Candida albicans Elicits Pro-Inflammatory Differential Gene Expression in Intestinal Peyer’s Patches

The details of how gut-associated lymphoid tissues such as Peyer’s patches (PPs) in the small intestine play a role in immune surveillance, microbial differentiation and the mucosal barrier protection in response to fungal organisms such as Candida albicans are still unclear. We particularly focus on PPs as they are the immune sensors and inductive sites of the gut that influence inflammation and tolerance. We have previously demonstrated that CD11c⁺ phagocytes that include dendritic cells and macrophages are located in the sub-epithelial dome within PPs sample C. albicans. To gain insight on how specific cells within PPs sense and respond to the sampling of fungi, we gavaged naïve mice with C. albicans strains ATCC 18804 and SC5314 as well as Saccharomyces cerevisiae. We measured the differential gene expression of sorted CD45⁺ B220⁺ B-cells, CD3⁺ T-cells and CD11c⁺ DCs within the first 24 h post-gavage using nanostring nCounter^® technology. The results reveal that at 24 h, PP phagocytes were the cell type that displayed differential gene expression. These phagocytes were able to sample C. albicans and discriminate between strains. In particular, strain ATCC 18804 upregulated fungal-specific pro-inflammatory genes pertaining to innate and adaptive immune responses. Interestingly, PP CD11c⁺ phagocytes also differentially expressed genes in response to C. albicans that were important in the protection of the mucosal barrier. These results highlight that the mucosal barrier not only responds to C. albicans, but also aids in the protection of the host.

     

Peyer’s Patches and Mesenteric Lymph Nodes Cooperatively Promote Enteropathy in a Mouse Model of Food Allergy

Background and Objective

To improve the efficacy and safety of tolerance induction for food allergies, identifying the tissues responsible for inducing intestinal inflammation and subsequent oral tolerance is important. We used OVA23-3 mice, which express an ovalbumin-specific T-cell receptor, to elucidate the roles of local and systemic immune tissues in intestinal inflammation.

Methods and Results

OVA23-3 mice developed marked enteropathy after consuming a diet containing egg white (EW diet) for 10 days but overcame the enteropathy (despite continued moderate inflammation) after receiving EW diet for a total of 28 days. Injecting mice with anti-IL-4 antibody or cyclosporine A confirmed the involvement of Th2 cells in the development of the enteropathy. To assess the individual contributions of Peyer’s patches (PPs), mesenteric lymph nodes (MLNs), and the spleen to the generation of effector CD4⁺ T-cells, we analyzed the IL-4 production, proliferation in response to ovalbumin, and CD4⁺ T-cell numbers of these tissues. EW feeding for 10 days induced significant IL-4 production in PPs, the infiltration of numerous CD4⁺ T-cells into MLNs, and a decrease in CD4⁺ T-cell numbers in spleen. On day 28, CD4⁺ T-cells from all tissues had attenuated responses to ovalbumin, suggesting tolerance acquisition, although MLN CD4⁺ T-cells still maintained IL-4 production with proliferation. In addition, removal of MLNs but not the spleen decreased the severity of enteropathy and PP-disrupted mice showed delayed onset of EW-induced inflammatory responses. Disruption of peripheral lymphoid tissues or of both PPs and MLNs almost completely prevented the enteropathy.

Conclusions

PPs and MLNs coordinately promote enteropathy by generating effector T-cells during the initial and exacerbated phases, respectively; the spleen is dispensable for enteropathy and shows tolerogenic responses throughout EW-feeding. The regulation of PPs may suppress the initiation of intestinal inflammation, subsequently restricting MLNs and inhibiting the progression of food-allergic enteropathy.     

Cigarette smoke and the terminal ileum: increased autophagy in murine follicle-associated epithelium and Peyer’s patches

Cigarette smoke (CS) exposure is associated with increased autophagy in several cell types, such as bronchial epithelial cells. Smoking is also an environmental risk factor in Crohn’s disease, in which impairment of the autophagy-mediated anti-bacterial pathway has been implicated. So far, it is unknown whether CS induces autophagy in the gut. Here, we examined the effect of chronic CS exposure on autophagy in the follicle-associated epithelium (FAE) of murine Peyer’s patches. Transmission electron microscopy revealed that the proportion of cell area occupied by autophagic vesicles significantly increased in the FAE after CS exposure. An increased number of autophagic vesicles was observed in the FAE, whereas the vesicle size remained unaltered. Besides enterocytes, also M-cells contain more autophagic vesicles upon CS exposure. In addition, the mRNA level of the autophagy-related protein Atg7 in the underlying Peyer’s patches is increased after CS exposure, which indicates that the autophagy-inducing effect of CS is not limited to the FAE. In conclusion, our results demonstrate that CS exposure induces autophagy in murine FAE and in the underlying immune cells of Peyer’s patches, suggesting that CS exposure increases the risk for Crohn’s disease by causing epithelial oxidative damage, which needs to be repaired by autophagy.     

Gene expression profiling of jejunal Peyer’s patches in juvenile and adult pigs

Peyer's patches are organized lymphoid tissues of the small intestine that play a critical role in disease resistance and oral tolerance. Peyer's patches in the jejunum contain lymphocytes, dendritic cells, macrophages, villous epithelium, and specialized follicle-associated epithelium. Little is known about the mechanisms and processes by which cells of the Peyer's patches discriminate food nutrients and commensal microflora from pathogenic microbiota. We hypothesize that the jejunal Peyer's patches express genes that mediate and regulate its essential functions. Expression patterns of approximately 2600 cDNAs from a porcine Peyer's patch subtracted library were examined by microarray profiling. Individual mRNAs of interest were further examined by quantitative RT-PCR. Innate immunity-associated genes, including complement 3 and lysozyme, and the genes for epithelial chloride channel and trappin 1 were highly expressed by jejunal Peyer's patch in both juvenile and adult pigs. The growth- and apoptosis-associated genes CIDE-B, GW112, and PSP/Reg I (pancreatic stone protein or regenerating gene) were differentially expressed in juvenile pig Peyer's patches. Many sequences which were highly expressed in jejunal Peyer's patches have previously been described with functions in epithelial cells. Animal-to-animal variation in basal jejunal Peyer's patch gene expression was considerable and reflects the dynamic physiological environment of the gut in addition to genetic, epigenetic, and microbiological variation in the small intestine.     

Identification of intestinal M cells in isolated lymphoid follicles and Peyer’s patches of the Angora rabbit

The presence, distribution, and localization of M cells in isolated lymphoid follicles (ILF) and in follicle-associated epithelia (FAE) covering Peyer’s patches (PP) in Angora rabbits were investigated by immunohistochemistry and electron microscopy. Although PP could macroscopically be identified along the length of the mucosal and serosal surfaces of jejunum and ileum, the presence of ILF could only be located microscopically. Typical M cells in FAE were detected within the periphery of the dome regions of the PP, and immature columnar M cells in the FAE resided in the vicinity of the crypts. M cells in the FAE of both ILF and PP showed vimentin-positive reaction. M cells in the FAE of ILF were morphologically similar to the immature M cells found in the FAE of PP. Typical mature M cells were also observed in the FAE of a few ILF. In contrast to FAE of PP, numerous goblet cells were observed in the FAE of many ILF. Moreover, among intestinal villi, we noticed villi-like solitary lymphoid structures that showed abundant lymphocytes in their lamina propria and that were surrounded with vimentin-positive cells and goblet cells. Thus, the occurrence of copious immature M cells and goblet cells, in addition to the detection of villi-like solitary lymphoid structures full of lymphocytes in the FAE of many ILF, indicate that ILF do not complete their immunological maturation in contrast to PP. Various antigenic stimulations conceivably induce the formation and maturation of ILF along the length of the small intestine. The morphological resemblance between ILF M cells and PP M cells suggests that these two types of cells perform similar or the same immunological functions.     

Loss of Function of the Mouse Sharpin Gene Results in Peyer’s Patch Regression

Peyer’s patches (PP) are an important component in the immune response against intestinal pathogens. Two independent, spontaneous mutations in the mouse Sharpin gene (Sharpin^cpdm and Sharpin^cpdm-Dem) result in the absence of PP and disrupted splenic white pulp in adult mice, although a full complement of lymph nodes is present. Here we report that rudimentary PP begin to develop in Sharpin^cpdm mice during embryogenesis, but lack the organizational patterns that are typical of this tissue. In the present study, small intestines examined at weekly intervals from birth to maturity showed spontaneous regression of PP in mutant mice with concurrent infiltration of granulocytes. At 5 to 6 weeks of age, only indistinct remnants of granulocytic accumulations remain. Transplantation of normal bone marrow into Sharpin^cpdm mice at 7 days of age did not prevent regression of PP in bone marrow chimeras examined at 7 to 8 weeks of age. These findings indicate that SHARPIN expression is required for the normal development and maintenance, but not initiation, of PP.     

Oral scrapie infection modifies the homeostasis of Peyer’s patches’ dendritic cells

In transmitted prion diseases the immune system supports the replication and the propagation of the pathogenic agent (PrPSc). DCs, which are mobile cells present in large numbers within lymph organs, are suspected to carry prions through the lymphoid system and to transfer them towards the peripheral nervous system. In this study, C57Bl/6 mice were orally inoculated with PrPSc (scrapie strain 139A) and sacrificed at the preclinical stages of the disease. Immunolabelled cryosections of Peyer’s patches were analysed by confocal microscopy. Membrane prion protein expression was studied by flow cytometry. In Peyer’s patches (PP), dissected at day one and day 105 after oral exposure to scrapie, we observed an increased population of DCs localised in the follicular-associated epithelium. On day 105, PrPSc was found in the follicles inside the PP of prion-infected mice. A subset of Peyer’s patches DCs, which did not express cellular prion protein on their surface in non-infected mice conditions, was prion-positive in scrapie conditions. Within Peyer’s patches oral scrapie exposure thus induced modifications of the homeostasis of DCs at the preclinical stages of the disease. These results give new arguments in favour of the implication of DCs in prion diseases.     

Copper in the brain and Alzheimer’s disease

Alzheimer’s disease (AD) is the most common form of neurodegenerative disease. The brain is particularly vulnerable to oxidative damage induced by unregulated redox-active metals such as copper and iron, and the brains of AD patients display evidence of metal dyshomeostasis and increased oxidative stress. The colocalisation of copper and amyloid β (Aβ) in the glutamatergic synapse during NMDA-receptor-mediated neurotransmission provides a microenvironment favouring the abnormal interaction of redox-potent Aβ with copper under conditions of copper dysregulation thought to prevail in the AD brain, resulting in the formation of neurotoxic soluble Aβ oligomers. Interactions between Aβ oligomers and copper can further promote the aggregation of Aβ, which is the core component of extracellular amyloid plaques, a central pathological hallmark of AD. Copper dysregulation is also implicated in the hyperphosphorylation and aggregation of tau, the main component of neurofibrillary tangles, which is also a defining pathological hallmark of AD. Therefore, tight regulation of neuronal copper homeostasis is essential to the integrity of normal brain functions. Therapeutic strategies targeting interactions between Aβ, tau and metals to restore copper and metal homeostasis are discussed.     

Differentiation of the follicle-associated epithelium in ileal Peyer’s patch and production of 50-nm particles are maintained in B-cell-depleted fetal sheep

To evaluate the dependence of the differentiation of the follicle-associated epithelium (FAE) on the presence of follicular B-cells, the FAE of ileal Peyers patch follicles was examined in B-cell-depleted fetal lambs. The FAE of these rudimentary follicles, which are devoid of lymphocytes, showed normal differentiation, including carbonic anhydrase reactivity and ultrastructural characteristics of transcytosis, extensive interdigitation of the lateral plasma membrane and the shedding of membrane-bounded particles, approximately 50 nm in size, resembling exosomes. These 50-nm membrane-bounded particles were abundant in the extracellular space of the epithelium and the dome but no particles were found in the rudimentary follicles. This study confirms that the rudimentary follicles consist of clusters of follicular dendritic cells. Our findings suggest that the differentiation of FAE of ileal Peyers patch and the production of the 50-nm particles constitute features that appear to be independent of B-cells. This study was supported in part by grants from the Norwegian Research Council     

Slc26a7 Chloride Channel Activity and Localization in Mouse Reissner’s Membrane Epithelium

Several members of the SLC26 gene family have highly-restricted expression patterns in the auditory and vestibular periphery and mutations in mice of at least two of these (SLC26A4 and SLC26A5) lead to deficits in hearing and/or balance. A previous report pointed to SLC26A7 as a candidate gene important for cochlear function. In the present study, inner ears were assayed by immunostaining for Slc26a7 in neonatal and adult mice. Slc26a7 was detected in the basolateral membrane of Reissner’s membrane epithelial cells but not neighboring cells, with an onset of expression at P5; gene knockout resulted in the absence of protein expression in Reissner’s membrane. Whole-cell patch clamp recordings revealed anion currents and conductances that were elevated for NO₃ ⁻ over Cl⁻ and inhibited by I⁻ and NPPB. Elevated NO₃ ⁻ currents were absent in Slc26a7 knockout mice. There were, however, no major changes to hearing (auditory brainstem response) of knockout mice during early adult life under constitutive and noise exposure conditions. The lack of Slc26a7 protein expression found in the wild-type vestibular labyrinth was consistent with the observation of normal balance. We conclude that SLC26A7 participates in Cl⁻ transport in Reissner’s membrane epithelial cells, but that either other anion pathways, such as ClC-2, possibly substitute satisfactorily under the conditions tested or that Cl⁻ conductance in these cells is not critical to cochlear function. The involvement of SLC26A7 in cellular pH regulation in other epithelial cells leaves open the possibility that SLC26A7 is needed in Reissner’s membrane cells during local perturbations of pH.     

Uptake and transport of foreign particles in Peyer’s patches of both distal ileum and jejunum of calves

To investigate the uptake and transport patterns of variously sized particles in Peyer’s patches (PPs) of calves, intestinal loops were created in four newborn and two 2-month-old calves, and the loops were inoculated with various particles, including carbon black, fluorescein isothiocyanate (FITC)-labeled latex, FITC-labeled dextran, bovine serum, and recombinant mouse prion protein (rMPrP). The intestinal loops were recovered at 3, 6, 9, and 24 h in newborn calves and at 24 h in 2-month-old calves after inoculation, and the transport of the particles was examined by histological and immunohistochemical means. The uptake of the particles was quantified by estimation of signal intensities. A greater intensity was found in newborn calves compared with the 2-month-old calves. The peak uptake of carbon black, FITC-labeled latex, and rMPrP in the PPs of the distal ileum occurred at 6 h after inoculation in newborn calves and then progressively decreased with time. Uptake was also dependent on the site within the small intestine and the size of the particle studied. The transport of carbon black, FITC-labeled latex, and FITC-labeled dextran occurred via the bloodstream, the mesenteric lymph nodes, and the liver of newborn calves. rMPrP was found primarily in the interfollicular regions of the submucosa of the distal ileum of newborn calves. Thus, distal ileal PPs are probably more effective at particle absorption than the jejunal PPs, and the peak uptake of the PPs within the newborn calf occurs at 6 h after inoculation. This study was partly supported by a grant for BSE research from the Ministry of Health, Labour, and Welfare, Japan (17270701) and Grant-in-Aid (no. 17380180) from the Ministry of Education, Culture, Sports, Science, and Technology, Japan.     

Distribution of immune cells and expression of interleukin receptors in ileal Peyer’s patches of calves

Newborn calves lack a mature immune system. The immune system develops with age, but the role of the expression of cytokine receptors in the development of immune cells of Peyer’s patches (PPs) in the intestines of calves in the first 2 months has not yet been elucidated. In this study, the distribution of immune cells and the expression of interleukin (IL) receptors (R) in the ileal PPs of newborn and 2-month-old calves were investigated immunohistochemically with monoclonal antibodies against bovine CD4, CD8, IgM, γδTCR, T19, WC3, WC5, and WC6 antigens. The expression of ILRs was examined with antibodies against CD25 (IL-2Rα), IL-2Rγ, IL-4R, IL-6R, IL-10R, and IL-13R antigens. CD4⁺, CD8⁺, γδTCR⁺, T19⁺, and WC6⁺ cells were found to be more widely distributed in the ileal PPs of 2-month-old calves than in those of newborn calves. Moreover, the expression of CD25 (IL-2Rα), IL-4R, and IL-13R in the ileal PPs of 2-month-old calves was more prominent than that in newborn calves. These data suggest that the immune system of calves at 2 months of age is developed by reactions to foreign antigens and aging.     

Mango introduction in Florida and the ’haden’ cultivar’s significance to the modern industry

Mango (Mangifera indica L.) introductions to Florida began in 1861 with the importation of ’No. 11’, a polyembryonic, seed-propagated (nucellar) cultivarfrom Cuba. In the 1880s a collection of Cuban mangos was established near Bradenton. One resulting popular cultivar was ’Turpentine’, now widely used as a rootstock. The U. S. Department of Agriculture introduced ’Mulgoba’, an improved cultivarfrom India, in 1889. Other mangos were later brought from India, Vietnam, the Philippines, Thailand, Israel, Australia and Kenya. Related Mangifera species were collected in East Malaysian Borneo in 1990. Inasmuch as the breeding system of Mangifera favors outcrossing, the proximity of numerous genotypes of disparate geographic origin in Florida has made that state a secondary center of diversity for the mango and enabled it to make a unique contribution to the fruit industry.     

Maltotriose transport and utilization in Baker’s and Brewer’s yeast

Maltotriose is metabolized by baker’s and brewer’s yeast only oxidatively, with a respiratory quotient of 1.0, the being, depending on the strain used, 0–11, as compared with of 6–42μL CO₂ per h per mg dry substance. The transport appeared to proceed by facilitated diffusion (no effects of NaF, iodoacetamide and 3-chlorophenylhydrazonomalononitrile) with a K_T of more than 50mm and was inhibited by maltose > maltotriose > methyl-α-D-glucoside > maltotetraose >D-fruetose >D-glucose. The transport was present constitutively in bothSaccharomyces cerevisiae (baker’s yeast) and inS. uvarum (brewer’s yeast) and it was not significantly stimulated by preincubation with glucose or maltose. The pH optimum was 4.5–5.5, the temperature dependence yielded an activation energy of 26 kJ/mol.     

Immune cell types involved in early uptake and transport of recombinant mouse prion protein in Peyer’s patches of calves

We have previously reported the early uptake and transport of foreign particles into Peyer’s patches (PPs) of newborn and 2-month-old calves and shown that the peak uptake of particles occurs 6 h after inoculation, in addition to site- and size-related effects on particle uptake. We now report the distribution of immune cells within PPs of the distal ileum in newborn and 2-month-old calves inoculated with carbon black. The types of immune cells involved in the early uptake and transport of recombinant mouse prion protein (rMPrP) within PPs of newborn calf were investigated by using monoclonal antibodies CD11c, CD14, CD68, CD172a, and CD21. CD11c⁺, CD14⁺, CD68⁺, CD172a⁺, and CD21⁺ immune cells were widely distributed in four tissue compartments (villi, dome, interfollicular region, and follicles) of PPs in the distal ileum of newborn and 2-month-old calves, whereas CD11c⁺, CD14⁺, CD172a⁺, and CD21⁺ immune cells were more prominently distributed in the dome areas of newborn calves than in 2-month-old calves. Moreover, CD11c⁺ and CD14⁺ dendritic cells, CD172a⁺ and CD68⁺ macrophages, and CD21⁺ follicular dendritic cells containing rMPrP were primarily observed in the dome and inner follicular regions. The deposition of rMPrP within CD11c⁺, CD14⁺, CD172a⁺, and CD68⁺ cells, but not CD21⁺ cells, was detected in villous regions. rMPrP-positive immune cells within the interfollicular regions included only CD11c⁺ and CD172⁺ cells. Although the particles used in this investigation do not include the infectious prion protein, PrP^Sc, our experimental setup provides a useful model for studying immune cells involved in the early uptake and transport of PrP^Sc.     

Chasing genes in Alzheimer’s and Parkinson’s disease

Alzheimers disease (AD), the most common type of dementia, and Parkinsons disease (PD), the most common movement disorder, are both neurodegenerative adult-onset diseases characterized by the progressive loss of specific neuronal populations and the accumulation of intraneuronal inclusions. The search for genetic and environmental factors that determine the fate of neurons during the ageing process has been a widespread approach in the battle against neurodegenerative disorders. Genetic studies of AD and PD initially focused on the search for genes involved in the aetiological mechanisms of monogenic forms of these diseases. They later expanded to study hundreds of patients, affected relative-pairs and population-based studies, sometimes performed on special isolated populations. A growing number of genes (and pathogenic mutations) is being identified that cause or increase susceptibility to AD and PD. This review discusses the way in which strategies of gene hunting have evolved during the last few years and the significance of finding genes such as the presenilins, -synuclein, parkin and DJ-1. In addition, we discuss possible links between these two neurodegenerative disorders. The clinical, pathological and genetic presentation of AD and PD suggests the involvement of a few overlapping interrelated pathways. Their imbricate features point to a spectrum of neurodegeneration (tauopathies, synucleinopathies, amyloidopathies) that need further intense investigation to find the missing links.     

Role of zinc and copper ions in the pathogenetic mechanisms of Alzheimer’s and Parkinson’s diseases

Disbalance of zinc (Zn²⁺) and copper (Cu²⁺) ions in the central nervous system is involved in the pathogenesis of numerous neurodegenerative disorders such as multisystem atrophy, amyotrophic lateral sclerosis, Creutzfeldt-Jakob disease, Wilson-Konovalov disease, Alzheimer’s disease, and Parkinson’s disease. Among these, Alzheimer’s disease (AD) and Parkinson’s disease (PD) are the most frequent age-related neurodegenerative pathologies with disorders in Zn²⁺ and Cu²⁺ homeostasis playing a pivotal role in the mechanisms of pathogenesis. In this review we generalized and systematized current literature data concerning this problem. The interactions of Zn²⁺ and Cu²⁺ with amyloid precursor protein (APP), β-amyloid (Abeta), tau-protein, metallothioneins, and GSK3β are considered, as well as the role of these interactions in the generation of free radicals in AD and PD. Analysis of the literature suggests that the main factors of AD and PD pathogenesis (oxidative stress, structural disorders and aggregation of proteins, mitochondrial dysfunction, energy deficiency) that initiate a cascade of events resulting finally in the dysfunction of neuronal networks are mediated by the disbalance of Zn²⁺ and Cu²⁺.     

Hodgkin’s disease in the spleen

Spleens with proven though small Hodgkin lesions were examined expecially in relation to the lymphoid tissue normally engaged in the immune response. These Hodgkin foci were always very close to small arteries and surrounded by a lymphocyte corona. Most of the red and white pulp seemed normal, but in some instances abnormal looking large and also multinucleated cells were found scattered through the p.a.l.s. and especially through some follicles. It is considered possible that these isolated cellular abnormalities in the white pulp, when associated with pre-existent Hodgkin foci, represent early Hodgkin lesions. The implications for the dissemination of the disease are discussed. Spread of malignant cells to the spleen is only acceptable within the concept of a homing principle. It is also possible that the lesions arise "de novo". The nature of the observed abnormal cells is not clear. An explanation for the origin of these Sternberg-Reed-like cells from B-lymphocytes would be in accordance with recent data, but another possibility still is that they originate from antigen trapping cells.