/metabolismo , Glicoproteínas de Membrana/metabolismo , Neurônios/virologia , Animais , Proteínas do Capsídeo/metabolismo , Enterovirus Humano A/genética , Enterovirus Humano A/patogenicidade , Infecções por Enterovirus/genética , Infecções por Enterovirus/virologia , Interações Hospedeiro-Patógeno , Humanos , Glicoproteínas de Membrana/genética , Camundongos , Camundongos SCID , Mutação de Sentido Incorreto , Neurônios/metabolismo , Tropismo Viral , Virulência , Internalização do Vírus
9.
J Biol Regul Homeost Agents ; 33(3): 929-933, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31184098

RESUMO

Newcastle disease (ND) and avian influenza (AI) are globally considered as a serious threat to the chicken and other avian species. The paramyxovirus type 1 and orthomyxovirus type A are RNA viruses, which cause ND and AI infection, respectively.


Assuntos
Coinfecção/veterinária , Influenza Aviária/patologia , Doença de Newcastle/patologia , Tropismo Viral , Animais , Galinhas , Coinfecção/virologia , Vírus da Influenza A Subtipo H9N2 , Vírus da Doença de Newcastle
10.
Vet Microbiol ; 234: 119-127, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31213267

RESUMO

Ex vivo organ cultures (EVOCs) are extensively used to study the cellular tropism and infectivity of different pathogens. In this study, we used ovine and porcine respiratory EVOCs to investigate the replication kinetics and cellular tropism of selected emerging reoviruses namely Pteropine orthoreovirus, an emerging bat-borne zoonotic respiratory virus, and atypical Bluetongue virus (BTV) serotypes which, unlike classical serotypes, do not cause Bluetongue, a major OIE-listed disease of ruminants. BTV failed to replicate in ovine EVOCs. Instead, PRV showed slight replication in porcine lower respiratory EVOCs and a more sustained replication in all ovine respiratory tissues. By confocal laser scanning microscopy, PRV was demonstrated to infect bronchiolar and type I pneumocytes of ovine tissues. Overall, respiratory EVOCs from different animal species, eventually obtained at slaughterhouse, are a useful tool for testing and preliminarily characterize novel and emerging viruses addressing the essential in vivo animal work. Further experiments are, indeed, warranted in order to characterize the pathogenesis and transmission of these emerging reoviruses.


Assuntos
Orthoreovirus/fisiologia , Tropismo Viral , Replicação Viral , Células Epiteliais Alveolares/virologia , Animais , Vírus Bluetongue/fisiologia , Brônquios/citologia , Brônquios/virologia , Cinética , Técnicas de Cultura de Órgãos , Ovinos , Suínos
11.
Vet Microbiol ; 233: 102-112, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31176394

RESUMO

Pseudorabies virus (PRV) is considered as an infectious agent with a wide of host range, causing considerable economic losses in animal husbandry. Although the commercial vaccine against PRV plays an critical role in control of this disease in swine industry, the potential risk of commercial vaccines against PRV for other host is unclear. Here, we report that the commercial vaccine against PRV is a hidden health risk for dogs. We found that different attenuated PRV strains in commercial vaccines possess different tissue tropism, and that the attenuated PRV strains are lethal to dogs, and that the attenuated PRV strain possesses the ability to spread horizontally among the dogs. Collectively, our findings provide clues that the commercial vaccine against PRV is a hidden risk for dogs, even for the owner of pet dogs to take seriously.


Assuntos
Transmissão de Doença Infecciosa/veterinária , Doenças do Cão/virologia , Herpesvirus Suídeo 1/patogenicidade , Vacinas contra Pseudorraiva/efeitos adversos , Pseudorraiva/prevenção & controle , Animais , Anticorpos Antivirais/imunologia , Cães , Fazendas , Herpesvirus Suídeo 1/imunologia , Animais de Estimação/virologia , Pseudorraiva/transmissão , Vacinas contra Pseudorraiva/imunologia , Fatores de Risco , Vacinas Atenuadas/efeitos adversos , Tropismo Viral , Eliminação de Partículas Virais
12.
Ticks Tick Borne Dis ; 10(5): 1070-1077, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31176662

RESUMO

A wide range of arthropod species harbour bacterial endosymbionts in various tissues, many of them playing important roles in the fitness and biology of their hosts. In several cases, many different symbionts have been reported to coexist simultaneously within the same host and synergistic or antagonistic interactions can occur between them. While the associations with endosymbiotic bacteria have been widely studied in many insect species, in ticks such interactions are less investigated. The females and immatures of Ixodes ricinus (Ixodidae), the most common hard tick in Europe, harbour the intracellular endosymbiont "Candidatus Midichloria mitochondrii" with a prevalence up to 100%, suggesting a mutualistic relationship. Considering that the tissue distribution of a symbiont might be indicative of its functional role in the physiology of the host, we investigated M. mitochondrii specific localization pattern and the corresponding abundance in selected organs of I. ricinus females. We paired these experiments with in silico analysis of the metabolic pathways of M. mitochondrii, inferred from the available genome sequence, and additionally compared the presence of these pathways in seven other symbionts commonly harboured by ticks to try to obtain a comparative understanding of their biological effects on the tick hosts. M. mitochondrii was found to be abundant in ovaries and tracheae of unfed I. ricinus, and in ovaries, Malpighian tubules and salivary glands of semi-engorged females. These results, together with the in silico metabolic reconstruction allow to hypothesize that the bacterium could play multiple tissue-specific roles in the host, both enhancing the host fitness (supplying essential nutrients, enhancing the reproductive fitness, helping in the anti-oxidative defence, in the energy production and in the maintenance of homeostasis and water balance) and/or for ensuring its presence in the host population (nutrients acquisition, vertical and horizontal transmission). The ability of M. mitochondrii to colonize different tissues allows to speculate that distinctive sub-populations may display different specializations in accordance with tissue tropism. Our hypotheses should be corroborated with future nutritional and physiological experiments for a better understanding of the mechanisms underlying this symbiotic interaction.


Assuntos
Genoma Bacteriano , Ixodes/microbiologia , Redes e Vias Metabólicas , Rickettsiales/fisiologia , Simbiose , Tropismo Viral , Animais , Simulação por Computador , Feminino , Itália , Rickettsiales/genética , Rickettsiales/metabolismo
13.
Virol Sin ; 34(4): 454-466, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31201733

RESUMO

Baculovirus can transduce a wide range of mammalian cells and is considered a promising gene therapy vector. However, the low transduction efficiency of baculovirus into many mammalian cells limits its practical application. Co-expressing heterologous viral glycoproteins (GPs), such as vesicular stomatitis virus G protein (VSV G), with baculovirus native envelope protein GP64 is one of the feasible strategies for improving virus transduction. Tick-borne thogotoviruses infect mammals and their GPs share sequence/structure homology and common evolutionary origins with baculovirus GP64. Herein, we tested whether thogotovirus GPs could facilitate the entry of the prototype baculovirus Autographa californica multiple multiple nucleopolyhedrovirus (AcMNPV) into mammalian cells. The gp genes of two thogotoviruses, Thogoto virus and Dhori virus, were inserted into the AcMNPV genome. Both GPs were properly expressed and incorporated into the envelope of the recombinant AcMNPVs. The transduction rates of recombinant AcMNPVs expressing the two thogotovirus GPs increased for approximately 4-12 fold compared to the wild type AcMNPV in six of the 12 tested mammalian cell lines. It seemed that thogotovirus GPs provide the recombinant AcMNPVs with different cell tropisms and showed better performance in several mammalian cells compared to VSV G incorporated AcMNPV. Further studies showed that the improved transduction was a result of augmented virus-endosome fusion and endosome escaping, rather than increased cell binding or internalization. We found the AcMNPV envelope protein GP64-mediated fusion was enhanced by the thogotovirus GPs at relatively higher pH conditions. Therefore, the thogotovirus GPs represent novel candidates to improve baculovirus-based gene delivery vectors.


Assuntos
Baculoviridae/genética , Glicoproteínas/genética , Thogotovirus/genética , Transdução Genética , Internalização do Vírus , Animais , Linhagem Celular , Vetores Genéticos , Genoma Viral , Humanos , Glicoproteínas de Membrana/genética , Proteínas Recombinantes/genética , Proteínas do Envelope Viral/genética , Proteínas Virais de Fusão/genética , Tropismo Viral
14.
Microb Pathog ; 135: 103581, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31175971

RESUMO

Chikungunya virus (CHIKV) is mosquito-borne alphavirus that has caused epidemics around the world. Many individuals affected by the disease may experience joint pain that persists for months after the acute phase. The pathophysiology of viral arthritis is not completely elucidated. And it is important to emphasize that the effects of the viral infection in each host may depend on host factors that include immune response, as well as factors specific to the virus as tissue tropism. The main pathway for the response against viral infection is through induction of type I interferon (IFN-I), whose function is important to control viral replication. Beside this, T cell and macrophage mediated immunopathology in CHIKV infections has been reported. It has been demonstrated that some association with the Arginase I and macrophages type II are involved in the infection profile along with myeloid-derived suppressor cells (MDSC) that are responsible for T cell suppression. Therefore, in this review, will be discuss an overview on CHIKV immunopathogenesis and the importance of Arginase I.


Assuntos
Arginase/metabolismo , Febre de Chikungunya/imunologia , Vírus Chikungunya/patogenicidade , Interações Hospedeiro-Patógeno/imunologia , Citocinas/metabolismo , Humanos , Interferon Tipo I , Macrófagos , Células Supressoras Mieloides/imunologia , Células Supressoras Mieloides/metabolismo , Fatores Supressores Imunológicos , Linfócitos T , Tropismo Viral/imunologia , Replicação Viral
15.
PLoS Pathog ; 15(6): e1007790, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31194854

RESUMO

Bourbon virus (BRBV) is an emerging tick-borne RNA virus in the orthomyxoviridae family that was discovered in 2014. Although fatal human cases of BRBV have been described, little is known about its pathogenesis, and no antiviral therapies or vaccines exist. We obtained serum from a fatal case in 2017 and successfully recovered the second human infectious isolate of BRBV. Next-generation sequencing of the St. Louis isolate of BRBV (BRBV-STL) showed >99% nucleotide identity to the original reference isolate. Using BRBV-STL, we developed a small animal model to study BRBV-STL tropism in vivo and evaluated the prophylactic and therapeutic efficacy of the experimental antiviral drug favipiravir against BRBV-induced disease. Infection of Ifnar1-/- mice lacking the type I interferon receptor, but not congenic wild-type animals, resulted in uniformly fatal disease 6 to 10 days after infection. RNA in situ hybridization and viral yield assays demonstrated a broad tropism of BRBV-STL with highest levels detected in liver and spleen. In vitro replication and polymerase activity of BRBV-STL were inhibited by favipiravir. Moreover, administration of favipiravir as a prophylaxis or as post-exposure therapy three days after infection prevented BRBV-STL-induced mortality in immunocompromised Ifnar1-/- mice. These results suggest that favipiravir may be a candidate treatment for humans who become infected with BRBV.


Assuntos
Amidas/farmacologia , Antivirais/farmacologia , Infecções por Orthomyxoviridae/prevenção & controle , Pirazinas/farmacologia , Thogotovirus/imunologia , Animais , Modelos Animais de Doenças , Humanos , Camundongos , Camundongos Knockout , Infecções por Orthomyxoviridae/genética , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/patologia , Receptor de Interferon alfa e beta/deficiência , Receptor de Interferon alfa e beta/imunologia , Thogotovirus/patogenicidade , Células Vero , Tropismo Viral/efeitos dos fármacos , Tropismo Viral/genética , Tropismo Viral/imunologia
16.
BMC Res Notes ; 12(1): 242, 2019 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-31036079

RESUMO

OBJECTIVE: Resting CD4+ T cells are major reservoirs of latent HIV-1 infection, and may be formed during the early phase of the infection. Although CCR5-tropic (R5) HIV-1 is highly transmissible during the early phase, newly infected individuals have usually been exposed to a mixture of R5 and CXCR4-tropic (X4) viruses, and X4 viral DNA is also detectable in the host. Our aim was to identify which subsets of resting CD4+ T cells contribute to forming the latent reservoir in the presence of both X4 and R5 viruses. RESULTS: Primary resting CD4+ naïve T (TN) cells, CCR5- memory T (TM) cells, and CCR5+ TM cells isolated by flow cytometry were infected simultaneously with X4 and R5 HIV-1, which harbored different reporter genes, and were cultured in the resting condition. Flow cytometry at 3 days post-infection demonstrated that X4 HIV-1+ cells were present in all three subsets of cells, whereas R5 HIV-1+ cells were present preferentially in CCR5+ TM cells, but not in TN cells. Following CD3/CD28-mediated activation at 3 days post-infection, numbers of R5 HIV-1+ cells and X4 HIV-1+ cells increased significantly only in the CCR5+ TM subset, suggesting that it provides a major reservoir of replication-competent, latently infected viruses.


Assuntos
Linfócitos T CD4-Positivos/virologia , DNA Viral/genética , HIV-1/fisiologia , Receptores CCR5/genética , Receptores CXCR4/genética , Latência Viral , Adulto , Linfócitos T CD4-Positivos/imunologia , DNA Viral/metabolismo , Expressão Gênica , HIV-1/patogenicidade , Voluntários Saudáveis , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Humanos , Memória Imunológica , Cultura Primária de Células , Receptores CCR5/imunologia , Receptores CXCR4/imunologia , Tropismo Viral , Replicação Viral
17.
Elife ; 82019 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-31074414

RESUMO

The restricted host tropism of hepatitis C virus (HCV) remains incompletely understood, especially post-entry, and has hindered developing an immunocompetent, small animal model. HCV replication in non-permissive species may be limited by incompatibilities between the viral replication machinery and orthologs of essential host factors, like cyclophilin A (CypA). We thus compared the ability of CypA from mouse, tree shrew, and seven non-human primate species to support HCV replication, finding that murine CypA only partially rescued viral replication in Huh7.5-shRNA CypA cells. We determined the specific amino acid differences responsible and generated mutants able to fully rescue replication. We expressed these mutants in engineered murine hepatoma cells and although we observed increases in HCV replication following infection, they remained far lower than those in highly permissive human hepatoma cells, and minimal infectious particle release was observed. Together, these data suggest additional co-factors remain unidentified. Future work to determine such factors will be critical for developing an immunocompetent mouse model supporting HCV replication.


Assuntos
Ciclofilina A/genética , Variação Genética , Hepacivirus/crescimento & desenvolvimento , Especificidade de Hospedeiro , Tropismo Viral , Animais , Linhagem Celular , Humanos , Camundongos , Primatas , Tupaiidae , Replicação Viral
18.
Clin Microbiol Infect ; 25(8): 1042.e1-1042.e4, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31075547

RESUMO

OBJECTIVES: Zika virus (ZIKV) is mostly mosquito borne but it can also be transmitted via the sexual route and persists in semen for a prolonged time. Moreover, viral RNA has been detected in breast milk, saliva, lacrimal fluids and urine, suggesting other possible transmission routes. The aim of our research is to better define ZIKV tropism. METHODS: We investigated the tropism of Asian and African strains of ZIKV using human-derived neural, vaginal, intestinal and respiratory tissues. RESULTS: Asian and African strains of ZIKV were able to grow in all tissues tested, although with different efficiency (7.3 log RNA copies released apically in vaginal tissues versus 9.8 log RNA copies released in intestinal tissues), without the need for major adaptation. CONCLUSIONS: Our results underline that ZIKV tropism may be broader than expected in humans and stress the need to better explore all possible virus-shedding sites and transmission routes.


Assuntos
Intestinos/virologia , Tecido Nervoso/virologia , Sistema Respiratório/virologia , Vagina/virologia , Tropismo Viral , Zika virus/crescimento & desenvolvimento , África , Ásia , Epidemias , Feminino , Humanos , RNA Viral/análise , Zika virus/isolamento & purificação , Infecção por Zika virus/transmissão
19.
BMC Infect Dis ; 19(1): 467, 2019 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-31126239

RESUMO

BACKGROUND: The circumstances of prescription of tropism tests clinically relevant in treatment-experienced patients are unclear. METHODS: We performed a monocentric retrospective analysis of all tropism tests performed between 2006 and 2015 in HIV-infected patients on antiretroviral therapy (ART) without MVC. The motivation of tropism determination was collected. Factors associated with MVC prescription were determined using logistic regression analysis. RESULTS: Five hundred sixty-three tests were performed in experienced patients not receiving MVC. Reasons for tropism performance were: virological failure (44%), side effects or drug-interactions (37%), simplification or sparing strategies (11%), immunological failure (5%), and improvement of neurological diffusion (3%). MVC was prescribed in 110 cases (20%), though 366 tests (65%) revealed a tropism CCR5. MVC was more often prescribed before 2011 (OR 3.65, 95% CI 2.17-6.13) and in patients with multiple previous ART regimens (less than 4 ART regimens compare to more than 10 ART regimens (OR 0.34, 95% CI 0.15-0.74)). CONCLUSIONS: In experienced patients not receiving MVC, tropism test prescription should be restricted to patients with virological failure and limited therapeutic options such as patients already treated with a wide range of ART regimens.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , HIV-1/fisiologia , Tropismo Viral , Adulto , Antagonistas dos Receptores CCR5/uso terapêutico , Feminino , HIV-1/genética , Humanos , Masculino , Maraviroc/uso terapêutico , Pessoa de Meia-Idade , Estudos Retrospectivos , Falha de Tratamento , Resultado do Tratamento
20.
Viruses ; 11(4)2019 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-31022887

RESUMO

Influenza viruses are notorious pathogens that frequently cross the species barrier with often severe consequences for both animal and human health. In 2011, a novel member of the Orthomyxoviridae family, Influenza D virus (IDV), was identified in the respiratory tract of swine. Epidemiological surveys revealed that IDV is distributed worldwide among livestock and that IDV-directed antibodies are detected in humans with occupational exposure to livestock. To identify the transmission capability of IDV to humans, we determined the viral replication kinetics and cell tropism using an in vitro respiratory epithelium model of humans. The inoculation of IDV revealed efficient replication kinetics and apical progeny virus release at different body temperatures. Intriguingly, the replication characteristics of IDV revealed higher replication kinetics compared to Influenza C virus, despite sharing the cell tropism preference for ciliated cells. Collectively, these results might indicate why IDV-directed antibodies are detected among humans with occupational exposure to livestock.


Assuntos
Diferenciação Celular , Células Epiteliais/virologia , Mucosa Respiratória/citologia , Thogotovirus/fisiologia , Tropismo Viral , Replicação Viral , Temperatura Corporal , Brônquios/citologia , Brônquios/virologia , Células Cultivadas , Humanos , Cinética , RNA Viral/genética , Thogotovirus/genética
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