Size-Dependent Internalization of Microplastics and Nanoplastics Using In Vitro Model of the Human Intestine-Contribution of Each Cell in the Tri-Culture Models

Pollution by microplastics and nanoplastics (MNPs) raises concerns, not only regarding their environmental effects, but also their potential impact on human health by internalization via the small intestine. However, the detailed pathways of MNP internalization and their toxicities to the human intestine have not sufficiently been understood, thus, further investigations are required. This work aimed to understand the behavior of MNPs, using in vitro human intestine models, tri-culture models composed of enterocyte Caco-2 cells, goblet-like HT29-MTX-E12 cells, and microfold cells (M cells) induced by the lymphoblast cell line Raji B. Three sizes (50, 100, and 500 nm) of polystyrene (PS) particles were exposed as MNPs on the culture model, and size-dependent translocation of the MNPs and the contributions of each cell were clarified, emphasizing the significance of the tri-culture model. In addition, potential concerns of MNPs were suggested when they invaded the circulatory system of the human body.

Exploring host-commensal-pathogen dynamics in cell line and organotypic human intestinal epithelial models

Host and microbiome intricately interact in the ecosystem of the human digestive tract, playing a crucial role in our health. These interactions can initiate immune responses in the epithelial cells, which, in turn, activate downstream responses in other immune cells. Here, we used a CaCo-2 and a human intestinal enteroid (HIE) model to explore epithelial responses to both commensal and pathogenic bacteria, individually and combined. CaCo-2 cells were co-cultured with peripheral blood mononuclear cells, revealing downstream activation of immune cells. While both systems showed comparable cytokine profiles, they differed in their responses to the different bacteria, with the organoid system being more representative of responses observed in humans. We provide evidence of the pro-inflammatory responses associated with these bacteria. These models contribute to a deeper understanding of the interactions between the microbiota, intestinal epithelium, and immune cells in the gut, promoting advances in the field of host-microbe interactions.

3D culture of mesenchymal stem cells from the yolk sac to generate intestinal organoid

Organoids are in vitro models that originated from the three-dimensional culture of stem cells with the ability to reproduce part of the in vivo structural and functional specificities of body organs. Intestinal organoids have great relevance in cell therapy, as they provide more accurate information about tissue composition and architecture in relation to two-dimensional culture, in addition to serving as a study model for host interaction and drug testing. The yolk sac (YS) is a promising source of mesenchymal stem cells (MSCs), which are multipotent stem cells with self-renewal ability and potential to differentiated into mesenchymal lineages. Besides this, the YS is responsible for the formation of intestinal epithelium during embryonic development. Thus, the aim of this study was to verify if the three-dimensional in vitro culture of stem cells derived from the canine YS is capable of developing intestinal organoids. MSCs from the canine YS and gut cells were isolated and characterized, then three-dimensionally cultured in Matrigel. In both cells lineages, spherical organoids were observed and after 10 days the gut cells formed crypt-like buds and villus-like structures. Despite having the same induction of differentiation process and having the expression of intestinal markers, the MSC from the YS morphology was not in the form of crypt budding. The hypothesis is that these cells could generate structures equivalent to the intestinal organoids of the colon that other studies showed formed only spherical structures. The culture of MSC from the YS, as well as the establishment of protocols for 3D cultivation of this tissue, is relevant, as it will serve as a tool in various applications in basic and scientific biology.

Gegen Qinlian decoction (GQD) inhibits ulcerative colitis by modulating ferroptosis-dependent pathway in mice and organoids

BACKGROUND

Gegen Qinlian decoction (GQD) is a classic prescription for treating ulcerative colitis (UC) in traditional Chinese medicine. However, the therapeutic mechanism has not been fully clarified.

PURPOSE

In the present study, we aimed to evaluate the role of ferroptosis-mediated IEC death in UC treated mice with GQD by using DSS-induced a colitis mouse model and RSL3-induced ferroptosis in intestinal organoids.

METHODS

The effects of GQD on DSS-treated colitis were examined via daily body weight, DAI, colon length, HE staining, PAS staining, ZO-1 and Occludin immunohistochemical staining. Ferroptosis was determined by analysis of iron load, MDA, GSH, mitochondrial morphology, and expression of ferroptosis-associated proteins (GPX4, SLC7A11 and ACSL4).

RESULTS

In vivo, GQD administration reduced body weight loss and DAI scores, increased colon length, and improved intestinal histological characteristics and epithelial barrier dysfunction. GQD administration obviously improved the levels of ferroptosis markers (iron load, MDA, GSH, and mitochondrial morphology) and the expression of ferroptosis-associated proteins (GPX4, SLC7A11 and ACSL4). Consistent with in vivo results, GQD administration partially reversed the levels of mtROS, Fe2+ and MDA in intestinal organoids induced by RSL3, and notably improved morphological destruction, histological damage and epithelial barrier dysfunction in organoids.

CONCLUSIONS

In this study, we demonstrated that ferroptosis was triggered in DSS-induced experimental colitis and that GQD adiministration could protect against colonic damage and intestinal epithelial barrier dysfunction by inhibiting ferroptosis.

Organoids

Organoids have attracted increasing attention because they are simple tissue-engineered cell-based in vitro models that recapitulate many aspects of the complex structure and function of the corresponding in vivo tissue. They can be dissected and interrogated for fundamental mechanistic studies on development, regeneration, and repair in human tissues. Organoids can also be used in diagnostics, disease modeling, drug discovery, and personalized medicine. Organoids are derived from either pluripotent or tissue-resident stem (embryonic or adult) or progenitor or differentiated cells from healthy or diseased tissues, such as tumors. To date, numerous organoid engineering strategies that support organoid culture and growth, proliferation, differentiation and maturation have been reported. This Primer serves to highlight the rationale underlying the selection and development of these materials and methods to control the cellular/tissue niche; and therefore, structure and function of the engineered organoid. We also discuss key considerations for generating robust organoids, such as those related to cell isolation and seeding, matrix and soluble factor selection, physical cues and integration. The general standards for data quality, reproducibility and deposition within the organoid community is also outlined. Lastly, we conclude by elaborating on the limitations of organoids in different applications, and key priorities in organoid engineering for the coming years.

Effect of Toll-like receptor-2, -4, -5, -7, and NOD2 stimulation on potassium channel conductance in intestinal epithelial cells

Disproportionate activation of pattern recognition receptors plays a role in inflammatory bowel disease (IBD) pathophysiology. Diarrhea is a hallmark symptom of IBD, resulting at least in part from an electrolyte imbalance that may be caused by changes in potassium channel activity. We evaluated the impact of Toll-like receptors (TLRs) and nucleotide-binding oligomerization domain 2 (NOD2) stimulation on potassium conductance of the basolateral membrane in human intestinal epithelial cells (IECs) and the role of potassium channels through electrophysiological assays under short-circuit current in Ussing chambers. TLRs and NOD2 were stimulated using specific agonists, and potassium channels were selectively blocked using triarylmethane-34 (TRAM-34), adenylyl-imidodiphosphate (AMP-PNP), and BaCl₂. Potassium conductance of the basolateral membrane decreased upon activation of TLR2, TLR4, and TLR7 in T84 cells (means ± SE, -11.2 ± 4.5, -40.4 ± 7.2, and -19.4 ± 5.9, respectively) and in Caco-2 cells (-13.1 ± 5.7, -55.7 ± 7.4, and -29.1 ± 7.2, respectively). In contrast, activation of TLR5 and NOD2 increased basolateral potassium conductance, both in T84 cells (18.0 ± 4.1 and 18.4 ± 2.8, respectively) and in Caco-2 cells (21.2 ± 8.4 and 16.0 ± 3.6, respectively). TRAM-34 and AMP-PNP induced a decrease in basolateral potassium conductance upon TLR4 stimulation in both cell lines. Both K_Ca3.1- and K_ir6-channels appear to be important mediators of this effect in IECs and could be potential targets for therapeutic agent development.NEW & NOTEWORTHY This study highlights that PRRs stimulation directly influences K⁺-channel conductance in IECs. TLR-2, -4, -7 stimulation decreased K⁺ conductance, whereas TLR5 and NOD2 stimulation had the opposite effect, leading to an increase of it instead. This study reports for the first time that K_Ca3.1- and K_ir6-channels play a role in K⁺ transport pathways triggered by TLR4 stimulation. These findings suggest that K_Ca3.1- and K_ir6-channels modulation may be a potential target for new therapeutic agents in IBD.

Human duodenal organoid-derived monolayers serve as a suitable barrier model for duodenal tissue

Usually, duodenal barriers are investigated using intestinal cell lines like Caco-2, which in contrast to native tissue are limited in cell-type representation. Organoids can consist of all intestinal cell types and are supposed to better reflect the in vivo situation. Growing three-dimensionally, with the apical side facing the lumen, application of typical physiological techniques to analyze the barrier is difficult. Organoid-derived monolayers (ODMs) were developed to overcome this. After optimizing culturing conditions, ODMs were characterized and compared to Caco-2 and duodenal tissue. Tight junction composition and appearance were analyzed, and electrophysiological barrier properties, like paracellular and transcellular barrier function and macromolecule permeability, were evaluated. Furthermore, transcriptomic data were analyzed. ODMs had tight junction protein expression and paracellular barrier properties much more resembling the originating tissue than Caco-2. Transcellular barrier was similar between ODMs and native tissue but was increased in Caco-2. Transcriptomic data showed that Caco-2 expressed fewer solute carriers than ODMs and native tissue. In conclusion, while Caco-2 cells differ mostly in transcellular properties, ODMs reflect trans- and paracellular properties of the originating tissue. If cultured under optimized conditions, ODMs possess reproducible functionality, and the variety of different cell types makes them a suitable model for human tissue-specific investigations.

TMT-Based Quantitative Proteomic Analysis of Intestinal Organoids Infected by Listeria monocytogenes Strains with Different Virulence

L. monocytogenes, consisting of 13 serotypes, is an opportunistic food-borne pathogen that causes different host reactions depending on its serotypes. In this study, highly toxic L. monocytogenes 10403s resulted in more severe infections and lower survival rates. Additionally, to investigate the remodeling of the host proteome by strains exhibiting differential toxicity, the cellular protein responses of intestinal organoids were analyzed using tandem mass tag (TMT) labeling and high-performance liquid chromatography−mass spectrometry. The virulent strain 10403s caused 102 up-regulated and 52 down-regulated proteins, while the low virulent strain M7 caused 188 up-regulated and 25 down-regulated proteins. Based on the analysis of gene ontology (GO) and KEGG databases, the expressions of differential proteins in organoids infected by L. monocytogenes 10403s (virulent strain) or M7 (low virulent strain) were involved in regulating essential processes such as the biological metabolism, the energy metabolism, and immune system processes. The results showed that the immune system process, as the primary host defense response to L. monocytogenes, comprised five pathways, including ECM−receptor interaction, the complement and coagulation cascades, HIF-1, ferroptosis, and NOD-like receptor signaling pathways. As for the L. monocytogenes 10403s vs. M7 group, the expression of differential proteins was involved in two pathways: systemic lupus erythematosus and transcriptional mis-regulation in cancer. All in all, these results revealed that L. monocytogenes strains with different toxicity induced similar biological functions and immune responses while having different regulations on differential proteins in the pathway.

Vitamin D Receptor Influences Intestinal Barriers in Health and Disease

Vitamin D receptor (VDR) executes most of the biological functions of vitamin D. Beyond this, VDR is a transcriptional factor regulating the expression levels of many target genes, such as genes for tight junction proteins claudin-2, -5, -12, and -15. In this review, we discuss the progress of research on VDR that influences intestinal barriers in health and disease. We searched PubMed and Google Scholar using key words vitamin D, VDR, tight junctions, cancer, inflammation, and infection. We summarize the literature and progress reports on VDR regulation of tight junction distribution, cellular functions, and mechanisms (directly or indirectly). We review the impacts of VDR on barriers in various diseases, e.g., colon cancer, infection, inflammatory bowel disease, and chronic inflammatory lung diseases. We also discuss the limits of current studies and future directions. Deeper understanding of the mechanisms by which the VDR signaling regulates intestinal barrier functions allow us to develop efficient and effective therapeutic strategies based on levels of tight junction proteins and vitamin D/VDR statuses for human diseases.

The Progress of Intestinal Epithelial Models from Cell Lines to Gut-On-Chip

Over the past years, several preclinical in vitro and ex vivo models have been developed that helped to understand some of the critical aspects of intestinal functions in health and disease such as inflammatory bowel disease (IBD). However, the translation to the human in vivo situation remains problematic. The main reason for this is that these approaches fail to fully reflect the multifactorial and complex in vivo environment (e.g., including microbiota, nutrition, and immune response) in the gut system. Although conventional models such as cell lines, Ussing chamber, and the everted sac are still used, increasingly more sophisticated intestinal models have been developed over the past years including organoids, InTESTine™ and microfluidic gut-on-chip. In this review, we gathered the most recent insights on the setup, advantages, limitations, and future perspectives of most frequently used in vitro and ex vivo models to study intestinal physiology and functions in health and disease.

Organoids and Their Use in Modeling Gut Epithelial Cell Lineage Differentiation and Barrier Properties During Intestinal Diseases

Maintenance of intestinal epithelium homeostasis is a complex process because of the multicellular and molecular composition of the gastrointestinal wall and the involvement of surrounding interactive signals. The complex nature of this intestinal barrier system poses challenges in the detailed mechanistic understanding of intestinal morphogenesis and the onset of several gut pathologies, including intestinal inflammatory disorders, food allergies, and cancer. For several years, the gut scientific community has explored different alternatives in research involving animals and in vitro models consisting of cultured monolayers derived from the immortalized or cancerous origin cell lines. The recent ability to recapitulate intestinal epithelial dynamics from mini-gut cultures has proven to be a promising step in the field of scientific research and biomedicine. The organoids can be grown as two- or three-dimensional structures, and are derived from adult or pluripotent stem cells that ultimately establish an intestinal epithelium that is composed of all differentiated cell types present in the normal epithelium. In this review, we summarize the different origins and recent use of organoids in modeling intestinal epithelial differentiation and barrier properties.

Generation of equine enteroids and enteroid-derived 2D monolayers that are responsive to microbial mimics

Enteroid cultures are three-dimensional in vitro models that reflect the cellular composition and architecture of the small intestine. One limitation with the enteroid conformation is the enclosed lumen, making it difficult to expose the apical surface of the epithelium to experimental treatments. The present study was therefore conducted to generate cultures of equine enteroids and to develop methods for culture of enteroid-derived cells on a two-dimensional plane, enabling easy access to the apical surface of the epithelium. Equine enteroids were established from small intestinal crypts within 7-9 days of culture. Transcriptional analysis of cell type markers confirmed the presence of enterocytes, stem-, Paneth-, proliferative-, enteroendocrine-, goblet- and tuft cells. This cellular composition was maintained over multiple passages, showing that the enteroids can be kept for prolonged periods. The transfer from 3D enteroids to 2D monolayers slightly modified the relative expression levels of the cell type markers, indicating a decrease of goblet- and Paneth cells in the monolayers. Stimulation with the TLR2, 3 and 4 agonists Pam3CSK4, Poly I:C and LPS, respectively, induced the pro-inflammatory cytokines TNF-α and IL-8, while the TLR5 agonist FliC only induced TNF-α. In addition, an up-regulation of TGF-β, IL-33 and IFN-β was recorded after exposure to lipofected Poly I:C that also affected the monolayer integrity. Thus, the equine enteroid-derived 2D monolayers described in the present study show both genetic and functional similarities with the equine intestine making it an interesting in vitro model for studies demanding access to the apical surface, e.g. in studies of host-microbe interactions.

Organoids and Colorectal Cancer

Organoids were first established as a three-dimensional cell culture system from mouse small intestine. Subsequent development has made organoids a key system to study many human physiological and pathological processes that affect a variety of tissues and organs. In particular, organoids are becoming very useful tools to dissect colorectal cancer (CRC) by allowing the circumvention of classical problems and limitations, such as the impossibility of long-term culture of normal intestinal epithelial cells and the lack of good animal models for CRC. In this review, we describe the features and current knowledge of intestinal organoids and how they are largely contributing to our better understanding of intestinal cell biology and CRC genetics. Moreover, recent data show that organoids are appropriate systems for antitumoral drug testing and for the personalized treatment of CRC patients.

The Intestinal Barrier and Current Techniques for the Assessment of Gut Permeability

The intestinal barrier is essential in human health and constitutes the interface between the outside and the internal milieu of the body. A functional intestinal barrier allows absorption of nutrients and fluids but simultaneously prevents harmful substances like toxins and bacteria from crossing the intestinal epithelium and reaching the body. An altered intestinal permeability, a sign of a perturbed barrier function, has during the last decade been associated with several chronic conditions, including diseases originating in the gastrointestinal tract but also diseases such as Alzheimer and Parkinson disease. This has led to an intensified interest from researchers with diverse backgrounds to perform functional studies of the intestinal barrier in different conditions. Intestinal permeability is defined as the passage of a solute through a simple membrane and can be measured by recording the passage of permeability markers over the epithelium via the paracellular or the transcellular route. The methodological tools to investigate the gut barrier function are rapidly expanding and new methodological approaches are being developed. Here we outline and discuss, in vivo, in vitro and ex vivo techniques and how these methods can be utilized for thorough investigation of the intestinal barrier.

Involvement of nuclear factor erythroid 2‑related factor 2 in neonatal intestinal interleukin‑17D expression in hyperoxia

Interleukin 17D (IL-17D) plays an important role in host defense against inflammation and infection. In the present study, the role of nuclear factor erythroid 2-related factor 2 (Nrf2) in regulating the production of IL-17D was investigated under hyperoxia. For this purpose, neonatal rats were randomized into two groups; the model group was exposed to hyperoxia (80-85% O₂), while the control group was maintained under normoxic conditions (21% O₂). Small intestine tissue was collected on postnatal days 3, 7, 10 and 14. IL-17D expression was detected by immunofluorescence, immunohistochemistry and western blotting. The levels of Nrf2 and kelch-like ECH-associated protein 1 (keap1) were detected by immunohistochemistry and western blotting. Results showed that IL-17D expression in intestine epithelial cells increased steadily, reaching a peak on day 7, and decreased gradually on days 10 and 14 under hyperoxia. Nrf2 expression was consis-tent with IL-17D, and it was positively correlated with IL-17D. However, on postnatal days 10 and 14, the number of CD4⁺ T cells and CD19⁺ B cells expressing IL-17D was increased, and positive cells of the model group were significantly more than that of the control group. Keap1 levels were lower at the early stage. In conclusion, the expression levels of intestinal IL-17D and Nrf2 were altered simultaneously following neonatal rat development in hyperoxia, indicating that Nrf2 may be involved in regulating the expression of IL-17D in intestinal epithelial cells. Moreover, IL-17D in intestinal epithelial cells may play a unique immunological role during hyperoxia.

Maturation of human intestinal organoids in vitro facilitates colonization by commensal lactobacilli by reinforcing the mucus layer

Lactobacilli, which are probiotic commensal bacteria that mainly reside in the human small intestine, have attracted attention for their ability to exert health-promoting effects and beneficially modulate host immunity. However, host epithelial-commensal bacterial interactions are still largely unexplored because of limited access to human small intestinal tissues. Recently, we described an in vitro maturation technique for generating adult-like, mature human intestinal organoids (hIOs) from human pluripotent stem cells (hPSCs) that closely resemble the in vivo tissue structure and cellular diversity. Here, we established an in vitro human model to study the response to colonization by commensal bacteria using luminal microinjection into mature hIOs, allowing for the direct examination of epithelial-bacterial interactions. Lactobacillus reuteri and Lactobacillus plantarum were more likely to survive and colonize when microinjected into the lumen of mature hIOs than when injected into immature hIOs, as determined by scanning electron microscopy, colony formation assay, immunofluorescence, and real-time imaging with L plantarum expressing red fluorescent protein. The improved mature hIO-based host epithelium system resulted from enhanced intestinal epithelial integrity via upregulation of mucus secretion and tight junction proteins. Our study indicates that mature hIOs are a physiologically relevant in vitro model system for studying commensal microorganisms.

A Human 2D Primary Organoid-Derived Epithelial Monolayer Model to Study Host-Pathogen Interaction in the Small Intestine

Gut organoids are stem cell derived 3D models of the intestinal epithelium that are useful for studying interactions between enteric pathogens and their host. While the organoid model has been used for both bacterial and viral infections, this is a closed system with the luminal side being inaccessible without microinjection or disruption of the organoid polarization. In order to overcome this and simplify their applicability for transepithelial studies, permeable membrane based monolayer approaches are needed. In this paper, we demonstrate a method for generating a monolayer model of the human fetal intestinal polarized epithelium that is fully characterized and validated. Proximal and distal small intestinal organoids were used to generate 2D monolayer cultures, which were characterized with respect to epithelial cell types, polarization, barrier function, and gene expression. In addition, viral replication and bacterial translocation after apical infection with enteric pathogens Enterovirus A71 and Listeria monocytogenes were evaluated, with subsequent monitoring of the pro-inflammatory host response. This human 2D fetal intestinal monolayer model will be a valuable tool to study host-pathogen interactions and potentially reduce the use of animals in research.

Production and characterization of avian crypt-villus enteroids and the effect of chemicals

BACKGROUND

Three-dimensional models of cell culture such as organoids and mini organs accord better advantage over regular cell culture because of their ability to simulate organ functions hence, used for disease modeling, metabolic research, and the development of therapeutics strategies. However, most advances in this area are limited to mammalian species with little progress in others such as poultry where it can be deployed to study problems of agricultural importance. In the course of enterocyte culture in chicken, we observed that intestinal mucosal villus-crypts self-repair and form spheroid-like structures which appear to be useful as ex vivo models to study enteric physiology and diseases.

RESULTS

The villus-crypts harvested from chicken intestinal mucosa were cultured to generate enteroids, purified by filtration then re cultured with different chemicals and growth factors to assess their response based on their morphological dispositions. Histochemical analyses using marker antibodies and probes showed the enteroids consisting different cell types such as epithelial, goblet, and enteroendocrine cells typical to villi and retain functional characteristics of intestinal mucosa.

CONCLUSIONS

We present a simple procedure to generate avian crypt-villous enteroids containing different cell types. Because the absorptive cells are functionally positioned outwards, similar to the luminal enterocytes, the cells have better advantages to interact with the factors present in the culture medium. Thus, the enteroids have the potential to study the physiology, metabolism, and pathology of the intestinal villi and can be useful for preliminary screenings of the factors that may affect gut health in a cost-effective manner and reduce the use of live animals.

Exposure of Intestinal Epithelial Cells to 2'-Fucosyllactose and CpG Enhances Galectin Release and Instructs Dendritic Cells to Drive Th1 and Regulatory-Type Immune Development

Intestinal epithelial cells (IEC) release immunomodulatory galectins upon exposure to CpG DNA (mimicking bacterial triggers) and short-chain galacto- and long-chain fructo-oligosaccharides (GF). This study aims to investigate the immunomodulatory properties of 2'-fucosyllactose (2'-FL), a non-digestible oligosaccharide (NDO) abundantly present in human milk, using a co-culture model developed to study the crosstalk between IEC and innate and adaptive immune cells. IECs, co-cultured with αCD3/CD28-activated peripheral blood mononuclear cells (PBMC), were apically exposed to NDOs and CpG, washed and co-cultured with immature monocyte-derived dendritic cells (moDC). Subsequently, moDC were co-cultured with naïve CD4+ T-cells. In the presence of CpG, both 2'-FL or GF-exposed IEC enhanced Th1-type IFNγ and regulatory IL-10 secretion of PBMCs, compared to CpG alone, while Th2-type IL-13 was reduced. Both NDOs increased IEC-derived galectin-3, -4, -9 and TGF-β1 of CpG-exposed IEC. Only galectin-9 correlated with all modified immune parameters and TGF-β1 secretion. MoDCs exposed to 2'-FL and CpG-conditioned IEC instructed IFNγ and IL-10 secretion by CD4+ T-cells, suggesting the development of a regulatory Th1 response. These results reveal that 2'-FL and GF could contribute to the mucosal immune development by supporting the effect of microbial CpG DNA associated with the modulation of epithelial galectin and TGF-β1 secretion.

Effect of long-term consumption of tea (Camellia sinensis L.) flower polysaccharides on maintaining intestinal health in BALB/c mice

Polysaccharides have various health-promoting functions. However, dietary polysaccharides cannot be digested by the human alimentary tract, thus the gut is the most important location where polysaccharides play their role. The effect of polysaccharides from tea (Camellia sinensis L.) flower (TFPS) on intestinal health was investigated in the present study. TFPS with the molecular weight of 1,316.29 kDa was prepared, and twenty 6-week-old BALB/c male mice were randomly allotted to a chow diet (normal control group, NC group) or with 200 mg/kg (body weight)/day of TFPS for 13 weeks (n = 10 each). Histomorphology observation of jejunum and colons showed that TFPS maintained the adequate gut barrier. qPCR analysis revealed that the expression of colonic tight junction proteins of claudin1 (1.29 ± 0.15 compared with 1.00 ± 0.13, P < 0.05) and claudin5 (2.91 ± 0.44 compared with 1.00 ± 0.27, P < 0.01) at mRNA level with a significant difference between TFPS supplement or not, while the expression of TLR4 and TNF-α mRNA was not changed statistically. 16S rDNA amplicons sequencing was applied to measure the compositions of gut microbiota from feces of mice. TFPS treatment exhibited similar relative abundances in Bacteroidetes and Firmicutes; however, it decreased the relative abundance of Akkermansia and increased that of Lactobacillus compared with the NC group. The contents of short-chain fatty acids after TFPS supplementation, both in cecal contents and feces, were significantly higher than those of the NC group. Besides, TFPS significantly increased IgA production. These results suggest that TFPS is beneficial to intestinal health and can improve intestinal adaptive immune tolerance. PRACTICAL APPLICATION: Dietary polysaccharides improve human intestinal health. Understanding the effect of TFPS, safe and healthy food components, on gut health increases the likelihood that TFPS will be developed as a functional food.

Towards manufacturing of human organoids

Organoids are 3D miniature versions of organs produced from stem cells derived from either patient or healthy individuals in vitro that recapitulate the actual organ. Organoid technology has ensured an alternative to pre-clinical drug testing as well as being currently used for "personalized medicine" to modulate the treatment as they are uniquely identical to each patient's genetic makeup. Researchers have succeeded in producing different types of organoids and have demonstrated their efficient application in various fields such as disease modeling, pathogenesis, drug screening and regenerative medicine. There are several protocols for fabricating organoids in vitro. In this comprehensive review, we focus on key methods of producing organoids and manufacturing considerations for each of them while providing insights on the advantages, applications and challenges of these methods. We also discuss pertinent challenges faced during organoid manufacturing and various bioengineering approaches that can improve the organoid manufacturing process. Organoids size, number and the reproducibility of the fabrication processes are touched upon. The major factors which are involved in organoids manufacturing such as spatio-temporal controls, scaffold designs/types, cell culture parameters and vascularization have been highlighted.

From Entry to Early Dissemination-Toxoplasma gondii's Initial Encounter With Its Host

Toxoplasma gondii is a zoonotic intracellular parasite, able to infect any warm-blooded animal via ingestion of infective stages, either contained in tissue cysts or oocysts released into the environment. While immune responses during infection are well-studied, there is still limited knowledge about the very early infection events in the gut tissue after infection via the oral route. Here we briefly discuss differences in host-specific responses following infection with oocyst-derived sporozoites vs. tissue cyst-derived bradyzoites. A focus is given to innate intestinal defense mechanisms and early immune cell events that precede T. gondii's dissemination in the host. We propose stem cell-derived intestinal organoids as a model to study early events of natural host-pathogen interaction. These offer several advantages such as live cell imaging and transcriptomic profiling of the earliest invasion processes. We additionally highlight the necessity of an appropriate large animal model reflecting human infection more closely than conventional infection models, to study the roles of dendritic cells and macrophages during early infection.