scholarly journals The multiplicity of infection does not affect interactions between Cryptococcus neoformans and macrophages

2020 ◽  
Author(s):  
Katherine Pline ◽  
Simon Johnston
Keyword(s):  
Cryptococcus Neoformans ◽  
Human Monocyte ◽  
Time Lapse ◽  
Cryptococcal Infection ◽  
Murine Cell Line ◽  
Time Lapse Imaging ◽  
Dose Dependent ◽  
Extracellular Environment ◽  
Phagocytic Response

SummaryMajor determinants of the outcome of infection include growth of the pathogen and response of immune cells such as macrophages. Cryptococcus neoformans is a fungal pathogen which may grow within the extracellular environment, or may exploit host macrophages as a niche for replication and dissemination. The clinical outcome of cryptococcal infection varies widely between individuals even when key host and pathogen molecular factors are the same. For a broad range of infections altering pathogen density is known to influence progression and outcome of infection by affecting immune response and pathogen biology (e.g. via innate immune signalling or microbial quorum sensing). Here, using time lapse imaging of murine cell line and human primary macrophages in vitro, we examined the effect of altering pathogen density on the interactions of macrophages with cryptococci. We find that increasing fungal burden over several orders of magnitude did not increase or decrease phagocytosis by murine J774 macrophage-like cells or human monocyte-derived macrophages, illustrating neither dose-dependent immune activation nor dampening of the phagocytic response. Furthermore, increasing fungal density alone was not sufficient to alter the ability of cryptococci to grow intracellularly and has no significant effect on fungal doubling time for cryptococci that were intracellular or extracellular. This suggested that individual macrophage-Cryptococcus interactions were not affected by even large changes in fungal density, an important finding in understanding what determines the outcome of cryptococcal infection.

scholarly journals Antifungal activity of dendritic cell lysosomal proteins against Cryptococcus neoformans

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Benjamin N. Nelson ◽  
Savannah G. Beakley ◽  
Sierra Posey ◽  
Brittney Conn ◽  
Emma Maritz ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Cryptococcus Neoformans ◽  
Mammalian Cells ◽  
Cysteine Proteases ◽  
Dependent Manner ◽  
Life Threatening ◽  
Opportunistic Fungal Pathogen ◽  
Dose Dependent ◽  
Lysosomal Proteins

AbstractCryptococcal meningitis is a life-threatening disease among immune compromised individuals that is caused by the opportunistic fungal pathogen Cryptococcus neoformans. Previous studies have shown that the fungus is phagocytosed by dendritic cells (DCs) and trafficked to the lysosome where it is killed by both oxidative and non-oxidative mechanisms. While certain molecules from the lysosome are known to kill or inhibit the growth of C. neoformans, the lysosome is an organelle containing many different proteins and enzymes that are designed to degrade phagocytosed material. We hypothesized that multiple lysosomal components, including cysteine proteases and antimicrobial peptides, could inhibit the growth of C. neoformans. Our study identified the contents of the DC lysosome and examined the anti-cryptococcal properties of different proteins found within the lysosome. Results showed several DC lysosomal proteins affected the growth of C. neoformans in vitro. The proteins that killed or inhibited the fungus did so in a dose-dependent manner. Furthermore, the concentration of protein needed for cryptococcal inhibition was found to be non-cytotoxic to mammalian cells. These data show that many DC lysosomal proteins have antifungal activity and have potential as immune-based therapeutics.

scholarly journals Live-cell time-lapse imaging and single-cell tracking of in vitro cultured neural stem cells – Tools for analyzing dynamics of cell cycle, migration, and lineage selection

Methods ◽  
2018 ◽  
Vol 133 ◽  
pp. 81-90 ◽  
Author(s):  
Katja M. Piltti ◽  
Brian J. Cummings ◽  
Krystal Carta ◽  
Ayla Manughian-Peter ◽  
Colleen L. Worne ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Neural Stem Cells ◽  
Single Cell ◽  
Cell Tracking ◽  
Time Lapse ◽  
Live Cell ◽  
Time Lapse Imaging

scholarly journals In Vitro Comparative Efficacy of Voriconazole and Itraconazole against Fluconazole-Susceptible and -Resistant Cryptococcus neoformans Isolates

1998 ◽  
Vol 42 (2) ◽  
pp. 471-472 ◽  
Author(s):  
M. Hong Nguyen ◽  
Christine Y. Yu
Keyword(s):  
Cryptococcus Neoformans ◽  
Susceptibility Testing ◽  
Clinical Isolates ◽  
Comparative Efficacy ◽  
In Vitro Susceptibility ◽  
In Vitro Susceptibility Testing ◽  
Fluconazole Resistant ◽  
Dose Dependent

ABSTRACT In vitro susceptibility testing for 50 clinical isolates of fluconazole-susceptible or -resistant Cryptococcus neoformans was performed with itraconazole and voriconazole. Voriconazole was more potent than itraconazole for fluconazole-susceptible isolates and as potent as itraconazole for fluconazole-susceptible dose-dependent isolates and for fluconazole-resistant isolates. For fluconazole-resistant isolates, the voriconazole and itraconazole MICs ranged from 1 to 2 μg/ml.

Timing of cleavage divisions determined with time-lapse imaging is linked to blastocyst formation rates and quality of in vitro-produced ovine embryos

2021 ◽  
Vol 159 ◽  
pp. 147-152
Author(s):  
Karolina Fryc ◽  
Agnieszka Nowak ◽  
Barbara Kij ◽  
Joanna Kochan ◽  
Pawel M. Bartlewski ◽  
...  
Keyword(s):  
Time Lapse ◽  
Blastocyst Formation ◽  
Time Lapse Imaging

Use of time-lapse imaging to evaluate morphokinetics of in vitro equine blastocyst development after oocyte holding for two days at 15°C versus room temperature before intracytoplasmic sperm injection

2019 ◽  
Vol 31 (12) ◽  
pp. 1862 ◽  
Author(s):  
N. A. Martino ◽  
G. Marzano ◽  
A. Mastrorocco ◽  
G. M. Lacalandra ◽  
L. Vincenti ◽  
...  
Keyword(s):  
Embryo Development ◽  
Intracytoplasmic Sperm Injection ◽  
Room Temperature ◽  
Time Lapse ◽  
Blastocyst Stage ◽  
Blastocyst Development ◽  
Cell Stage ◽  
Group 13 ◽  
Time Lapse Imaging

Time-lapse imaging was used to establish the morphokinetics of equine embryo development to the blastocyst stage after invitro oocyte maturation (IVM), intracytoplasmic sperm injection (ICSI) and embryo culture, in oocytes held overnight at room temperature (22–27°C; standard conditions) before IVM. Embryos that developed to the blastocyst stage underwent precleavage cytoplasmic extrusion and cleavage to the 2-, 3- and 4-cell stages significantly earlier than did embryos that arrested in development. We then determined the rate of blastocyst formation after ICSI in oocytes held for 2 days at either 15°C or room temperature before IVM (15-2d and RT-2d treatment groups respectively). The blastocyst development rate was significantly higher in the 15-2d than in the RT-2d group (13% vs 0% respectively). The failure of blastocyst development in the RT-2d group precluded comparison of morphokinetics of blastocyst development between treatments. In any condition examined, development to the blastocyst stage was characterised by earlier cytoplasmic extrusion before cleavage, earlier cleavage to 2- and 4-cell stages and reduced duration at the 2-cell stage compared with non-competent embryos. In conclusion, this study presents morphokinetic parameters predictive of embryo development invitro to the blastocyst stage after ICSI in the horse. We conclude that time-lapse imaging allows increased precision for evaluating effects of different treatments on equine embryo development.

scholarly journals Sindbis Virus-Induced Neuronal Death Is both Necrotic and Apoptotic and Is Ameliorated byN-Methyl-d-Aspartate Receptor Antagonists

2001 ◽  
Vol 75 (15) ◽  
pp. 7114-7121 ◽  
Author(s):  
Jennifer L. Nargi-Aizenman ◽  
Diane E. Griffin
Keyword(s):  
Cell Death ◽  
Cortical Neurons ◽  
Sindbis Virus ◽  
Apoptotic Cell ◽  
Time Lapse ◽  
Apoptotic Cell Death ◽  
Time Lapse Imaging ◽  
Alphavirus Infection

ABSTRACT Virus infection of neurons leads to different outcomes ranging from latent and noncytolytic infection to cell death. Viruses kill neurons directly by inducing either apoptosis or necrosis or indirectly as a result of the host immune response. Sindbis virus (SV) is an alphavirus that induces apoptotic cell death both in vitro and in vivo. However, apoptotic changes are not always evident in neurons induced to die by alphavirus infection. Time lapse imaging revealed that SV-infected primary cortical neurons exhibited both apoptotic and necrotic morphological features and that uninfected neurons in the cultures also died. Antagonists of the N-methyl-d-aspartate (NMDA) subtype of glutamate receptors protected neurons from SV-induced death without affecting virus replication or SV-induced apoptotic cell death. These results provide evidence that SV infection activates neurotoxic pathways that result in aberrant NMDA receptor stimulation and damage to infected and uninfected neurons.

scholarly journals Temporal Kinetics and Quantitative Analysis of Cryptococcus neoformans Nonlytic Exocytosis

2014 ◽  
Vol 82 (5) ◽  
pp. 2059-2067 ◽  
Author(s):  
Sabriya A. Stukes ◽  
Hillel W. Cohen ◽  
Arturo Casadevall
Keyword(s):  
Cryptococcus Neoformans ◽  
Time Lapse ◽  
Host Cells ◽  
Type I ◽  
Phagocytic Cells ◽  
Macrophage Infection ◽  
Content Type ◽  
Type Iii ◽  
Cell To Cell Transfer ◽  
Extracellular Environment

ABSTRACTCryptococcus neoformansis a facultative intracellular pathogen and the causative agent of cryptococcosis, a disease that is often fatal to those with compromised immune systems.C. neoformanshas the capacity to escape phagocytic cells through a process known as nonlytic exocytosis whereby the cryptococcal cell is released from the macrophage into the extracellular environment, leaving both the host and pathogen alive. Little is known about the mechanism behind nonlytic exocytosis, but there is evidence that both the fungal and host cells contribute to the process. In this study, we used time-lapse movies ofC. neoformans-infected macrophages to delineate the kinetics and quantitative aspects of nonlytic exocytosis. We analyzed approximately 800 macrophages containing intracellularC. neoformansand identified 163 nonlytic exocytosis events that were further characterized into three subcategories: type I (complete emptying of macrophage), type II (partial emptying of macrophage), and type III (cell-to-cell transfer). The majority of type I and II events occurred after several hours of intracellular residence, whereas type III events occurred significantly (P< 0.001) earlier in the course of macrophage infection. Our results show that nonlytic exocytosis is a morphologically and temporally diverse process that occurs relatively rapidly in the course of macrophage infection.

scholarly journals Migration of immortalized nasopharyngeal epithelia and carcinoma cells through porous membrane in 3D platforms

2020 ◽  
Vol 40 (6) ◽  
Author(s):  
Ziyu Liu ◽  
Weiguan Zhang ◽  
Stella W. Pang
Keyword(s):  
Cell Migration ◽  
Nasopharyngeal Carcinoma ◽  
Cell Line ◽  
Time Lapse ◽  
Porous Membrane ◽  
Epithelial Cell Line ◽  
3D Microenvironment ◽  
Porous Interface ◽  
Time Lapse Imaging

Abstract In the present study, 3D biomimetic platforms were fabricated with guiding grating to mimic extracellular matrix topography, porous membrane to resemble the epithelial porous interface and trenches below to represent blood vessels as an in vitro tissue microenvironment. Fabrication technologies were developed to integrate the transparent biocompatible polydimethylsiloxane platforms with preciously controlled dimensions. Cell migration behaviors of an immortalized nasopharyngeal epithelial cell line (NP460) and a nasopharyngeal carcinoma cell line (NPC43) were studied on the 2D and 3D platforms. The NP460 and NPC43 cells traversing through the porous membrane and migrating in the trenches below were studied by time-lapse imaging. Before traversing through the pores, NP460 and NPC43 cells migrated around the pores but NPC43 cells had a lower migration speed with less lamellipodia spreading. After traversing to trenches below, NPC43 cells moved faster with an alternated elongated morphology (mesenchymal migration mode) and round morphology (amoeboid migration mode) compared with only mesenchymal migration mode for NP460 cells. The cell traversing probability through porous membrane on platforms with 30 μm wide trenches below was found to be the highest when the guiding grating was perpendicular to the trenches below and the lowest when the guiding grating was parallel to the trenches below. The present study shows important information on cell migration in complex 3D microenvironment with various dimensions and could provide insight for pathology and treatment of nasopharyngeal carcinoma.

Time-lapse imaging: the state of the art†

2019 ◽  
Vol 101 (6) ◽  
pp. 1146-1154 ◽  
Author(s):  
Raquel Del Gallego ◽  
José Remohí ◽  
Marcos Meseguer
Keyword(s):  
Embryo Development ◽  
Clinical Success ◽  
Time Lapse ◽  
Embryo Cell ◽  
Cell Dynamics ◽  
Vitro Fertilization ◽  
Cycle Lengths ◽  
Novel Concept ◽  
Time Lapse Imaging

Abstract The introduction of time-lapse imaging to clinical in vitro fertilization practice enabled the undisturbed monitoring of embryos throughout the entire culture period. Initially, the main objective was to achieve a better embryo development. However, this technology also provided an insight into the novel concept of morphokinetics, parameters regarding embryo cell dynamics. The vast amount of data obtained defined the optimal ranges in the cell-cycle lengths at different stages of embryo development. This added valuable information to embryo assessment prior to transfer. Kinetic markers became part of embryo evaluation strategies with the potential to increase the chances of clinical success. However, none of them has been established as an international standard. The present work aims at describing new approaches into time-lapse: progress to date, challenges, and possible future directions.

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