HOST-PARASITE INTERACTION IN THE RAT RENAL PELVIS

The initial interaction between bacteria and the renal pelvic epithelium may determine whether intrarenal infection occurs. A model of retrograde pyelonephritis was employed to study these events by electron microscopy. Female rats received an intravesicular inoculation of a 0.5-ml suspension of Proteus mirabilis containing 108 organisms. At intervals after inoculation, the kidneys were fixed by intravascular perfusion and the tissues were prepared for electron microscopy. During the first 24 h, increasing numbers of bacteria were seen to be attached by pili to the renal pelvic epithelial cells. The organism appeared to cross the mucosal barrier by several mechanisms: (a) penetration into the cytoplasm of intact epithelial cells, (b) passage between epithelial cells that were separated by excessive hydrostatic pressure generated during bladder inoculation, (c) passage across necrotic regions of the pelvis, and (d) translocation to the cortex by calicotubular backflow. Whereas at inoculation bacteria possessed pili 40 Å in diameter (type III pili) 24 h after reflux, the predominant type of pili measured 70 A in thickness (type IV pili). Repetitive subculture induced a similar transition in vitro. To assess the influence of pili type on virulence in this model, 80 rats were challenged with either type III or type IV pilated organisms and the frequency of rats with cortical abscesses were compared at 1 wk. A significantly greater number of rats inoculated with type IV pilated Proteus manifested macroscopic evidence of infection. These results suggest that pili play a role in the pathogenesis of ascending pyelonephritis.

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IV. Paneth cell antimicrobial peptides and the biology of the mucosal barrier

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1999.277.2.g257 ◽

1999 ◽

Vol 277 (2) ◽

pp. G257-G261 ◽

Cited By ~ 18

Author(s):

Andre J. Ouellette

Keyword(s):

Innate Immunity ◽

Epithelial Cells ◽

Antimicrobial Peptides ◽

Paneth Cell ◽

Chloride Ion ◽

Paneth Cells ◽

In Vitro Assays ◽

Mucosal Barrier ◽

Intermediate Cells

The hypothesis that epithelial cells release preformed antibiotic peptides as components of mucosal innate immunity has gained experimental support in recent years. In the mammalian small intestine, Paneth cells secrete granules that are rich in α-defensins and additional antimicrobial peptides into the lumen of the crypt. The α-defensins are homologues of peptides that function as mediators of nonoxidative microbial cell killing in phagocytic leukocytes, and they are potent microbicidal agents in in vitro assays. Because certain mouse α-defensins stimulate cultured epithelial cells to secrete chloride ion, those peptides appear to be capable of interacting directly with the apical membranes of neighboring cells and perhaps influencing crypt physiology. In instances of crypt disruption or induced Paneth cell deficiency, crypt intermediate cells appear to compensate by accumulating and secreting Paneth cell antimicrobial peptides. Challenges for the future will be to understand the mechanisms of this epithelial plasticity and to show that Paneth cells contribute directly to innate immunity in the crypt microenvironment.

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Isolation, in vitro cultivation, and electron microscopy of normal and malignant prostatic epithelial cells from the Copenhagen rat

Urological Research ◽

10.1007/bf00256409 ◽

1980 ◽

Vol 8 (3) ◽

pp. 139-152 ◽

Cited By ~ 7

Author(s):

Frederick A. Feuchter ◽

David R. Rowley ◽

Paul M. Heidger

Keyword(s):

Electron Microscopy ◽

Epithelial Cells ◽

In Vitro Cultivation ◽

Copenhagen Rat

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Modulation of Cytosolic Ca2+ Concentration in Airway Epithelial Cells by Pseudomonas aeruginosa

Infection and Immunity ◽

10.1128/iai.70.11.6399-6408.2002 ◽

2002 ◽

Vol 70 (11) ◽

pp. 6399-6408 ◽

Cited By ~ 15

Author(s):

Tobias Jacob ◽

Rebecca J. Lee ◽

Joanne N. Engel ◽

Terry E. Machen

Keyword(s):

Pseudomonas Aeruginosa ◽

Epithelial Cells ◽

Type Iii Secretion ◽

Airway Epithelial Cells ◽

Ca Channel ◽

Airway Epithelial ◽

Slow Increase ◽

Type Iii ◽

Apical Chamber ◽

Type Iv

ABSTRACT Modulation of cytosolic (intracellular) Ca2+ concentration (Cai) may be an important host response when airway epithelial cells are exposed to Pseudomonas aeruginosa. We measured Cai in Calu-3 cells exposed from the apical or basolateral surface to cytotoxic and noncytotoxic strains of P. aeruginosa. Apical addition of either noncytotoxic strains or cytotoxic strains failed to affect Cai over a 3-h time period, nor were changes observed after basolateral addition of noncytotoxic strains. In contrast, basolateral addition of cytotoxic strains caused a slow increase in Cai from 100 nM to 200 to 400 nM. This increase began after 20 to 50 min and persisted for an additional 30 to 75 min, at which time the cells became nonviable. P. aeruginosa-induced increases in Cai were blocked by the addition of the Ca channel blocker La3+ to the basolateral but not to the apical chamber. Likewise, replacing the basolateral but not the apical medium with Ca-free solution prevented P. aeruginosa-mediated changes in Cai. With isogenic mutants of PA103, we demonstrated that the type III secretion apparatus, the type III-secreted effector ExoU, and type IV pili were necessary for increased Cai. We propose that translocation of ExoU through the basolateral surface of polarized airway epithelial cells via the type III secretion apparatus leads to release of Ca stored in the endoplasmic reticulum and activation of Ca channels in the basolateral membranes of epithelial cells.

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Lens metabolic cooperation: a study of mouse lens transport and permeability visualized with freeze-substitution autoradiography and electron microscopy.

The Journal of Cell Biology ◽

10.1083/jcb.86.2.576 ◽

1980 ◽

Vol 86 (2) ◽

pp. 576-589 ◽

Cited By ~ 113

Author(s):

D A Goodenough ◽

J S Dick ◽

J E Lyons

Keyword(s):

Electron Microscopy ◽

Epithelial Cells ◽

Freeze Fracture ◽

Freeze Substitution ◽

Species Variation ◽

Metabolic Cooperation ◽

Zonulae Occludentes ◽

Lens Fibers ◽

Mouse Lens

Transport of metabolites is demonstrated between compartments of the adult mouse lens by freeze-substitution autoradiography. In vivo patterns of lysine incorporation are compared with in vitro patterns of lysine, glucose, uridine, and deoxyglucose incorporation. Intracellular and extracellular distributions of tritiated metabolites are determined by comparison of transported substrates with the nontransported molecules of similar molecular size: mannitol and sucrose. The permeability of the lens intercellular spaces is probed with Procion Yellow at the level of fluorescence microscopy, and with horseradish peroxidase at the electron microscope level. Freeze-fracture electron microscopy reveals gap junctions between epithelial cells, between lens fibers, and between epithelial cells and lens fibers. Zonulae occludentes (tight junctions) are not routinely observed between epithelial cells in the mouse. This latter result is subject to species variation, however, since zonulae occludentes are abundant between chicken epithelial cells. The permeability results suggest that the lens cells are capable of metabolic cooperation, mediated by an extensive gap junction network.

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Interleukin-10 Expands Transit-Amplifying Cells While Depleting Lgr5+ Stem Cells via Inhibition of Wnt and Notch Signaling

10.21203/rs.3.rs-44220/v1 ◽

2020 ◽

Author(s):

Fan Deng ◽

Jingjuan Hu ◽

Xiao Yang ◽

Yifan Wang ◽

Kexuan Liu

Keyword(s):

Stem Cells ◽

Epithelial Cells ◽

Interleukin 10 ◽

Mucosal Healing ◽

Mucosal Barrier ◽

Inflammatory Factor ◽

Epithelial Regeneration ◽

Immune Mediated

Abstract Background & Aims: Epithelial regeneration is essential for homeostasis and mucosal barrier repair. In infectious and immune-mediated intestinal diseases, interleukin (IL)-10 is thought to enhance these processes. We aimed to define the mechanism by which IL-10 played in mucosal healing or injury.Methods: Intestinal stem cells (ISCs) cultures and mice were treated with recombinant mice IL-10 (rmIL-10). The level of cell proliferation, differentiation, death and related signaling pathways for self-renewal of ISCs were measured in vitro and in vivo.Results: It was uncovered that rmIL-10 increased the size and death, but reduced the total number of organoids. In addition, rmIL-10 depleted Lgr5+ ISCs and reduced epithelial proliferation, but enhanced the differentiation of epithelial cells and expanded numbers of transit-amplifying (TA) cells. These changes are related to the decrease of Wnt and Notch signals in vivo and in vitro. Meanwhile, increased expression of Paneth cells and decreased expression of enteroendocrine cells and goblet cells were induced by rmIL-10.Conclusions: IL-10 reduces the survival of Lgr5+ ISCs and proliferation of epithelial cells by inhibiting Notch and Wnt signaling, but promotes enhanced the differentiation of epithelial cells and expanded numbers of TA cells. Therefore, IL-10 acts as an anti-inflammatory factor, but may damage intestinal mucosa repair and maybe a potential target for the treatment of intestinal injury.

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T4SS-dependent TLR5 activation by Helicobacter pylori infection

Nature Communications ◽

10.1038/s41467-019-13506-6 ◽

2019 ◽

Vol 10 (1) ◽

Cited By ~ 7

Author(s):

Suneesh Kumar Pachathundikandi ◽

Nicole Tegtmeyer ◽

Isabelle Catherine Arnold ◽

Judith Lind ◽

Matthias Neddermann ◽

...

Keyword(s):

Helicobacter Pylori ◽

Epithelial Cells ◽

Pathogenic Bacteria ◽

Type Iv Secretion ◽

Downstream Signaling ◽

Type Iv ◽

Efficient Control ◽

H Pylori ◽

Highly Virulent

AbstractToll-like receptor TLR5 recognizes a conserved domain, termed D1, that is present in flagellins of several pathogenic bacteria but not in Helicobacter pylori. Highly virulent H. pylori strains possess a type IV secretion system (T4SS) for delivery of virulence factors into gastric epithelial cells. Here, we show that one of the H. pylori T4SS components, protein CagL, can act as a flagellin-independent TLR5 activator. CagL contains a D1-like motif that mediates adherence to TLR5+ epithelial cells, TLR5 activation, and downstream signaling in vitro. TLR5 expression is associated with H. pylori infection and gastric lesions in human biopsies. Using Tlr5-knockout and wild-type mice, we show that TLR5 is important for efficient control of H. pylori infection. Our results indicate that CagL, by activating TLR5, may modulate immune responses to H. pylori.

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In vitro modeling of host-parasite interactions: the 'subgingival' biofilm challenge of primary human epithelial cells

BMC Microbiology ◽

10.1186/1471-2180-9-280 ◽

2009 ◽

Vol 9 (1) ◽

pp. 280 ◽

Cited By ~ 83

Author(s):

Bernhard Guggenheim ◽

Rudolf Gmür ◽

Johnah C Galicia ◽

Panagiota G Stathopoulou ◽

Manjunatha R Benakanakere ◽

...

Keyword(s):

Epithelial Cells ◽

In Vitro Modeling ◽

Host Parasite Interactions ◽

Human Epithelial Cells ◽

Host Parasite

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Cells that emerge from embryonic explants produce fibers of type IV collagen.

The Journal of Cell Biology ◽

10.1083/jcb.101.4.1175 ◽

1985 ◽

Vol 101 (4) ◽

pp. 1175-1181 ◽

Cited By ~ 16

Author(s):

J M Chen ◽

C D Little

Keyword(s):

Extracellular Matrix ◽

Epithelial Cells ◽

Basement Membrane ◽

Type Iv Collagen ◽

Polyclonal Antibodies ◽

Mouse Lung ◽

Embryonic Mouse ◽

Type Iv ◽

Collagen Substratum

Double immunofluorescence staining experiments designed to examine the synthesis and deposition of collagen types I and IV in cultured explants of embryonic mouse lung revealed the presence of connective tissue-like fibers that were immunoreactive with anti-type IV collagen antibodies. This observation is contrary to the widely accepted belief that type IV collagen is found only in sheet-like arrangements beneath epithelia or as a sheath-like layer enveloping bundles of nerve or muscle cells. The extracellular matrix produced by cells that migrate from embryonic mouse lung rudiments in vitro was examined by double indirect immunofluorescence microscopy. Affinity-purified monospecific polyclonal antibodies were used to examine cells after growth on glass or native collagen substrata. The data show that embryonic mesenchymal cells can produce organized fibers of type IV collagen that are not contained within a basement membrane, and that embryonic epithelial cells deposit fibers and strands of type IV collagen beneath their basal surface when grown on glass; however, when grown on a rat tail collagen substratum the epithelial cells produce a fine meshwork. To our knowledge this work represents the first report that type IV collagen can be organized by cells into a fibrous extracellular matrix that is not a basement membrane.

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Streptococcus Thermophilus UASt-09 Upregulates Goblet Cell Activity in Colonic Epithelial Cells to a Greater Degree than other Probiotic Strains

Microorganisms ◽

10.3390/microorganisms8111758 ◽

2020 ◽

Vol 8 (11) ◽

pp. 1758

Author(s):

Madhur D. Shastri ◽

Wai Chin Chong ◽

Ravichandra Vemuri ◽

Christopher J. Martoni ◽

Santosh Adhikari ◽

...

Keyword(s):

Immune Response ◽

Epithelial Cells ◽

Bacterial Species ◽

Cell Activity ◽

Streptococcus Thermophilus ◽

Mucosal Barrier ◽

Intestinal Barrier Function ◽

Colonic Epithelial Cells ◽

Gastrointestinal Health

Probiotics have been widely used in maintaining gastrointestinal health, despite their actual mechanism remaining obscure. There are several hypotheses behind the beneficial effects of probiotics including the regulation of intestinal barrier function and improvement in immune responses in the gastrointestinal system. Multiple probiotics have been introduced in the market as effective dietary supplements in improving gastrointestinal integrity, but there are no or few studies that demonstrate their underlying mechanism. In the current study, we investigated and compared the efficacy of four probiotics (based on different bacterial species) in refining gastrointestinal health by improving mucus biosynthesis and intestinal immune response under in-vitro conditions. By analyzing the gene expression of mucus biosynthesis and intestinal immune response markers, we found that probiotic Streptococcus thermophilus UASt-09 showed promising potential in refining mucosal barrier and gastrointestinal health in human colonic epithelial cells, as compared to other commercial probiotics.

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