scholarly journals Elucidating spatially-resolved changes in host signaling during Plasmodium liver-stage infection

2021 ◽  
Author(s):  
Elizabeth K.K. Glennon ◽  
Tinotenda Tongogara ◽  
Veronica I. Primavera ◽  
Sophia M. Reeder ◽  
Ling Wei ◽  
...  
Keyword(s):  
Blood Stream ◽  
Plasmodium Yoelii ◽  
Infected Hepatocyte ◽  
Spatially Resolved ◽  
Spatial Profiling ◽  
Host Signaling ◽  
Infected Cells ◽  
Spatial Locations

AbstractUpon transmission to the human host, Plasmodium sporozoites exit the skin, are taken up by the blood stream, and then travel to the liver where they infect and significantly modify a single hepatocyte. Low infection rates within the liver have made proteomic studies of infected hepatocytes challenging, particularly in vivo, and existing studies have been largely unable to consider how protein and phosphoprotein differences are altered at different spatial locations within the heterogeneous liver. Using digital spatial profiling, we characterized changes in host signaling during Plasmodium yoelii infection in vivo without disrupting the liver tissue, and measured variation between infected cells. Moreover, we measured alterations in protein expression around infected hepatocytes and identified a subset of CD163+ Kupffer cells that migrate towards infected cells during infection. These data offer the first insight into the heterogeneity of the infected hepatocyte in situ and provide insights into how the parasite may alter the local microenvironment to influence its survival and modulate immunity.

scholarly journals Elucidating Spatially-Resolved Changes in Host Signaling During Plasmodium Liver-Stage Infection

2022 ◽  
Vol 11 ◽  
Author(s):  
Elizabeth K. K. Glennon ◽  
Tinotenda Tongogara ◽  
Veronica I. Primavera ◽  
Sophia M. Reeder ◽  
Ling Wei ◽  
...  
Keyword(s):  
Blood Stream ◽  
Plasmodium Yoelii ◽  
Liver Stage ◽  
Infected Hepatocyte ◽  
Spatially Resolved ◽  
Spatial Profiling ◽  
Host Signaling ◽  
Infected Cells ◽  
Spatial Locations

Upon transmission to the human host, Plasmodium sporozoites exit the skin, are taken up by the blood stream, and then travel to the liver where they infect and significantly modify a single hepatocyte. Low infection rates within the liver have made proteomic studies of infected hepatocytes challenging, particularly in vivo, and existing studies have been largely unable to consider how protein and phosphoprotein differences are altered at different spatial locations within the heterogeneous liver. Using digital spatial profiling, we characterized changes in host signaling during Plasmodium yoelii infection in vivo without disrupting the liver tissue. Moreover, we measured alterations in protein expression around infected hepatocytes and identified a subset of CD163+ Kupffer cells that migrate towards infected cells during infection. These data offer the first insight into the heterogeneous microenvironment that surrounds the infected hepatocyte and provide insights into how the parasite may alter its milieu to influence its survival and modulate immunity.

scholarly journals Seeing the Light: The Use of Zebrafish for Optogenetic Studies of the Heart

2021 ◽  
Vol 12 ◽  
Author(s):  
Jonathan S. Baillie ◽  
Matthew R. Stoyek ◽  
T. Alexander Quinn
Keyword(s):  
Experimental Model ◽  
Optical Measurement ◽  
Cardiac Activity ◽  
Experimental Models ◽  
Spatially Resolved ◽  
And Control ◽  
Spatiotemporal Control ◽  
Insight Into

Optogenetics, involving the optical measurement and manipulation of cellular activity with genetically encoded light-sensitive proteins (“reporters” and “actuators”), is a powerful experimental technique for probing (patho-)physiological function. Originally developed as a tool for neuroscience, it has now been utilized in cardiac research for over a decade, providing novel insight into the electrophysiology of the healthy and diseased heart. Among the pioneering cardiac applications of optogenetic actuators were studies in zebrafish, which first demonstrated their use for precise spatiotemporal control of cardiac activity. Zebrafish were also adopted early as an experimental model for the use of optogenetic reporters, including genetically encoded voltage- and calcium-sensitive indicators. Beyond optogenetic studies, zebrafish are becoming an increasingly important tool for cardiac research, as they combine many of the advantages of integrative and reduced experimental models. The zebrafish has striking genetic and functional cardiac similarities to that of mammals, its genome is fully sequenced and can be modified using standard techniques, it has been used to recapitulate a variety of cardiac diseases, and it allows for high-throughput investigations. For optogenetic studies, zebrafish provide additional advantages, as the whole zebrafish heart can be visualized and interrogated in vivo in the transparent, externally developing embryo, and the relatively small adult heart allows for in situ cell-specific observation and control not possible in mammals. With the advent of increasingly sophisticated fluorescence imaging approaches and methods for spatially-resolved light stimulation in the heart, the zebrafish represents an experimental model with unrealized potential for cardiac optogenetic studies. In this review we summarize the use of zebrafish for optogenetic investigations in the heart, highlighting their specific advantages and limitations, and their potential for future cardiac research.

scholarly journals Spatial heterogeneity of the immune compartment within the lungs of critical COVID-19 patients

2021 ◽  
Vol 2 (4) ◽  
Author(s):  
Amy Cross
Keyword(s):  
In Situ Hybridisation ◽  
Severe Infection ◽  
Spatial Separation ◽  
Spatially Resolved ◽  
Spatial Profiling ◽  
Cancer Transcriptome ◽  
Tcr Activation ◽  
Interferon Gamma Response ◽  
Viral Nucleocapsid

Cross AR, Sansom S, Roberts I, Cerundolo L, Melero I, De Andrea C, Landecho MF, Klenerman P,Hester J, Issa F Acute respiratory distress syndrome (ARDS) is a defining feature of severe infection with theSARS-CoV-2 virus. Approaches to understand the immune response during COVID-19 are largelyconfined to characterisation of circulating leukocytes, however this approach excludes the mostrelevant cells that are active at the site of infection and injury. The aim of this study was to characterise the immune landscape across the lungs of COVID-19patients. Lung samples from three critical COVID-19 patients were assessed for histopathology,viral load, and distribution using qPCR, in situ hybridisation and immunohistochemistry.Leukocyte distribution was then assessed, and the transcript profile of selected areas examinedagainst the >1800 genes in the Cancer Transcriptome Atlas panel on the NanoString GeoMxDigital Spatial Profiling platform. Lung samples exhibited a spectrum of typical COVID-19 pathology with diffuse alveolar damageconsistent with hyaline membrane and type II pneumocyte hyperplasia, interstitialinflammation, organising pneumonia and thrombi. All tissues tested positive for SARS-CoV-2RNA using qPCR, whilst spatially resolved techniques revealed only few and sparsely distributedcells carrying the viral nucleocapsid protein. Multiplexed immunofluorescence for lymphocytes(CD3+) and macrophages (CD68+) was used to select areas of immune enrichment for spatialtranscriptomic profiling. These targeted analyses highlighted functional pathways involved inthe interferon gamma response, TCR activation and antigen presentation. Comparison acrossimmune-enriched areas identified a heterogeneity in lung infiltrates with spatial separation ofchemokine and complement production. Our data identify pathological immune pathways thatare amenable to therapeutic intervention in critical disease.

scholarly journals Vaccinia Virus Infection during Murine Pregnancy: a New Pathogenesis Model for Vaccinia Fetalis

2004 ◽  
Vol 78 (6) ◽  
pp. 3133-3139 ◽  
Author(s):  
Nicola Benning ◽  
Daniel E. Hassett
Keyword(s):  
Vaccinia Virus ◽  
Virus Infections ◽  
Fatal Complication ◽  
Vertical Transfer ◽  
Maternal Infections ◽  
Acute Viral Infection ◽  
Infected Cells ◽  
Murine Pregnancy

ABSTRACT Vaccinia fetalis, the vertical transfer of vaccinia virus from mother to fetus, is a relatively rare but often fatal complication of primary vaccinia virus vaccination during pregnancy. To date there has been no attempt to develop an animal model to study the pathogenesis of this acute viral infection in vivo. Here we report that infection of gestating BALB/c mice by either intravenous or intraperitoneal routes with the Western Reserve strain of vaccinia virus results in the rapid colonization of the placenta and vertical transfer of virus to the developing fetus. Systemic maternal infections during gestation lead to the death of all offspring prior to or very shortly after birth. Using in situ hybridization for vaccinia virus mRNA to identify infected cells, we show that the virus initially colonizes cells lining maternal lacunae within the trophospongium layer of the placenta. The study of this model will significantly enhance our understanding of the pathogenesis of fetal vaccinia virus infections and aid in the development of effective treatments designed to reduce the risk of vaccinia virus-associated complications during pregnancy.

scholarly journals Strong Replication Interference Between Hepatitis Delta Viruses in Human Liver Chimeric Mice

2021 ◽  
Vol 12 ◽  
Author(s):  
Katja Giersch ◽  
Lennart Hermanussen ◽  
Tassilo Volz ◽  
Annika Volmari ◽  
Lena Allweiss ◽  
...  
Keyword(s):  
Human Liver ◽  
Sequence Divergence ◽  
Chimeric Mice ◽  
Hepatitis D ◽  
Viral Interference ◽  
B Virus ◽  
Infected Cells ◽  
Super Infection

BackgroundHepatitis D Virus (HDV) is classified into eight genotypes with distinct clinical outcomes. Despite the maintenance of highly conserved functional motifs, it is unknown whether sequence divergence between genotypes, such as HDV-1 and HDV-3, or viral interference mechanisms may affect co-infection in the same host and cell, thus hindering the development of HDV inter-genotypic recombinants. We aimed to investigate virological differences of HDV-1 and HDV-3 and assessed their capacity to infect and replicate within the same liver and human hepatocyte in vivo.MethodsHuman liver chimeric mice were infected with hepatitis B virus (HBV) and with one of the two HDV genotypes or with HDV-1 and HDV-3 simultaneously. In a second set of experiments, HBV-infected mice were first infected with HDV-1 and after 9 weeks with HDV-3, or vice versa. Also two distinct HDV-1 strains were used to infect mice simultaneously and sequentially. Virological parameters were determined by strain-specific qRT-PCR, RNA in situ hybridization and immunofluorescence staining.ResultsHBV/HDV co-infection studies indicated faster spreading kinetics and higher intrahepatic levels of HDV-3 compared to HDV-1. In mice that simultaneously received both HDV strains, HDV-3 became the dominant genotype. Interestingly, antigenomic HDV-1 and HDV-3 RNA were detected within the same liver but hardly within the same cell. Surprisingly, sequential super-infection experiments revealed a clear dominance of the HDV strain that was inoculated first, indicating that HDV-infected cells may acquire resistance to super-infection.ConclusionInfection with two largely divergent HDV genotypes could be established in the same liver, but rarely within the same hepatocyte. Sequential super-infection with distinct HDV genotypes and even with two HDV-1 isolates was strongly impaired, suggesting that virus interference mechanisms hamper productive replication in the same cell and hence recombination events even in a system lacking adaptive immune responses.

In vitro and in vivo polysaccharides assembly: ultrastructural and cytochemical study of growing plant cell wall components.

1978 ◽  
Vol 36 (2) ◽  
pp. 434-435
Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland
Keyword(s):  
Cell Wall ◽  
Self Assembly ◽  
Plant Cell Wall ◽  
Higher Plants ◽  
Three Dimensional ◽  
Cytochemical Study ◽  
Wall Components

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.

FT-IR microspectroscopic analysis of diseased white matter brain tissues

1995 ◽  
Vol 53 ◽  
pp. 968-969
Author(s):  
Steven M. Le Vine ◽  
David L. Wetzel
Keyword(s):  
White Matter ◽  
Gray Matter ◽  
Twitcher Mouse ◽  
Grid Pattern ◽  
Marked Contrast ◽  
Spatially Resolved ◽  
Ft Ir ◽  
Ir Microspectroscopy ◽  
Chemical Evidence

In situ FT-IR microspectroscopy has allowed spatially resolved interrogation of different parts of brain tissue. In previous work the spectrrscopic features of normal barin tissue were characterized. The white matter, gray matter and basal ganglia were mapped from appropriate peak area measurements from spectra obtained in a grid pattern. Bands prevalent in white matter were mostly associated with the lipid. These included 2927 and 1469 cm-1 due to CH2 as well as carbonyl at 1740 cm-1. Also 1235 and 1085 cm-1 due to phospholipid and galactocerebroside, respectively (Figs 1and2). Localized chemical changes in the white matter as a result of white matter diseases have been studied. This involved the documentation of localized chemical evidence of demyelination in shiverer mice in which the spectra of white matter lacked the marked contrast between it and gray matter exhibited in the white matter of normal mice (Fig. 3).The twitcher mouse, a model of Krabbe’s desease, was also studied. The purpose in this case was to look for a localized build-up of psychosine in the white matter caused by deficiencies in the enzyme responsible for its breakdown under normal conditions.

Three-Dimensional Subcellular Organization of Hepatocytes in Intact Liver: Simultaneous Visualization of Cytoskeletal and Membrane Markers by Confocal Microscopy

1996 ◽  
Vol 54 ◽  
pp. 288-289
Author(s):  
Greg V. Martin ◽  
Ann L. Hubbard
Keyword(s):  
Three Dimensional ◽  
Integral Membrane Proteins ◽  
Polarized Secretion ◽  
Microscope Images ◽  
Computer Aided ◽  
Intracellular Organelles ◽  
Cytoskeletal Elements ◽  
Simultaneous Visualization

The microtubule (MT) cytoskeleton is necessary for many of the polarized functions of hepatocytes. Among the functions dependent on the MT-based cytoskeleton are polarized secretion of proteins, delivery of endocytosed material to lysosomes, and transcytosis of integral plasma membrane (PM) proteins. Although microtubules have been shown to be crucial to the establishment and maintenance of functional and structural polarization in the hepatocyte, little is known about the architecture of the hepatocyte MT cytoskeleton in vivo, particularly with regard to its relationship to PM domains and membranous organelles. Using an in situ extraction technique that preserves both microtubules and cellular membranes, we have developed a protocol for immunofluorescent co-localization of cytoskeletal elements and integral membrane proteins within 20 µm cryosections of fixed rat liver. Computer-aided 3D reconstruction of multi-spectral confocal microscope images was used to visualize the spatial relationships among the MT cytoskeleton, PM domains and intracellular organelles.

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