Air-liquid Interface Cultures Research Articles

T84 Monolayer Cell Cultures Support Productive HBoV and HSV-1 Replication and Enable In Vitro Co-Infection Studies

T84 Monolayer Cell Cultures Support Productive HBoV and HSV-1 Replication and Enable In Vitro Co-Infection Studies

Air-liquid intestinal cell culture allows in situ rheological characterization of intestinal mucus.

Intestinal health heavily depends on establishing a mucus layer within the gut with physical properties that strike a balance between being sufficiently elastic to keep out harmful pathogens yet viscous enough to flow and turnover the contents being digested. Studies investigating dysfunction of the mucus layer in the intestines are largely confined to animal models, which require invasive procedures to collect the mucus fluid. In this work, we develop a nondestructive method to study intestinal mucus. We use an air-liquid interface culture of primary human intestinal epithelial cells that exposes their apical surface to allow in situ analysis of the mucus layer. Mucus collection is not only invasive but also disrupts the mucus microstructure, which plays a crucial role in the interaction between mucus and the gut microbiome. Therefore, we leverage a noninvasive rheology technique that probes the mechanical properties of the mucus without removal from the culture. Finally, to demonstrate biomedical uses for this cell culture system, we characterize the biochemical and biophysical properties of intestinal mucus due to addition of the cytokine IL-13 to recapitulate the gut environment of Nippostrongylus brasiliensis infection.

A cholangiocyte organoid system for Cryptosporidium parvum cultivation and transcriptomic studies of biliary cryptosporidiosis

Biliary cryptosporidiosis caused by Cryptosporidium is life-threatening in immunocompromised individuals, particularly those with acquired immune deficiency syndrome (AIDS), resulting in AIDS cholangiopathy. However, studies of biliary cryptosporidiosis have lagged due to the lack of in vitro models that allow complete pathogen development. Here we describe procedures for the generation of mouse cholangiocyte organoids (Chol-orgs). The Chol-orgs, which expressed stem and biliary cell markers, could be clonally expanded for three months and stored in liquid nitrogen for more than one year. Combined with cell differentiation using the air-liquid interface (ALI) approach, we established a culture system for Cryptosporidium parvum. ALI cultures using Chol-orgs have supported ∼50-fold amplification of the pathogen and generated viable oocysts in vitro. In addition, we analyzed the transcriptome of Chol-ALI cultures infected with the IId subtype of C. parvum to characterize host cell responses. RNA-seq analysis revealed that C. parvum upregulated immune and inflammatory responses and downregulated metabolic and cell proliferation signaling pathways in Chol-orgs. A similar system using bovine cholangiocytes also supported the complete development of C. parvum in vitro. These in vitro models provide convenient methods to study biliary cryptosporidiosis and other hepatic infections and to develop effective therapies for AIDS cholangiopathy.

In vitro platform to model the function of ionocytes in the human airway epithelium

BackgroundPulmonary ionocytes have been identified in the airway epithelium as a small population of ion transporting cells expressing high levels of CFTR (cystic fibrosis transmembrane conductance regulator), the gene mutated in cystic fibrosis. By providing an infinite source of airway epithelial cells (AECs), the use of human induced pluripotent stem cells (hiPSCs) could overcome some challenges of studying ionocytes. However, the production of AEC epithelia containing ionocytes from hiPSCs has proven difficult. Here, we present a platform to produce hiPSC-derived AECs (hiPSC-AECs) including ionocytes and investigate their role in the airway epithelium.MethodshiPSCs were differentiated into lung progenitors, which were expanded as 3D organoids and matured by air-liquid interface culture as polarised hiPSC-AEC epithelia. Using CRISPR/Cas9 technology, we generated a hiPSCs knockout (KO) for FOXI1, a transcription factor that is essential for ionocyte specification. Differences between FOXI1 KO hiPSC-AECs and their wild-type (WT) isogenic controls were investigated by assessing gene and protein expression, epithelial composition, cilia coverage and motility, pH and transepithelial barrier properties.ResultsMature hiPSC-AEC epithelia contained basal cells, secretory cells, ciliated cells with motile cilia, pulmonary neuroendocrine cells (PNECs) and ionocytes. There was no difference between FOXI1 WT and KO hiPSCs in terms of their capacity to differentiate into airway progenitors. However, FOXI1 KO led to mature hiPSC-AEC epithelia without ionocytes with reduced capacity to produce ciliated cells.ConclusionOur results suggest that ionocytes could have role beyond transepithelial ion transport by regulating epithelial properties and homeostasis in the airway epithelium.

SERS Microsensors for the Study of pH Regulation in Cystic Fibrosis Patient-Derived Airway Cultures.

Acidification of the airway surface liquid in the respiratory system could play a role in the pathology of Cystic Fibrosis, but its low volume and proximity to the airway epithelium make it a challenging biological environment in which to noninvasively collect pH measurements. To address this challenge, we explored surface enhanced Raman scattering microsensors (SERS-MS), with a 4-mercaptobenzoic acid (MBA) pH reporter molecule, as pH sensors for the airway surface liquid of patient-derived in vitro models of the human airway. Using air-liquid interface (ALI) cultures to model the respiratory epithelium, we show that SERS-MS facilitates the optical measurement of trans-epithelial pH gradients between the airway surface liquid and the basolateral culture medium. SERS-MS also enabled the successful quantification of pH changes in the airway surface liquid following stimulation of the Cystic Fibrosis transmembrane conductance regulator (CFTR, the apical ion channel that is dysfunctional in Cystic Fibrosis airways). Finally, the influence of CFTR mutations on baseline airway surface liquid pH was explored by using SERS-MS to measure the pH in ALIs grown from Cystic Fibrosis and non-Cystic Fibrosis donors.

In utero and postnatal ivacaftor/lumacaftor therapy rescues multiorgan disease in CFTR-F508del ferrets.

Cystic fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene, with F508del being the most prevalent mutation. The combination of CFTR modulators (potentiator and correctors) has provided benefit to CF patients carrying the F508del mutation; however, the safety and effectiveness of in utero combination modulator therapy remains unclear. We created a F508del ferret model to test whether ivacaftor/lumacaftor (VX-770/VX-809) therapy can rescue in utero and postnatal pathologies associated with CF. Using primary intestinal organoids and air-liquid interface cultures of airway epithelia, we demonstrate that the F508del mutation in ferret CFTR results in a severe folding and trafficking defect, which can be partially restored by treatment with CFTR modulators. In utero treatment of pregnant jills with ivacaftor/lumacaftor prevented meconium ileus at birth in F508del kits and sustained postnatal treatment of CF offspring improved survival and partially protected from pancreatic insufficiency. Withdrawal of ivacaftor/lumacaftor treatment from juvenile CF ferrets reestablished pancreatic and lung diseases, with altered pulmonary mechanics. These findings suggest that in utero intervention with a combination of CFTR modulators may provide therapeutic benefits to individuals with F508del. This CFTR-F508del ferret model may be useful for testing therapies using clinically translatable endpoints.

S. aureus biofilm properties correlate with immune B cell subset frequencies and severity of chronic rhinosinusitis

Staphylococcus aureus mucosal biofilms are associated with recalcitrant chronic rhinosinusitis (CRS). However, S. aureus colonisation of sinus mucosa is frequent in the absence of mucosal inflammation. This questions the relevance of S. aureus biofilms in CRS etiopathogenesis. This study aimed to investigate whether strain-level variation in in vitro-grown S. aureus biofilm properties relates to CRS disease severity, in vitro toxicity, and immune B cell responses in sinonasal tissue from CRS patients and non-CRS controls. S. aureus clinical isolates, tissue samples, and matched clinical datasets were collected from CRS patients with nasal polyps (CRSwNP), CRS without nasal polyps (CRSsNP), and controls. B cell responses in tissue samples were characterised by FACS. S. aureus biofilms were established in vitro, followed by measuring their properties of metabolic activity, biomass, colony-forming units, and exoprotein production. S. aureus virulence was evaluated using whole-genome sequencing, mass spectrometry and application of S. aureus biofilm exoproteins to air-liquid interface cultures of primary human nasal epithelial cells (HNEC-ALI). In vitro S. aureus biofilm properties were correlated with increased CRS severity scores, infiltration of antibody-secreting cells and loss of regulatory B cells in tissue samples. Biofilm exoproteins from S. aureus with high biofilm metabolic activity had enriched virulence genes and proteins, and negatively affected the barrier function of HNEC-ALI cultures. These findings support the notion of strain-level variation in S. aureus biofilms to be critical in the pathophysiology of CRS.

SARS-CoV-2 nsp15 endoribonuclease antagonizes dsRNA-induced antiviral signaling

Severe acute respiratory syndrome coronavirus (SARS-CoV)-2 has caused millions of deaths since its emergence in 2019. Innate immune antagonism by lethal CoVs such as SARS-CoV-2 is crucial for optimal replication and pathogenesis. The conserved nonstructural protein 15 (nsp15) endoribonuclease (EndoU) limits activation of double-stranded (ds)RNA-induced pathways, including interferon (IFN) signaling, protein kinase R (PKR), and oligoadenylate synthetase/ribonuclease L (OAS/RNase L) during diverse CoV infections including murine coronavirus and Middle East respiratory syndrome (MERS)-CoV. To determine how nsp15 functions during SARS-CoV-2 infection, we constructed a recombinant SARS-CoV-2 (nsp15mut) expressing catalytically inactivated nsp15, which we show promoted increased dsRNA accumulation. Infection with SARS-CoV-2 nsp15mut led to increased activation of the IFN signaling and PKR pathways in lung-derived epithelial cell lines and primary nasal epithelial air-liquid interface (ALI) cultures as well as significant attenuation of replication in ALI cultures compared to wild-type virus. This replication defect was rescued when IFN signaling was inhibited with the Janus activated kinase (JAK) inhibitor ruxolitinib. Finally, to assess nsp15 function in the context of minimal (MERS-CoV) or moderate (SARS-CoV-2) innate immune induction, we compared infections with SARS-CoV-2 nsp15mut and previously described MERS-CoV nsp15 mutants. Inactivation of nsp15 had a more dramatic impact on MERS-CoV replication than SARS-CoV-2 in both Calu3 cells and nasal ALI cultures suggesting that SARS-CoV-2 can better tolerate innate immune responses. Taken together, SARS-CoV-2 nsp15 is a potent inhibitor of dsRNA-induced innate immune response and its antagonism of IFN signaling is necessary for optimal viral replication in primary nasal ALI cultures.

Oxygen levels affect oviduct epithelium functions in air-liquid interface culture.

Key reproductive events such as fertilization and early embryonic development occur in the lumen of the oviduct. Since investigating these processes in vivo is both technically challenging and ethically sensitive, cell culture models have been established to reproduce the oviductal microenvironment. Compartmentalized culture systems, particularly air-liquid interface cultures (ALI; cells access the culture medium only from the basolateral cell side), result in highly differentiated oviduct epithelial cell cultures. The oxygen (O2) tension within the oviduct is 4-10% across species, and its reduced O2 content is presumed to be important for early reproductive processes. However, cell culture models of the oviduct are typically cultivated without O2 regulation and therefore at about 18% O2. To investigate the impact of O2 levels on oviduct epithelium functions in vitro, we cultured porcine oviduct epithelial cells (POEC) at the ALI using both physiological (5%) and supraphysiological (18%) O2 levels and two different media regimes. Epithelium architecture, barrier function, secretion of oviduct fluid surrogate (OFS), and marker gene expression were comparatively assessed. Under all culture conditions, ALI-POEC formed polarized, ciliated monolayers with appropriate barrier function. Exposure to 18% O2 accelerated epithelial differentiation and significantly increased the apical OFS volume and total protein content. Expression of oviduct genes and the abundance of OVGP1 (oviduct-specific glycoprotein1) in the OFS were influenced by both O2 tension and medium choice. In conclusion, oviduct epithelial cells can adapt to a supraphysiological O2 environment. This adaptation, however, may alter their capability to replicate in vivo tissue characteristics.

Abstract 6774: Establishment and optimization of an air liquid interface co-culture system to evaluate phenotypic changes in primary human Barrett's esophagus cells upon different environmental exposures

Abstract Esophageal adenocarcinoma (EAC) is a deadly cancer with an increasing incidence which arises out of it's precancerous precursor, termed Barrett’s esophagus (BE). A better understanding of the factors that influence BE progression is essential for early detection and novel therapeutics. 3D Air Liquid Interface (ALI) cultures provide an edge over traditional 2D cultures as they better mimic the in vivo conditions of the esophagus. The aim of the study was to establish conditions for a BE ALI model and to evaluate the phenotypic and molecular changes in primary human BE cells upon interaction with different types of esophageal fibroblasts (EF) and exposure to bile acids(BA) (a major component of gastroesophageal reflux). ALI conditions that allowed growth of both primary BE and fibroblast for at least 30 days were optimized. Non dysplastic BE cells from two patients were utilized with one having EAC (P) and the other with no history of progression (NP). The BE cells were cultured in our ALI model with 3 types of EFs: normal esophageal fibroblasts(NFs), BE associated fibroblasts(BFs) and EAC associated fibroblasts(CFs). To determine the effect of BA exposure, ALI cultures underwent daily 1 hour exposure to bile salts. To determine if BE cells that lacked p53 responded differently to BA exposure, CRISPR Cas9 was utilized to knockout TP53. ALI cultures were conducted for 28 days. Phenotypic differences were determined by H&E staining and immunofluorescence (IF). Changes in cell proliferation was evaluated by Ki67 IF. Successful ALI cultures were validated by positive expression of laminin, pan-cytokeratin, Muc2 and Muc5ac by IF. Upon co-culture, we observed opposing histologic changes in the BE cells from the P and NP patients. The NP BE cells had a less complex structure upon culture with the BFs and CFs compared to NFs. The P BE cells showed the development of a complex morphology upon culture with the CFs compared to the BFs and the NFs. In both patients, we observed an increase in Ki67 positivity with fibroblast co culture; NFs (NP: 6.91%, p=0.070, P: 10.6%, p=0.001), BFs (NP: 12.49%, p=0.0001, P: 11.196%, p=0.003) and CFs (NP: 19.88%, p<0.0001, P:14.63 %, p=0.0001) compared to no fibroblasts (NP = 5.32%, P= 7.25% Ki67+). Co-culture with CFs increased Ki67 staining compared to either NFs or BFs (p=0.007,0.014). Exposure to BA showed a thinning but intact BE epithelial surface in both patients with and without TP53 knockout. Overall, primary BE cells and fibroblasts can be maintained long term in an ALI culture and co-culture with fibroblasts drive increased proliferation in BE cells. The histology changes observed in NP and P cell could be an indication of possible activation and interaction of differential signaling pathways. Ongoing studies aim to identify these pathways and determine transcriptional changes due to co-culture and BA exposure. Citation Format: Annesha Chatterjee, Jordana Maria Azevedo-Martins, Chira Chen Tanyolac, Qurat-Ul Ain, Hui Yu, Sophie Camilleri-Broet, Lorenzo Ferri, Philippe Gascard, Thea D. Tlsty, Matthew D. Stachler. Establishment and optimization of an air liquid interface co-culture system to evaluate phenotypic changes in primary human Barrett's esophagus cells upon different environmental exposures [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6774.

Abstract 6099: Identification of intrinsic precursors of Barrett's and gastric intestinal metaplasia

Abstract The origin of Barrett's esophagus (BE) and gastric intestinal metaplasia (GIM), obligate precursors of esophageal adenocarcinoma (EAC) and intestinal gastric cancer (iGC), has intrigued investigators for decades and would likely guide preemptive strategies. From endoscopic biopsies of clinically confirmed BE and GIM, we have cloned stem cells committed to intestinal metaplasia in vitro. Remarkably, the gene expression profiles of BE and GIM stem cells are highly related down to broad arrays of transcription factors compared with stem cells of the normal gastric mucosa. Using cell surface markers in common between BE and GIM stem cells, we have identified clusters of cells at the squamocolumnar junction and the distal stomach in mice and have used Fluorescence-activated cell sorting (FACS) to clone these cells from both sites. These murine clones can be differentiated in air-liquid interface cultures, and both are committed to intestinal metaplasia marked by goblet cells and Alcian blue staining. To ask whether similar cells exist in humans, we generated stem cell libraries from endoscopic biopsies taken from the gastroesophageal junction (GEJ) and the antrum-body junction (ABJ) in patients without BE or GIM. FACS sorting of these stem cell libraries using the same cell surface markers common to BE and GIM stem cells and the murine precursors, we have identified stem cells from the GEJ and ABJ that show similar gene expression profiles and share a commitment to intestinal metaplasia upon in vitro differentiation. Using identical transformation protocols involving retrovirally transduced protooncogenes, we find that these transformed intrinsic cells give rise to tumors with expression profiles similar to EAC and iGC in TCGA datasets, whereas transformed gastric mucosal stem cells yield tumors marked by signet ring cells typical of diffuse gastric cancer. Lastly, we find that drugs we have developed that target the stem cells of BE and GIM also eliminate the putative precursor cells of BE and GIM, suggesting the potential of therapeutics that might eliminate the emergence of intestinal metaplasia and the cancers derived from them. Citation Format: Wa Xian, Frank McKeon, Yusuke Yamamoto, Melika Khorrami, Melina Khorrami, Zaal Mory, Jeremy Siegelman, Amber Su, Raul Caballero Montes, Ashley Hoffman, Jaffer Ajani, Christopher Crum, William Bachovchin, Shan Wang, Matthew Vincent, Crystal Nguyen. Identification of intrinsic precursors of Barrett's and gastric intestinal metaplasia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6099.

Abstract 237: Establishment of an ex vivo tissue culture model as a potential preclinical drug testing platform for hepatocellular carcinoma

Abstract Background: Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths worldwide, and there is a critical need for more effective treatments. The development of new therapies, especially those aiming to modulate the tumor microenvironment (TME), is limited by the lack of in vitro and in vivo models that recapitulate the complexity of the TME and spatial architecture of HCC. Here, we aimed to establish an HCC model to assess the treatment response and hepatotoxicity of selected drugs by ex vivo culturing fresh human liver tumor tissue and adjacent normal tissue, respectively. Materials and Methods: Fresh human liver tissues, including 5 malignant and 20 adjacent-normal, were obtained from surgical resections. PDX tumors were generated from patient-derived organoids. Tissue resections were cut into ultra-thin slices (from 150µm to 350µm) using a vibratome. Related culture conditions such as high oxygen partial pressure, air-liquid interface (ALI) culture, artificial extracellular matrix (AEM), and delay duration were evaluated to optimize the protocol. As a readout, cell viability was quantified by an expert pathologist using Hematoxylin/Eosin staining. The preservation and complexity of the TME were evaluated by immunohistochemistry or flow cytometry using specific antibodies for each cell population (T cells, anti-CD3; stroma cells, a-SMA; endothelial cells, CD34; Kupffer cells, CD68). Liver cell function was tested by measuring ALT/AST activity, albumin release, and CYP340 activity. Results: The highest tissue viability was observed in normal and tumor tissue with a thickness of 150µm and 250µm, respectively. Compared to standard conditions, the combination of ALI and high-oxygen partial pressure conditions dramatically improved tissue viability, with most of the samples having 70% and 50% cell viability at days 3 and 5 of ex vivo culture, respectively (p<0.05). AEM could prevent the efflux of cellular components (p=0.016). The impact of the time delay between the liver resection and the start of slicing was minimal when the slicing occurred within two hours after hepatectomy (p<0.05). Key cellular components including hepatocytes, T cells, fibroblasts, and Kupffer cells also remained better preserved throughout the 5-day culture period in optimized conditions. Conclusion: Our study has successfully optimized the ex vivo tissue culture model of liver tissue, capable of maintaining the tissue for several days while preserving the unique TME. These results highlight the potential of using the ex vivo tissue culture model in the preclinical setting to further investigate and evaluate TME-related treatments and their hepatotoxicity in HCC tissues. Citation Format: Huiche Feng, Miriam Cieri, Cinzia Esposito, Karolina Guja-Jarosz, Daniela Liberati, Lukas Bubendorf, Savas Deniz Soysal, Mairene Coto-Llerena, Luigi Maria Terracciano, Otto Kollmar, Salvatore Piscuoglio. Establishment of an ex vivo tissue culture model as a potential preclinical drug testing platform for hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 237.

Novel air-liquid interface culture model to investigate stiffness-dependent behaviors of alveolar epithelial cells

Pulmonary alveoli are functional units in gas exchange in the lung, and their dysfunctions in lung diseases such as interstitial pneumonia are accompanied by fibrotic changes in structure, elevating the stiffness of extracellular matrix components. The present study aimed to test the hypothesis that such changes in alveoli stiffness induce functional alteration of epithelial cell functions, exacerbating lung diseases. For this, we have developed a novel method of culturing alveolar epithelial cells on polyacrylamide gel with different elastic modulus at an air-liquid interface. It was demonstrated that A549 cells on soft gels, mimicking the modulus of a healthy lung, upregulated mRNA expression and protein synthesis of surfactant protein C (SFTPC). By contrast, the cells on stiff gels, mimicking the modulus of the fibrotic lung, exhibited upregulation of SFTPC gene expression but not at the protein level. Cell morphology, as well as cell nucleus volume, were also different between the two types of gels.

German cockroach extract prevents IL-13-induced CCL26 expression in airway epithelial cells through IL-13 degradation.

Inhaled aeroallergens can directly activate airway epithelial cells (AECs). Exposure to cockroach allergens is a strong risk factor for asthma. Cockroach allergens mediate some of their effects through their serine protease activity; protease activity is also a major contributor to allergenicity. The Th2 cytokine interleukin-13 (IL-13) induces upregulation of the eosinophil chemotactic factor CCL26. CCL26 induces eosinophil migration in allergic inflammation. In this work, we studied the effect of cockroach proteases on IL-13-induced effects. Immersed cultures of the human bronchial epithelial cell line BEAS-2B and air-liquid interface (ALI) cultures of primary normal human bronchial epithelial (NHBE) cells were stimulated with IL-13, Blattella Germanica cockroach extract (CE), or both. IL-13-induced genes were analyzed with qRT-PCR. IL-13 induced upregulation of CCL26, periostin, and IL-13Rα2 in bronchial epithelial cells which were decreased by CE. CE was heat-inactivated (HICE) or pre-incubated with protease inhibitors. HICE and CE preincubated with serine protease inhibitors did not prevent IL-13-induced CCL26 upregulation. CE-degraded IL-13 and specific cleavage sites were identified. CE also decreased IL-4-induced CCL26 upregulation and degraded IL-4. Other serine proteases such as bovine trypsin and house dust mite (HDM) serine proteases did not have the same effects on IL-13-induced CCL26. We conclude that CE serine proteases antagonize IL-13-induced effects in AECs, and this CE effect is mediated primarily through proteolytic cleavage of IL-13. IL-13 cleavage by cockroach serine proteases may modulate CCL26-mediated effects in allergic airway inflammation by interfering directly with the pro-inflammatory effects of IL-13 invivo.

Lentiviral expression of wild-type LAMA3A restores cell adhesion in airway basal cells from children with epidermolysis bullosa

The hallmark of epidermolysis bullosa (EB) is fragile attachment of epithelia due to genetic variants in cell adhesion genes. We describe 16 EB patients treated in the Ear, Nose and Throat department of a tertiary pediatric hospital linked to the United Kingdom’s National EB unit between 1992 and 2023. Patients suffered a high degree of morbidity and mortality from laryngotracheal stenosis. Variants in laminin subunit alpha-3 (LAMA3) were found in 10/15 patients where genotype was available. LAMA3 encodes a subunit of the laminin-332 heterotrimeric extracellular matrix protein complex and is expressed by airway epithelial basal stem cells. We investigated the benefit of restoring wildtype LAMA3 expression in primary EB patient-derived basal cell cultures. EB basal cells demonstrated weak adhesion to cell culture substrates, but could otherwise be expanded similarly to non-EB basal cells. In vitro lentiviral overexpression of LAMA3A in EB basal cells enabled them to differentiate in air-liquid interface cultures, producing cilia with normal ciliary beat frequency. Moreover, transduction restored cell adhesion to levels comparable to a non-EB donor culture. These data provide proof-of-concept for a combined cell and gene therapy approach to treat airway disease in LAMA3-affected EB.

Seihaito, a Kampo medicine, attenuates IL-13-induced mucus production and goblet cell metaplasia

Goblet cell hyperplasia and increased mucus production are features of airway diseases, including asthma, and excess airway mucus often worsens these conditions. Even steroids are not uniformly effective in mucus production in severe asthma, and new therapeutic options are needed. Seihaito is a Japanese traditional medicine that is used clinically as an antitussive and expectorant. In the present study, we examined the effect of Seihaito on goblet cell differentiation and mucus production. In in vitro studies, using air–liquid interface culture of guinea-pig tracheal epithelial cells, Seihaito inhibited IL-13-induced proliferation of goblet cells and MUC5AC, a major component of mucus production. Seihaito suppressed goblet cell-specific gene expression, without changing ciliary cell-specific genes, suggesting that it inhibits goblet cell differentiation. In addition, Seihaito suppressed MUC5AC expression in cells transfected with SPDEF, a transcription factor activated by IL-13. Furthermore, Seihaito attenuated in vivo goblet cell proliferation and MUC5AC mRNA expression in IL-13-treated mouse lungs. Collectively, these findings demonstrated that Seihaito has an inhibitory effect on goblet cell differentiation and mucus production, which is at least partly due to the inhibition of SPDEF.

A Cell-Based Nasal Model for Screening the Deposition, Biocompatibility, and Transport of Aerosolized PLGA Nanoparticles.

The olfactory region of the nasal cavity directly links the brain to the external environment, presenting a potential direct route to the central nervous system (CNS). However, targeting drugs to the olfactory region is challenging and relies on a combination of drug formulation, delivery device, and administration technique to navigate human nasal anatomy. In addition, in vitro and in vivo models utilized to evaluate the performance of nasal formulations do not accurately reflect deposition and uptake in the human nasal cavity. The current study describes the development of a respirable poly(lactic-co-glycolic acid) nanoparticle (PLGA NP) formulation, delivered via a pressurized metered dose inhaler (pMDI), and a cell-containing three-dimensional (3D) human nasal cast model for deposition assessment of nasal formulations in the olfactory region. Fluorescent PLGA NPs (193 ± 3 nm by dynamic light scattering) were successfully formulated in an HFA134a-based pMDI and were collected intact following aerosolization. RPMI 2650 cells, widely employed as a nasal epithelial model, were grown at the air-liquid interface (ALI) for 14 days to develop a suitable barrier function prior to exposure to the aerosolized PLGA NPs in a glass deposition apparatus. Direct aerosol exposure was shown to have little effect on cell viability. Compared to an aqueous NP suspension, the transport rate of the aerosolized NPs across the RPMI 2650 barrier was higher at all time points indicating the potential advantages of delivery via aerosolization and the importance of employing ALI cellular models for testing respirable formulations. The PLGA NPs were then aerosolized into a 3D-printed human nasal cavity model with an insert of ALI RPMI 2650 cells positioned in the olfactory region. Cells remained highly viable, and there was significant deposition of the fluorescent NPs on the ALI cultures. This study is a proof of concept that pMDI delivery of NPs is a viable means of targeting the olfactory region for nose-to-brain drug delivery (NTBDD). The cell-based model allows not only maintenance under ALI culture conditions but also sampling from the basal chamber compartment; hence, this model could be adapted to assess drug deposition, uptake, and transport kinetics in parallel under real-life settings.

1. ORGANOID DEVELOPMENT IN COLORECTAL CANCER: NEW MODELS FOR PERSONALIZED MEDICINE

Abstract Introduction Despite the great advances in recent decades in identifying mechanisms related to tumor progression and resistance to treatment, there are still no safe and effective therapies to treat colorectal cancer (the most common neoplasm in Spain). Organoid models represent a highly promising tool for studying this pathology since they recapitulate, with great precision, the structure and functionality of the original organ. Methods At our center, we have generated an extensive collection of human intestinal organoids, including rectum and colon, from biopsies of healthy tissue and tumor tissue from 72 colorectal cancer patients. For the generation of these models, two different approaches were employed: 1. Organoid generation from intestinal crypts embedded in extracellular matrix droplets; 2. Air-liquid interface (ALI) culture that allows recreating the native microenvironment of the tumor while excluding endogenous infiltrating immune cell populations. Results These organoid collections have been highly characterized, confirming that they retain the molecular, structural, and functional characteristics of their tissues of origin. We present the different findings and their correlation. Conclusion The technology developed by our research group serves as a tool of great translational value for studying response/resistance mechanisms to current colorectal cancer treatments. Additionally, it serves as a predictive model for drug response, playing a crucial role in defining the efficacy of personalized antineoplastic treatments for each patient and advancing the development of personalized therapies against colorectal cancer.

Chemically-defined and scalable culture system for intestinal stem cells derived from human intestinal organoids

Three-dimensional human intestinal organoids (hIO) are widely used as a platform for biological and biomedical research. However, reproducibility and challenges for large-scale expansion limit their applicability. Here, we establish a human intestinal stem cell (ISC) culture method expanded under feeder-free and fully defined conditions through selective enrichment of ISC populations (ISC3D-hIO) within hIO derived from human pluripotent stem cells. The intrinsic self-organisation property of ISC3D-hIO, combined with air-liquid interface culture in a minimally defined medium, forces ISC3D-hIO to differentiate into the intestinal epithelium with cellular diversity, villus-like structure, and barrier integrity. Notably, ISC3D-hIO is an ideal cell source for gene editing to study ISC biology and transplantation for intestinal diseases. We demonstrate the intestinal epithelium differentiated from ISC3D-hIO as a model system to study severe acute respiratory syndrome coronavirus 2 viral infection. ISC3D-hIO culture technology provides a biological tool for use in regenerative medicine and disease modelling.

DOP38 A rare KRT17+ population emerges from the epithelium in the inflamed intestinal mucosa of patients with Ulcerative Colitis

Abstract Background KRT17 is an epithelial "alarmin" that contributes to the early host innate immune response to insults. We previously found that KRT17 transcription, not detectable in the healthy colon, is up-regulated in the intestinal mucosa of patients with active ulcerative colitis (UC). Here, we aimed to characterize the epithelial cells expressing KRT17 in UC mucosa and explore the contribution of the intestinal environment in promoting the emergence of this cell population. Methods We conducted single-cell RNAseq (scRNA-seq) on the epithelial compartment of intestinal biopsies from a cohort of non-inflammatory bowel disease (IBD) controls and patients with active UC. Analysis was performed using our own-curated pipeline in Seurat1. Spatial protein localization was analysed by immunofluorescence on fixed intestinal samples. To measure the modulation of KRT17 and associated markers, ex vivo air-liquid interface (ALI) epithelial cultures derived from human non-IBD organoids were used. The signatures of UC-derived organoids2 were mapped onto the scRNA-seq dataset. Results ScRNA-seq analysis identified a rare KRT17+ epithelial cell population emerging in active UC characterized by the expression of KRT17 (Fig. 1A) and other alarmins (KRT6A, KRT16, S100A8), metalloproteinases (MMP1, MMP10), and inflammatory markers (SAA1, DUOX2…). KRT17 protein, absent in non-IBD colon, was expressed in the epithelium of the inflamed UC mucosa exhibiting a patchy pattern, and marked epithelial clusters with both columnar and squamous-like morphology (Fig. 1B). The ALI culture closely recapitulated the differentiated intestinal epithelium in homeostasis by showing a columnar aspect, high expression of differentiation markers, and low or undetectable expression of stem/proliferation or KRT17+-cell markers. Exposure of the ALI culture to hypoxic stress (by re-submersion in expansion medium) induced the expression of KRT17+ cell-specific and inflammation markers (Fig. 1C), and the acquisition of a squamous morphology (Fig. 1D). IBD-related IFN-ɣ and IL-22 cytokines could not fully replicate this phenotype (Fig. 1E). Lastly, we observed that genes up-regulated in UC, compared to non-IBD organoids, were predominantly expressed within the KRT17+ population (Fig. 1F). Conclusion Our results suggest that a novel KRT17+ epithelial population may arise from the intestinal cells of inflamed UC mucosa under the influence of specific environmental factors. This population could contribute to the persistence of the disease over time.