scholarly journals A Low-Serum Culture System for Prolonged in Vitro Toxicology Experiments on a Macrophage System

2021 ◽  
Vol 3 ◽  
Author(s):  
Bastien Dalzon ◽  
Anaelle Torres ◽  
Julie Devcic ◽  
Daphna Fenel ◽  
Jacques-Aurélien Sergent ◽  
...  

Immunotoxicology sensu lato comprises not only toxicity toward immune cells, but also biological reactions from immune cells exposed to toxicants, reactions that may have deleterious effects at the organismal level. Within this wide frame, a specific case of interest is represented by the response of macrophages to particulate materials, with the epitome examples of asbestos and crystalline silica. For such toxicants that are both persistent and often encountered in an occupational setting, i.e. at low but repeated doses, there is a need for in vitro systems that can take into account these two parameters. Currently, most in vitro systems are used in an acute exposure mode, i.e., with a single dose and a readout made shortly if not immediately after exposure. We describe here how adequate changes of the culture methods applied to the murine macrophage cell line J774A.1 enable longer periods of culture (several days), which represents a first opportunity to address the persistence and dose-rate issues. To respond to this, the protocol uses a reduction in the concentration of the animal serum used for cell culture, as well as a switch from fetal to adult serum, which is less rich in proliferation factors. By doing so, we have considerably reduced cell proliferation, which is a problem with cell lines when they are supposed to represent slowly-dividing cells such as resident macrophages. We also succeeded in maintaining the differentiated functions of macrophages, such as phagocytosis or inflammatory responses, over the whole culture period. Furthermore, the presence of serum, even at low concentrations, provides excellent cell viability and keeps the presence of a protein corona on particulate materials, a feature that is known to strongly modulate their effects on cells and is lost in serum-free culture. Besides data showing the impact of these conditions on macrophages cell line cultures, illustrative examples are shown on silica- and cobalt-based pigments.

2018 ◽  
Vol 16 (2) ◽  
pp. 127-137
Author(s):  
Paula Sofia Coutinho Medeiros ◽  
Ana Lúcia Marques Batista de Carvalho ◽  
Cristina Ruano ◽  
Juan Carlos Otero ◽  
Maria Paula Matos Marques

Background: The impact of the ubiquitous dietary phenolic compound p-coumaric acid on human breast cancer cells was assessed, through a multidisciplinary approach: Combined biological assays for cytotoxicity evaluation and biochemical profiling by Raman microspectroscopic analysis in cells. </P><P> Methods: Para-coumaric acid was shown to exert in vitro chemoprotective and antitumor activities, depending on the concentration and cell line probed: a significant anti-invasive ability was detected for the triple-negative MDA-MB-231 cells, while a high pro-oxidant effect was found for the estrogen- dependent MCF-7 cells. A striking cell selectivity was obtained, with a more noticeable outcome on the triple-negative MDA-MB-231 cell line. Results: The main impact on the cellular biochemical profile was verified to be on proteins and lipids, thus justifying the compound´s anti-invasive effect and chemoprotective ability. Conclusion: p-Coumaric acid was thus shown to be a promising chemoprotective/chemotherapeutic agent, particularly against the low prognosis triple-negative human breast adenocarcinoma.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Anderson B. Guimaraes-Costa ◽  
John P. Shannon ◽  
Ingrid Waclawiak ◽  
Jullyanna Oliveira ◽  
Claudio Meneses ◽  
...  

AbstractApart from bacterial formyl peptides or viral chemokine mimicry, a non-vertebrate or insect protein that directly attracts mammalian innate cells such as neutrophils has not been molecularly characterized. Here, we show that members of sand fly yellow salivary proteins induce in vitro chemotaxis of mouse, canine and human neutrophils in transwell migration or EZ-TAXIScan assays. We demonstrate murine neutrophil recruitment in vivo using flow cytometry and two-photon intravital microscopy in Lysozyme-M-eGFP transgenic mice. We establish that the structure of this ~ 45 kDa neutrophil chemotactic protein does not resemble that of known chemokines. This chemoattractant acts through a G-protein-coupled receptor and is dependent on calcium influx. Of significance, this chemoattractant protein enhances lesion pathology (P < 0.0001) and increases parasite burden (P < 0.001) in mice upon co-injection with Leishmania parasites, underlining the impact of the sand fly salivary yellow proteins on disease outcome. These findings show that some arthropod vector-derived factors, such as this chemotactic salivary protein, activate rather than inhibit the host innate immune response, and that pathogens take advantage of these inflammatory responses to establish in the host.


Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1378
Author(s):  
Peyton Gibler ◽  
Jeffrey Gimble ◽  
Katie Hamel ◽  
Emma Rogers ◽  
Michael Henderson ◽  
...  

Human adipose-derived stromal/stem cells (hASC) are widely used for in vitro modeling of physiologically relevant human adipose tissue. These models are useful for the development of tissue constructs for soft tissue regeneration and 3-dimensional (3D) microphysiological systems (MPS) for drug discovery. In this systematic review, we report on the current state of hASC culture and assessment methods for adipose tissue engineering using 3D MPS. Our search efforts resulted in the identification of 184 independent records, of which 27 were determined to be most relevant to the goals of the present review. Our results demonstrate a lack of consensus on methods for hASC culture and assessment for the production of physiologically relevant in vitro models of human adipose tissue. Few studies have assessed the impact of different 3D culture conditions on hASC adipogenesis. Additionally, there has been a limited use of assays for characterizing the functionality of adipose tissue in vitro. Results from this study suggest the need for more standardized culture methods and further analysis on in vitro tissue functionality. These will be necessary to validate the utility of 3D MPS as an in vitro model to reduce, refine, and replace in vivo experiments in the drug discovery regulatory process.


2020 ◽  
Author(s):  
Yinquan Fang ◽  
Qingling Jiang ◽  
Shanshan Li ◽  
Hong Zhu ◽  
Xiao Ding ◽  
...  

Abstract Background Although β-arrestins (ARRBs) regulate diverse physiological and pathophysiological processes, their function and regulation in Parkinson’s disease (PD) remain poorly defined. Methods We measured expression of ARRB1 and ARRB2 in liposaccharide (LPS)-induced and 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP)-induced PD mice. ARRB1-deficient and ARRB2-deficient mouse were used to assess the impact of ARRBs on dopaminergic (DA) neuron loss and microglia activation in PD mouse models. After primary mouse DA neurons were exposed to the conditioned medium from ARRB1 knockdown or ARRB2 knockout microglia stimulated by LPS plus interferon γ (IFN-γ), the degeneration of DA neurons was quantified. Gain- and loss-of-function studies were used to study the effects of ARRBs on microglia activation in vitro. To further understand the mechanism, we measured the activation of classical inflammatory pathways and used RNA sequencing to identify the novel downstream effector of ARRBs. Result In this study, we demonstrate that expression of ARRB1 and ARRB2, particularly in microglia, is reciprocally regulated in PD mouse models. ARRB1 ablation ameliorates, whereas ARRB2 knockout aggravates, the pathological features of PD, including DA neuron loss, neuroinflammation and microglia activation in vivo, as well as microglia-mediated neuron damage and inflammation in vitro. In parallel, ARRB1 and ARRB2 produce adverse effects on the activation of inflammatory signal transducers and activators of transcription 1 (STAT1) and nuclear factor-κB (NF-κB) pathways in microglia. We also show that two ARRBs competitively interact with activated p65 in the NF-κB pathway and that nitrogen permease regulator-like 3 (Nprl3), a functionally poorly characterized protein, is a novel effector acting downstream of both ARRBs. Conclusion Collectively, these data demonstrate that two closely related ARRBs have completely opposite functions in microglia-mediated inflammatory responses, via Nprl3, and differentially affect the pathogenesis of PD, and suggest a potential therapeutic strategy.


Cancers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2661
Author(s):  
Matti Ullah ◽  
Warda Aoudjeghout ◽  
Cynthia Pimpie ◽  
Marc Pocard ◽  
Massoud Mirshahi

Cancer is a result of “aggressive” division and uncontrolled proliferation of the abnormal cells that survive attack by immune cells. We investigated the expression of HLA-G and PD-L1 with the different stages of cancer cell division along with their role in the interaction of immune cells in vitro. Ovarian cancer (OVCAR-3) and chronic myeloid leukemia cell line (K-562) are used for this study. The correlation of protein expression with percentage of cells in each phase (G1, S and G2 phase) was evaluated through FACS. Cells were synchronized in G1, G2 and mitotic phase to evaluate gene (RT-qPCR) and protein expression (FACS). Real-time immune cell attack (RTICA) analysis with PBMCs (peripheral blood mono-nuclear cells) and cancer cells were performed. We found that cells expressing higher levels of HLA-G and PD-L1 are mainly in G2 phase and those expressing lower levels are mainly in G1 phase. Evidently, the higher expression of the two proteins was observed when synchronized in mitotic phase as compared to low expression when synchronized in G1 phase. RTICA analysis showed the presence of HLA-G delayed the lysis of the cells. In conclusion, the cancer cell can escape from immune cells in division stage that suggests the impact of mitosis index for cancer immunotherapy.


2017 ◽  
Vol 70 (1) ◽  
pp. 299-312 ◽  
Author(s):  
Aleksandra N. Gornostaeva ◽  
Elena R. Andreeva ◽  
Polina I. Bobyleva ◽  
Ludmila B. Buravkova

2016 ◽  
Vol 82 (24) ◽  
pp. 7185-7196 ◽  
Author(s):  
Elisa Schiavi ◽  
Marita Gleinser ◽  
Evelyn Molloy ◽  
David Groeger ◽  
Remo Frei ◽  
...  

ABSTRACTThe immune-modulating properties of certain bifidobacterial strains, such asBifidobacterium longumsubsp.longum35624 (B. longum35624), have been well described, although the strain-specific molecular characteristics associated with such immune-regulatory activity are not well defined. It has previously been demonstrated thatB. longum35624 produces a cell surface exopolysaccharide (sEPS), and in this study, we investigated the role played by this exopolysaccharide in influencing the host immune response.B. longum35624 induced relatively low levels of cytokine secretion from human dendritic cells, whereas an isogenic exopolysaccharide-negative mutant derivative (termed sEPSneg) induced vastly more cytokines, including interleukin-17 (IL-17), and this response was reversed when exopolysaccharide production was restored in sEPSnegby genetic complementation. Administration ofB. longum35624 to mice of the T cell transfer colitis model prevented disease symptoms, whereas sEPSnegdid not protect against the development of colitis, with associated enhanced recruitment of IL-17+lymphocytes to the gut. Moreover, intranasal administration of sEPSnegalso resulted in enhanced recruitment of IL-17+lymphocytes to the murine lung. These data demonstrate that the particular exopolysaccharide produced byB. longum35624 plays an essential role in dampening proinflammatory host responses to the strain and that loss of exopolysaccharide production results in the induction of local TH17 responses.IMPORTANCEParticular gut commensals, such asB. longum35624, are known to contribute positively to the development of mucosal immune cells, resulting in protection from inflammatory diseases. However, the molecular basis and mechanisms for these commensal-host interactions are poorly described. In this report, an exopolysaccharide was shown to be decisive in influencing the immune response to the bacterium. We generated an isogenic mutant unable to produce exopolysaccharide and observed that this mutation caused a dramatic change in the response of human immune cellsin vitro. In addition, the use of mouse models confirmed that lack of exopolysaccharide production induces inflammatory responses to the bacterium. These results implicate the surface-associated exopolysaccharide of theB. longum35624 cell envelope in the prevention of aberrant inflammatory responses.


2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Saskia Stier ◽  
Claudia Maletzki ◽  
Ulrike Klier ◽  
Michael Linnebacher

Toll-like receptors (TLRs), a family of pattern recognition receptors recognizing molecules expressed by pathogens, are typically expressed by immune cells. However, several recent studies revealed functional TLR expression also on tumor cells. Their expression is a two-sided coin for tumor cells. Not only tumor-promoting effects of TLR ligands are described but also direct oncopathic and immunostimulatory effects. To clarify TLRs’ role in colorectal cancer (CRC), we tested the impact of the TLR ligands LPS, Poly I:C, R848, and Taxol on primary human CRC cell lines (HROC40, HROC60, and HROC69)in vitroandin vivo(CT26). Taxol, not only a potent tumor-apoptosis-inducing, but also TLR4-activating chemotherapeutic compound, inhibited growth and viability of all cell lines, whereas the remaining TLR ligands had only marginal effects (R848 > LPS > Poly I:C). Combinations of the substances here did not improve the results, whereas antitumoral effects were dramatically boosted when human lymphocytes were added. Here, combining the TLR ligands often diminished antitumoral effects.In vivo, best tumor growth control was achieved by the combination of Taxol and R848. However, when combined with LPS, Taxol accelerated tumor growth. These data generally prove the potential of TLR ligands to control tumor growth and activate immune cells, but they also demonstrate the importance of choosing the right combinations.


2020 ◽  
Author(s):  
Leandra B. Jones ◽  
Sanjay Kumar ◽  
Courtnee’ R. Bell ◽  
Brennetta J. Crenshaw ◽  
Mamie T. Coats ◽  
...  

AbstractExtracellular vesicles (EVs) play a fundamental role in cell and infection biology and have the potential to act as biomarkers for novel diagnostic tools. In this study, we explored the in vitro impact of bacterial lipopolysaccharide administration on a cell line that represents a target for bacterial infection in the host. Administration of lipopolysaccharide at varying concentrations to this A549 cell line caused only modest changes in cell death, but EV numbers were significantly changed. After treatment with the highest concentration of lipopolysaccharide, EVs derived from A549 cells packaged significantly less interleukin-6 and lysosomal-associated membrane protein 1. We also examined the impact of lipopolysaccharide administration on exosome biogenesis and cargo composition in BALB/c mice. Serum-isolated EVs from lipopolysaccharide-treated mice showed significantly increased lysosomal-associated membrane protein 1 and toll-like receptor 4 levels compared with EVs from control mice. In summary, this study demonstrated that EV numbers and cargo were altered using these in vitro and in vivo models of bacterial infection.


2021 ◽  
Author(s):  
◽  
Marie Clare Lydia Kharkrang

<p>Autoimmunities are extremely difficult to treat and involved in their pathogenesis are pro-inflammatory immune responses redirected against one's own tissues. Studies in our lab have shown macrophages that are induced to become type II macrophages protect against an animal model of MS, experimental autoimmune encephalomyelitis (EAE), with protection due to immune deviation. Another way to deviate immune responses away from inflammation is by infection with the parasitic helminth Schistosoma mansoni, which also protects against EAE. The contribution of type II macrophages in this protection is unknown, as are the mechanisms involved in promoting the phenotype induced by type II activation. This project investigates key mechanisms involved in type II activation, while also elucidating the possible effect of schistosome exposure on the induction of this activation state. Using a validated model of type II activation in vitro, we compared the effects of schistosome immune complexes on various macrophage properties such as cytokine, surface marker and enzymatic profiles. This thesis identified that exposure to schistosome complexes induces a macrophage state with characteristics of two distinct activation states (type II and alternative activation), as well as completely novel characteristics. This activation state shows many phenotypic properties associated with immune regulation, and may have important consequences for understanding mechanisms involved in protection against inflammatory illnesses. We also investigated key mechanisms involved in the anti-inflammatory responses induced by type II activation. Cytokine, chemokine and surface marker profiles of macrophages were assessed in response to type II activation in vitro, with the main emphasis on determining the effects of IL-10 and CD40 on the type II activation phenotype and function. This investigation found that type II activated macrophages depend on low levels of CD40/CD40L signalling to polarise Th2 development, as the expression of receptors for Th2-inducing cytokines are significantly impaired in the absence of this interaction. This suggests an important role for the low but maintained levels of CD40 on type II activated macrophages, in aiding the deviation of immune responses, while maintaining Th2 polarization. We also suggest a suppressive role of CD40/CD40L in IL-10 production, which is a novel find. The requirement of new treatments for MS is escalating as more people are affected each year. The impact of MS on the quality of life is severe and long lasting. Having a greater understanding of the mechanisms involved in deviating pro-inflammatory or anti-inflammatory responses will enable the development of much more effective treatments and therapies in the future.</p>


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