scholarly journals Heterogeneity in the Response of Different Subtypes of Drosophila melanogaster Midgut Cells to Viral Infections

Viruses ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2284
Author(s):  
João M. F. Silva ◽  
Tatsuya Nagata ◽  
Fernando L. Melo ◽  
Santiago F. Elena
Keyword(s):  
Drosophila Melanogaster ◽  
Cellular Response ◽  
Viral Infections ◽  
Cellular Responses ◽  
Cellular Level ◽  
Viral Rna ◽  
Systemic Response ◽  
Cell Subtype ◽  
Replication Strategy ◽  
Rna Accumulation

Single-cell RNA sequencing (scRNA-seq) offers the possibility to monitor both host and pathogens transcriptomes at the cellular level. Here, public scRNA-seq datasets from Drosophila melanogaster midgut cells were used to compare the differences in replication strategy and cellular responses between two fly picorna-like viruses, Thika virus (TV) and D. melanogaster Nora virus (DMelNV). TV exhibited lower levels of viral RNA accumulation but infected a higher number of cells compared to DMelNV. In both cases, viral RNA accumulation varied according to cell subtype. The cellular heat shock response to TV and DMelNV infection was cell-subtype- and virus-specific. Disruption of bottleneck genes at later stages of infection in the systemic response, as well as of translation-related genes in the cellular response to DMelNV in two cell subtypes, may affect the virus replication.

scholarly journals Heterogeneity in the response of different subtypes of Drosophila melanogaster enteroendocrine cells to viral infections

2020 ◽  
Author(s):  
João M. F. Silva ◽  
Tatsuya Nagata ◽  
Fernando L. Melo ◽  
Santiago F. Elena
Keyword(s):  
Drosophila Melanogaster ◽  
Cellular Response ◽  
Viral Infections ◽  
Fruit Fly ◽  
Cellular Level ◽  
Enteroendocrine Cells ◽  
Systemic Response ◽  
Down Regulation ◽  
Replication Strategy ◽  
Systemic Level

SummarySingle cell RNA sequencing (scRNA-seq) offers the possibility to monitor both host and pathogens transcriptomes at the cellular level. Here, public scRNA-seq data from Drosophila melanogaster have been used to compare the differences in replication strategy and cellular response between two viruses, Thika virus (TV) and D. melanogaster Nora virus (DMelNV) in enteroendocrine cells (EEs). TV and DMelNV exhibited different patterns of replication and for TV, accumulation varied according to cell subtype. Cells infected with TV underwent down-regulation of genes that represent bottlenecks in the fruit fly interactome, while cells infected with DMelNV went through a down-expression of translation-related genes that represent both hubs and bottlenecks in the host interactome. In contrast, flies infected with DMelNV show only a systemic level down-regulation of bottleneck genes. Here, we use scRNA-seq to highlight the differences and commonalities between cellular response to TV and DMelNV and between cellular and systemic response to DMelNV.

scholarly journals Effects of Length and Location on the Cellular Response to Double-Stranded RNA

2004 ◽  
Vol 68 (3) ◽  
pp. 432-452 ◽  
Author(s):  
Qiaoqiao Wang ◽  
Gordon G. Carmichael
Keyword(s):  
Cell Growth ◽  
Viral Infection ◽  
Normal Cell ◽  
Cellular Response ◽  
Viral Infections ◽  
Cellular Responses ◽  
Double Stranded Rna ◽  
Antiviral Responses ◽  
And Function ◽  
In Cells

SUMMARY Since double-stranded RNA (dsRNA) has not until recently generally been thought to be deliberately expressed in cells, it has commonly been assumed that the major source of cellular dsRNA is viral infections. In this view, the cellular responses to dsRNA would be natural and perhaps ancient antiviral responses. While the cell may certainly react to some dsRNAs as an antiviral response, this does not represent the only response or even, perhaps, the major one. A number of recent observations have pointed to the possibility that dsRNA molecules are not seen only as evidence of viral infection or recognized for degradation because they cannot be translated. In some instances they may also play important roles in normal cell growth and function. The purpose of this review is to outline our current understanding of the fate of dsRNA in cells, with a focus on the apparent fact that their fates and functions appear to depend critically not only on where in the cell dsRNA molecules are found, but also on how long they are and perhaps on how abundant they are.

Nanoparticle-plasma Membrane Interactions: Thermodynamics, Toxicity and Cellular Response

2020 ◽  
Vol 27 (20) ◽  
pp. 3330-3345
Author(s):  
Ana G. Rodríguez-Hernández ◽  
Rafael Vazquez-Duhalt ◽  
Alejandro Huerta-Saquero
Keyword(s):  
Gene Expression ◽  
Immune Responses ◽  
Cellular Response ◽  
Cellular Level ◽  
Membrane Interactions ◽  
Daily Lives ◽  
Cellular Physiology ◽  
Associated Proteins ◽  
First Contact ◽  
Insight Into

Nanomaterials have become part of our daily lives, particularly nanoparticles contained in food, water, cosmetics, additives and textiles. Nanoparticles interact with organisms at the cellular level. The cell membrane is the first protective barrier against the potential toxic effect of nanoparticles. This first contact, including the interaction between the cell membranes -and associated proteins- and the nanoparticles is critically reviewed here. Nanoparticles, depending on their toxicity, can cause cellular physiology alterations, such as a disruption in cell signaling or changes in gene expression and they can trigger immune responses and even apoptosis. Additionally, the fundamental thermodynamics behind the nanoparticle-membrane and nanoparticle-proteins-membrane interactions are discussed. The analysis is intended to increase our insight into the mechanisms involved in these interactions. Finally, consequences are reviewed and discussed.

scholarly journals Electric Cell-Substrate Impedance Sensing To Monitor Viral Growth and Study Cellular Responses to Infection with Alphaherpesviruses in Real Time

mSphere ◽  
2017 ◽  
Vol 2 (2) ◽  
Author(s):  
Matthew R. Pennington ◽  
Gerlinde R. Van de Walle
Keyword(s):  
Real Time ◽  
Cellular Response ◽  
Cellular Responses ◽  
Cellular Damage ◽  
Impedance Sensing ◽  
Novel Technologies ◽  
Antiviral Therapies ◽  
Mucosal Surfaces ◽  
Cell Substrate ◽  
Hsv 1

ABSTRACT Alphaherpesviruses, including those that commonly infect humans, such as HSV-1 and HSV-2, typically infect and cause cellular damage to epithelial cells at mucosal surfaces, leading to disease. The development of novel technologies to study the cellular responses to infection may allow a more complete understanding of virus replication and the creation of novel antiviral therapies. This study demonstrates the use of ECIS to study various aspects of herpesvirus biology, with a specific focus on changes in cellular morphology as a result of infection. We conclude that ECIS represents a valuable new tool with which to study alphaherpesvirus infections in real time and in an objective and reproducible manner. Electric cell-substrate impedance sensing (ECIS) measures changes in an electrical circuit formed in a culture dish. As cells grow over a gold electrode, they block the flow of electricity and this is read as an increase in electrical impedance in the circuit. ECIS has previously been used in a variety of applications to study cell growth, migration, and behavior in response to stimuli in real time and without the need for cellular labels. Here, we demonstrate that ECIS is also a valuable tool with which to study infection by alphaherpesviruses. To this end, we used ECIS to study the kinetics of cells infected with felid herpesvirus type 1 (FHV-1), a close relative of the human alphaherpesviruses herpes simplex virus 1 (HSV-1) and HSV-2, and compared the results to those obtained with conventional infectivity assays. First, we demonstrated that ECIS can easily distinguish between wells of cells infected with different amounts of FHV-1 and provides information about the cellular response to infection. Second, we found ECIS useful in identifying differences between the replication kinetics of recombinant DsRed Express2-labeled FHV-1, created via CRISPR/Cas9 genome engineering, and wild-type FHV-1. Finally, we demonstrated that ECIS can accurately determine the half-maximal effective concentration of antivirals. Collectively, our data show that ECIS, in conjunction with current methodologies, is a powerful tool that can be used to monitor viral growth and study the cellular response to alphaherpesvirus infection. IMPORTANCE Alphaherpesviruses, including those that commonly infect humans, such as HSV-1 and HSV-2, typically infect and cause cellular damage to epithelial cells at mucosal surfaces, leading to disease. The development of novel technologies to study the cellular responses to infection may allow a more complete understanding of virus replication and the creation of novel antiviral therapies. This study demonstrates the use of ECIS to study various aspects of herpesvirus biology, with a specific focus on changes in cellular morphology as a result of infection. We conclude that ECIS represents a valuable new tool with which to study alphaherpesvirus infections in real time and in an objective and reproducible manner.

scholarly journals Inflammatory responses to secondary organic aerosols (SOA) generated from biogenic and anthropogenic precursors

2017 ◽  
Vol 17 (18) ◽  
pp. 11423-11440 ◽  
Author(s):  
Wing Y. Tuet ◽  
Yunle Chen ◽  
Shierly Fok ◽  
Julie A. Champion ◽  
Nga L. Ng
Keyword(s):  
Cellular Response ◽  
Secondary Organic Aerosols ◽  
Inflammatory Responses ◽  
Organic Aerosols ◽  
Cellular Responses ◽  
Carbon Chain ◽  
Formation Condition ◽  
Carbon Chain Length ◽  
Health Implications ◽  
Tnf Α

Abstract. Cardiopulmonary health implications resulting from exposure to secondary organic aerosols (SOA), which comprise a significant fraction of ambient particulate matter (PM), have received increasing interest in recent years. In this study, alveolar macrophages were exposed to SOA generated from the photooxidation of biogenic and anthropogenic precursors (isoprene, α-pinene, β-caryophyllene, pentadecane, m-xylene, and naphthalene) under different formation conditions (RO2 + HO2 vs. RO2 + NO dominant, dry vs. humid). Various cellular responses were measured, including reactive oxygen and nitrogen species (ROS/RNS) production and secreted levels of cytokines, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). SOA precursor identity and formation condition affected all measured responses in a hydrocarbon-specific manner. With the exception of naphthalene SOA, cellular responses followed a trend where TNF-α levels reached a plateau with increasing IL-6 levels. ROS/RNS levels were consistent with relative levels of TNF-α and IL-6, due to their respective inflammatory and anti-inflammatory effects. Exposure to naphthalene SOA, whose aromatic-ring-containing products may trigger different cellular pathways, induced higher levels of TNF-α and ROS/RNS than suggested by the trend. Distinct cellular response patterns were identified for hydrocarbons whose photooxidation products shared similar chemical functionalities and structures, which suggests that the chemical structure (carbon chain length and functionalities) of photooxidation products may be important for determining cellular effects. A positive nonlinear correlation was also detected between ROS/RNS levels and previously measured DTT (dithiothreitol) activities for SOA samples. In the context of ambient samples collected during summer and winter in the greater Atlanta area, all laboratory-generated SOA produced similar or higher levels of ROS/RNS and DTT activities. These results suggest that the health effects of SOA are important considerations for understanding the health implications of ambient aerosols.

scholarly journals Variations within oxygen-regulated gene expression in humans

2009 ◽  
Vol 106 (1) ◽  
pp. 212-220 ◽  
Author(s):  
Jerome T. S. Brooks ◽  
Gareth P. Elvidge ◽  
Louisa Glenny ◽  
Jonathan M. Gleadle ◽  
Chun Liu ◽  
...  
Keyword(s):  
Cellular Response ◽  
Genetic Manipulation ◽  
Hypoxia Inducible Factor ◽  
Hereditary Disease ◽  
Peripheral Blood Lymphocytes ◽  
Cellular Level ◽  
Normal Individuals ◽  
Regulated Gene Expression ◽  
Open Question ◽  
Hif Pathway

The effects of hypoxia on gene transcription are mainly mediated by a transcription factor complex termed hypoxia-inducible factor (HIF). Genetic manipulation of animals and studies of humans with rare hereditary disease have shown that modifying the HIF pathway affects systems-level physiological responses to hypoxia. It is, however, an open question whether variations in systems-level responses to hypoxia between individuals could arise from variations within the HIF system. This study sought to determine whether variations in the responsiveness of the HIF system at the cellular level could be detected between normal individuals. Peripheral blood lymphocytes (PBL) were isolated on three separate occasions from each of 10 healthy volunteers. After exposure of PBL to eight different oxygen tensions ranging from 20% to 0.1%, the expression levels of four HIF-regulated transcripts involved in different biological pathways were measured. The profile of expression of all four transcripts in PBL was related to oxygen tension in a curvilinear manner. Double logarithmic transformation of these data resulted in a linear relationship that allowed the response to be parameterized through a gradient and intercept. Analysis of variance (ANOVA) on these parameters showed that the level of between-subject variation in the gradients of the responses that was common across all four HIF-regulated transcripts was significant ( P = 0.008). We conclude that statistically significant variation within the cellular response to hypoxia can be detected between normal humans. The common nature of the variability across all four HIF-regulated genes suggests that the source of this variation resides within the HIF system itself.

scholarly journals Viral route of infection determines the effect of Drosophila melanogaster gut bacteria on host resistance and tolerance to disease

2021 ◽  
Author(s):  
Miguel Landum ◽  
Marta Salvado Silva ◽  
Nelson Martins ◽  
Luís Teixeira
Keyword(s):  
Drosophila Melanogaster ◽  
Viral Infections ◽  
Systemic Infection ◽  
Lactobacillus Brevis ◽  
Gut Bacteria ◽  
Associated Bacteria ◽  
Germ Free ◽  
Viral Loads ◽  
Route Of Infection ◽  
The Impact

AbstractThe microbial community interacting with a host can modulate the outcome of pathogenic infections. For instance, Wolbachia, one of the most prevalent invertebrate endosymbionts, strongly increases resistance of Drosophila melanogaster and other insect hosts, to many RNA viruses. D. melanogaster is also in continuous association with gut bacteria, whose role in antiviral immunity is poorly characterized. Here we asked how gut-colonizing bacteria impact viral titres and host survival, and how these interact with route of infection or Wolbachia presence. We compared germ-free flies and flies associated with two gut bacteria species recently isolated from wild flies (Acetobacter thailandicus and Lactobacillus brevis). We found that Wolbachia-conferred protection to both DCV or FHV is not affected by the presence or absence of these gut bacteria. Flies carrying A. thailandicus have lower DCV loads than germ-free flies, upon systemic infection, but reduced survival, indicating that these bacteria increase resistance to virus and decrease disease tolerance. Association with L. brevis, alone or in combination with A. thailandicus, did not lead to changes in survival to systemic infection. In contrast to the effect on systemic infection, we did not observe an impact of these bacteria on survival or viral loads after oral infection. Overall, the impact of gut-associated bacteria in resistance and tolerance to viruses was mild, when compared with Wolbachia. These results indicate that the effect of gut-associated bacteria to different viral infections, and different routes of infection, is complex and understanding it requires a detailed characterization of several parameters of infection.

scholarly journals Original SARS-CoV-2 vaccine model

2020 ◽  
pp. 128-132
Author(s):  
I. E. Khoroshilov
Keyword(s):  
Immune System ◽  
Gastrointestinal Tract ◽  
Respiratory System ◽  
Clinical Picture ◽  
Viral Infections ◽  
Single Case ◽  
Viral Rna ◽  
Human Gastrointestinal Tract ◽  
Oral Transmission ◽  
Coronavirus Infection

The new coronavirus infection COVID-19 that appeared at the end of 2019 is signifi cantly different from the viral infections that existed previously. The new SARS-CoV-2 coronavirus combines two transmission routes—aerosol and oral-intestinal. The targets for this virus are both cells of the respiratory system and the human gastrointestinal tract. Along with the classical form of this disease, the so-called “gastrointestinal” form is described, in which the clinical picture is dominated by signs of damage to the gastrointestinal tract (diarrhea, vomiting, anorexia). These symptoms are detected, in general, in 20% of patients with COVID-19. More than 80% of patients have mild forms, a third of these individuals had diarrhea. Although SARSCoV-2 viral RNA is detected in faeces samples of patients with COVID-19, it does not carry an infectious onset, and not a single case of fecal-oral transmission has been confi rmed. Since the intestines are the most powerful organ of our immune system, we can introduce SARS-CoV-2 viral RNA into the gastrointestinal tract to ensure the formation of immunity to this infection.

scholarly journals Unicellular associative conditioning: an interspecies analysis

2020 ◽  
Author(s):  
Jose Carrasco-Pujante ◽  
Carlos Bringas ◽  
Iker Malaina ◽  
Maria Fedetz ◽  
Luis Martínez ◽  
...  
Keyword(s):  
Cellular Responses ◽  
Amoeba Proteus ◽  
Systemic Response ◽  
Migration Patterns ◽  
Specific Stimulus ◽  
Associative Conditioning ◽  
Adaptive Mechanisms ◽  
Unicellular Organisms ◽  
Quantitative Results ◽  
Conditioned Behaviour

AbstractThe capacity to learn new systemic behaviour is a fundamental issue to understand the adaptive mechanisms involved in cellular evolution. We have recently observed, in a preliminary analysis, the emergence of conditioned behaviour in individual amoebae cells. In these experiments, cells were able to acquire new migratory conduct and remember it for long periods of their cellular cycle, forgetting it later on. Here, following a similar conceptual framework of Pavlov’s experiments, we have exhaustively studied the migration trajectories of more than 2000 individual cells belonging to three different species: Amoeba proteus, Metamoeba leningradensis, and Amoeba borokensis. Fundamentally, we have analysed several properties of conditioned cells, such as the intensity of the responses, the directionality persistence, the total distance traveled, the directionality ratio, the average speed, and the persistence times. We have observed that these three species can modify the systemic response to a specific stimulus by associative conditioning. Our main analysis shows that such new behaviour is very robust and presents a similar structure of migration patterns in the three species, which was characterized by the presence of conditioning for long periods, remarkable straightness in their trajectories and strong directional persistence. Our quantitative results, compared with other studies on complex cellular responses in bacteria, protozoa, fungus-like organisms and metazoans, allow us to conclude that cellular associative conditioning might be a widespread characteristic of unicellular organisms. This finding could be essential to understand some key evolutionary principles involved in increasing the cellular adaptive fitness to microenvironments.

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