Cell Suspension Research Articles

Integrated transcriptomics and metabolomics provide insights into the biosynthesis of militarine in the cell suspension culture system of Bletilla striata

Militarine is a monomer molecule with abundant and distinctive biological properties, also the lead member of secondary metabolites in Bletilla striata, while its biosynthesis mechanism is still unknown. To improve the production efficiency of militarine, sodium acetate and salicylic acid (SA) were introduced as elicitors into the suspension-cultured callus of B. striata. Subsequently, samples were taken from callus at different culturing stages to investigate the synthesis mechanisms of militarine in B. striata through integrated metabolomics and transcriptomics. Metabolomics analysis revealed that acetate ions promoted militarine synthesis, while SA had an inhibitory effect. Additionally, regulators such as ferulic acid, 2-hydroxy-3-phenylpropionic acid, and cis-beta-D-Glucosyl-2-hydroxycinnamate were identified as influencing militarine synthesis. Transcriptomics analysis indicated that the expression levels of genes involved in phenylalanine metabolism, phenylpropanoid biosynthesis, and tyrosine metabolism were correlated with militarine content. This study sheds light on the regulatory mechanism of militarine biosynthesis in plants. The results suggested that acetate ions and SA impact militarine synthesis through specific metabolic pathways and gene expression changes. This knowledge serves as a foundation for future research on militarine biosynthesis and its industrial production.

Unveiling the potential: Extracellular vesicles from plant cell suspension cultures as a promising source.

Extracellular vesicles are secreted by all eukaryotic cells and they have an important role in intercellular signaling. Plant extracellular vesicles (PEVs) are a novel area of research that has gained attention due to their potential implications in biomolecule transport and therapeutic applications. PEVs are lipid bilayer-enclosed structures that contain a diverse cargo of biomolecules such as proteins and lipids. Moreover, it is known that PEVs have a noticeable therapeutic potential for various conditions such as inflammation and oxidative stress. However, there are critical problems such as removing the endosomes and plant-derived biomolecules that decrease the standardization and therapeutic efficacy of PEVs. In our study, the aim was to characterize plant cell suspension-derived extracellular vesicles (PCSEVs) obtained from two different plant cell suspension cultures: Stevia rebaudiana and Vaccaria hispanica. These vesicles were isolated using ultrafiltration and characterized with nanoparticle tracking analysis (NTA) and atomic force microscopy (AFM). The molecular composition of PCSEVs was profiled and the cellular uptake assay was performed. Our results demonstrated that PCSEVs have a spherical shape, less than 200 nm. In the fatty acid analysis, the primary components in PCSEVs were palmitic acid, linoleic acid, and cis-vaccenic acid. The protein content of Stevia rebaudiana-derived EVs (SDEVs) was largely associated with proteins involved in extracellular structures and functions. Conversely, Vaccaria hispanica-derived EVs (HDEVs) displayed a higher presence of cytosolic proteins. These findings contribute to the understanding of PCSEVs and open up potential avenues in extracellular vesicle research, pointing to promising prospects for future innovations in various fields.

Establishment of Physalis alkekengi cell suspension culture: time-dependent behavior of genes related to the steroidal compounds, key enzymes, and physalins under static magnetic field.

Cell suspension culture has the potential to be a valuable source for the bioactive compound productions. In this study, an optimized procedure was established for callus and cell suspension culture of Physalis alkekengi for the first time, and the impact of static magnetic field (SMF, 6 mT) was studied on the high-value metabolic compounds through investigation of signaling molecules and gene expressions at the late log-to-stationary phase. Results showed that the growth regulators of 6-benzyl amino purine (BAP, 1.5mg-1 L) and 1-naphthaleneacetic acid (NAA, 0.4mg-1 L) induced the highest fresh weight, callus rate, callus index, and total withanolides. Cell suspension culture was established in the liquid MS medium supplied with BAP (1.5mg-1 L) and NAA (0.1mg-1 L). SMF application decreased slightly the cell growth and viability and enhanced the number of round-shaped cells. The hydrogen peroxide (H2O2) and nitric oxide (NO) levels increased at an all-time series after SMF exposure, and their maximum contents were observed after 12h. A significant alteration of malondialdehydecontent was also identified after 12h of SMF exposure. The expression of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR), 1-deoxyD-xylulose 5-phosphate synthase (DXS), squalene synthase (SQS), sterol Δ7-reductase (DWF5), and C-7,8 sterol isomerase (HYD1) genes was upregulated significantly after 24 and 48h. An increase in the total withanolides was related to more activity of HMGR and DXS enzymes in SMF-exposed cells and the maximum physalin A (12.8mgg-1 DW) and physalin B (1.92mgg-1 DW) obtained after 24h compared to controls. Findings suggest that SMF can play a supportive factor in inducing steroidal compounds in P. alkekengi through modulating H2O2 and NO levels and the related-gene expressions.

Rosmarinic Acid Content and Antioxidant Activity in Ehretia asperula Zollinger et Moritzi Cell Suspension Cultures

Background: Ehretia asperula Zollinger et Moritzi is a medicinal tree abundant in rosmarinic acid, the primary phenolic component, with numerous beneficial biological properties, including antioxidant, antibacterial, antiviral, anti-allergy, anti-arthritis, asthma and anti-cancer. Methods: The cell suspension cultures of E. asperula Zollinger et Moritzi derived from the leaf in vitro callus were established in liquid B5 medium added with 0.4 mg/L NAA, 0.1 mg/L BA and 45 g/L glucose. After four weeks, 50 mg/L of chitosan was given to the cell suspension cultures to stimulate rosmarinic acid (RA) production after a 48-hour treatment period. RA content was analyzed using the HPLC and spectrophotometry method after four weeks and 48 hours of chitosan treatment. In addition, the antioxidant capacity of the extracts from E. asperula Zollinger et Moritzi was also tested using DPPH free radical scavenging assay. Result: The RA content and antioxidant capacity of E. asperula Zollinger et Moritzi’ extracts from the leaf in vitro greater than callus derived from the leaf in vitro greater than field-grown leaf greater than biomass of cell suspension cultures. These results suggested a strong correlation between RA concentration and antioxidant capacity. The use of E. asperula Zollinger et Moritzi cell suspension cultures with chitosan as an elicitor for RA production and evaluation of antioxidant activity is presented in this study for the first time. Our results suggest that cell suspension cultures and others may be a good source of RA, an antioxidant compound.

BTB and CNC homology 1 deficiency disrupts intestinal IgA secretion through regulation of polymeric immunoglobulin receptor expression.

Immunoglobulin A (IgA)-mediated mucosal immunity is important for the host because it contributes to reducing infection risk and to establishing host-microbe symbiosis. BTB and CNC homology 1 (Bach1) is a transcriptional repressor with physiological and pathophysiological functions that are of particular interest for their relation to gastrointestinal diseases. However, Bach1 effects on IgA-mediated mucosal immunity remain unknown. For this study using Bach1-deficient (Bach1-/-) mice, we investigated the function of Bach1 in IgA-mediated mucosal immunity. Intestinal mucosa, feces, and plasma IgA were examined using immunosorbent assay. After cell suspensions were prepared from Peyer's patches and colonic lamina propria, they were examined using flow cytometry. The expression level of polymeric immunoglobulin receptor (pIgR), which plays an important role in the transepithelial transport of IgA, was evaluated using Western blotting, quantitative real-time PCR, and immunohistochemistry. Although no changes in the proportions of IgA-producing cells were observed, the amounts of IgA in the intestinal mucosa were increased in Bach1-/- mice. Furthermore, plasma IgA was increased in Bach1-/- mice, but fecal IgA was decreased, indicating that Bach1-/- mice have abnormal secretion of IgA into the intestinal lumen. In fact, Bach1 deficiency reduced pIgR expression in colonic mucosa at both the protein and mRNA levels. In the human intestinal epithelial cell line LS174T, suppression of Bach1 reduced pIgR mRNA stability. In contrast, overexpression of Bach1 increased pIgR mRNA stability. These results demonstrate that Bach1 deficiency causes abnormal secretion of IgA into the intestinal lumen via suppression of pIgR expression.

BTB and CNC homology 1 deficiency disrupts intestinal IgA secretion through regulation of polymeric immunoglobulin receptor expression.

Immunoglobulin A (IgA)-mediated mucosal immunity is important for the host because it contributes to reducing infection risk and to establishing host-microbe symbiosis. BTB and CNC homology 1 (Bach1) is a transcriptional repressor with physiological and pathophysiological functions that are of particular interest for their relation to gastrointestinal diseases. However, Bach1 effects on IgA-mediated mucosal immunity remain unknown. For this study using Bach1-deficient (Bach1-/-) mice, we investigated the function of Bach1 in IgA-mediated mucosal immunity. Intestinal mucosa, feces, and plasma IgA were examined using immunosorbent assay. After cell suspensions were prepared from Peyer's patches and colonic lamina propria, they were examined using flow cytometry. The expression level of polymeric immunoglobulin receptor (pIgR), which plays an important role in the transepithelial transport of IgA, was evaluated using Western blotting, quantitative real-time PCR, and immunohistochemistry. Although no changes in the proportions of IgA-producing cells were observed, the amounts of IgA in the intestinal mucosa were increased in Bach1-/- mice. Furthermore, plasma IgA was increased in Bach1-/- mice, but fecal IgA was decreased, indicating that Bach1-/- mice have abnormal secretion of IgA into the intestinal lumen. In fact, Bach1 deficiency reduced pIgR expression in colonic mucosa at both the protein and mRNA levels. In the human intestinal epithelial cell line LS174T, suppression of Bach1 reduced pIgR mRNA stability. In contrast, overexpression of Bach1 increased pIgR mRNA stability. These results demonstrate that Bach1 deficiency causes abnormal secretion of IgA into the intestinal lumen via suppression of pIgR expression.

Short-term cultured tumor fragments to study immunotherapy combinations based on CD137 (4-1BB) agonism

ABSTRACT Biomarkers for cancer immunotherapy are an unmet medical need. The group of Daniela Thommen at the NKI recently reported on novel methodologies based on short-term cultures of patient-derived tumor fragments whose cytokine concentrations in the supernatants and activation markers on infiltrating T cells were associated with clinical response to PD-1 blockade. We set up a similar culture technology with tumor-derived fragments using mouse tumors transplanted into syngeneic immunocompetent mice to test an agonist anti-CD137 mAb and its combinations with anti-PD-1 and/or anti-TGF-β. Increases in IFNγ concentrations in the tissue culture supernatants were detected upon in-culture activation with the anti-CD137 and anti-PD-1 mAb combinations or concanavalin A as a positive control. No other cytokine from a wide array was informative of stimulation with these mAbs. Interestingly, increases in Ki67 and other activation markers were substantiated in lymphocytes from cell suspensions gathered at the end of 72 h cultures. In mice bearing bilateral tumors in which one was excised prior to in vivo anti-CD137 + anti-PD-1 treatment to perform the fragment culture evaluation, no association was found between IFNγ production from the fragments and the in vivo therapeutic outcome in the non-resected contralateral tumors. The experimental system permitted freezing and thawing of the fragments with similar functional outcomes. Using a series of patient-derived tumor fragments from excised solid malignancies, we showed IFNγ production in a fraction of the studied cases, that was conserved in frozen/thawed fragments. The small tumor fragment culture technique seems suitable to preclinically explore immunotherapy combinations.

Parallel Multifactorial Process Optimization and Intensification for High-Yield Production of Live YF17D-Vectored Zika Vaccine

The live-attenuated yellow fever 17D strain is a potent vaccine and viral vector. Its manufacture is based on embryonated chicken eggs or adherent Vero cells. Both processes are unsuitable for rapid and scalable supply. Here, we introduce a high-throughput workflow to identify suspension cells that are fit for the high-yield production of live YF17D-based vaccines in an intensified upstream process. The use of an automated parallel ambr15 microbioreactor system for screening and process optimization has led to the identification of two promising cell lines (AGE1.CR.pIX and HEKDyn) and the establishment of optimized production conditions, which have resulted in a >100-fold increase in virus titers compared to the current state of the art using adherent Vero cells. The process can readily be scaled up from the microbioreactor scale (15 mL) to 1 L stirred tank bioreactors. The viruses produced are genetically stable and maintain their favorable safety and immunogenicity profile, as demonstrated by the absence of neurovirulence in suckling BALB/c mice and consistent seroprotection in AG129 mice. In conclusion, the presented workflow allows for the rapid establishment of a robust, scalable, and high-yield process for the production of live-attenuated orthoflavivirus vaccines, which outperforms current standards. The approach described here can serve as a model for the development of scalable processes and the optimization of yields for other virus-based vaccines that face challenges in meeting growing demands.

An easy-to-perform protocol for culturing primary murine lung tumor cells as organoids

Cancer research involves significant animal consumption and suffering. Tumor cells can be differentiated in vitro into three-dimensional organoids that resemble the primary tumor. In basic cancer research, however, tumor organoids are usually only used alongside animal experiments. We have established an easy-to-perform protocol that allows to culture KRAS-driven lung tumor cells as organoids for extended periods of time. Like the corresponding tumors in mice, the organoids produce surfactant protein C but no markers of airway epithelial cells (e.g. SCGB1A1, KRT5). The organoids can be passaged as single cell suspensions. Our organoid model contributes to replace animal experiments with cell culture systems and can be used for drug testing or functional studies in cancer research.

A Rapid Human Lung Tissue Dissociation Protocol Maximizing Cell Yield and Minimizing Cellular Stress.

The human lung is a complex organ comprised of diverse populations of epithelial, mesenchymal, vascular and immune cells, which gains even greater complexity during disease states. To effectively study the lung at a single cell level, a dissociation protocol that achieves the highest yield of viable cells of interest with minimal dissociation-associated protein or transcription changes key. Here, we detail a rapid collagenase-based dissociation protocol (Col-Short), which provides a high-yield single cell suspension suitable for a variety of downstream applications. Diseased human lung explants were obtained and dissociated through the Col-Short protocol and compared to four other dissociation protocols. Resulting single cell suspensions were then assessed with flow cytometry, differential staining, and quantitative real-time PCR to identify major hematopoietic and non-hematopoietic cell populations, as well as their activation states. We observed that the Col-Short protocol provides the greatest number of cells per gram of lung tissue with no reduction in viability when compared to previously described dissociation protocols. Col-Short had no observable surface protein marker cleavage as well as lower expression of protein activation markers and stress-related transcripts compared to four other protocols. The Col-Short dissociation protocol can be used as a rapid strategy to generate single cells for respiratory cell biology research.

Highly Sensitive Spatial Glycomics at Near-Cellular Resolution by On-Slide Derivatization and Mass Spectrometry Imaging.

Glycans on proteins and lipids play important roles in maturation and cellular interactions, contributing to a variety of biological processes. Aberrant glycosylation has been associated with various human diseases including cancer; however, elucidating the distribution and heterogeneity of glycans in complex tissue samples remains a major challenge. Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) is routinely used to analyze the spatial distribution of a variety of molecules including N-glycans directly from tissue surfaces. Sialic acids are nine carbon acidic sugars that often exist as the terminal sugars of glycans and are inherently difficult to analyze using MALDI-MSI due to their instability prone to in- and postsource decay. Here, we report on a rapid and robust method for stabilizing sialic acid on N-glycans in FFPE tissue sections. The established method derivatizes and identifies the spatial distribution of α2,3- and α2,6-linked sialic acids through complete methylamidation using methylamine and PyAOP ((7-azabenzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate). Our in situ approach increases the glycans detected and enhances the coverage of sialylated species. Using this streamlined, sensitive, and robust workflow, we rapidly characterize and spatially localize N-glycans in human tumor tissue sections. Additionally, we demonstrate this method's applicability in imaging mammalian cell suspensions directly on slides, achieving cellular resolution with minimal sample processing and cell numbers. This workflow reveals the cellular locations of distinct N-glycan species, shedding light on the biological and clinical significance of these biomolecules in human diseases.

Multi‐omics reveal the molecular basis of LrAN2 overexpression in black goji callus promoting the excessive accumulation of petanin, a promising food blue colorant

AbstractLycium ruthenicum fruit (LRF) is a potential source of natural colorant in a wide pH range due to richness in monoacylated anthocyanin petanin. However, the yield of LRF largely lags behind the market demand in food industry. In this study, overexpressing LrAN2 (LrAN2OE), an anthocyanin activator in LRF, produced excessive acylated anthocyanins including petanin in L. ruthenicum callus (LRC). Physiological analysis indicates that LrAN2OE extensively orchestrate the redox homeostasis, including antioxidant enzymes system and antioxidants with low molecular weight. KEGG enrichment analysis indicates that LrAN2 hierarchically orchestrate the acylated anthocyanin biosynthesis in LRC at multi‐omics level, such as small RNAome, transcriptome, and metabolome. The anthocyanin yield of LrAN2OE callus cultured by 5% sucrose or glucose is significantly enhanced. Furthermore, the anthocyanin yield approach to 96.23 mg/g dry weight, approximately 3.5 folds of that in LRF, when LrAN2OE suspension cells are cultured in liquid MS medium supplement with 5% sucrose and 100 mM NaCl. Notably, anthocyanins extracted from LrAN2OE callus are stable in pH 1.0–2.0, pH 7.0, and pH 9.0, showing red or blue color within 30 days at 4°C. Our findings suggest that LrAN2 is perfect gene resource for metabolic engineering of acylated anthocyanins in LRC, a promising chassis producing acylated anthocyanins. Taken together, LRC metabolically engineered by LrAN2 is a potential source of natural food color, which facilitates to make up the shortfall of LRF as source of natural colorant in future food industry.

Cryopreservation of Mesenchymal Stem/Stromal Cells using a DMSO-free Solution is Comparable to DMSO-containing Cryoprotectants: Results of An International Multicenter PACT/BEST Collaborative Study

Background and AimAn essential aspect of ensuring availability and stability of mesenchymal stem/stromal cells (MSCs) products for clinical use is that these cells are cryopreserved before individual infusion into patients. Currently, cryopreservation of MSCs involves use of a cryoprotectant solution containing dimethyl sulfoxide (DMSO). However, it is recognized that DMSO may be toxic for both the patient and the MSC product. In this Production Assistance for Cellular Therapies (PACT) and Biomedical Excellence for Safer Transfusion (BEST) Collaborative study, we compared a novel DMSO-free solution with DMSO containing cryoprotectant solutions for freezing MSCs. MethodsA DMSO-free cryoprotectant solution containing sucrose, glycerol, and isoleucine (SGI) in a base of Plasmalyte A was prepared at the University of Minnesota. Cryoprotectant solutions containing 5-10% DMSO (in-house) were prepared at seven participating centers (five from USA, one each from Australia and Germany). The MSCs were isolated from bone marrow or adipose tissue and cultured ex vivo per local protocols at each center. The cells in suspension were frozen by aliquoting into vials/bags. For six out of the seven centers, the vials/bags were placed in a controlled rate freezer (one center placed them at -80°C freezer overnight) before transferring to liquid nitrogen. The cells were kept frozen for at least one week before thawing and testing. Pre- and post-thaw assessment included cell viability and recovery, immunophenotype as well as transcriptional and gene expression profiles. Linear regression, mixed effects models and two-sided t-tests were applied for statistical analysis. ResultsMSCs had an average viability of 94.3% (95% CI, 87.2-100%) before cryopreservation, decreasing by 4.5% (95% CI: 0.03-9.0%; p: 0.049) and 11.4% (95% CI: 6.9-15.8%; p<0.001), for MSCs cryopreserved in the in-house and SGI solutions, respectively. The average recovery of viable MSCs cryopreserved in the SGI was 92.9% (95% CI: 85.7-100.0%), and it was lower by 5.6% (95% CI: 1.3-9.8%, p<0.013) for the in-house solution. Additionally, MSCs cryopreserved in the two solutions had expected level of expressions for CD45, CD73, CD90 and CD105 with no significant difference in global gene expression profiles. ConclusionMSCs cryopreserved in a DMSO-free solution containing sucrose, glycerol, and isoleucine in a base of Plasmalyte A had slightly lower cell viability, better recovery, and comparable immunophenotype and global gene expression profiles compared to MSCs cryopreserved in DMSO containing solutions. The average viability of MSCs in the novel solution was above 80% and, thus, likely clinically acceptable. Future studies are suggested to test the post-thaw functions of MSCs cryopreserved in the novel DMSO-free solution.

Unlocking the secrets of Hofbauer cells in placental (patho-) physiology: Isolation and quality assessment in human term placenta

IntroductionHofbauer cells (HBCs) are macrophages of fetal origin that reside in the villous tissue. They are the only immune cells within healthy villi. While HBCs perform innate immune functions such as phagocytosis and antigen presentation, they are increasingly recognized for their diverse roles in placental physiology e.g. vascular functionality, tissue homeostasis, tolerance. Consequently, HBCs are of utmost interest in a variety of non-physiological placental conditions. IsolationVillous tissue is collected freshly after delivery and finely minced. The resulting tissue is digested in a two-step process, using Trypsin/DNase to separate cytotrophoblasts and collagenase/DNase to penetrate deeper into the villous stroma, containing HBCs, and obtain a single cell suspension. After a density gradient centrifugation, the corresponding cell layer is collected and subjected to negative immune selection of HBCs, yielding unaffected cells that have not been activated during the isolation process. Quality controlIn addition to a classical immunocytochemistry (ICC) approach including macrophage markers, and markers for potentially contaminating cell types (e.g. fibroblasts, muscle, mesenchymal cells), we have developed a multi-color flow cytometry (FC) panel. This panel assesses Hofbauer cell purity and polarization states more accurately and comprehensively than qualitative ICC, using percentage analysis of parent cells to estimate the expression levels of specific markers. DiscussionThe presented protocol allows us to isolate HBCs in significant numbers and high purity, even from placentae compromised by preeclampsia (PE) with limited placental volume. We have successfully developed and implemented this protocol to study healthy, diabetic and PE macrophages, aiding a better understanding of the underlying placental pathophysiology at the cellular level.

Establishment and identification of bladder cancer cell sheet

Cell sheet technology (CST) has primarily been applied in tissue engineering for repair purposes. Our preliminary research indicates that an in vivo prostate cancer model established using CST outperforms traditional cell suspension methods. However, the potential for CST to be used with bladder cancer cells has not yet been explored. In this study, we investigated the ability of two bladder cancer cell lines, T24 and 5637, to form cell sheets. We found that T24 cells successfully formed cell sheets. We then performed staining to evaluate the integrity, specific markers, and proliferation characteristics of the T24 cell sheets. Our findings demonstrate that bladder cancer cell sheets can be established, providing a valuable tool for both in vivo and in vitro bladder cancer studies and for personalized drug selection for patients.

Establishment and Identification of Bladder Cancer Cell Sheet

Cell sheet technology (CST) has primarily been applied in tissue engineering for repair purposes. Our preliminary research indicates that an in vivo prostate cancer model established using CST outperforms traditional cell suspension methods. However, the potential for CST to be used with bladder cancer cells has not yet been explored. In this study, we investigated the ability of two bladder cancer cell lines, T24 and 5637, to form cell sheets. We found that T24 cells successfully formed cell sheets. We then performed staining to evaluate the integrity, specific markers, and proliferation characteristics of the T24 cell sheets. Our findings demonstrate that bladder cancer cell sheets can be established, providing a valuable tool for both in vivo and in vitro bladder cancer studies and for personalized drug selection for patients.

Establishment of an animal model of immune-related adverse events induced by immune checkpoint inhibitors.

Immunotherapy, specifically immune checkpoint inhibitors (ICIs), has revolutionized cancer treatment. However, it can also cause immune-related adverse events (irAEs). This study aimed to develop a clinically practical animal model of irAEs using BALB/c mice. Subcutaneous tumors of mouse breast cancer 4T1 cells were generated in inbred BALB/c mice. The mice were treated with programmed death-1 (PD-1) and cytotoxic t-lymphocyte antigen 4 (CTLA-4) inhibitors once every 3 days for five consecutive administration cycles. Changes in tumor volume and body weight were recorded. Lung computed tomography (CT) scans were conducted. The liver, lungs, heart, and colon tissues of the mice were stained with hematoxylin-eosin (H&E) staining to observe inflammatory infiltration and were scored. Serum samples were collected, and enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of ferritin, glutamic-pyruvic transaminase (ALT), tumor necrosis factor-α (TNF-α), interferon-gamma (IFN-γ), and interleukin-6 (IL-6). Mouse liver and lung cell suspensions were prepared, and changes in macrophages, T cells, myeloid-derived suppressor cells (MDSCs), and regulatory (Treg) cells were detected by flow cytometry. Mice treated with PD-1 and CTLA-4 inhibitors showed significant reductions in tumor volume and body weight. The tissue inflammatory scores in the experimental group were significantly higher than those in the control group. Lung CT scans of mice in the experimental group showed obvious inflammatory spots. Serum levels of ferritin, IL-6, TNF-α, IFN-γ, and ALT were significantly elevated in the experimental group. Flow cytometry analysis revealed a substantial increase in CD3+T cells, Treg cells, and macrophages in the liver and lung tissues of mice in the experimental group compared with the control group, and the change trend of MDSCs was opposite. The irAE-related animal model was successfully established in BALB/c mice using a combination of PD-1 and CTLA-4 inhibitors through multiple administrations with clinical translational value and practical. This model offers valuable insights into irAE mechanisms for further investigation.

Cell attachment defines sensitivity to cold stress via the Hippo pathway

Although cells are frequently maintained at cold temperatures during experiments, the effects of cold stress on cell viability and subsequent cellular conditions remain elusive. In this study, we investigated the effects of cold stress on cancer cells under various culture conditions. We showed that cold stress induces ferroptosis, a form of cell death characterized by lipid peroxidation, in sensitive cancer cell lines. High cell density and serum starvation activate the Hippo pathway and suppress cold-induced cell death. Genetic deletion of Hippo pathway components enhances cold stress susceptibility. Furthermore, the cell attachment status influences the response to cold stress, with suspended cells showing greater resistance and faster recovery than attached cells. This study highlights the importance of cellular conditions and the Hippo pathway in the handling and storage of cancer cells at cold temperatures, thereby offering insights into experimental and clinical contexts.

Promotion of perineural invasion of cholangiocarcinoma by Schwann cells via nerve growth factor.

Cholangiocarcinoma (CCA), a highly lethal tumor of the hepatobiliary system originating from bile duct epithelium, can be divided into the intrahepatic, hilar, and extrahepatic types. Due to its insidious onset and atypical early clinical symptoms, the overall prognosis is poor. One of the important factors contributing to the poor prognosis of CCA is the occurrence of perineural invasion (PNI), but the specific mechanisms regarding how it contributes to the occurrence of PNI are still unclear. The main purpose of this study is to explore the molecular mechanism leading to the occurrence of PNI and provide new ideas for clinical treatment. CCA cell lines and Schwann cells (SCs) were stimulated to observe the changes in cell behavior. SCs cocultured with tumor supernatant and SCs cultured in normal medium were subjected to transcriptome sequencing to screen the significantly upregulated genes. Following this, the two types of tumor cells were cultured with SC supernatant, and the changes in behavior of the tumor cells were observed. Nonobese diabetic-severe combined immunodeficiency disease (NOD-SCID) mice were injected with cell suspension supplemented with nerve growth factor (NGF) via the sciatic nerve. Four weeks later, the mice were euthanized and the tumor sections were removed and stained. Nerve invasion by tumor cells was common in CCA tissues. SCs were observed in tumor tissues, and the number of SCs in tumor tissues and the degree of PNI were much higher than were those in normal tissues or tissues without PNI. The overall survival time was shorter in patients with CCA with PNI than in patients without PNI. SCs were enriched in CCA tissues, indicating the presence of PNI and associated with poor prognosis in CCA patients. CCA was found to promote NGF secretion from SCs in vitro. After the addition of exogenous NGF in CCA cell culture medium, the proliferation activity and migration ability of CCA cells were significantly increased, suggesting that SCs can promote the proliferation and migration of CCA through the secretion of NGF. NGF, in turn, was observed to promote epithelial-mesenchymal transition in CCA through tropomyosin receptor kinase A (TrkA), thus promoting its progression. Tumor growth in mice shows that NGF can promote PNI in CCA. In CCA, tumor cells can promote the secretion of NGF by SCs, which promotes the progression of CCA and PNI by binding to its high-affinity receptor TrkA, leading to poor prognosis.

Impact of Fixation of Camel Lymph Node Cells on Marker Expression Stability in Flow Cytometry

Single cell immunophenotyping by flow cytometry has proven a useful and high sensitive method for the analysis of immune cell composition and phenotype in different lymphatic and non-lymphatic tissues. Fixation of stained cells is usually recommended when the cells need to be preserved for later analysis by flow cytometry to avoid changes in cell morphology and expression of the level of cellular antigens. In the present study, a stain-fix approach was used in combination with flow cytometry to investigate the impact of fixation of camel lymph node cell suspension (n = 5 camels) after labeling with monoclonal antibodies to some leukocyte antigens on their cellular composition and expression density of immune cell markers. The obtained results indicated that camel lymph node cell suspension stained with fluorochrome-conjugated mAbs to leukocyte antigens and fixed with paraformaldehyde (PFA) will keep stable values for their immune cell composition for at least six days when analyzed by flow cytometry. However, if cell subsets were to be identified, fixation may result in different values that were obtained when analyzing fresh stained unfixed cells. Especially the instability in the fluorescence intensity of CD14, CD172a, and MHCII will lead to significant changes in the frequency of monocyte subsets (classical versus intermediate or non-classical) and the identification of macrophage functional subtype (M1 versus M2). Similarly, the instability in CD44 expression may affect the identified phenotype of T cells with significantly lower frequency of activated T cells. In conclusion, flow cytometric data collected from stained and PFA-fixed cell suspension prepared from camel lymph nodes should be interpreted with care if the functional subtype of cells is to be identified based on surface molecule expression.