scholarly journals The Role of Biofilms, Bacterial Phenotypes, and Innate Immune Response in Mycobacterium avium Colonization to Infection

2021 ◽  
Author(s):  
Catherine Weathered ◽  
Kelly Pennington ◽  
Patricio Escalante ◽  
Elsje Pienaar
Keyword(s):  
Pulmonary Disease ◽  
Mycobacterium Avium ◽  
Three Dimensional ◽  
Published Data ◽  
Agent Based ◽  
Macrophage Recruitment ◽  
Infection Dynamics ◽  
Phenotype Distribution

Mycobacterium avium complex (MAC), is known for colonizing and infecting humans following inhalation of the bacteria. MAC pulmonary disease is notoriously difficult to treat and prone to recurrence. Both the incidence and prevalence MAC pulmonary disease have been increasing globally. MAC is well known to form biofilms in the environment, and in vitro, these biofilms have been shown to aid MAC in epithelial cell invasion, protect MAC from phagocytosis, and cause premature apoptosis in macrophages. In vivo, the system of interactions between MAC, biofilms and host macrophages is complex, difficult to replicate in vitro and in animal models, has not been fully characterized. Here we present a three-dimensional agent-based model of a lung airway to help understand how these interactions evolve in the first 14 days post-bacterial inhalation. We parameterized the model using published data and performed uncertainty analysis to characterize outcomes and parameters effects on those outcomes. Model results show diverse outcomes, including wide ranges of macrophage recruitment levels, and bacterial loads and phenotype distribution. Though most bacteria are phagocytosed by macrophages and remain intracellular, there are also many simulations in which extracellular bacteria continue to drive the colonization and infection. Initial parameters dictating host immune levels, bacterial loads introduced to the airway, and biofilm conditions have significant and lasting impacts on the course of these results. Additionally, though macrophage recruitment is key for suppressing bacterial loads, there is evidence of significant excess recruitment that fail to impact bacterial numbers. These results highlight a need and identify a path for further exploration into the inhalation events in MAC infection. Early infection dynamics could have lasting impacts on the development of nodular bronchiectatic or fibrocavitary disease as well as inform possible preventative and treatment intervention targeting biofilm-macrophage interactions.

Platelet Release from Infused CD34+-Derived Human Megakaryocytes: Lessons from a Natural-Occurring Platelet Bioreactor

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1375-1375
Author(s):  
Ian Johnston ◽  
Vincent M Hayes ◽  
Jing Dai ◽  
Danuta Jadwiga Jarocha ◽  
Paul Kubes ◽  
...  
Keyword(s):  
Conflicts Of Interest ◽  
Ex Vivo ◽  
Three Dimensional ◽  
Blood Stream ◽  
Published Data ◽  
Vascular Bed ◽  
Platelet Release ◽  
Pulmonary Vascular Bed

Abstract The release of biologically intact platelets from in vitro-grown megakaryocytes remains one of the challenges in an attempt to replace donor-derived platelets with platelets prepared from in vitro-grown megakaryocytes. Thrombopoiesis, the process by which megakaryocytes release platelets, is thought to occur as megakaryocytes exit from the medullar space and transit into the blood stream. Two-photon fluorescence microscopy studies by several groups have documented megakaryocytes transitioning into the blood stream and extending mostly a single protrusion that appears to release large cytoplasmic fragments downstream. These studies have been widely interpreted to support platelet release in the bone marrow environment. A counter proposal made by Dr. William Howell over 75 years ago is that either whole megakaryocytes or large cytoplasmic fragments circulate to the lungs and release platelets in the lungs. Studies by our group infusing in vitro-grown megakaryocytes (both human and mouse) have shown that infused megakaryocytes do indeed become entrapped in the lungs and release platelets. These in vivo-released platelets have a much longer half-life than in vitro-prepared platelets from static cultures and have the same size distribution and nearly the same functionality as infused donor-derived platelets. Using confocal intravital microscopy, we now directly visualized the lungs of recipient NOD-SCID interferon 2 receptor γ-deficient mice during the infusion of calcein-loaded CD34+-derived megakaryocytes. Infused human megakaryocytes were immediately arrested in the pulmonary bed in vessels ~50 µm in diameter. Each cell then extended several distinct protrusions winding down presumed pulmonary capillaries that are presumably wrapped around alveoli. Some of these protrusions reached 200-300 µm in length and assumed the appearance of beads on a string. Consistent with our recently published data, this thrombopoiesis process appears to take 30 minutes to be near-complete, similar to the timeframe we showed for detecting newly released human platelet-like particles after megakaryocyte infusion. At 30 minutes, remaining bodies of the megakaryocytes are still present and we presume these are mostly the remaining nuclei. To better define whether the pulmonary bed is unique for releasing platelets, we also infused megakaryocytes intra-arteriole rather than intravenously to have the megakaryocytes encounter other organ capillary beds before the lung. These studies showed poor platelet release compared to parallel studies in mice receiving the megakaryocytes intravenously. Many of the intra-arterial infused megakaryocytes were entrapped in the spleen and very few were notable in other organs, including the lungs, liver and kidney. Our studies showed that megakaryocytes can shed platelets in the lungs where they may take advantage of the unique three-dimensional organization of the pulmonary vascular bed, flow conditions, vascular surface receptors and glycocalyx as well as a sudden shift from hypoxic to normoxic conditions. Whether these features of the pulmonary vascular bed can be simulated ex vivo and whether this will enhance true platelet release from megakaryocytes in vitro needs to be examined. Disclosures No relevant conflicts of interest to declare.

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.

Epithelial Organotypic Cultures: A Viable Model to Address Mechanisms of Carcinogenesis by Epitheliotropic Viruses

2018 ◽  
Vol 18 (4) ◽  
pp. 246-255 ◽  
Author(s):  
Lara Termini ◽  
Enrique Boccardo
Keyword(s):  
Three Dimensional ◽  
Cell Types ◽  
Experimental Models ◽  
Biological Research ◽  
Specific Gene ◽  
Specific Cell ◽  
Organotypic Cultures ◽  
Skin Physiology

In vitro culture of primary or established cell lines is one of the leading techniques in many areas of basic biological research. The use of pure or highly enriched cultures of specific cell types obtained from different tissues and genetics backgrounds has greatly contributed to our current understanding of normal and pathological cellular processes. Cells in culture are easily propagated generating an almost endless source of material for experimentation. Besides, they can be manipulated to achieve gene silencing, gene overexpression and genome editing turning possible the dissection of specific gene functions and signaling pathways. However, monolayer and suspension cultures of cells do not reproduce the cell type diversity, cell-cell contacts, cell-matrix interactions and differentiation pathways typical of the three-dimensional environment of tissues and organs from where they were originated. Therefore, different experimental animal models have been developed and applied to address these and other complex issues in vivo. However, these systems are costly and time consuming. Most importantly the use of animals in scientific research poses moral and ethical concerns facing a steadily increasing opposition from different sectors of the society. Therefore, there is an urgent need for the development of alternative in vitro experimental models that accurately reproduce the events observed in vivo to reduce the use of animals. Organotypic cultures combine the flexibility of traditional culture systems with the possibility of culturing different cell types in a 3D environment that reproduces both the structure and the physiology of the parental organ. Here we present a summarized description of the use of epithelial organotypic for the study of skin physiology, human papillomavirus biology and associated tumorigenesis.

scholarly journals The Revolutionary Roads to Study Cell–Cell Interactions in 3D In Vitro Pancreatic Cancer Models

Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 930
Author(s):  
Donatella Delle Cave ◽  
Riccardo Rizzo ◽  
Bruno Sainz ◽  
Giuseppe Gigli ◽  
Loretta L. del Mercato ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Therapeutic Response ◽  
Three Dimensional ◽  
Cellular Models ◽  
Common Cancer ◽  
Cancer Models ◽  
Anti Cancer ◽  
Tumor Environment

Pancreatic cancer, the fourth most common cancer worldwide, shows a highly unsuccessful therapeutic response. In the last 10 years, neither important advancements nor new therapeutic strategies have significantly impacted patient survival, highlighting the need to pursue new avenues for drug development discovery and design. Advanced cellular models, resembling as much as possible the original in vivo tumor environment, may be more successful in predicting the efficacy of future anti-cancer candidates in clinical trials. In this review, we discuss novel bioengineered platforms for anticancer drug discovery in pancreatic cancer, from traditional two-dimensional models to innovative three-dimensional ones.

Three-dimensional Growth of Renal Epithelial Cells in Vitro: A Tool in Toxicity Testing

1993 ◽  
Vol 21 (2) ◽  
pp. 191-195 ◽  
Author(s):  
Knut-Jan Andersen ◽  
Erik Ilsø Christensen ◽  
Hogne Vik
Keyword(s):  
Epithelial Cells ◽  
Three Dimensional ◽  
Toxicity Testing ◽  
Renal Tissue ◽  
Epithelial Cell Line ◽  
Multicellular Spheroids ◽  
Renal Epithelial Cell ◽  
Renal Epithelial Cells

The tissue culture of multicellular spheroids from the renal epithelial cell line LLC-PK1 (proximal tubule) is described. This represents a biological system of intermediate complexity between renal tissue in vivo and simple monolayer cultures. The multicellular structures, which show many similarities to kidney tubules in vivo, including a vectorial water transport, should prove useful for studying the potential nephrotoxicity of drugs and chemicals in vitro. In addition, the propagation of renal epithelial cells as multicellular spheroids in serum-free culture may provide information on the release of specific biological parameters, which may be suppressed or masked in serum-supplemented media.

scholarly journals Review of T-2307, an Investigational Agent That Causes Collapse of Fungal Mitochondrial Membrane Potential

2021 ◽  
Vol 7 (2) ◽  
pp. 130
Author(s):  
Nathan P. Wiederhold
Keyword(s):  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Candida Species ◽  
Mammalian Cells ◽  
Mitochondrial Membrane ◽  
Fungal Infections ◽  
Published Data ◽  
Candida Auris

Invasive infections caused by Candida that are resistant to clinically available antifungals are of increasing concern. Increasing rates of fluconazole resistance in non-albicans Candida species have been documented in multiple countries on several continents. This situation has been further exacerbated over the last several years by Candida auris, as isolates of this emerging pathogen that are often resistant to multiple antifungals. T-2307 is an aromatic diamidine currently in development for the treatment of invasive fungal infections. This agent has been shown to selectively cause the collapse of the mitochondrial membrane potential in yeasts when compared to mammalian cells. In vitro activity has been demonstrated against Candida species, including C. albicans, C. glabrata, and C. auris strains, which are resistant to azole and echinocandin antifungals. Activity has also been reported against Cryptococcus species, and this has translated into in vivo efficacy in experimental models of invasive candidiasis and cryptococcosis. However, little is known regarding the clinical efficacy and safety of this agent, as published data from studies involving humans are not currently available.

scholarly journals Mammary gland 3D cell culture systems in farm animals

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Laurence Finot ◽  
Eric Chanat ◽  
Frederic Dessauge
Keyword(s):  
Cell Culture ◽  
Mammary Gland ◽  
Bacterial Infections ◽  
Three Dimensional ◽  
3D Cell Culture ◽  
Farm Animals ◽  
Culture Systems ◽  
Cell Culture Systems

AbstractIn vivo study of tissue or organ biology in mammals is very complex and progress is slowed by poor accessibility of samples and ethical concerns. Fortunately, however, advances in stem cell identification and culture have made it possible to derive in vitro 3D “tissues” called organoids, these three-dimensional structures partly or fully mimicking the in vivo functioning of organs. The mammary gland produces milk, the source of nutrition for newborn mammals. Milk is synthesized and secreted by the differentiated polarized mammary epithelial cells of the gland. Reconstructing in vitro a mammary-like structure mimicking the functional tissue represents a major challenge in mammary gland biology, especially for farm animals for which specific agronomic questions arise. This would greatly facilitate the study of mammary gland development, milk secretion processes and pathological effects of viral or bacterial infections at the cellular level, all with the objective of improving milk production at the animal level. With this aim, various 3D cell culture models have been developed such as mammospheres and, more recently, efforts to develop organoids in vitro have been considerable. Researchers are now starting to draw inspiration from other fields, such as bioengineering, to generate organoids that would be more physiologically relevant. In this chapter, we will discuss 3D cell culture systems as organoids and their relevance for agronomic research.

scholarly journals Three-Dimensional Zirconia-Based Scaffolds for Load-Bearing Bone-Regeneration Applications: Prospects and Challenges

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3207
Author(s):  
Kumaresan Sakthiabirami ◽  
Vaiyapuri Soundharrajan ◽  
Jin-Ho Kang ◽  
Yunzhi Peter Yang ◽  
Sang-Won Park
Keyword(s):  
Bone Regeneration ◽  
Biological Activities ◽  
Three Dimensional ◽  
In Vivo Studies ◽  
High Mechanical Strength ◽  
Real World Applications ◽  
3D Fabrication ◽  
Dental Applications

The design of zirconia-based scaffolds using conventional techniques for bone-regeneration applications has been studied extensively. Similar to dental applications, the use of three-dimensional (3D) zirconia-based ceramics for bone tissue engineering (BTE) has recently attracted considerable attention because of their high mechanical strength and biocompatibility. However, techniques to fabricate zirconia-based scaffolds for bone regeneration are in a stage of infancy. Hence, the biological activities of zirconia-based ceramics for bone-regeneration applications have not been fully investigated, in contrast to the well-established calcium phosphate-based ceramics for bone-regeneration applications. This paper outlines recent research developments and challenges concerning numerous three-dimensional (3D) zirconia-based scaffolds and reviews the associated fundamental fabrication techniques, key 3D fabrication developments and practical encounters to identify the optimal 3D fabrication technique for obtaining 3D zirconia-based scaffolds suitable for real-world applications. This review mainly summarized the articles that focused on in vitro and in vivo studies along with the fundamental mechanical characterizations on the 3D zirconia-based scaffolds.

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