RESUMO
Heartland bandavirus (HRTV), which is an emerging tick-borne virus first identified in Missouri in 2009, causes fever, fatigue, decreased appetite, headache, nausea, diarrhea, and muscle or joint pain in humans. HRTV is genetically close to Dabie bandavirus, which is the causative agent of severe fever with thrombocytopenia syndrome (SFTS) in humans and is known as SFTS virus (SFTSV). The generation of infectious HRTV entirely from cloned cDNAs has not yet been reported. The absence of a reverse genetics system for HRTV has delayed efforts to understand its pathogenesis and to generate vaccines and antiviral drugs. Here, we developed a reverse genetics system for HRTV, which employs an RNA polymerase I-mediated expression system. A recombinant nonstructural protein (NSs)-knockout HRTV (rHRTV-NSsKO) was generated. We found that NSs interrupted signaling associated with innate immunity in HRTV-infected cells. The rHRTV-NSsKO was highly attenuated, indicated by the apparent absence of symptoms in a mouse model of HRTV infection. Moreover, mice immunized with rHRTV-NSsKO survived a lethal dose of HRTV. These findings suggest that NSs is a virulence factor of HRTV and that rHRTV-NSsKO could be a vaccine candidate for HRTV. IMPORTANCE Heartland bandavirus (HRTV) is a tick-borne virus identified in the United States in 2009. HRTV causes fever, fatigue, decreased appetite, headache, nausea, diarrhea, and muscle or joint pain in humans. FDA-approved vaccines and antiviral drugs are unavailable. The lack of a reverse genetics system hampers efforts to develop such antiviral therapeutics. Here, we developed a reverse genetics system for HRTV that led to the generation of a recombinant nonstructural protein (NSs)-knockout HRTV (rHRTV-NSsKO). We found that NSs interrupted signaling associated with innate immunity in HRTV-infected cells. Furthermore, rHRTV-NSsKO was highly attenuated and immunogenic in a mouse model. These findings suggest that NSs is a virulence factor of HRTV and that rHRTV-NSsKO could be a vaccine candidate for HRTV.
Assuntos
Phlebovirus , Genética Reversa , Proteínas não Estruturais Virais , Animais , Antivirais/metabolismo , Artralgia , Bunyaviridae/genética , Bunyaviridae/imunologia , Bunyaviridae/patogenicidade , Diarreia , Fadiga , Cefaleia , Humanos , Imunidade Inata/imunologia , Camundongos , Náusea , Phlebovirus/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Genética Reversa/métodos , Transdução de Sinais/imunologia , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/imunologia , Virulência/genética , Fatores de Virulência/genéticaRESUMO
Zika virus (ZIKV) strains are classified into the African and Asian genotypes. The higher virulence of the African MR766 strain, which has been used extensively in ZIKV research, in adult IFNα/ß receptor knockout (IFNAR-/-) mice is widely viewed as an artifact associated with mouse adaptation due to at least 146 passages in wild-type suckling mouse brains. To gain insights into the molecular determinants of MR766's virulence, a series of genes from MR766 were swapped with those from the Asian genotype PRVABC59 isolate, which is less virulent in IFNAR-/- mice. MR766 causes 100% lethal infection in IFNAR-/- mice, but when the prM gene of MR766 was replaced with that of PRVABC59, the chimera MR/PR(prM) showed 0% lethal infection. The reduced virulence was associated with reduced neuroinvasiveness, with MR766 brain titers ≈3 logs higher than those of MR/PR(prM) after subcutaneous infection, but was not significantly different in brain titers of MR766 and MR/PR(prM) after intracranial inoculation. MR/PR(prM) also showed reduced transcytosis when compared with MR766 in vitro. The high neuroinvasiveness of MR766 in IFNAR-/- mice could be linked to the 10 amino acids that differ between the prM proteins of MR766 and PRVABC59, with 5 of these changes affecting positive charge and hydrophobicity on the exposed surface of the prM protein. These 10 amino acids are highly conserved amongst African ZIKV isolates, irrespective of suckling mouse passage, arguing that the high virulence of MR766 in adult IFNAR-/- mice is not the result of mouse adaptation.
Assuntos
Proteínas do Envelope Viral/genética , Virulência/genética , Infecção por Zika virus/virologia , Zika virus/genética , Zika virus/patogenicidade , Animais , Barreira Hematoencefálica , Permeabilidade Capilar , Genótipo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Zika virus/metabolismoRESUMO
Severe fever with thrombocytopenia syndrome (SFTS) caused by a species Dabie bandavirus (formerly SFTS virus [SFTSV]) is an emerging hemorrhagic infectious disease with a high case-fatality rate. One of the best strategies for preventing SFTS is to develop a vaccine, which is expected to induce both humoral and cellular immunity. We applied a highly attenuated but still immunogenic vaccinia virus strain LC16m8 (m8) as a recombinant vaccine for SFTS. Recombinant m8s expressing SFTSV nucleoprotein (m8-N), envelope glycoprotein precursor (m8-GPC), and both N and GPC (m8-N+GPC) in the infected cells were generated. Both m8-GPC- and m8-N+GPC-infected cells were confirmed to produce SFTSV-like-particles (VLP) in vitro, and the N was incorporated in the VLP produced by the infection of cells with m8-N+GPC. Specific antibodies to SFTSV were induced in mice inoculated with each of the recombinant m8s, and the mice were fully protected from lethal challenge with SFTSV at both 103 TCID50 and 105 TCID50. In mice that had been immunized with vaccinia virus strain Lister in advance of m8-based SFTSV vaccine inoculation, protective immunity against the SFTSV challenge was also conferred. The pathological analysis revealed that mice immunized with m8-GPC or m8-N+GPC did not show any histopathological changes without any viral antigen-positive cells, whereas the control mice showed focal necrosis with inflammatory infiltration with SFTSV antigen-positive cells in tissues after SFTSV challenge. The passive serum transfer experiments revealed that sera collected from mice inoculated with m8-GPC or m8-N+GPC but not with m8-N conferred protective immunity against lethal SFTSV challenge in naïve mice. On the other hand, the depletion of CD8-positive cells in vivo did not abrogate the protective immunity conferred by m8-based SFTSV vaccines. Based on these results, the recombinant m8-GPC and m8-N+GPC were considered promising vaccine candidates for SFTS.
Assuntos
Antígenos Virais/imunologia , Nucleoproteínas/imunologia , Phlebovirus/imunologia , Febre Grave com Síndrome de Trombocitopenia/prevenção & controle , Vacinas Atenuadas/administração & dosagem , Vacinas Sintéticas/administração & dosagem , Proteínas do Envelope Viral/imunologia , Animais , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Febre Grave com Síndrome de Trombocitopenia/imunologia , Febre Grave com Síndrome de Trombocitopenia/virologiaRESUMO
Herpesviruses exist in nature within each host animal. Ten herpesviruses have been isolated from bats and their biological properties reported. A novel bat alphaherpesvirus, which we propose to name "Pteropus lylei-associated alphaherpesvirus (PLAHV)," was isolated from urine of the fruit bat Pteropus lylei in Vietnam and characterized. The entire genome sequence was determined to be 144,008 bp in length and predicted to include 72 genes. PLAHV was assigned to genus Simplexvirus with other bat alphaherpesviruses isolated from pteropodid bats in Southeast Asia and Africa. The replication capacity of PLAHV in several cells was evaluated in comparison with that of herpes simplex virus 1 (HSV-1). PLAHV replicated better in the bat-originated cell line and less in human embryonic lung fibroblasts than HSV-1 did. PLAHV was serologically related to another bat alphaherpesvirus, Pteropodid alphaherpesvirus 1 (PtAHV1), isolated from a Pteropus hypomelanus-related bat captured in Indonesia, but not with HSV-1. PLAHV caused lethal infection in mice. PLAHV was as susceptible to acyclovir as HSV-1 was. Characterization of this new member of bat alphaherpesviruses, PLAHV, expands the knowledge on bat-associated alphaherpesvirology.IMPORTANCE A novel bat alphaherpesvirus, Pteropus lylei-associated alphaherpesvirus (PLAHV), was isolated from urine of the fruit bat Pteropus lylei in Vietnam. The whole-genome sequence was determined and was predicted to include 72 open reading frames in the 144,008-bp genome. PLAHV is circulating in a species of fruit bats, Pteropus lylei, in Asia. This study expands the knowledge on bat-associated alphaherpesvirology.
Assuntos
Alphaherpesvirinae/genética , Quirópteros/virologia , Genoma Viral , Infecções por Herpesviridae/veterinária , Proteínas Virais/genética , Aciclovir/farmacologia , Alphaherpesvirinae/classificação , Alphaherpesvirinae/efeitos dos fármacos , Alphaherpesvirinae/patogenicidade , Animais , Antivirais/farmacologia , Células COS , Linhagem Celular , Chlorocebus aethiops , Fibroblastos/virologia , Expressão Gênica , Tamanho do Genoma , Células HeLa , Infecções por Herpesviridae/tratamento farmacológico , Infecções por Herpesviridae/epidemiologia , Infecções por Herpesviridae/mortalidade , Herpesvirus Humano 1/classificação , Herpesvirus Humano 1/genética , Herpesvirus Humano 1/crescimento & desenvolvimento , Herpesvirus Humano 1/patogenicidade , Humanos , Camundongos , Filogenia , Análise de Sobrevida , Células Vero , Vietnã/epidemiologia , Proteínas Virais/metabolismo , Replicação ViralRESUMO
INTRODUCTION: Diagnosing tuberculous pleurisy is important in Japan because it currently has a moderate tuberculosis prevalence. However, physicians often have difficulty making a diagnosis. It was reported that thoracoscopy under local anesthesia is useful for the diagnosis of tuberculous pleurisy, but there are no reports focusing on elderly patients. METHODS: In this study, the usefulness of thoracoscopy under local anesthesia was evaluated in elderly patients. Among 170 patients who underwent thoracoscopy under local anesthesia at our hospital during 11 years from January 2008 to December 2018, those aged 75 years or older (n = 75) were investigated retrospectively. RESULTS: A total of 55 patients underwent thoracoscopy under local anesthesia for detailed examination of pleural effusion of unknown cause. Of these, 18 were diagnosed as tuberculous pleurisy. The median age was 82 years (range: 75-92 years). The diagnosis of tuberculous pleurisy was made in 11 patients in whom Mycobacterium tuberculosis was detected and in four patients whose pathological findings indicated epithelioid granuloma accompanied by caseous necrosis. Clinical diagnosis was made in the remaining three patients based on thoracoscopic findings of the pleural cavity and a high level of adenosine deaminase in pleural fluid. No serious complications attributable to the examination were observed in any patient. CONCLUSIONS: Thoracoscopy under local anesthesia was useful for the diagnosis of tuberculous pleurisy in elderly patients, with useful information being also obtained for the treatment of tuberculosis.
Assuntos
Derrame Pleural , Tuberculose Pleural , Idoso , Idoso de 80 Anos ou mais , Anestesia Local , Humanos , Japão , Pleura , Estudos Retrospectivos , Toracoscopia , Tuberculose Pleural/diagnósticoRESUMO
BACKGROUND: Human cytomegalovirus (HCMV) causes asymptomatic infections, but also causes congenital infections when women were infected with HCMV during pregnancy, and life-threatening diseases in immunocompromised patients. To better understand the mechanism of the neutralization activity against HCMV, the association of HCMV NT antibody titers was assessed with the antibody titers against each glycoprotein complex (gc) of HCMV. METHODS: Sera collected from 78 healthy adult volunteers were used. HCMV Merlin strain and HCMV clinical isolate strain 1612 were used in the NT assay with the plaque reduction assay, in which both the MRC-5 fibroblasts cells and the RPE-1 epithelial cells were used. Glycoprotein complex of gB, gH/gL complexes (gH/gL/gO and gH/gL/UL128-131A [PC]) and gM/gN were selected as target glycoproteins. 293FT cells expressed with gB, gM/gN, gH/gL/gO, or PC, were prepared and used for the measurement of the antibody titers against each gc in an indirect immunofluorescence assay (IIFA). The correlation between the IIFA titers to each gc and the HCMV-NT titers was evaluated. RESULTS: There were no significant correlations between gB-specific IIFA titers and the HCMV-NT titers in epithelial cells or between gM/gN complex-specific IIFA titers and the HCMV-NT titers. On the other hand, there was a statistically significant positive correlation between the IIFA titers to gH/gL complexes and HCMV-NT titers. CONCLUSIONS: The data suggest that the gH/gL complexes might be the major target to induce NT activity against HCMV.
Assuntos
Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Citomegalovirus/imunologia , Imunoglobulina G/sangue , Proteínas do Envelope Viral/imunologia , Adulto , Linhagem Celular , Citomegalovirus/genética , Feminino , Fibroblastos/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
Acyclovir (ACV) resistance-associated mutations in two recombinant herpes simplex virus 1 (HSV-1) clones were compared. Recombinant HSV-1 lacking its thymidine kinase (TK) and expressing varicella-zoster virus (VZV) TK ectopically had no mutations in the VZV TK gene. In contrast, recombinant HSV-1 expressing HSV-1 TK ectopically harbored mutations in the HSV-1 TK gene. These results suggest that the relatively low frequency of ACV-resistant VZV is a consequence of the characteristics of the TK gene.
Assuntos
Aciclovir/farmacologia , Antivirais/farmacologia , Herpesvirus Humano 1/efeitos dos fármacos , Animais , Linhagem Celular , Chlorocebus aethiops , Farmacorresistência Viral/genética , Herpesvirus Humano 1/genética , Herpesvirus Humano 3/efeitos dos fármacos , Herpesvirus Humano 3/genética , Humanos , Mutação/genética , Timidina Quinase/genética , Células VeroRESUMO
Pulmonary cryptococcosis is difficult to distinguish from lung cancer clinically, and is often diagnosed by surgery. A 72-year-old woman, who underwent distal pancreatectomy and splenectomy for pancreatic carcinoma. Four months after surgery, a tumor shadow was detected in the left lung as a groundglass nodule (GGN)of 12 mm in diameter, which was found to change to 15 mm with increased density by the computed tomography(CT)scan after 2 months. The nodule showed positive accumulation of fluorodeoxyglucose(FDG)by positron emission tomography(PET), and was suspected of malignant tumor. She underwent a partial resection of the left lung under thoracoscopy.
Assuntos
Criptococose/diagnóstico por imagem , Pneumopatias Fúngicas/diagnóstico por imagem , Neoplasias Pulmonares/diagnóstico por imagem , Idoso , Diagnóstico Diferencial , Feminino , Fluordesoxiglucose F18 , Humanos , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Tomografia Computadorizada por Raios XRESUMO
The patient was a 74-year-old man who had undergone surgery for rectal cancer 9 years before and had developed left lung metastasis(S3)3 years and 4 months prior to admission. He had received video assisted left lung wedge resection. He presented with a growing nodular lesion close to the remaining left lung margin and elevated serum carcinoembryonic antigen(CEA)levels, and underwent open extended segmentectomy. The chest drain tube was removed on 3rd post-operative day, but he developed left pneumothorax on 4th post-operative day and a computed tomography(CT)scan revealed a cystic lesion 5.0 cm in size at the base of his left lung. Revision surgery was performed on 8th post-operative day. A pulmonary cyst on the diaphragmatic surface of the lung(S10)was found and location of the air leak was confirmed in the same area. Following wedge resection of the cyst-containing region, the leak ceased completely. Rapid manifestation of a newly formed pulmonary cyst during the acute post-operative period is rare.
Assuntos
Cistos/cirurgia , Pneumopatias/cirurgia , Neoplasias Pulmonares/cirurgia , Pneumonectomia/efeitos adversos , Pneumotórax/etiologia , Complicações Pós-Operatórias/cirurgia , Idoso , Antígeno Carcinoembrionário/sangue , Tubos Torácicos , Cistos/diagnóstico por imagem , Humanos , Pulmão , Pneumopatias/diagnóstico por imagem , Pneumopatias/etiologia , Neoplasias Pulmonares/sangue , Neoplasias Pulmonares/secundário , Masculino , Pneumonectomia/métodos , Complicações Pós-Operatórias/diagnóstico por imagem , Neoplasias Retais/patologia , Neoplasias Retais/cirurgia , Tomografia Computadorizada por Raios XRESUMO
BACKGROUND: Acyclovir (ACV)-resistant (ACVr) herpes simplex virus type 1 (HSV-1) infections are concern in immunocompromised patients. Most clinical ACVr HSV-1 isolates have mutations in the viral thymidine kinase (vTK) genes. The vTK-associated ACVr HSV-1 shows reduced virulence, but the association between the level of resistance and the virulence of the vTK-associated ACVr HSV-1 is still unclear. METHODS: The virulence in mice of 5 vTK-associated ACVr HSV-1 clones with a variety of ACV sensitivities, when inoculated through intracerebral and corneal routes, was evaluated in comparison with ACV-sensitive (ACVs) parent HSV-1 TAS. RESULTS: Although all the 5 ACVr HSV-1 clones and ACVs HSV-1 TAS showed a similar single-step growth capacity in vitro, the virulence of ACVr HSV-1 clones significantly decreased. A 50% lethal dose (LD50) of each clone was closely correlated with 50% inhibitory concentrations (IC50), demonstrating that the higher the ACV-sensitvity, the the higher the virulence among the ACVr clones. One of the ACVr HSV-1 clones with a relatively low IC50 value maintained similar virulence to that of the parent TAS. The infection in mice with ACVr HSV-1 due to a single amino acid substitution in vTK induced local diseases, keratitis and dermatitis, while vTK-deficient clone did not. CONCLUSIONS: A statistically significant correlation between the virulence and susceptibility to ACV among ACVr HSV-1 clones was demonstrated.
Assuntos
Aciclovir/farmacologia , Antivirais/farmacologia , Farmacorresistência Viral , Herpes Simples/patologia , Herpesvirus Humano 1/efeitos dos fármacos , Herpesvirus Humano 1/patogenicidade , Timidina Quinase/genética , Animais , Modelos Animais de Doenças , Feminino , Herpes Simples/virologia , Herpesvirus Humano 1/enzimologia , Herpesvirus Humano 1/genética , Camundongos Endogâmicos BALB C , Proteínas Mutantes/genética , VirulênciaRESUMO
Chronic myeloid leukemia is a clonal disease characterized by the presence of the Philadelphia chromosome and its oncogenic product, BCR-ABL, which activates multiple pathways involved in cell survival, growth promotion, and disease progression. We previously reported that in murine hematopoietic Ba/F3 cells, signal transducing adaptor protein-2 (STAP-2) binds to BCR-ABL and up-regulates BCR-ABL phosphorylation, leading to enhanced activation of its downstream signaling molecules. The binding of STAP-2 to BCR-ABL also influenced the expression levels of chemokine receptors, such as CXCR4 and CCR7. For the induction of CCR7 expression, signals mediated by the MAPK/ERK pathway were critical in Ba/F3 cells expressing BCR-ABL and STAP-2. In addition, STAP-2 cooperated with BCR-ABL to induce the production of CCR7 ligands, CCL19 and CCL21. Our results demonstrate a contribution of CCR7 to STAP-2-dependent enhancement of BCR-ABL-mediated cell growth in Ba/F3 cells.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/fisiologia , Células da Medula Óssea/citologia , Divisão Celular/fisiologia , Proteínas de Fusão bcr-abl/fisiologia , Receptores CCR7/fisiologia , Animais , Sequência de Bases , Linhagem Celular , Primers do DNA , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Quinases/metabolismo , Reação em Cadeia da Polimerase em Tempo RealRESUMO
Neutralizing antibodies (NAbs) to human cytomegalovirus (HCMV) are associated with the risk of transplacental HCMV infection of the fetus in pregnant women. The IgG-positivity rate to HCMV determined by enzyme immunoassay (EIA) or indirect immunofluorescence assay has decreased from approximately 100% to 70% over the past 30 years in Japan. We tested serum samples from 630 Japanese women aged 20-49 years whose blood samples were obtained between 1980 and 2015. IgG titer was measured using an EIA-based assay. HCMV-NAb titer was measured using a neutralization test assay with an HCMV isolate on human retinal epithelial cells. Longitudinal transitions in HCMV-NAb prevalence were clarified. The prevalence of HCMV-EIA-IgG, and HCMV-NAb at a titer of 16-fold, and HCMV-NAb at a titer of 100-fold, changed from 96.7% to 78.9%, 93.3% to 85.6%, and 35.5% to 41.1%, respectively, between 1980-1990 and 2010-2015. Prevalence of HCMV-NAb at a titer of 16-fold decreased by 7.7%, whereas that at a titer of 100-fold increased by 5.6%. A high titer of HCMV-NAb in pregnant women is expected to reduce the risk of intrauterine HCMV transmission from the mother to the fetus. The association between the risk of congenital HCMV infection and the prevalence of HCMV-NAb remains to be addressed.
Assuntos
Anticorpos Neutralizantes , Citomegalovirus , Anticorpos Antivirais , Feminino , Humanos , Imunoglobulina G , Japão/epidemiologia , Gravidez , PrevalênciaRESUMO
To "mark" the nitrogen atoms in phenyl-(2-pyridyl)-(3-pyridyl)-(4-pyridyl)methane (1), we have synthesized the corresponding tris(pyridine N-oxide) 2 by oxidation of 1 with m-chloroperbenzoic acid. The nitrogen atoms of 2 are unequivocally determined by the X-ray crystal analysis of a single crystal of rac-2 whereas the nitrogen atoms cannot be assigned at all in the case of rac-1. N-Oxide 2 can be resolved by chiral high-performance liquid chromatography under similar conditions to those used for the resolution of 1. The calculated circular dichroism (CD) curve for (R)-2 on the basis of time-dependent density functional theory reproduces the experimental spectra very well to suggest that the second-eluted fraction ([CD(+)283]-2) is the R isomer, namely (R)-[CD(+)283]-2. The independent absolute configuration determinations for 1 and 2 are in keeping with the chemical correlation between the two compounds by oxidation of (R)-1 into (R)-2.
Assuntos
Óxidos N-Cíclicos/química , Óxidos N-Cíclicos/síntese química , Metano/análogos & derivados , Metano/química , Nitrogênio/química , Piridinas/química , Piridinas/síntese química , Óxidos N-Cíclicos/isolamento & purificação , Fenômenos Ópticos , Piridinas/isolamento & purificação , Teoria Quântica , EstereoisomerismoRESUMO
Genotype V (GV) Japanese encephalitis virus (JEV) has emerged in Korea and China since 2009. Recent findings suggest that current Japanese encephalitis (JE) vaccines may reduce the ability to induce neutralizing antibodies against GV JEV compared to other genotypes. This study sought to produce a novel live attenuated JE vaccine with a high efficacy against GV JEV. Genotype I (GI)-GV intertypic recombinant strain rJEV-EXZ0934-M41 (EXZ0934), in which the E region of the GI Mie/41/2002 strain was replaced with that of GV strain XZ0934, was introduced with the same 10 attenuation substitutions in the E region found in the live attenuated JE vaccine strain SA 14-14-2 to produce a novel mutant virus rJEV-EXZ/SA14142m-M41 (EXZ/SA14142m). In addition, another mutant rJEV-EM41/SA14142m-M41 (EM41/SA14142m), which has the same substitutions in the Mie/41/2002, was also produced. The neuroinvasiveness and neurovirulence of the two mutant viruses were significantly reduced in mice. The mutant viruses induced neutralizing antibodies against GV JEV in mice. The growth of EXZ/SA14142m was lower than that of EM41/SA14142m. In mouse challenge tests, a single inoculation with a high dose of the mutants blocked lethal GV JEV infections; however, the protective efficacy of EXZ/SA14142m was weaker than that of EM41/SA14142m in low-dose inoculations. The lower protection potency of EXZ/SA14142m may be ascribed to the reduced growth ability caused by the attenuation mutations.
RESUMO
Zika virus (ZIKV) is a mosquito-borne flavivirus that causes febrile illness. The recent spread of ZIKV from Asia to the Americas via the Pacific region has revealed unprecedented features of ZIKV, including transplacental congenital infection causing microcephaly. Amino acid changes have been hypothesized to underlie the spread and novel features of American ZIKV strains; however, the relationship between genetic changes and the epidemic remains controversial. A comparison of the characteristics of a Southeast Asian strain (NIID123) and an American strain (PRVABC59) revealed that the latter had a higher replication ability in cultured cells and higher virulence in mice. In this study, we aimed to identify the genetic region of ZIKV responsible for these different characteristics using reverse genetics. A chimeric NIID123 strain in which the E protein was replaced with that of PRVABC59 showed a lower growth ability than the recombinant wild-type strain. Adaptation of the chimeric NIID123 to Vero cells induced a Phe-to-Leu amino acid substitution at position 146 of the prM protein; PRVABC59 also has Leu at this position. Leu at this position was found to be responsible for the viral replication ability and partially, for the pathogenicity in mouse testes.
Assuntos
Substituição de Aminoácidos , Interações Hospedeiro-Patógeno , Mutação , Proteínas do Envelope Viral/genética , Infecção por Zika virus/virologia , Zika virus/genética , Animais , Chlorocebus aethiops , Modelos Animais de Doenças , Genoma Viral , Genômica/métodos , Camundongos , Células Vero , Virulência , Replicação Viral , Zika virus/patogenicidade , Infecção por Zika virus/patologiaRESUMO
We previously showed that the growth ability of the Japanese encephalitis virus (JEV) genotype V (GV) strain Muar is clearly lower than that of the genotype I (GI) JEV strain Mie/41/2002 in murine neuroblastoma cells. Here, we sought to identify the region in GV JEV that is involved in its low growth potential in cultured cells. An intertypic virus containing the NS1-3 region of Muar in the Mie/41/2002 backbone (NS1-3Muar) exhibited a markedly diminished growth ability in murine neuroblastoma cells. Moreover, the growth rate of a Muar NS2A-bearing intertypic virus (NS2AMuar) was also similar to that of Muar in these cells, indicating that NS2A of Muar is one of the regions responsible for the Muar-specific growth ability in murine neuroblastoma cells. Sequencing analysis of murine neuroblastoma Neuro-2a cell-adapted NS1-3Muar virus clones revealed that His-to-Tyr mutation at position 166 of NS2A (NS2A166) could rescue the low replication ability of NS1-3Muar in Neuro-2a cells. Notably, a virus harboring a Tyr-to-His substitution at NS2A166 (NS2AY166H) showed a decreased growth ability relative to that of the parental virus Mie/41/2002, whereas an NS2AMuar-based mutant virus, NS2AMuar-H166Y, showed a higher growth ability than NS2AMuar in Neuro-2a cells. Thus, these results indicate that the NS2A166 amino acid in JEV is critical for the growth and tissue tropism of JEV in vitro.
Assuntos
Vírus da Encefalite Japonesa (Espécie)/crescimento & desenvolvimento , Vírus da Encefalite Japonesa (Espécie)/metabolismo , Encefalite Japonesa/virologia , Proteínas não Estruturais Virais/química , Proteínas não Estruturais Virais/genética , Motivos de Aminoácidos , Animais , Linhagem Celular , Vírus da Encefalite Japonesa (Espécie)/química , Vírus da Encefalite Japonesa (Espécie)/genética , Genoma Viral , Genótipo , Humanos , Camundongos , Proteínas não Estruturais Virais/metabolismoRESUMO
Morphological changes in the structure of the herpes simplex virus 1 (HSV-1) viral thymidine kinase (vTK) polypeptide usually lead to conferring acyclovir (ACV) resistance. HSV-1 I4-2, in which a UAG stop codon is present at the 8th position between the 1st initiation AUG codon (1st position) and the 2nd initiation AUG codon (46th position) of the HSV-1 vTK gene, showed sensitivity to ACV. In contrast, HSV-1 KG111, in which a UAG stop codon was artificially inserted at the 44th position, showed resistance to ACV at 39ËC. The mechanism underlying the difference in the sensitivity profiles was elucidated. The virus recombinants HSV-1-TK(8UAG) and HSV-1-TK(44UAG) containing a UAG stop codon at the 8th and 44th positions counted from the 1st initiation codon, respectively, were generated and tested for susceptibility to antiviral compounds. HSV-1-TK(8UAG) and HSV-1-TK(44UAG) were sensitive and resistant to ACV and BVdU at 37ËC, respectively. The expression level of the truncated vTK translated from the 2nd initiation codon in Vero cells infected with HSV-1-TK(44UAG) was clearly less than that with HSV-1-TK(8UAG) in a temperature-dependent manner. The differences in the antiviral sensitivity profiles were due to the position of the UAG stop codon between the 1st and the 2nd initiation codons.
Assuntos
Aciclovir/farmacologia , Antivirais/farmacologia , Farmacorresistência Viral/genética , Herpesvirus Humano 1/genética , Timidina Quinase/genética , Animais , Bromodesoxiuridina/análogos & derivados , Bromodesoxiuridina/farmacologia , Linhagem Celular , Chlorocebus aethiops , Códon de Iniciação/genética , Códon de Terminação/genética , Herpesvirus Humano 1/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana/métodos , Mutação , Células Vero , Ensaio de Placa Viral , Replicação Viral/efeitos dos fármacosRESUMO
Middle East respiratory syndrome-coronavirus (MERS-CoV) is an emerging virus that causes severe disease with fatal outcomes; however, there are currently no approved vaccines or specific treatments against MERS-CoV. Here, we developed a novel bivalent vaccine against MERS-CoV and rabies virus (RV) using the replication-incompetent P-gene-deficient RV (RVΔP), which has been previously established as a promising and safe viral vector. MERS-CoV spike glycoprotein comprises S1 and S2 subunits, with the S1 subunit being a primary target of neutralizing antibodies. Recombinant RVΔP, which expresses S1 fused with transmembrane and cytoplasmic domains together with 14 amino acids from the ectodomains of the RV-glycoprotein (RV-G), was developed using a reverse genetics method and named RVΔP-MERS/S1. Following generation of RVΔP-MERS/S1 and RVΔP, our analysis revealed that they shared similar growth properties, with the expression of S1 in RVΔP-MERS/S1-infected cells confirmed by immunofluorescence and western blot, and the immunogenicity and pathogenicity evaluated using mouse infection experiments. We observed no rabies-associated signs or symptoms in mice inoculated with RVΔP-MERS/S1. Moreover, virus-specific neutralizing antibodies against both MERS-CoV and RV were induced in mice inoculated intraperitoneally with RVΔP-MERS/S1. These findings indicate that RVΔP-MERS/S1 is a promising and safe bivalent-vaccine candidate against both MERS-CoV and RV.
Assuntos
Infecções por Coronavirus/prevenção & controle , Imunogenicidade da Vacina , Coronavírus da Síndrome Respiratória do Oriente Médio/imunologia , Vírus da Raiva/genética , Vacinas Sintéticas/imunologia , Vacinas Virais/imunologia , Replicação Viral , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Linhagem Celular Tumoral , Chlorocebus aethiops , Feminino , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos ICR , Vírus da Raiva/fisiologia , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinas Sintéticas/genética , Células Vero , Vacinas Virais/genéticaRESUMO
Several cases of herpes simplex encephalitis (HSE) caused by acyclovir (ACV)-resistant herpes simplex virus type 1 (HSV-1) have been reported. Amino acid substitutions of R41H, Q125H, and A156V in the viral thymidine kinase (vTK) gene have been reported to confer ACV resistance. Recombinant HSV-1 clones, containing each amino acid substitution in the vTK gene, were generated using the bacterial artificial chromosome system. A recombinant HSV-1 with the Q125H substitution showed ACV resistance while the R41H or A156V substitutions were ACV-sensitive. Furthermore, the Q125H recombinant HSV-1 was less virulent than the repaired virus, but it maintained neurovirulence in mice at relatively high levels. Substitution of Q125H, which was detected in the neonatal HSE patient, conferred ACV resistance, but the substitutions of R41H and A156V, which were detected in immunocompetent adult HSE patients, did not. This suggests that HSE caused by ACV-resistant HSV-1 might be a very rare event to occur during the course of ACV treatment in immunocompetent patients. Showing resistance to ACV treatment does not always indicate emergence of ACV-resistant HSV-1 in HSE patients.
Assuntos
Aciclovir/farmacologia , Substituição de Aminoácidos , Antivirais/farmacologia , Encefalite por Herpes Simples/virologia , Herpesvirus Humano 1/efeitos dos fármacos , Herpesvirus Humano 1/patogenicidade , Timidina Quinase/genética , Adulto , Idoso , Animais , Linhagem Celular , Cromossomos Artificiais Bacterianos , Modelos Animais de Doenças , Farmacorresistência Viral , Encefalite por Herpes Simples/patologia , Feminino , Herpesvirus Humano 1/genética , Herpesvirus Humano 1/isolamento & purificação , Humanos , Recém-Nascido , Masculino , Camundongos Endogâmicos ICR , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Proteínas Mutantes/genética , Genética Reversa , Virulência , Fatores de Virulência/genéticaRESUMO
Purpose: Higher serum 25-hydroxyvitamin D (25(OH)D) levels are reportedly associated with better survival in early-stage non-small cell lung cancer (NSCLC). Therefore, whether vitamin D supplementation can improve the prognosis of patients with NSCLC was examined (UMIN000001869).Patients and Methods: A randomized, double-blind trial comparing vitamin D supplements (1,200 IU/day) with placebo for 1 year after operation was conducted. The primary and secondary outcomes were relapse-free survival (RFS) and overall survival (OS), respectively. Prespecified subgroup analyses were performed with stratification by stage (early vs. advanced), pathology (adenocarcinoma vs. others), and 25(OH)D levels (low, <20 ng/mL vs. high, ≥20 ng/mL). Polymorphisms of vitamin D receptor (VDR) and vitamin D-binding protein (DBP) and survival were also examined.Results: Patients with NSCLC (n = 155) were randomly assigned to receive vitamin D (n = 77) or placebo (n = 78) and followed for a median of 3.3 years. Relapse and death occurred in 40 (28%) and 24 (17%) patients, respectively. In the total study population, no significant difference in either RFS or OS was seen with vitamin D compared with the placebo group. However, by restricting the analysis to the subgroup with early-stage adenocarcinoma with low 25(OH)D, the vitamin D group showed significantly better 5-year RFS (86% vs. 50%, P = 0.04) and OS (91% vs. 48%, P = 0.02) than the placebo group. Among the examined polymorphisms, DBP1 (rs7041) TT and CDX2 (rs11568820) AA/AG genotypes were markers of better prognosis, even with multivariate adjustment.Conclusions: In patients with NSCLC, vitamin D supplementation may improve survival of patients with early-stage lung adenocarcinoma with lower 25(OH)D levels. Clin Cancer Res; 24(17); 4089-97. ©2018 AACR.