Increase In Number Of Cells Research Articles

Re-Evaluation of Vascular Histogenesis in the Root Tips of Selected Species in the Poaceae Using New Methods: Analysis of the Plerome, Vascular Initials, Pericycle and Late-Maturing Metaxylem Vessels

Serial sectioning and 3D image reconstruction methods were applied to elucidate the structures of the apices of root vascular cylinders (VCs) in taxa of the Poaceae: Zea mays “Honey Bantam”, Z. mays ssp. mexicana, Hordeum vulgare and Oryza sativa. The primary and nodal roots were investigated. Observations were performed using high-quality sectioning and 3D image-processing techniques improved and developed by the authors. We found that a quiescent uniseriate plerome was located at the most distal part of each VC. Vascular initials were located immediately basipetally to the plerome as a specific uniseriate layer that could be classified into central and peripheral initials that produced all the cells in the VC. No supplying of cells from the plerome to the vascular initials was observed. Numerical analysis revealed a “boundary point” along the root axis where the rate of increase of the vascular cell number markedly declined, and the VC diameter, number of vascular cells, and number of late-maturing metaxylem vessels (LMXs) at that point showed a similar relationship among the taxa and the types of roots examined (primary vs. nodal). The plerome and vascular initials layer can be considered independent after seed germination in these taxa. A boundary point at which procambial cell proliferation sharply declined was identified. The diameters of the VCs, number of LMXs, and number of vascular cells at the boundary point were found to be strongly related to each other.

Id1 expression in CD4 T cells promotes differentiation and function of follicular helper T cells and upregulation of related functional molecules.

Although the roles of E proteins and inhibitors of DNA-binding (Id) in T follicular helper (TFH) and T follicular regulatory (TFR) cells have been previously reported, direct models demonstrating the impact of multiple E protein members have been lacking. To suppress all E proteins including E2A, HEB and E2-2, we overexpressed Id1 in CD4 cells using a CD4-Id1 mouse model, to observe any changes in TFH and TFR cell differentiation. Our objective was to gain better understanding of the roles that E proteins and Id molecules play in the differentiation of TFH and TFR cells. The CD4-Id1 transgenic (TG) mice that we constructed overexpressed Id1 in CD4 cells, inhibiting E protein function. Our results showed an increase in the proportion and absolute numbers of Treg, TFH and TFR cells in the spleen of TG mice. Additionally, the expression of surface characterisation molecules PD-1 and ICOS was significantly upregulated in TFH and TFR cells. The study also revealed a downregulation of the marginal zone B cell precursor and an increase in the activation and secretion of IgG1 in spleen B cells. Furthermore, the peripheral TFH cells of TG mice enhanced the function of assisting B cells. RNA sequencing results indicated that a variety of TFH-related functional molecules were upregulated in TFH cells of Id1 TG mice. In conclusion, E proteins play a crucial role in regulating TFH/TFR cell differentiation and function and suppressing E protein activity promotes germinal centre humoral immunity, which has important implications for immune regulation and treating related diseases.

TXA2 attenuates allergic lung inflammation through regulation of Th2, Th9, and Treg differentiation.

In lung, thromboxane A2 (TXA2) activates the TP receptor to induce proinflammatory and bronchoconstrictor effects. Thus, TP receptor antagonists and TXA2 synthase inhibitors have been tested as potential asthma therapeutics in humans. Th9 cells play key roles in asthma and regulate the lung immune response to allergens. Herein, we found that TXA2 reduces Th9 cell differentiation during allergic lung inflammation. Th9 cells were decreased approximately 2-fold and airway hyperresponsiveness was attenuated in lungs of allergic mice treated with TXA2. Naive CD4+ T cell differentiation to Th9 cells and IL-9 production were inhibited dose-dependently by TXA2 in vitro. TP receptor-deficient mice had an approximately 2-fold increase in numbers of Th9 cells in lungs in vivo after OVA exposure compared with wild-type mice. Naive CD4+ T cells from TP-deficient mice exhibited increased Th9 cell differentiation and IL-9 production in vitro compared with CD4+ T cells from wild-type mice. TXA2 also suppressed Th2 and enhanced Treg differentiation both in vitro and in vivo. Thus, in contrast to its acute, proinflammatory effects, TXA2 also has longer-lasting immunosuppressive effects that attenuate the Th9 differentiation that drives asthma progression. These findings may explain the paradoxical failure of anti-thromboxane therapies in the treatment of asthma.

The effect of myeloablative radiation on urinary bladder mast cells

Radiation-induced cystitis is an inflammatory condition affecting the urinary bladder, which can develop as a side effect of abdominopelvic radiotherapy, specifically external-beam radiation therapy or myeloablative radiotherapy. A possible involvement of mast cells in the pathophysiology of radiation-induced cystitis has been indicated in cases of external-beam radiation therapy; however, there is no evidence that these findings apply to the myeloablative aetiology. As such, this study investigated potential changes to urinary bladder mast cell prevalence when exposed to myeloablative radiation. Lethally irradiated C57BL/6J mice that received donor rescue bone marrow cells exhibited an increased mast cell frequency amongst host leukocytes 1 week following irradiation. By 4 weeks, no significant difference in either frequency or cell density was observed. However mast cell diameter was smaller, and a significant increase in mast cell number in the adventitia was observed. This study highlights that mast cells constitute a significant portion of the remaining host leukocyte population following radiation exposure, with changes to mast cell distribution and decreased cell diameter four weeks following radiation-induced injury.

Keratinocyte-derived circulating microRNAs in extracellular vesicles: a novel biomarker of psoriasis severity and potential therapeutic target

BackgroundPsoriasis is a chronic inflammatory disorder characterized by pathogenic hyperproliferation of keratinocytes and immune dysregulation. Currently, objective evaluation tools reflecting the severity of psoriasis are insufficient. MicroRNAs in extracellular vesicles (EV miRNAs) have been shown to be potential biomarkers for various inflammatory diseases. Our objective was to investigate the possibility of plasma-derived EV miRNAs as a marker for the psoriasis disease severity.MethodsEVs were extracted from the plasma of 63 patients with psoriasis and 12 with Behçet’s disease. We performed next-generation sequencing of the plasma-derived EV miRNAs from the psoriasis patients. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to validate the level of EV miRNA expression. In situ hybridization was used to discern the anatomical location of miRNAs. qRT-PCR, western blotting, and cell counting kits (CCKs) were used to investigate IGF-1 signaling in cells transfected with miRNA mimics.ResultsWe identified 19 differentially expressed EV miRNAs and validated the top three up-and down-regulated EV miRNAs. Among these, miR-625-3p was significantly increased in patients with severe psoriasis in both plasma and skin and most accurately distinguished moderate-to-severe psoriasis from mild-to-moderate psoriasis. It was produced and secreted by keratinocytes upon stimulation. We also observed a significant intensification of IGF-1 signalling and increased cell numbers in the miR-625-3p mimic transfected cells.ConclusionsWe propose keratinocyte-derived EV miR-625-3p as a novel and reliable biomarker for estimating the severity of psoriasis. This biomarker could objectively evaluate the severity of psoriasis in the clinical setting and might serve as a potential therapeutic target.Trial registration None.

Role of CD4+ T-cells for regulating splenic myelopoiesis and monocyte differentiation after experimental myocardial infarction

Myocardial infarction (MI) induces the generation of proinflammatory Ly6Chigh monocytes in the spleen and the recruitment of these cells to the myocardium. CD4+ Foxp3+ CD25+ T-cells (Tregs) promote the healing process after myocardial infarction by engendering a pro-healing differentiation state in myocardial monocyte-derived macrophages. We aimed to study the effects of CD4+ T-cells on splenic myelopoiesis and monocyte differentiation. We instigated MI in mice and found that MI-induced splenic myelopoiesis is abrogated in CD4+ T-cell deficient animals. Conventional CD4+ T-cells promoted myelopoiesis in vitro by cell–cell-contact and paracrine mechanisms, including interferon-gamma (IFN-γ) signalling. Depletion of regulatory T-cells enhanced myelopoiesis in vivo, as evidenced by increases in progenitor cell numbers and proliferative activity in the spleen 5 days after MI. The frequency of CD4+ T-cells-producing factors that promote myelopoiesis increased within the spleen of Treg-depleted mice. Moreover, depletion of Tregs caused a proinflammatory bias in splenic Ly6Chigh monocytes, which showed predominantly upregulated expression of IFN-γ responsive genes after MI. Our results indicate that conventional CD4+ T-cells promote and Tregs attenuate splenic myelopoiesis and proinflammatory differentiation of monocytes.

Роль клеточного иммунитета в развитии злокачественных новообразований у лиц, подвергшихся хроническому облучению

Some long-term effects of radiation could be related to changes in the immune system resulting from radiation exposure. Immunity disorders caused by radiation can influence carcinogenesis. Cellular immunity factors were investigated in peripheral blood of workers chronically exposed to occupational combined radiation (external gamma-rays and internal alpha-particles), with malignant neoplasms diagnosed after blood samples were taken or without them, and in the control group. The aim of this study was examine effects of radiation on the cellular immunity status in individuals chronically exposed to ionizing radiation who had malignant neoplasms developed after blood sampling. The relative and absolute number of lymphocyte subpopulations (total T-cells, T-helpers, T-cytotoxic, total B-cells, NK-cells, NKT-cells and activated T-cells) was detected by flow cytofluorometry. The absolute number of T-cells was significantly reduced in workers chronically exposed to occupational combined irradiation, with or without malignancies, compared to the control, which may contribute to tumor progression at an early stage of its onset. At the same time, workers without malignancies had a significant increase in the relative number of T-cytotoxic lymphocytes, which may be a factor preventing tumor development. A significant increase in the relative number of natural killer cells (NK cells) was detected in individuals with malignant neoplasms chronically exposed to occupational combined irradiation, compared with the control, which may indicate enhanced antitumor defense that developed in response to exposure to tumor antigens. In addition, a significant decrease in the absolute and relative number of T- and B-lymphocytes was found in the group of workers with malignant neoplasm, compared with the control. A significant increase in the relative number of T-helpers was found in both groups of workers. Since the role of T-helpers in the antitumor response is ambiguous, additional research on types of T-helpers is planned to clarify the results of the present study

Role of cellular immunity in malignant tumors development in individuals chronically ex-posed to ionising radiation

Some long-term effects of radiation could be related to changes in the immune system resulting from radiation exposure. Immunity disorders caused by radiation can influence carcinogenesis. Cellular immunity factors were investigated in peripheral blood of workers chronically exposed to occupational combined radiation (external gamma-rays and internal alpha-particles), with malignant neoplasms diagnosed after blood samples were taken or without them, and in the control group. The aim of this study was examine effects of radiation on the cellular immunity status in individuals chronically exposed to ionizing radiation who had malignant neoplasms developed after blood sampling. The relative and absolute number of lymphocyte subpopulations (total T-cells, T-helpers, T-cytotoxic, total B-cells, NK-cells, NKT-cells and activated T-cells) was detected by flow cytofluorometry. The absolute number of T-cells was significantly reduced in workers chronically exposed to occupational combined irradiation, with or without malignancies, compared to the control, which may contribute to tumor progression at an early stage of its onset. At the same time, workers without malignancies had a significant increase in the relative number of T-cytotoxic lymphocytes, which may be a factor preventing tumor development. A significant increase in the relative number of natural killer cells (NK cells) was detected in individuals with malignant neoplasms chronically exposed to occupational combined irradiation, compared with the control, which may indicate enhanced antitumor defense that developed in response to exposure to tumor antigens. In addition, a significant decrease in the absolute and relative number of T- and B-lymphocytes was found in the group of workers with malignant neoplasm, compared with the control. A significant increase in the relative number of T-helpers was found in both groups of workers. Since the role of T-helpers in the antitumor response is ambiguous, additional research on types of T-helpers is planned to clarify the results of the present study.

A Simple and Rapid Protocol for the Isolation of Murine Bone Marrow Suitable for the Differentiation of Dendritic Cells.

The generation of bone-marrow-derived dendritic cells is a widely used approach in immunological research to study antigen processing and presentation, as well as T-cell activation responses. However, the initial step of isolating the bone marrow can be time-consuming, especially when larger numbers of precursor cells are required. Here, we assessed whether an accelerated bone marrow isolation method using centrifugation is suitable for the differentiation of FMS-like tyrosine kinase 3 ligand-driven dendritic cells. Compared to the conventional flushing method, the centrifugation-based isolation method resulted in a similar bone marrow cell yield on Day 0, increased cell numbers by Day 8, similar proportions of dendritic cell subsets, and consequently a higher number of type 1 conventional dendritic cells (cDC1) from the culture. Although the primary purpose of this method of optimization was to improve experimental efficiency and increase the output of cDC1s, the protocol is also compatible with the differentiation of other dendritic cell subsets such as cDC2 and plasmacytoid dendritic cells, with an improved output cell count and a consistent phenotype.

The peptide GOLVEN10 alters root development and noduletaxis in Medicago truncatula.

The conservation of GOLVEN (GLV)/ROOT MERISTEM GROWTH FACTOR (RGF) peptide encoding genes across plant genomes capable of forming roots or root-like structures underscores their potential significance in the terrestrial adaptation of plants. This study investigates the function and role of GOLVEN peptide-coding genes in Medicago truncatula. Five out of fifteen GLV/RGF genes were notably upregulated during nodule organogenesis and were differentially responsive to nitrogen deficiency and auxin treatment. Specifically, the expression of MtGLV9 and MtGLV10 at nodule initiation sites was contingent upon the NODULE INCEPTION transcription factor. Overexpression of these five nodule-induced GLV genes in hairy roots of M. truncatula and application of their synthetic peptide analogues led to a decrease in nodule count by 25-50%. Uniquely, the GOLVEN10 peptide altered the positioning of the first formed lateral root and nodule on the primary root axis, an observation we term 'noduletaxis'; this decreased the length of the lateral organ formation zone on roots. Histological section of roots treated with synthetic GOLVEN10 peptide revealed an increased cell number within the root cortical cell layers without a corresponding increase in cell length, leading to an elongation of the root likely introducing a spatiotemporal delay in organ formation. At the transcription level, the GOLVEN10 peptide suppressed expression of microtubule-related genes and exerted its effects by changing expression of a large subset of Auxin responsive genes. These findings advance our understanding of the molecular mechanisms by which GOLVEN peptides modulate root morphology, nodule ontogeny, and interactions with key transcriptional pathways.

Phyllanthus emblica‐Loaded Cryogels for Improved Wound Care: Characterization and In Vitro Studies

AbstractWound dressings developed by combining plant extracts with polymers have made a great progress in wound care treatment. One plant with remarkable healing properties is Phyllanthus emblica Linn (P. emblica), which is described as having potent antioxidant, antimicrobial and anti‐inflammatory properties. The aim of this study is to evaluate the biocompatibility of P. emblica‐loaded polyvinyl alcohol/gelatin‐based cryogels (PVA/Gel/P.emblica) through cytotoxicity and proliferation tests in HaCaT cells and examine their potential in wound dressing applications. Accordingly, PVA/Gel/P.emblica cryogels are successfully synthesized and characterization studies and in vitro cell culture studies are performed. The swelling tests and Brunauer–Emmett–Teller analysis results show that swelling and surface area properties of cryogels increase with increasing P. emblica amounts. Morphological results display that the cryogels have a dense, interconnected pore morphology and a macroporous structure. 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide, trypan blue exclusion, and live–dead assay results reveal that P. emblica enhances cell proliferation, increases cell number, and improves cell viability. Based on the scanning electron microscope, immunofluorescence, and Giemsa staining images, it is observed that P. emblica promotes cell attachment, proliferation, and penetration. These findings confirm that PVA/Gel/P.emblica cryogels are suitable for use as wound dressing materials and can be developed with further studies.

Increased Mass-Rearing of Queens in High Royal-Jelly-Producing Honey Bee Colonies (Apis mellifera ligustica) Generates Smaller Queens with Comparable Fecundity

The mass rearing of high-quality queen bees is an essential beekeeping practice for producing new queens to maintain colony productivity. A strain of high royal-jelly-producing bees (RJBs; Apis mellifera ligustica) in China exhibits high potential for the rapid mass rearing of queens. To explore the potential changes in the quality of mass-reared queens, a set of morphometric traits and the sealed brood area were compared between the queens reared from 64 and 320 queen cells in RJB colonies. The increase in the queen cell number was found to induce a slightly but significantly reduced body weight and smaller wing length and thorax width in the reared queens at emergence. However, the ovariole number and sealed brood area, an indicator of the queen fecundity, were not observed to be significantly influenced. With respect to body weight and ovariole number, all the reared queens satisfied the current criteria for high-quality queens. Our findings provide evidence for the efficient mass production of high-quality queens using RJB colonies.

Pharmacokinetics, pharmacodynamics, and toxicity of a PD-1-targeted IL-15 in cynomolgus monkeys.

PF-07209960 is a novel bispecific fusion protein composed of an anti-PD-1 antibody and engineered IL-15 cytokine mutein with reduced binding affinity to its receptors. The pharmacokinetics (PK), pharmacodynamics (PD), and toxicity of PF-07209960 were evaluated following once every other week subcutaneous (SC) or intravenous (IV) administration to cynomolgus monkeys in a repeat-dose PKPD (0.01-0.3 mg/kg/dose) and GLP toxicity study (0.1-3 mg/kg/dose). PF-07209960 showed dose dependent pharmacokinetics with a terminal T1/2 of 8 and 13 hours following IV administration at 0.03 and 0.1 mg/kg, respectively. The clearance is faster than a typical IgG1 antibody. Slightly faster clearance was also observed following the second dose, likely due to increased target pool and formation of anti-drug antibodies (ADA). Despite a high incidence rate of ADA (92%) observed in GLP toxicity study, PD-1 receptor occupancy, IL-15 signaling (STAT5 phosphorylation) and T cell expansion were comparable following the first and second doses. Activation and proliferation of T cells were observed with largest increase in cell numbers found in gamma delta T cells, followed by CD4+ and CD8+ T cells, and then NK cells. Release of cytokines IL-6, IFNγ, and IL-10 were detected, which peaked at 72 hours postdose. There was PF-07209960-related mortality at ≥1 mg/kg. At scheduled necropsy, microscopic findings were generalized mononuclear infiltration in various tissues. Both the no observed adverse effect level (NOAEL) and the highest non severely toxic dose (HNSTD) were determined to be 0.3 mg/kg/dose, which corresponded to mean Cmax and AUC48 values of 1.15 μg/mL and 37.9 μg*h/mL, respectively.

Ex vivo culture resting time impacts transplantation outcomes of genome-edited human hematopoietic stem and progenitor cells in xenograft mouse models

Ex vivo resting culture is a standard procedure following genome editing in hematopoietic stem and progenitor cells (HSPCs). However, prolonged culture may critically affect cell viability and stem cell function. We investigated whether varying durations of culture resting times impact the engraftment efficiency of human CD34+ HSPCs edited at the BCL11A enhancer, a key regulator in the expression of fetal hemoglobin. We employed electroporation to introduce CRISPR-Cas9 components for BCL11A enhancer editing and compared outcomes with nonelectroporated (NEP) and electroporated-only (EP) control groups. Post-electroporation, we monitored cell viability, death rates, and the frequency of enriched hematopoietic stem cell (HSC) fractions (CD34+CD90+CD45RA- cells) over a 48-hour period. Our findings reveal that while the NEP group showed an increase in cell numbers 24 hours post-electroporation, both EP and BCL11A-edited groups experienced significant cell loss. Although CD34+ cell frequency remained high in all groups for up to 48 hours post-electroporation, the frequency of the HSC-enriched fraction was significantly lower in the EP and edited groups compared to the NEP group. In NBSGW xenograft mouse models, both conditioned with busulfan and nonconditioned, we found that immediate transplantation post-electroporation led to enhanced engraftment without compromising editing efficiency. Human glycophorin A+ (GPA+) red blood cells (RBCs) sorted from bone marrow of all BCL11A edited mice exhibited similar levels of γ-globin expression, regardless of infusion time. Our findings underscore the critical importance of optimizing the culture duration between genome editing and transplantation. Minimizing this interval may significantly enhance engraftment success and minimize cell loss without compromising editing efficiency. These insights offer a pathway to improve the success rates of genome editing in HSPCs, particularly for conditions like sickle cell disease.

The Effect of Structural Characteristics of Deproteinized Spongy Bone on Activity of Adipose Tissue Mesenchymal Stromal Cells.

We studied the effect of structural properties of deproteinized spongy bone (DSB) on functional activity of adipose tissue mesenchymal stromal cells of (MSC) for the potential use of these materials as components of a combined tissue-engineered construct. The porosity of the structure of DSB samples and the pore size promote MSC adhesion, migration, and proliferation on their surface and in the depth, revealing the architectonics of this bone matrix. The depth of cell penetration into the samples (from 273 to 702 μm) and an increase in the total number of cells (from 302 on day 1 to 1744 on day 7) demonstrated MSC adhesion, migration, and proliferation. The viability of cultured MSC was preserved for up to 7 days. The obtained results prove the possibility of using allogeneic DSB from femoral heads as a bone matrix in tissue-engineered constructs in combination with MSC. Such constructs can be used to efficiently restore the structural and functional integrity of the bone tissue in abnormal processes of various etiopathogenesis associated with the formation of bone defects or bone tissue deficiency.

Pulsed inputs of high molecular weight organic matter shift the mechanisms of substrate utilisation in marine bacterial communities.

Heterotrophic bacteria hydrolyze high molecular weight (HMW) organic matter extracellularly prior to uptake, resulting in diffusive loss of hydrolysis products. An alternative 'selfish' uptake mechanism that minimises this loss has recently been found to be common in the ocean. We investigated how HMW organic matter addition affects these two processing mechanisms in surface and bottom waters at three stations in the North Atlantic Ocean. A pulse of HMW organic matter increased cell numbers, as well as the rate and spectrum of extracellular enzymatic activities at both depths. The effects on selfish uptake were more differentiated: in Gulf Stream surface waters and productive surface waters south of Newfoundland, selfish uptake of structurally simple polysaccharides increased upon HMW organic matter addition. The number of selfish bacteria taking up structurally complex polysaccharides, however, was largely unchanged. In contrast, in the oligotrophic North Atlantic gyre, despite high external hydrolysis rates, the number of selfish bacteria was unchanged, irrespective of polysaccharide structure. In deep bottom waters (> 4000 m), structurally complex substrates were processed only by selfish bacteria. Mechanisms of substrate processing-and the extent to which hydrolysis products are released to the external environment-depend on substrate structural complexity and the resident bacterial community.

The effect of near-infrared rays on the decrease in the number of adipocyte cells using the flow cytometry method

Adipose tissue, composed of adipocyte cells, can become problematic due to an increase in cell number (hyperplasia) and size (hypertrophy). To address this concern, interventions are needed to reduce these probabilities. Near Infrared (NIR) is an electromagnetic wave that affects tissues by being absorbed and penetrating them. NIR can induce cell death (necrosis or apoptosis), where cells respond to external factors causing tissue damage. The purpose of this study was to examine the effect of near-infrared rays on the decrease in the number of adipocyte cells using the flow cytometry method. This study, conducted in vitro using adipocyte cell cultures isolated from rat visceral adipose tissue, explores the effects of NIR exposure at various distances (1 cm, 2 cm, and 3 cm) for 20 minutes. Adipocyte cells were stained and examined using Confocal laser scanning microscopy (CLSM), and the percentage of cells was determined by flow cytometry. Statistical analyses were performed using One Way ANOVA and Duncan test. Significant differences (p-value < 0.05) were observed, and the Duncan test revealed variations in the percentage of living cells among control and treatment groups. The data indicated that exposure to high NIR energy with low wavelengths penetrated adipocyte cells, leading to a decrease in the percentage of cells and notable changes in cell morphology. Flow cytometry results demonstrated differences in live cell percentages, with group 2 (exposed at 2 cm for 20 minutes) being more effective, showing lower percentages of live cells. This research suggests that NIR exposure has an impact on adipocyte cell cultures, emphasizing its potential in influencing adipocyte cell behavior.

Non-haematopoietic Sca-1+ Cells in the Retina of Adult Mice Express Functional TLR2.

The mammal retina does not have the capacity to regenerate throughout life, although some stem and progenitor cells persist in the adult retina and might retain multipotentiality, as previously described in many tissues. In this work we demonstrate the presence of a small lineage- Sca-1+ cell population in the adult mouse retina which expresses functional TLR2 receptors as in vitro challenge with the pure TLR2 agonist Pam3CSK4 increases cell number and upregulates TLR2. Therefore, this population could be of interest in neuroregeneration studies to elucidate its role in these processes.

Dietary cystine restriction increases the proliferative capacity of the small intestine of mice.

Currently, over 88 million people are estimated to have adopted a vegan or vegetarian diet. Cysteine is a semi-essential amino acid, which availability is largely dependent on dietary intake of meat, eggs and whole grains. Vegan/vegetarian diets are therefore inherently low in cysteine. Sufficient uptake of cysteine is crucial, as it serves as substrate for protein synthesis and can be converted to taurine and glutathione. We found earlier that intermolecular cystine bridges are essential for the barrier function of the intestinal mucus layer. Therefore, we now investigate the effect of low dietary cystine on the intestine. Mice (8/group) received a high fat diet with a normal or low cystine concentration for 2 weeks. We observed no changes in plasma methionine, cysteine, taurine or glutathione levels or bile acid conjugation after 2 weeks of low cystine feeding. In the colon, dietary cystine restriction results in an increase in goblet cell numbers, and a borderline significant increase mucus layer thickness. Gut microbiome composition and expression of stem cell markers did not change on the low cystine diet. Remarkably, stem cell markers, as well as the proliferation marker Ki67, were increased upon cystine restriction in the small intestine. In line with this, gene set enrichment analysis indicated enrichment of Wnt signaling in the small intestine of mice on the low cystine diet, indicative of increased epithelial proliferation. In conclusion, 2 weeks of cystine restriction did not result in apparent systemic effects, but the low cystine diet increased the proliferative capacity specifically of the small intestine and induced the number of goblet cells in the colon.

Characterization of the immunosuppressive environment induced by larval Echinococcus granulosus during chronic experimental infection.

The larval stage of Echinococcus granulosus causes the chronic infection known as cystic echinococcosis, deploying strong inhibitory mechanisms on host immune responses. Using experimental intraperitoneal infection in C57BL/6 mice, we carried out an in-depth analysis of the local changes in macrophage populations associated with chronic infection. In addition, we analyzed T cells and relevant soluble mediators. Infected animals showed an increase in local cell numbers, mostly accounted for by eosinophils, T cells, and macrophages. Within macrophage populations, the largest increases in cell numbers corresponded to resident large peritoneal macrophages (LPM). Monocyte recruitment appeared to be active, as judged by the increased number of monocytes and cells in the process of differentiation towards LPM, including small (SPM) and converting peritoneal macrophages (CPM). In contrast, we found no evidence of macrophage proliferation. Infection induced the expression of M2 markers in SPM, CPM, and LPM. It also enhanced the expression of the co-inhibitor PD-L1 in LPM, SPM, and CPM and induced the co-inhibitor PD-L2 in SPM and CPM. Therefore, local macrophages acquire M2-like phenotypes with probable suppressive capacities. Regarding T cells, infection induced an increase in the percentage of CD4+ cells that are PD-1+, which represent a potential target of suppression by PD-L1+/PD-L2+ macrophages. In possible agreement, CD4+ T cells from infected animals showed blunted proliferative responses to in vitro stimulation with anti-CD3. Further evidence of immune suppression in the parasite vicinity arose from the observation of an expansion in FoxP3+ CD4+ regulatory T cells and increases in the local concentrations of the anti-inflammatory cytokines TGF-β and IL-1Ra.