scholarly journals Astrocyte Infection during Rabies Encephalitis Depends on the Virus Strain and Infection Route as Demonstrated by Novel Quantitative 3D Analysis of Cell Tropism

Cells ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 412 ◽  
Author(s):  
Madlin Potratz ◽  
Luca Zaeck ◽  
Michael Christen ◽  
Verena te Kamp ◽  
Antonia Klein ◽  
...  
Keyword(s):  
3D Analysis ◽  
Cell Tropism ◽  
3D Segmentation ◽  
Tissue Slices ◽  
High Preference ◽  
Field Virus ◽  
Inoculation Route ◽  
Highly Virulent

Although conventional immunohistochemistry for neurotropic rabies virus (RABV) usually shows high preference for neurons, non-neuronal cells are also potential targets, and abortive astrocyte infection is considered a main trigger of innate immunity in the CNS. While in vitro studies indicated differences between field and less virulent lab-adapted RABVs, a systematic, quantitative comparison of astrocyte tropism in vivo is lacking. Here, solvent-based tissue clearing was used to measure RABV cell tropism in infected brains. Immunofluorescence analysis of 1 mm-thick tissue slices enabled 3D-segmentation and quantification of astrocyte and neuron infection frequencies. Comparison of three highly virulent field virus clones from fox, dog, and raccoon with three lab-adapted strains revealed remarkable differences in the ability to infect astrocytes in vivo. While all viruses and infection routes led to neuron infection frequencies between 7–19%, striking differences appeared for astrocytes. Whereas astrocyte infection by field viruses was detected independent of the inoculation route (8–27%), only one lab-adapted strain infected astrocytes route-dependently [0% after intramuscular (i.m.) and 13% after intracerebral (i.c.) inoculation]. Two lab-adapted vaccine viruses lacked astrocyte infection altogether (0%, i.c. and i.m.). This suggests a model in which the ability to establish productive astrocyte infection in vivo functionally distinguishes field and attenuated lab RABV strains.

scholarly journals Astrocyte Infection during Rabies Encephalitis Depends on the Virus Strain and Infection Route as Demonstrated by Novel Quantitative 3D Analysis of Cell Tropism

2020 ◽  
Author(s):  
Madlin Potratz ◽  
Luca Zaeck ◽  
Michael Christen ◽  
Verena teKamp ◽  
Antonia Klein ◽  
...  
Keyword(s):  
Target Cells ◽  
3D Analysis ◽  
Cell Tropism ◽  
Tissue Slices ◽  
High Preference ◽  
Clearing Technique ◽  
Inoculation Route ◽  
Highly Virulent

Although conventional immunohistochemistry for neurotropic Rabies virus (RABV) usually shows a high preference for neurons, non-neuronal cells are also potential target cells and abortive infection of astrocytes is considered a main trigger of innate immunity in the CNS. While in vitro studies indicated differences between field and less virulent lab-adapted RABVs, a systematic and quantitative comparison of astrocyte tropism in vivo is lacking. Here, a recently developed solvent-based tissue clearing technique was used to measure the RABV cell tropism in infected brains. Immunofluorescence analysis of 1 mm-thick tissue slices enabled 3D segmentation and quantification of infection frequencies of astrocytes and neurons. Comparison of highly virulent street virus clones from fox, dog, and raccoon with three lab strains of intermediate and low virulence revealed remarkable differences in the ability to infect astrocytes in vivo. While all viruses and infection routes led to comparable neuron infection frequencies, striking differences were detected for the infection of astrocytes. Consistent and inoculation route-independent astrocyte infection by field viruses, together with route-dependent or undetectable astrocyte infection by lab-adapted or vaccine viruses strongly suggests a model in which the ability to establish productive astrocyte infection in vivo functionally distinguishes field and attenuated lab RABV strains.

Investigation of the Thermal and Injury Behavior During Microwave Thermal Therapy of Porcine Kidney

2002 ◽  
Author(s):  
Xiaoming He ◽  
Shawn Mcgee ◽  
James E. Coad ◽  
Paul A. Iaizzo ◽  
David J. Swanlund ◽  
...  
Keyword(s):  
Thermal Model ◽  
Histological Study ◽  
Kidney Cortex ◽  
Cellular Injury ◽  
Bioheat Equation ◽  
Tissue Slices ◽  
Thermal Histories ◽  
Microwave Probe

In this paper, we report on the characterization of microwave therapy of normal porcine kidneys both in vitro and in vivo. This technology is being developed for eventual use in the treatment of small renal cell carcinoma (RCC) by minimally invasive procedures. During experiments, microwave energy was applied through an interstitial microwave probe (Urologix, Plymouth, MN) to the kidney cortex with occasional involvement of the kidney medulla. The thermal histories at several locations were recorded. After treatment, the kidneys were bisected and small tissue slices were cut out at approximately the same depth as the thermal probes. The tissue slices were further processed for histological study. Both cellular injury and the area of microvascular stasis were quantitatively evaluated by histology. Absolute rate kinetic models of cellular injury and vascular stasis were developed and fit to this data. A 3-D finite element thermal model based on the Pennes Bioheat equation was developed and solved using a commercial software package (ANSYS, V5.7). The Specific Absorption Rate (SAR) of the microwave probe was measured experimentally in tissue equivalent gel-like solution. The thermal model was first validated by the measured in vitro thermal histories. It was then used to determine the blood perfusion term in vivo.

Surfactant metabolism in surfactant protein A-deficient mice

1997 ◽  
Vol 272 (3) ◽  
pp. L479-L485 ◽  
Author(s):  
M. Ikegami ◽  
T. R. Korfhagen ◽  
M. D. Bruno ◽  
J. A. Whitsett ◽  
A. H. Jobe
Keyword(s):  
Lung Tissue ◽  
Protein A ◽  
Surfactant Protein ◽  
Normal Lung ◽  
Tissue Slices ◽  
Normal Lung Function ◽  
Deficient Mice ◽  
Surfactant Metabolism

In the present study we asked if surfactant metabolism was altered in surfactant protein (SP) A-deficient mice in vivo. Although previous studies in vitro demonstrated that SP-A modulates surfactant secretion and reuptake by type II cells, mice made SP-A deficient by homologous recombination grow and reproduce normally and have normal lung function. Alveolar and lung tissue saturated phophatidylcholine (Sat PC) pools were 50 and 26% larger, respectively, in SP-A(-/-) mice than in SP-A(+/+) mice. Radiolabeled choline and palmitate incorporation into lung Sat PC was similar both in vivo and for lung tissue slices in vitro from SP-A(+/+) and SP-A(-/-) mice. Percent secretion of radiolabeled Sat PC was unchanged from 3 to 15 h, although SP-A(-/-) mice retained more labeled Sat PC in the alveolar lavages at 48 h (consistent with the increased surfactant pool sizes). Clearance of radiolabeled dipalmitoylphosphatidylcholine and SP-B from the air spaces after intratracheal injection was similar in SP-A(-/-) and SP-A(+/+) mice. Lack of SP-A had minimal effects on the overall metabolism of Sat PC or SP-B in mice.

Strontium-Loaded Nanotubes of Ti–24Nb–4Zr–8Sn Alloys for Biomedical Implantation

2021 ◽  
Vol 17 (9) ◽  
pp. 1812-1823
Author(s):  
Fei Liu ◽  
Xinyu Wang ◽  
Shujun Li ◽  
Yiheng Liao ◽  
Xinxin Zhan ◽  
...  
Keyword(s):  
Early Stage ◽  
Contact Rate ◽  
Hard Tissue ◽  
Tissue Slices ◽  
Bone Implant ◽  
P Elements ◽  
Low Elastic Modulus ◽  
Bone Implant Contact

Ti–24Nb–4Zr–8Sn (Ti2448) alloys, with a relatively low elastic modulus and unique mechanical properties, are desirable materials for oral implantation. In the current study, a multifaceted strontium-incorporating nanotube coating was fabricated on a Ti2448 alloy (Ti2-NTSr) through anodization and hydrothermal procedures. In vitro, the Ti2-NTSr specimens demonstrated better osteogenic properties and more favorable osteoimmunomodulatory abilities. Moreover, macrophages on Ti2-NTSr specimens could improve the recruitment and osteogenic differentiation of osteoblasts. In vivo, dense clots with highly branched, thin fibrins and small pores existed on the Ti2-NTSr implant in the early stage after surgery. Analysis of the deposition of Ca and P elements, hard tissue slices and the bone-implant contact rate (BIC%) of the Ti2-NTSr implants also showed superior osseointegration. Taken together, these results demonstrate that the Ti2-NTSr coating may maximize the clinical outcomes of Ti2448 alloys for implantation applications.

scholarly journals Human Cytomegalovirus Cell Tropism and Host Cell Receptors

Vaccines ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 70 ◽  
Author(s):  
Gerna ◽  
Kabanova ◽  
Lilleri
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Epithelial Cells ◽  
Human Cytomegalovirus ◽  
Current Data ◽  
Immunosuppressed Patient ◽  
Cell Tropism ◽  
Virus Envelope

In the 1970s–1980s, a striking increase in the number of disseminated human cytomegalovirus (HCMV) infections occurred in immunosuppressed patient populations. Autopsy findings documented the in vivo disseminated infection (besides fibroblasts) of epithelial cells, endothelial cells, and polymorphonuclear leukocytes. As a result, multiple diagnostic assays, such as quantification of HCMV antigenemia (pp65), viremia (infectious virus), and DNAemia (HCMV DNA) in patient blood, were developed. In vitro experiments showed that only low passage or endothelial cell-passaged clinical isolates, and not laboratory-adapted strains, could reproduce both HCMV leuko- and endothelial cell-tropism, which were found through genetic analysis to require the three viral genes UL128, UL130, and UL131 of the HCMV UL128 locus (UL128L). Products of this locus, together with gH/gL, were shown to form the gH/gL/pUL128L pentamer complex (PC) required for infection of epithelial cells/endothelial cells, whereas gH/gL and gO form the gH/gL/gO trimer complex (TC) required for infection of all cell types. In 2016, following previous work, a receptor for the TC that mediates entry into fibroblasts was identified as PDGFRα, while in 2018, a receptor for the PC that mediates entry into endothelial/epithelial cells was identified as neuropilin2 (Nrp2). Furthermore, the olfactory receptor family member OR14I1 was recently identified as a possible additional receptor for the PC in epithelial cells. Thus, current data support two models of viral entry: (i) in fibroblasts, following interaction of PDGFRα with TC, the latter activates gB to fuse the virus envelope with the cell membrane, whereas (ii) in epithelial cells/endothelial cells, interaction of Nrp2 (and OR14I1) with PC promotes endocytosis of virus particles, followed by gB activation by gH/gL/gO (or gH/gL) and final low-pH entry into the cell.

Intercellular Invertase in Developing Peach Mesocarp

1988 ◽  
Vol 15 (3) ◽  
pp. 377 ◽  
Author(s):  
TD Ugalde ◽  
DJ Chalmers ◽  
PH Jerie
Keyword(s):  
Dry Matter ◽  
Prunus Persica ◽  
Total Activity ◽  
Insoluble Fraction ◽  
Acid Invertase ◽  
Dry Matter Accumulation ◽  
Tissue Slices ◽  
Insoluble Particles

Acid invertase (β-fructofuranosidase, EC 3.2.1.26) was extracted from peach mesocarp (Prunus persica (L.) Batsch) using a range of extraction conditions. The enzyme always was attached to insoluble particles in the crude homogenate and was bound by a mechanism that could not have arisen during extraction. The activity in the insoluble fraction made up (essentially) all of the total activity extracted from the tissue and was the same as the activity shown by whole tissue slices placed directly into the assay solution. These results demonstrate that most of the acid invertase in developing peach mesocarp is located outside the cell. The amount of this enzyme, as measured in vitro, did not change during development at times when the rate of dry matter increase was changing rapidly. Either the action of intercellular invertase is not associated with the control of dry matter accumulation in peach mesocarp, or control is effected through activity of the enzyme in vivo, not its synthesis or degradation.

scholarly journals Non-viral delivery of therapeutic microRNAs to glioma cells using chitosan nanocomplexes

2019 ◽  
Vol 21 (Supplement_4) ◽  
pp. iv16-iv16
Author(s):  
Marjorie Boissinot ◽  
Sarra Limam ◽  
Maria Collado-González ◽  
Yadira Gonzalez-Espinosa ◽  
Heiko Wurdak ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Positive Control ◽  
3D Analysis ◽  
Cellular Targets ◽  
Mature Microrna ◽  
Efficient Delivery ◽  
Wide Range ◽  
Reverse Transfection

Abstract One of the biggest challenges when treating brain tumours is achieving efficient delivery of therapeutic agents to the brain and more specifically to the cancer cells. MicroRNA-1300 was identified in our group as a very promising therapeutic microRNA given its cytotoxic effect when introduced in both established as well as cancer-stem-like patient-derived glioblastoma cultures, while not affecting differentiated glioblastoma cells. We are now collaborating to assess the potential efficiency of the natural biopolymer chitosan to form nanocomplexes containing the mature form of microRNA-1300 for delivery. Chitosan has been established as a highly attractive biocompatible polymer to deliver both in vitro and in vivo therapeutic nucleotides intracellularly. In previous studies, we have shown chitosan’s efficacy to form spherical nanocomplexes with microRNA and apply them to the downregulation of JAMA-A mRNA in MCF-7 breast cancer cells. Chitosan can also be chemically conjugated to introduce affinity towards a wide range of cellular targets (e.g. with aptamers). Methods We have optimised of the composition and characterised the biophysical properties of chitosan-microRNA nanocomplexes of varying (+/-) charge ratios using both a control nontargeting microRNA coupled to a fluorochrome (CS-miRdy547, efficiency of cell entry) and mature microRNA-1300 (CS-mi1300, efficient release and biological effect). We have tested the nanocomplexes in 2D monolayers and 3D spheroid cultures on established U251 as well as two patient-derived cultures. Reverse transfection was used as positive control. Results The control nanoparticles of CS-miRdy547 are taken up by the patient-derived cultures in 2D and 3D. Analysis is ongoing using the CS-miR-1300 nanoparticles.

scholarly journals Evolution of the Equine Infectious Anemia Virus Long Terminal Repeat during the Alteration of Cell Tropism

2005 ◽  
Vol 79 (9) ◽  
pp. 5653-5664 ◽  
Author(s):  
Wendy Maury ◽  
Robert J. Thompson ◽  
Quentin Jones ◽  
Sarahann Bradley ◽  
Tara Denke ◽  
...  
Keyword(s):  
Long Terminal Repeat ◽  
Equine Infectious Anemia Virus ◽  
Terminal Repeat ◽  
Binding Motif ◽  
Cell Tropism ◽  
Transcription Factor Binding Motif ◽  
Equine Infectious Anemia ◽  
Anemia Virus

ABSTRACT Equine infectious anemia virus (EIAV) is a lentivirus with in vivo cell tropism primarily for tissue macrophages; however, in vitro the virus can be adapted to fibroblasts and other cell types. Tropism adaptation is associated with both envelope and long terminal repeat (LTR) changes, and findings strongly suggest that these regions of the genome influence cell tropism and virulence. Furthermore, high levels of genetic variation have been well documented in both of these genomic regions. However, specific EIAV nucleotide or amino acid changes that are responsible for cell tropism changes have not been identified. A study was undertaken with the highly virulent, macrophage-tropic strain of virus EIAVwyo to identify LTR changes associated with alterations in cell tropism. We found the stepwise generation of a new transcription factor binding motif within the enhancer that was associated with adaptation of EIAV to endothelial cells and fibroblasts. An LTR that contained the new motif had enhanced transcriptional activity in fibroblasts, whereas the new site did not alter LTR activity in a macrophage cell line. This finding supports a previous prediction that selection for new LTR genetic variants may be a consequence of cell-specific selective pressures. Additional investigations of the EIAVwyo LTR were performed in vivo to determine if LTR evolution could be detected over the course of a 3-year infection. Consistent with previous in vivo findings, we observed no changes in the enhancer region of the LTR over that time period, indicating that the EIAVwyo LTR was evolutionarily stable in vivo.

In vitro and in vivo interactions between Erwinia amylovora and related saprophytic bacteria

1975 ◽  
Vol 21 (1) ◽  
pp. 35-41 ◽  
Author(s):  
J. M. Erskine ◽  
L. E. Lopatecki
Keyword(s):  
Erwinia Amylovora ◽  
Virulent Strain ◽  
Sucrose Concentration ◽  
Sugar Content ◽  
Susceptible Host ◽  
The Status ◽  
Highly Virulent ◽  
Host Tissues

Under carefully controlled laboratory conditions, a highly virulent strain of Erwinia amylovora coinhabited susceptible host tissues with a yellow saprophytic bacterium, which was invariably isolated from fire blight infected trees, with or without producing symptoms of the disease depending on the status of a number of environmental factors, both climatic and physiological. In particular, variation of temperature and sucrose concentration determined, independently, the equilibrium of a readily reversible alternation of predominance of the two bacteria.It is suggested that E. amylovora may sometimes exist as an avirulent resident on the surface or within healthy host plants when environmental conditions favor growth of the yellow saprophyte rather than the pathogen. Such conditions, which are more likely to be obtained in midsummer and the fall, include temperature fall or rise below or above the optimum for E. amylovora, decreased humidity or diminution of sap flow, and increased sugar content in the host tissues.

scholarly journals The site of cellulose synthesis. Hormone treatment alters the intracellular location of alkali-insoluble beta-1,4-glucan (cellulose) synthetase activities.

1975 ◽  
Vol 64 (3) ◽  
pp. 557-571 ◽  
Author(s):  
G Shore ◽  
G A Maclachlan
Keyword(s):  
Cell Structure ◽  
Hormone Treatment ◽  
Cellulose Synthesis ◽  
Marker Enzyme ◽  
Tissue Slices ◽  
Intact Cells ◽  
Intracellular Location ◽  
Sites Of Action

Membrane preparations from growing regions of 8-day old Pisum sativum epicotyls contain multiple beta-1,4-glucan (cellulose) synthetase activities (UDP- or GDP-glucose: beta-1,4-glucan-glucosyl transferase), and the levels of some of these are influenced by treatments with the growth hormone, indoleacetic acid (IAA). When membranes from control epicotyl segments (zero time) are fractionated by isopycnic sedimentation in sucrose density gradients, all of the synthetase activities are associated mainly with Golgi membrane (density 1.55 g/cm3). After decapitation and treatment of epicotyls with IAA, synthetases also appear in a smooth vesicle fraction (density 1.11 g/cm3) which is rich in endoplasmic reticulum (ER) marker enzyme. Major fractions of these synthetases are not recovered in association with plasma membrane or washed cell walls. When [14-C]sucrose is supplied in vivo to segments +/- IAA, radioactive cellulose is deposited only in the wall. Cellulose or cellodextrin precursors do not accumulate in those membranes in which synthetase activities are recovered in vitro. In experiments where tissue slices containing intact cells are supplied with [14C]sugar nucleotide in vitro, alkali-insoluble beta-1,4-glucan is synthesized (presumably outside the protoplast) at rates which greatly exceeded (20-30 times) those obtained using isolated membrane preparations. Progressive disruption of cell structure results in increasing losses of this high activity. These results are consistent with the interpretation that Golgi and ER-associated synthetases are not themselves loci for cellulose synthesis in vivo, but represent enzymes in transit to sites of action at the wall:protoplast omterface. There they operate only if integrity of cellular organization is maintained.

Sign in / Sign up

Export Citation Format

Share Document