scholarly journals HSF1 inhibition attenuates HIV-1 latency reversal mediated by several candidate LRAs In Vitro and Ex Vivo

2020 ◽  
Vol 117 (27) ◽  
pp. 15763-15771 ◽  
Author(s):  
Andrew Timmons ◽  
Emily Fray ◽  
Mithra Kumar ◽  
Fengting Wu ◽  
Weiwei Dai ◽  
...  
Keyword(s):  
High Throughput Screening ◽  
Ex Vivo ◽  
In Vitro Models ◽  
Model Systems ◽  
Heat Shock Factor 1 ◽  
Primary Cells ◽  
Major Barrier ◽  
Hiv 1 ◽  
In Cells

HIV-1 latency is a major barrier to cure. Identification of small molecules that destabilize latency and allow immune clearance of infected cells could lead to treatment-free remission. In vitro models of HIV-1 latency involving cell lines or primary cells have been developed for characterization of HIV-1 latency and high-throughput screening for latency-reversing agents (LRAs). We have shown that the majority of LRAs identified to date are relatively ineffective in cells from infected individuals despite activity in model systems. We show here that, for diverse LRAs, latency reversal observed in model systems involves a heat shock factor 1 (HSF1)-mediated stress pathway. Small-molecule inhibition of HSF1 attenuated HIV-1 latency reversal by histone deactylase inhibitors, protein kinase C agonists, and proteasome inhibitors without interfering with the known mechanism of action of these LRAs. However, latency reversal by second mitochondria-derived activator of caspase (SMAC) mimetics was not affected by inhibition of HSF1. In cells from infected individuals, inhibition of HSF1 attenuated latency reversal by phorbol ester+ionomycin but not by anti-CD3+anti-CD28. HSF1 promotes elongation of HIV-1 RNA by recruiting P-TEFb to the HIV-1 long terminal repeat (LTR), and we show that inhibition of HSF1 attenuates the formation of elongated HIV-1 transcripts. We demonstrate that in vitro models of latency have higher levels of the P-TEFb subunit cyclin T1 than primary cells, which may explain why many LRAs are functional in model systems but relatively ineffective in primary cells. Together, these studies provide insights into why particular LRA combinations are effective in reversing latency in cells from infected individuals.

scholarly journals Evaluation of HIV-1 latency reversal and antibody-dependent viral clearance by quantification of singly spliced HIV-1 vpu/env mRNA

2021 ◽  
Author(s):  
Hongbo Gao ◽  
Ayşe N. Ozantürk ◽  
Qiankun Wang ◽  
Gray H. Harlan ◽  
Aaron J. Schmitz ◽  
...  
Keyword(s):  
T Cells ◽  
Neutralizing Antibodies ◽  
Ex Vivo ◽  
Viral Envelope ◽  
Latent Reservoir ◽  
Broadly Neutralizing Antibodies ◽  
Major Barrier ◽  
Hiv 1 ◽  
Reversing Agents

The latent reservoir of HIV-1 is a major barrier for viral eradication. Potent HIV-1 broadly neutralizing antibodies (bNabs) have been used to prevent and treat HIV-1 infections in animal models and clinical trials. Combination of bNabs and latency-reversing agents (LRAs) is considered a promising approach for HIV-1 eradication. PCR-based assays that can rapidly and specifically measure singly spliced HIV-1 vpu/env mRNA are needed to evaluate the induction of the viral envelope production at the transcription level and bNab-mediated reservoir clearance. Here we reported a PCR-based method to accurately quantify the production of intracellular HIV-1 vpu/env mRNA. With the vpu/env assay, we determined the LRA combinations that could effectively induce vpu/env mRNA production in CD4+ T cells from ART-treated individuals. None of the tested LRAs were effective alone. A comparison between the quantitative viral outgrowth assay (Q-VOA) and the vpu/env assay showed that vpu/env mRNA production was closely associated with the reactivation of replication-competent HIV-1, suggesting that vpu/env mRNA was mainly produced by intact viruses. Finally, antibody-mediated in vitro killing in HIV-1-infected humanized mice demonstrated that the vpu/env assay could be used to measure the reduction of infected cells in tissues and was more accurate than the commonly used gag-based PCR assay which measured unspliced viral genomic RNA. In conclusion, the vpu/env assay allows convenient and accurate assessment of HIV-1 latency reversal and bNab-mediated therapeutic strategies. Importance HIV-1 persists in individuals on antiretroviral therapy (ART) due to the long-lived cellular reservoirs that contain dormant viruses. Recent discoveries of HIV-1-specific broadly neutralizing antibodies (bNabs) targeting HIV-1 Env protein rekindled the interest in antibody-mediated elimination of latent HIV-1. Latency-reversing agents (LRAs) together with HIV-1 bNabs is a possible strategy to clear residual viral reservoirs, which makes the evaluation of HIV-1 Env expression upon LRA treatment critical. We developed a PCR-based assay to quantify the production of intracellular HIV-1 vpu/env mRNA. Using patient CD4+ T cells, we found that induction of HIV-1 vpu/env mRNA required a combination of different LRAs. Using in vitro, ex vivo and humanized mouse models, we showed that the vpu/env assay could be used to measure antibody efficacy in clearing HIV-1 infection. These results suggest that the vpu/env assay can accurately evaluate HIV-1 reactivation and bNab-based therapeutic interventions.

scholarly journals Ex VivoBioactivity and HIV-1 Latency Reversal by Ingenol Dibenzoate and Panobinostat in Resting CD4+T Cells from Aviremic Patients

2015 ◽  
Vol 59 (10) ◽  
pp. 5984-5991 ◽  
Author(s):  
Adam M. Spivak ◽  
Alberto Bosque ◽  
Alfred H. Balch ◽  
David Smyth ◽  
Laura Martins ◽  
...  
Keyword(s):  
T Cells ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Ex Vivo ◽  
Viral Reactivation ◽  
Major Barrier ◽  
Kinase C ◽  
Wide Range ◽  
Hiv 1 ◽  
In Cells

ABSTRACTThe human immunodeficiency virus type 1 (HIV-1) latent reservoir in resting CD4+T cells represents a major barrier to viral eradication. Small compounds capable of latency reversal have not demonstrated uniform responses acrossin vitroHIV-1 latency cell models. Characterizing compounds that demonstrate latency-reversing activity in resting CD4+T cells from aviremic patientsex vivowill help inform pilot clinical trials aimed at HIV-1 eradication. We have optimized a rapidex vivoassay using resting CD4+T cells from aviremic HIV-1+patients to evaluate both the bioactivity and latency-reversing potential of candidate latency-reversing agents (LRAs). Using this assay, we characterize the properties of two candidate compounds from promising LRA classes, ingenol 3,20-dibenzoate (a protein kinase C agonist) and panobinostat (a histone deacetylase inhibitor), in cells from HIV-1+antiretroviral therapy (ART)-treated aviremic participants, including the effects on cellular activation and cytotoxicity. Ingenol induced viral release at levels similar to those of the positive control (CD3/28 receptor stimulation) in cells from a majority of participants and represents an exciting LRA candidate, as it combines a robust viral reactivation potential with a low toxicity profile. At concentrations that blocked histone deacetylation, panobinostat displayed a wide range of potency among participant samples and consistently induced significant levels of apoptosis. The protein kinase C agonist ingenol 3,20-dibenzoate demonstrated significant promise in a rapidex vivoassay using resting CD4+T cells from treated HIV-1-positive patients to measure latent HIV-1 reactivation.

scholarly journals Complementarity of clinical trials, model systems, and metabolomic workflow to unravel the healthy effects of foods: BEBESANO vs MODELSANO: A case study

2021 ◽  
Vol 2 (3) ◽  
Author(s):  
Vicente Agulló ◽  
◽  
Raúl Domínguez-Perles ◽  
Cristina García-Viguera ◽  
◽  
...  
Keyword(s):  
Bioactive Compounds ◽  
Ex Vivo ◽  
In Vitro Models ◽  
Experimental Models ◽  
Model Systems ◽  
Food Science ◽  
Clinical Models ◽  
Safe Condition

Nowadays, the health benefits associated with the consumption of plant-based food constitute a hot topic. To further demonstrate such benefits, related to antioxidant, anti-microbial, and anti-inflammatory activities, as well as the reduction of the risk of several pathophysiological conditions, the study of bioaccessibility and bioavailability of specific food’s constituents, which require interdisciplinary networks, is essential. In this frame, although different experimental models can be developed, the workflow described in the present work support the application of intervention trials in humans as the first option to study the truly effects on health of foods (e.g., plant-based foods), due to the safe condition of them and the realistic approach of this kind of studies, later explored in depth resorting to in vitro, ex vivo, and pre-clinical models, as the most appropriate workflow to get reliable results in the field of Food Science and Nutrition, regarding mechanisms of actions and molecular interactions. Thereby, the work described in the present review is developed in the frame of two consecutive and interconnected projects: BEBESANO (concluded) and MODELSANO (in process) that demonstrate the efficiency of the workflow proposed for research in the Food Science and Nutrition fields. In this regard, in the frame of BEBESANO, acute and longitudinal interventions in humans, devoted to set-up bioavailability of bioactive compounds, followed by functional studies in vivo upon pre-clinical models were conducted to unravel the relationship between bioactive compounds in plant-based beverages and the use of sweetener replacer. Now, most relevant findings from BEBESANO are being further explored in the newly granted project MODELSANO, which is aimed to uncover gaps of knowledge about the mechanisms behind the descriptive results obtained in BEBESANO, using more restrictive in vitro models (allowing the development of studies on the cellular and molecular pathways involved), and integrative cutting edge mathematical modelling alternatives. Keywords: In vivo; in vitro; bioavailability; bioaccessibility; bioactivity; health-promoting foods; metabolomic; mechanistic studies

scholarly journals Use of in vitro bone models to screen for altered bone metabolism, osteopathies, and fracture healing: challenges of complex models

2020 ◽  
Vol 94 (12) ◽  
pp. 3937-3958
Author(s):  
Sabrina Ehnert ◽  
Helen Rinderknecht ◽  
Romina H. Aspera-Werz ◽  
Victor Häussling ◽  
Andreas K. Nussler
Keyword(s):  
Fracture Healing ◽  
Bone Metabolism ◽  
Ex Vivo ◽  
In Vitro Models ◽  
Complex Model ◽  
Model Systems ◽  
Full Potential ◽  
In Vivo Models

Abstract Approx. every third hospitalized patient in Europe suffers from musculoskeletal injuries or diseases. Up to 20% of these patients need costly surgical revisions after delayed or impaired fracture healing. Reasons for this are the severity of the trauma, individual factors, e.g, the patients’ age, individual lifestyle, chronic diseases, medication, and, over 70 diseases that negatively affect the bone quality. To investigate the various disease constellations and/or develop new treatment strategies, many in vivo, ex vivo, and in vitro models can be applied. Analyzing these various models more closely, it is obvious that many of them have limits and/or restrictions. Undoubtedly, in vivo models most completely represent the biological situation. Besides possible species-specific differences, ethical concerns may question the use of in vivo models especially for large screening approaches. Challenging whether ex vivo or in vitro bone models can be used as an adequate replacement for such screenings, we here summarize the advantages and challenges of frequently used ex vivo and in vitro bone models to study disturbed bone metabolism and fracture healing. Using own examples, we discuss the common challenge of cell-specific normalization of data obtained from more complex in vitro models as one example of the analytical limits which lower the full potential of these complex model systems.

In Vitro Testing of Neurotoxicity

1990 ◽  
Vol 18 (1_part_1) ◽  
pp. 153-179
Author(s):  
Erik Walum ◽  
Elisabeth Hansson ◽  
Alan L. Harvey
Keyword(s):  
Nervous System ◽  
Ex Vivo ◽  
Cell Types ◽  
Biochemical Properties ◽  
In Vitro Models ◽  
Model Systems ◽  
Culture Methods ◽  
Developmental Potential

Many of the toxic compounds that are at large in the environment represent a risk to our neuronal functions. Chemicals may have a direct or indirect effect on the nervous system and they may interfere with general biochemical properties or specific neuronal structures and processes. In this review, a brief presentation of the major neurotoxicological targets is given, together with a discussion of some aspects of the use of different in vitro models for screening purposes and mechanistic studies. It is believed that in vitro methods offer special opportunities for the development of new neurotoxicological assays, and that this development will mainly involve cultured model systems. Therefore, a presentation of nerve and glia tissue culture methods is given, followed by an overview of how information on the action of mercury and mercurials, excitotoxins and acrylamide has been obtained through the use of cultured cell models. It is concluded that the developmental potential in cell neurotoxicology lies within the areas of separation and identification of cells representative for different structures in the nervous system, co-cultivation of different cell types, in vivo/in vitro (ex vivo) procedures, chemically defined media, metabolic competent cultures of human cells and improved physiological conditions for cultivation and exposure.

3D Culture Modelling: An Emerging Approach for Translational Cancer Research in Sarcomas

2020 ◽  
Vol 27 (29) ◽  
pp. 4778-4788 ◽  
Author(s):  
Victoria Heredia-Soto ◽  
Andrés Redondo ◽  
José Juan Pozo Kreilinger ◽  
Virginia Martínez-Marín ◽  
Alberto Berjón ◽  
...  
Keyword(s):  
High Throughput Screening ◽  
Cancer Biology ◽  
Soft Tissues ◽  
Three Dimensional ◽  
3D Culture ◽  
Resistance Mechanisms ◽  
In Vitro Models ◽  
Tumour Spheroids ◽  
Current Therapies

Sarcomas are tumours of mesenchymal origin, which can arise in bone or soft tissues. They are rare but frequently quite aggressive and with a poor outcome. New approaches are needed to characterise these tumours and their resistance mechanisms to current therapies, responsible for tumour recurrence and treatment failure. This review is focused on the potential of three-dimensional (3D) in vitro models, including multicellular tumour spheroids (MCTS) and organoids, and the latest data about their utility for the study on important properties for tumour development. The use of spheroids as a particularly valuable alternative for compound high throughput screening (HTS) in different areas of cancer biology is also discussed, which enables the identification of new therapeutic opportunities in commonly resistant tumours.

scholarly journals 1592U89, a novel carbocyclic nucleoside analog with potent, selective anti-human immunodeficiency virus activity.

1997 ◽  
Vol 41 (5) ◽  
pp. 1082-1093 ◽  
Author(s):  
S M Daluge ◽  
S S Good ◽  
M B Faletto ◽  
W H Miller ◽  
M H St Clair ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Oral Bioavailability ◽  
Human Peripheral Blood ◽  
Cross Resistance ◽  
Immunodeficiency Virus ◽  
Carbocyclic Nucleoside ◽  
Hiv 1 ◽  
In Cells

1592U89, (-)-(1S,4R)-4-[2-amino-6-(cyclopropylamino)-9H-purin-9-yl]-2-cyclo pentene-1-methanol, is a carbocyclic nucleoside with a unique biological profile giving potent, selective anti-human immunodeficiency virus (HIV) activity. 1592U89 was selected after evaluation of a wide variety of analogs containing a cyclopentene substitution for the 2'-deoxyriboside of natural deoxynucleosides, optimizing in vitro anti-HIV potency, oral bioavailability, and central nervous system (CNS) penetration. 1592U89 was equivalent in potency to 3'-azido-3'-deoxythymidine (AZT) in human peripheral blood lymphocyte (PBL) cultures against clinical isolates of HIV type 1 (HIV-1) from antiretroviral drug-naive patients (average 50% inhibitory concentration [IC50], 0.26 microM for 1592U89 and 0.23 microM for AZT). 1592U89 showed minimal cross-resistance (approximately twofold) with AZT and other approved HIV reverse transcriptase (RT) inhibitors. 1592U89 was synergistic in combination with AZT, the nonnucleoside RT inhibitor nevirapine, and the protease inhibitor 141W94 in MT4 cells against HIV-1 (IIIB). 1592U89 was anabolized intracellularly to its 5'-monophosphate in CD4+ CEM cells and in PBLs, but the di- and triphosphates of 1592U89 were not detected. The only triphosphate found in cells incubated with 1592U89 was that of the guanine analog (-)-carbovir (CBV). However, the in vivo pharmacokinetic, distribution, and toxicological profiles of 1592U89 were distinct from and improved over those of CBV, probably because CBV itself was not appreciably formed from 1592U89 in cells or animals (<2%). The 5'-triphosphate of CBV was a potent, selective inhibitor of HIV-1 RT, with Ki values for DNA polymerases (alpha, beta, gamma, and epsilon which were 90-, 2,900-, 1,200-, and 1,900-fold greater, respectively, than for RT (Ki, 21 nM). 1592U89 was relatively nontoxic to human bone marrow progenitors erythroid burst-forming unit and granulocyte-macrophage CFU (IC50s, 110 microM) and human leukemic and liver tumor cell lines. 1592U89 had excellent oral bioavailability (105% in the rat) and penetrated the CNS (rat brain and monkey cerebrospinal fluid) as well as AZT. Having demonstrated an excellent preclinical profile, 1592U89 has progressed to clinical evaluation in HIV-infected patients.

scholarly journals HIV-1 subverts the complement system in semen to enhance viral transmission

2021 ◽  
Author(s):  
Bernadien M. Nijmeijer ◽  
Marta Bermejo-Jambrina ◽  
Tanja M. Kaptein ◽  
Carla M. S. Ribeiro ◽  
Doris Wilflingseder ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Virus Transmission ◽  
Sexual Contact ◽  
Target Cells ◽  
People Living With Hiv ◽  
Lectin Receptor ◽  
Pre Treatment ◽  
Living With Hiv ◽  
Hiv 1

AbstractSemen is important in determining HIV-1 susceptibility but it is unclear how it affects virus transmission during sexual contact. Mucosal Langerhans cells (LCs) are the first immune cells to encounter HIV-1 during sexual contact and have a barrier function as LCs are restrictive to HIV-1. As semen from people living with HIV-1 contains complement-opsonized HIV-1, we investigated the effect of complement on HIV-1 dissemination by human LCs in vitro and ex vivo. Notably, pre-treatment of HIV-1 with semen enhanced LC infection compared to untreated HIV-1 in the ex vivo explant model. Infection of LCs and transmission to target cells by opsonized HIV-1 was efficiently inhibited by blocking complement receptors CR3 and CR4. Complement opsonization of HIV-1 enhanced uptake, fusion, and integration by LCs leading to an increased transmission of HIV-1 to target cells. However, in the absence of both CR3 and CR4, C-type lectin receptor langerin was able to restrict infection of complement-opsonized HIV-1. These data suggest that complement enhances HIV-1 infection of LCs by binding CR3 and CR4, thereby bypassing langerin and changing the restrictive nature of LCs into virus-disseminating cells. Targeting complement factors might be effective in preventing HIV-1 transmission.

scholarly journals Advanced Spheroid, Tumouroid and 3D Bioprinted In-Vitro Models of Adult and Paediatric Glioblastoma

2021 ◽  
Vol 22 (6) ◽  
pp. 2962
Author(s):  
Louise Orcheston-Findlay ◽  
Samuel Bax ◽  
Robert Utama ◽  
Martin Engel ◽  
Dinisha Govender ◽  
...  
Keyword(s):  
Life Expectancy ◽  
High Throughput Screening ◽  
High Grade Glioma ◽  
Tumour Microenvironment ◽  
In Vitro Models ◽  
Treatment Modalities ◽  
High Grade ◽  
Future Improvement ◽  
Complex Models

The life expectancy of patients with high-grade glioma (HGG) has not improved in decades. One of the crucial tools to enable future improvement is advanced models that faithfully recapitulate the tumour microenvironment; they can be used for high-throughput screening that in future may enable accurate personalised drug screens. Currently, advanced models are crucial for identifying and understanding potential new targets, assessing new chemotherapeutic compounds or other treatment modalities. Recently, various methodologies have come into use that have allowed the validation of complex models—namely, spheroids, tumouroids, hydrogel-embedded cultures (matrix-supported) and advanced bioengineered cultures assembled with bioprinting and microfluidics. This review is designed to present the state of advanced models of HGG, whilst focusing as much as is possible on the paediatric form of the disease. The reality remains, however, that paediatric HGG (pHGG) models are years behind those of adult HGG. Our goal is to bring this to light in the hope that pGBM models can be improved upon.

scholarly journals In vitro models of fetal lung development to enhance research into congenital lung diseases

2021 ◽  
Author(s):  
Soichi Shibuya ◽  
Jessica Allen-Hyttinen ◽  
Paolo De Coppi ◽  
Federica Michielin
Keyword(s):  
Lung Development ◽  
Lung Diseases ◽  
Ex Vivo ◽  
Fetal Lung ◽  
Branching Morphogenesis ◽  
In Vitro Models ◽  
Normal Lung ◽  
Novel Therapeutic Strategies ◽  
Pseudoglandular Stage

Abstract Purpose This paper aims to build upon previous work to definitively establish in vitro models of murine pseudoglandular stage lung development. These can be easily translated to human fetal lung samples to allow the investigation of lung development in physiologic and pathologic conditions. Methods Lungs were harvested from mouse embryos at E12.5 and cultured in three different settings, i.e., whole lung culture, mesenchyme-free epithelium culture, and organoid culture. For the whole lung culture, extracted lungs were embedded in Matrigel and incubated on permeable filters. Separately, distal epithelial tips were isolated by firstly removing mesothelial and mesenchymal cells, and then severing the tips from the airway tubes. These were then cultured either in branch-promoting or self-renewing conditions. Results Cultured whole lungs underwent branching morphogenesis similarly to native lungs. Real-time qPCR analysis demonstrated expression of key genes essential for lung bud formation. The culture condition for epithelial tips was optimized by testing different concentrations of FGF10 and CHIR99021 and evaluating branching formation. The epithelial rudiments in self-renewing conditions formed spherical 3D structures with homogeneous Sox9 expression. Conclusion We report efficient protocols for ex vivo culture systems of pseudoglandular stage mouse embryonic lungs. These models can be applied to human samples and could be useful to paediatric surgeons to investigate normal lung development, understand the pathogenesis of congenital lung diseases, and explore novel therapeutic strategies.

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