RESUMEN
BACKGROUND: Immunotherapy combined with chemotherapy significantly improves progression-free survival (PFS) compared to first-line chemotherapy alone in advanced endometrial cancer (EC), with a much larger effect size in microsatellite instability-high (MSI-H) cases. New biomarkers might help to select patients who may have benefit among those with a microsatellite-stable (MSS) tumor. PATIENTS AND METHODS: In a pre-planned translational analysis of the MITO END-3 trial, we assessed the significance of genomic abnormalities in patients randomized to standard carboplatin/paclitaxel without or with avelumab. RESULTS: Out of 125 randomized patients, 109 had samples eligible for next-generation sequencing analysis, and 102 had MSI tested. According to The Cancer Genome Atlas (TCGA), there were 29 cases with MSI-H, 26 with MSS TP53 wild type (wt), 47 with MSS TP53 mutated (mut), and 1 case with POLE mutation. Four mutated genes were present in >30% of cases: TP53, PIK3CA, ARID1A, and PTEN. Eleven patients (10%) had a BRCA1/2 mutation (five in MSI-H and six in MSS). High tumor mutational burden (≥10 muts/Mb) was observed in all MSI-H patients, in 4 out of 47 MSS/TP53 mut, and no case in the MSS/TP53 wt category. The effect of avelumab on PFS significantly varied according to TCGA categories, being favorable in MSI-H and worst in MSS/TP53 mut (P interaction = 0.003); a similar non-significant trend was seen in survival analysis. ARID1A and PTEN also showed a statistically significant interaction with treatment effect, which was better in the presence of the mutation (ARID1A P interaction = 0.01; PTEN P interaction = 0.002). CONCLUSION: The MITO END-3 trial results suggest that TP53 mutation is associated with a poor effect of avelumab, while mutations of PTEN and ARID1A are related to a positive effect of the drug in patients with advanced EC.
Asunto(s)
Anticuerpos Monoclonales Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica , Neoplasias Endometriales , Inestabilidad de Microsatélites , Mutación , Paclitaxel , Humanos , Femenino , Anticuerpos Monoclonales Humanizados/uso terapéutico , Neoplasias Endometriales/tratamiento farmacológico , Neoplasias Endometriales/genética , Neoplasias Endometriales/patología , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Persona de Mediana Edad , Paclitaxel/uso terapéutico , Paclitaxel/administración & dosificación , Anciano , Carboplatino/administración & dosificación , Carboplatino/farmacología , Carboplatino/uso terapéutico , Inmunoterapia/métodos , Fosfohidrolasa PTEN/genética , Adulto , Supervivencia sin Progresión , Biomarcadores de Tumor/genética , Proteína p53 Supresora de Tumor/genética , Proteínas de Unión al ADN/genética , Secuenciación de Nucleótidos de Alto Rendimiento , Factores de Transcripción , Fosfatidilinositol 3-Quinasa Clase IRESUMEN
BACKGROUND: The treatment of patients with brain-spread renal cell carcinoma (RCC) is an unmet clinical need, although more recent therapeutic strategies have significantly improved RCC patients' life expectancy. Our multicenter, retrospective, observational study investigated a real-world cohort of patients with brain metastases (BM) from RCC (BMRCC). PATIENTS AND METHODS: A total of 226 patients with histological diagnosis of RCC and radiological evidence of BM from 22 Italian institutions were enrolled. Univariate and multivariate models were performed to investigate the impact of clinicopathological features and multimodal treatments on both overall survival (OS) from the BM diagnosis and intracranial progression-free survival (iPFS). RESULTS: The median OS from the BM diagnosis was 18.8 months (interquartile range: 6.2-43 months). Multivariate analysis confirmed the following as positive independent prognostic factors: a Karnofsky Performance Status >70% [hazard ratio (HR) = 0.49, 95% confidence interval (CI) 0.26-0.92, P = 0.0026] and a single BM (HR = 0.51, 95% CI 0.31-0.86, P = 0. 0310); in contrast, the following were confirmed as worse prognosis factors: progressive extracranial disease (HR = 1.66, 95% CI 1.003-2.74, P = 0.00181) and only one line of systemic therapy after the BM occurrence (HR = 2.98, 95% CI 1.62-5.49, P = 0.029). Subgroup analyses showed no difference in iPFS according to the type of the first systemic treatment [immunotherapy (IT) or targeted therapy (TT)] carried out after the BM diagnosis (HR = 1.033, 95% CI 0.565-1.889, P = 0.16), and revealed that external radiation therapy (eRT) significantly prolonged iPFS when combined with IT (10.7 months, 95% CI 4.9-48 months, P = 0.0321) and not when combined with TT (9.01 months, 95% CI 2.7-21.2 months, P = 0.59). CONCLUSIONS: Our results suggest a potential additive effect in terms of iPFS for eRT combined with IT and encourage a more intensive multimodal therapeutic strategy in a multidisciplinary context to improve the survival of BMRCC patients.
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Neoplasias Encefálicas , Carcinoma de Células Renales , Neoplasias Renales , Humanos , Carcinoma de Células Renales/terapia , Neoplasias Renales/terapia , Neoplasias Renales/patología , Estudios Retrospectivos , Pronóstico , Neoplasias Encefálicas/terapia , Neoplasias Encefálicas/secundarioRESUMEN
The baculoviral chitinase (CHIA) and cathepsin (V-CATH) enzymes promote terminal insect host liquefaction, which aids viral progeny dissemination. Recombinant Autographa californica nucleopolyhedrovirus (AcMNPV)-derived viruses were previously generated with reprogrammed chiA transcription by replacing the native promoter with the AcMNPV polyhedrin (polh) or core protein (p6.9) promoter sequences, but of both these chiA-reprogrammed viruses lacked v-cath transcription and V-CATH enzymatic activity. Here, we report that dual p6.9/polh promoter reprogramming of the adjacent chiA/v-cath genes resulted in modulated temporal transcription of both genes without impacting infectious budded virus production. These promoter changes increased CHIA and V-CATH enzyme activities in infected Spodoptera frugiperda-derived cultured cells and Trichoplusia ni larvae. In addition, larvae infected with the dual reprogrammed virus had earlier mortalities and liquefaction. This recombinant baculovirus, lacking exogenous genomic elements and increased chiA/v-cath expression levels, may be desirable for and amenable to producing enhanced baculovirus-based biopesticides.
Asunto(s)
Quitinasas , Animales , Baculoviridae , Catepsinas/genética , Quitinasas/genética , Larva , Spodoptera , Virulencia/genética , Transcripción GenéticaRESUMEN
Baculovirus-infected larvae release progeny viral occlusion bodies (OBs) to enable cyclical virus transmission to new hosts. The alphabaculovirus chitinase and cathepsin enzymes cause terminal liquefaction of host insect cadavers, aiding OB dispersal. The mechanism of cell lysis required to release the OBs is unclear but here we show Autographa californica multiple nucleopolyhedrovirus cathepsin protease activity is required for efficient release of the host tissue-degrading chitinase and cathepsin enzymes and critical for release of progeny OBs from virus-infected cells. Comparisons between viruses containing or lacking cathepsin indicate that cathepsin was necessary for OB release into cultured cell media or hemolymph of insects. In addition, pharmacological inhibition of cysteine protease activity in cells during infection blocked maturation of active cathepsin and OB release from infected cells. Together, these results suggest an important link between baculovirus-induced cell lysis, the concomitant maturation of cathepsin, and cellular release of chitinase, cathepsin and progeny OBs from cells.
Asunto(s)
Catepsinas/metabolismo , Proteasas de Cisteína/metabolismo , Nucleopoliedrovirus/patogenicidad , Cuerpos de Oclusión Viral/metabolismo , Proteínas Virales/metabolismo , Animales , Muerte Celular , Células Sf9 , SpodopteraRESUMEN
Fibroblast growth factors (FGFs) are conserved among vertebrate and invertebrate animals and function in cell proliferation, cell differentiation, tissue repair, and embryonic development. A viral fibroblast growth factor (vFGF) homolog encoded by baculoviruses, a group of insect viruses, is involved in escape of baculoviruses from the insect midgut by stimulating basal lamina remodeling. This led us to investigate whether cellular FGF is involved in the escape of an arbovirus from mosquito midgut. In this study, the effects of manipulating FGF expression on Sindbis virus (SINV) replication and escape from the midgut of the mosquito vector Aedes aegypti were examined. RNAi-mediated silencing of either Ae. aegypti FGF (AeFGF) or FGF receptor (AeFGFR) expression reduced SINV replication following oral infection of Ae. aegypti mosquitoes. However, overexpression of baculovirus vFGF using recombinant SINV constructs had no effect on replication of these viruses in cultured mosquito or vertebrate cells, or in orally infected Ae. aegypti mosquitoes. We conclude that reducing FGF signaling decreases the ability of SINV to replicate in mosquitoes, but that overexpression of vFGF has no effect, possibly because endogenous FGF levels are already sufficient for optimal virus replication. These results support the hypothesis that FGF signaling, possibly by inducing remodeling of midgut basal lamina, is involved in arbovirus midgut escape following virus acquisition from a blood meal.
Asunto(s)
Aedes/virología , Factores de Crecimiento de Fibroblastos/metabolismo , Proteínas de Insectos/metabolismo , Mosquitos Vectores/virología , Virus Sindbis/fisiología , Animales , Caspasas/metabolismo , Movimiento Celular , Factores de Crecimiento de Fibroblastos/genética , Tracto Gastrointestinal/virología , Proteínas de Insectos/genética , Interferencia de ARN , Receptores de Factores de Crecimiento de Fibroblastos/genética , Receptores de Factores de Crecimiento de Fibroblastos/metabolismo , Transducción de Señal , Replicación ViralRESUMEN
Prior studies have suggested that insect DNA viruses are negatively affected by dicer-2-mediated RNA interference (RNAi). To examine this further, we utilized an in vitro assay to measure dicer activity in lepidopteran and dipteran cells, combined with baculoviruses expressing the RNAi suppressor B2 from Flock House virus or Aedes aegypti dicer-2 (Aedicer-2) using a constitutive heat shock promoter. Addition of cell lysates containing baculovirus-expressed B2 to lysates from dipteran (S2, Aag2) or lepidopteran (Sf9) cells inhibited endogenous dicer activity in a dose-dependent manner, while expression of Aedicer-2 restored siRNA production in Ae. albopictus C6/36 cells, which are dicer-2 defective. However, B2 expression from the constitutive heat shock promoter had no impact on baculovirus replication or virulence in cell lines or larvae that were either highly permissive (Trichoplusia ni) or less susceptible (Spodoptera frugiperda) to infection. We determined that this constitutive level of B2 expression had little to no ability to suppress dicer activity in cell lysates, but higher expression of B2, following heat shock treatment, inhibited dicer activity in all cells tested. Thus, we cannot rule out the possibility that optimized expression of B2 or other RNAi suppressors may increase baculovirus replication and expression of heterologous proteins by baculoviruses.
Asunto(s)
Baculoviridae/genética , Nodaviridae/genética , Ribonucleasa III/genética , Animales , Dípteros/enzimología , Regulación Viral de la Expresión Génica/genética , Virus de Insectos/genética , Lepidópteros/enzimología , ARN Interferente PequeñoRESUMEN
BACKGROUND: Immune markers in the peripheral blood of melanoma patients provide useful information for clinical management although there is poor consensus on circulating cells which could putatively reflect the disease activity and play a prognostic role. Here, we investigated both dendritic cells (DCs) and T-regulatory cells (Tregs). METHODS: The number of DC subsets as myeloid (m) and plasmacytoid was measured by flowcytometry in 113 melanoma patients in different clinical stages and correlated with the disease activity to evaluate the recurrence free survival (RFS) calculated as difference between baseline and post-surgical values in relation to the criteria for the melanoma staging, as primary tumor removal, sentinel lymph node biopsy and completion of lymph node dissection. RESULTS: Circulating mDC levels were significantly lower in metastatic melanoma than in other stages and inversely correlated to Treg values while both populations were similarly expressed in inactive disease at stage I-III. Furthermore, the levels of these cells after melanoma removal were apparently related to the disease activity since their persistent defect reflected high risk of recurrence and reduced the RFS. CONCLUSIONS: This work highlighted the role of immune cell measurement for the management of melanoma activity and the identification of patients at potential risk of recurrence based on the mDC ratio.
Asunto(s)
Biomarcadores de Tumor/análisis , Células Dendríticas/inmunología , Melanoma/inmunología , Recurrencia Local de Neoplasia/inmunología , Neoplasias Cutáneas/inmunología , Linfocitos T Reguladores/inmunología , Adulto , Biomarcadores de Tumor/inmunología , Células Dendríticas/patología , Femenino , Estudios de Seguimiento , Humanos , Escisión del Ganglio Linfático , Ganglios Linfáticos/inmunología , Ganglios Linfáticos/patología , Masculino , Melanoma/patología , Melanoma/cirugía , Persona de Mediana Edad , Recurrencia Local de Neoplasia/patología , Recurrencia Local de Neoplasia/cirugía , Estadificación de Neoplasias , Pronóstico , Estudios Retrospectivos , Factores de Riesgo , Biopsia del Ganglio Linfático Centinela , Neoplasias Cutáneas/patología , Neoplasias Cutáneas/cirugía , Tasa de Supervivencia , Linfocitos T Reguladores/patología , Melanoma Cutáneo MalignoRESUMEN
Marine ecosystems are globally threatened by human activities, but some areas, such as those affected by abandoned industrial plants, show an overlap of acute and chronic impacts, which determine a considerable deterioration of their health status. Here we report the results of a research conducted on coastal sewers that discharge their loads in the highly contaminated area of Bagnoli-Coroglio (Tyrrhenian Sea, Western Mediterranean). The sampling area is characterized by heavy industrial activities (a steel plant using coal, iron and limestone) started in 1905 and ceased in 1990, which left widespread heavy metals and hydrocarbon contamination. After taking into account the potential influence of sediment grain size ranges through their inclusion as covariates in the analysis, we tested the potential impact of sewage discharge on the total abundance and multivariate structure of meiofaunal assemblages, as well as on the abundance of single taxa. The organic matter was analysed in terms of total phytopigment and biopolymeric carbon concentrations. Nematoda, Copepoda (including their nauplii), and Tardigrada were the most abundant meiofaunal taxa at all sites, but nematodes did not show a consistent pattern relative to the sewage outfalls. However, the sewer located in the historically most contaminated area showed a minimal abundance of all taxa, including nematodes, while copepods were relatively less abundant at the two southernmost sewers. Comparing the north vs. south site of the sewers, higher meiofaunal abundances were observed in the southward part, likely as a result of the local circulation. The results of this study indicate the general adaptation of meiofauna to multiple stressors (sewage discharge, superimposed to chronic industrial contamination) and its likely modulation by other local processes. They also provide relevant baseline information for future restoration interventions that would take into account the spatial variation of target organisms as needed.
Asunto(s)
Organismos Acuáticos/fisiología , Monitoreo del Ambiente , Sedimentos Geológicos/análisis , Invertebrados/fisiología , Aguas del Alcantarillado/efectos adversos , Contaminantes Químicos del Agua/efectos adversos , Animales , Organismos Acuáticos/efectos de los fármacos , Copépodos/efectos de los fármacos , Copépodos/fisiología , Invertebrados/efectos de los fármacos , Italia , Nematodos/efectos de los fármacos , Nematodos/fisiología , Tardigrada/efectos de los fármacos , Tardigrada/fisiologíaRESUMEN
Aedes aegypti is a major vector for arboviruses such as dengue, chikungunya and Zika viruses. During acquisition of a viremic bloodmeal, an arbovirus infects mosquito midgut cells before disseminating to secondary tissues, including the salivary glands. Once virus is released into the salivary ducts it can be transmitted to another vertebrate host. The midgut is surrounded by a basal lamina (BL) in the extracellular matrix, consisting of a proteinaceous mesh composed of collagen IV and laminin. BL pore size exclusion limit prevents virions from passing through. Thus, the BL probably requires remodelling via enzymatic activity to enable efficient virus dissemination. Matrix metalloproteinases (MMPs) are extracellular endopeptidases that are involved in remodelling of the extracellular matrix. Here, we describe and characterize the nine Ae. aegypti encoded MMPs, AeMMPs 1-9, which share common features with other invertebrate and vertebrate MMPs. Expression profiling in Ae. aegypti revealed that Aemmp4 and Aemmp6 were upregulated during metamorphosis, whereas expression of Aemmp1 and Aemmp2 increased during bloodmeal digestion. Aemmp1 expression was also upregulated in the presence of a bloodmeal containing chikungunya virus. Using polyclonal antibodies, AeMMP1 and AeMMP2 were specifically detected in tissues associated with the mosquito midgut.
Asunto(s)
Aedes/enzimología , Metaloproteinasas de la Matriz/metabolismo , Aedes/genética , Aedes/crecimiento & desarrollo , Aedes/virología , Secuencia de Aminoácidos , Animales , Virus Chikungunya/fisiología , Femenino , Tracto Gastrointestinal/enzimología , Expresión Génica , Genoma de los Insectos , Humanos , Masculino , Metaloproteinasas de la Matriz/genética , Metamorfosis Biológica , Datos de Secuencia Molecular , Homología de Secuencia de Ácido NucleicoRESUMEN
Chikungunya virus (CHIKV) is an emerging mosquito-borne virus belonging to the Togaviridae, which is transmitted to humans by Aedes aegypti and Ae. albopictus. We describe the infection pattern of CHIKV in two New World Ae. aegypti strains, HWE and ORL. Both mosquito strains were susceptible to the virus but showed different infection patterns in midguts and salivary glands. Even though acquisition of a bloodmeal showed moderate levels of apoptosis in midgut tissue, there was no obvious additional CHIKV-induced apoptosis detectable during midgut infection. Analysis of expression of apoptosis-related genes suggested that CHIKV infection dampens rather than promotes apoptosis in the mosquito midgut. In both mosquito strains, the virus was present in saliva within two days post-oral infection. HWE and ORL mosquitoes exhibited no salivary gland infection barrier; however, only 60% (HWE) to 65% (ORL) of the females had released the virus in their saliva at one week post-oral acquisition, suggesting a salivary gland escape barrier. CHIKV induced an apoptotic response in salivary glands of HWE and ORL mosquitoes, demonstrating that the virus caused pathology in its natural vector.
Asunto(s)
Aedes/virología , Virus Chikungunya/crecimiento & desarrollo , Mosquitos Vectores , Animales , Apoptosis , Tracto Gastrointestinal/patología , Tracto Gastrointestinal/virología , Interacciones Huésped-Patógeno , Saliva/virología , Glándulas Salivales/patología , Glándulas Salivales/virologíaRESUMEN
Arthropod-borne viruses (arboviruses) circulate in nature between arthropod vectors and vertebrate hosts. Arboviruses often cause devastating diseases in vertebrate hosts, but they typically do not cause significant pathology in their arthropod vectors. Following oral acquisition of a viremic bloodmeal from a vertebrate host, the arbovirus disease cycle requires replication in the cellular environment of the arthropod vector. Once the vector has become systemically and persistently infected, the vector is able to transmit the virus to an uninfected vertebrate host. In order to systemically infect the vector, the virus must cope with innate immune responses and overcome several tissue barriers associated with the midgut and the salivary glands. In this review we describe, in detail, the typical arbovirus infection route in competent mosquito vectors. Based on what is known from the literature, we explain the nature of the tissue barriers that arboviruses are confronted with in a mosquito vector and how arboviruses might surmount these barriers. We also point out controversial findings to highlight particular areas that are not well understood and require further research efforts.
Asunto(s)
Infecciones por Arbovirus/transmisión , Arbovirus/fisiología , Culicidae/virología , Insectos Vectores/virología , Animales , Infecciones por Arbovirus/virología , Humanos , Glándulas Salivales/virologíaRESUMEN
Baculovirus infection of a host insect involves several steps, beginning with initiation of virus infection in the midgut, followed by dissemination of infection from the midgut to other tissues in the insect, and finally culminating in "melting" or liquefaction of the host, which allows for horizontal spread of infection to other insects. While all of the viral gene products are involved in ultimately reaching this dramatic infection endpoint, this review focuses on two particular types of baculovirus-encoded proteins: degradative enzymes and protease inhibitors. Neither of these types of proteins is commonly found in other virus families, but they both play important roles in baculovirus infection. The types of degradative enzymes and protease inhibitors encoded by baculoviruses are discussed, as are the roles of these proteins in the infection process.
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Baculoviridae/enzimología , Baculoviridae/crecimiento & desarrollo , Quitinasas/metabolismo , Insectos/virología , Péptido Hidrolasas/metabolismo , Inhibidores de Proteasas/metabolismo , AnimalesRESUMEN
In vivo targeted gene disruption is a powerful tool to study gene function. Thus far, two tools for genome editing in Aedes aegypti have been applied, zinc-finger nucleases (ZFN) and transcription activator-like effector nucleases (TALEN). As a promising alternative to ZFN and TALEN, which are difficult to produce and validate using standard molecular biological techniques, the clustered regularly interspaced short palindromic repeats/CRISPR-associated sequence 9 (CRISPR/Cas9) system has recently been discovered as a "do-it-yourself" genome editing tool. Here, we describe the use of CRISPR/Cas9 in the mosquito vector, Aedes aegypti. In a transgenic mosquito line expressing both Dsred and enhanced cyan fluorescent protein (ECFP) from the eye tissue-specific 3xP3 promoter in separated but tightly linked expression cassettes, we targeted the ECFP nucleotide sequence for disruption. When supplying the Cas9 enzyme and two sgRNAs targeting different regions of the ECFP gene as in vitro transcribed mRNAs for germline transformation, we recovered four different G1 pools (5.5% knockout efficiency) where individuals still expressed DsRed but no longer ECFP. PCR amplification, cloning, and sequencing of PCR amplicons revealed indels in the ECFP target gene ranging from 2-27 nucleotides. These results show for the first time that CRISPR/Cas9 mediated gene editing is achievable in Ae. aegypti, paving the way for further functional genomics related studies in this mosquito species.
Asunto(s)
Aedes/genética , Sistemas CRISPR-Cas/genética , Genoma de los Insectos , Fiebre Amarilla/genética , Aedes/patogenicidad , Animales , Secuencia de Bases , Humanos , Mutación INDEL , Edición de ARN/genética , Fiebre Amarilla/transmisión , Dedos de Zinc/genéticaRESUMEN
The Cydia pomonella granulovirus open reading frame 46 (CpGV-ORF46) contains predicted domains found in matrix metalloproteases (MMPs), a family of zinc-dependent endopeptidases that degrade extracellular matrix proteins. We showed that CpGV-MMP was active in vitro. Autographa californica multiple nucleopolyhedrovirus (AcMNPV) expressing CpGV-ORF46 replicated similarly to a control virus lacking CpGV-ORF46 in cultured cells. The effects of AcMNPV expressing CpGV-MMP on virus infection in cultured cells and Trichoplusia ni larvae in the presence or absence of other viral degradative enzymes, cathepsin and chitinase, were evaluated. In the absence of cathepsin and chitinase or cathepsin alone, larval time of death was significantly delayed. This delay was compensated by the expression of CpGV-MMP. CpGV-MMP was also able to promote larvae melanization in the absence of cathepsin and chitinase. In addition, CpGV-MMP partially substituted for cathepsin in larvae liquefaction when chitinase, which is usually retained in the endoplasmic reticulum, was engineered to be secreted.
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Baculoviridae/enzimología , Catepsinas/metabolismo , Metaloproteinasas de la Matriz/metabolismo , Nucleopoliedrovirus/patogenicidad , Proteínas Virales/metabolismo , Secuencia de Aminoácidos , Animales , Baculoviridae/genética , Catepsinas/genética , Expresión Génica , Lepidópteros/virología , Metaloproteinasas de la Matriz/genética , Datos de Secuencia Molecular , Nucleopoliedrovirus/enzimología , Nucleopoliedrovirus/genética , Alineación de Secuencia , Proteínas Virales/genética , VirulenciaRESUMEN
The Autographa californica multiple nucleopolyhedrovirus ac92 is a conserved baculovirus gene with homology to flavin adenine dinucleotide-linked sulfhydryl oxidases. Its product, Ac92, is a functional sulfhydryl oxidase. Deletion of ac92 results in almost negligible levels of budded virus (BV) production, defects in occlusion-derived virus (ODV) co-envelopment and their inefficient incorporation into occlusion bodies. To determine the role of sulfhydryl oxidation in the production of BV, envelopment of nucleocapsids, and nucleocapsid incorporation into occlusion bodies, the Trichoplusia ni single nucleopolyhedrovirus ortholog, tn79, was substituted for ac92. Tn79 was found to be an active sulfhydryl oxidase that substituted for Ac92, resulting in the production of infectious BV, albeit about 10-fold less than an ac92-containing virus. Tn79 rescued defects in ODV morphogenesis caused by a lack of ac92. Active Tn79 sulfhydryl oxidase activity is required for efficient BV production, ODV envelopment, and their subsequent incorporation into occlusion bodies in the absence of ac92.
Asunto(s)
Nucleopoliedrovirus/enzimología , Oxidorreductasas/metabolismo , Proteínas Virales/metabolismo , Replicación Viral , Secuencia de Aminoácidos , Animales , Línea Celular , Datos de Secuencia Molecular , Mariposas Nocturnas/virología , Nucleopoliedrovirus/clasificación , Nucleopoliedrovirus/genética , Nucleopoliedrovirus/fisiología , Oxidorreductasas/química , Oxidorreductasas/genética , Filogenia , Alineación de Secuencia , Proteínas Virales/química , Proteínas Virales/genéticaRESUMEN
Aedes aegypti is the principal vector of dengue virus (DENV) throughout the tropical world. This anthropophilic mosquito species needs to be persistently infected with DENV before it can transmit the virus through its saliva to a new vertebrate host. In the mosquito, DENV is confronted with several innate immune pathways, among which RNA interference is considered the most important. The Ae. aegypti genome project opened the doors for advanced molecular studies on pathogen-vector interactions including genetic manipulation of the vector for basic research and vector control purposes. Thus, Ae. aegypti has become the primary model for studying vector competence for arboviruses at the molecular level. Here, we present recent findings regarding DENV-mosquito interactions, emphasizing how innate immune responses modulate DENV infections in Ae. aegypti. We also describe the latest advancements in genetic manipulation of Ae. aegypti and discuss how this technology can be used to investigate vector transmission of DENV at the molecular level and to control transmission of the virus in the field.
RESUMEN
Infection of the lepidopteran insect Trichoplusia ni with the baculovirus Autographa californica M nucleopolyhedrovirus (AcMNPV) by the oral route stimulates activation of host matrix metalloproteases (MMP) and effector caspases, a process dependent on expression of the viral fibroblast growth factor (vFGF). This pathway leads to tracheal cell basal lamina remodelling, enabling virus escape from the primary site of infection, the midgut epithelium, and establishment of efficient systemic infection. In this study, we asked whether the MMP-caspase pathway was also activated following infection by intrahaemocoelic injection. We found that intrahaemocoelic infection did not lead to any observable tracheal cell or midgut epithelium basal lamina remodelling. MMP and caspase activities were not significantly stimulated. We conclude that the main role of the AcMNPV vFGF is in facilitating virus midgut escape.
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Mariposas Nocturnas/virología , Nucleopoliedrovirus/fisiología , Animales , Membrana Basal/enzimología , Caspasas/genética , Caspasas/metabolismo , Factores de Crecimiento de Fibroblastos/genética , Factores de Crecimiento de Fibroblastos/metabolismo , Interacciones Huésped-Patógeno , Proteínas de Insectos/genética , Proteínas de Insectos/metabolismo , Metaloproteinasas de la Matriz/genética , Metaloproteinasas de la Matriz/metabolismo , Mariposas Nocturnas/enzimología , Mariposas Nocturnas/genética , Nucleopoliedrovirus/genética , Tráquea/enzimología , Tráquea/virología , Proteínas Virales/genética , Proteínas Virales/metabolismoRESUMEN
The Autographa californica M nucleopolyhedrovirus (AcMNPV) sulfhydryl oxidase Ac92 is essential for production of infectious virions. Ac92 also interacts with human p53 and enhances human p53-induced apoptosis in insect cells, but it is not known whether any relationship exists between Ac92 and native p53 homologs from insect hosts of AcMNPV. We found that Ac92 interacted with SfP53 from Spodoptera frugiperda in infected cells and oxidized SfP53 in vitro. However, Ac92 did not interact with or oxidize a mutant of SfP53 predicted to lack DNA binding. Silencing Sfp53 expression did not rescue the ability of an ac92-knockout virus to produce infectious virus. Similarly, ac92 expression did not affect SfP53-stimulated caspase activity or the localization of SfP53. Thus, although Ac92 binds to SfP53 during AcMNPV replication and oxidizes SfP53 in vitro, we could not detect any effects of this interaction on AcMNPV replication in cultured cells.
Asunto(s)
Interacciones Huésped-Patógeno , Nucleopoliedrovirus/enzimología , Oxidorreductasas/metabolismo , Procesamiento Proteico-Postraduccional , Proteína p53 Supresora de Tumor/metabolismo , Proteínas Virales/metabolismo , Animales , Nucleopoliedrovirus/fisiología , Oxidación-Reducción , Células Sf9 , SpodopteraRESUMEN
Autographa californica M nucleopolyhedrovirus (AcMNPV) open reading frame 109 (ac109) is conserved in all known baculovirus genomes, suggesting a crucial role in virus replication. Although viruses lacking ac109 have been previously characterized, the phenotypes differ from production of non-infectious virions to lack of virion production. To re-examine ac109 function, we constructed a recombinant AcMNPV bacmid, AcBAC109KO, with a deletion in ac109. We did not detect infectious budded virus after transfection of AcBAC109KO DNA into cells. In the nucleus, nucleocapsids had envelopment defects and polyhedra lacked virions. DNA synthesis and gene expression between AcBAC109KO and a control virus were similar. However, lower levels of non-infectious budded virus were detected from AcBAC109KO DNA-transfected cells compared to the parental virus using Q-PCR to detect viral DNA or by immunoblotting to detect a budded virus protein. Therefore, deletion of ac109 affects envelopment of nucleocapsids in the nucleus and the production of infectious budded virus.