scholarly journals The Terminal Sialic Acid of Glycoconjugates on the Surface of Intestinal Epithelial Cells Activates Excystation of Cryptosporidium parvum

2008 ◽  
Vol 76 (8) ◽  
pp. 3735-3741 ◽  
Author(s):  
Naheed Choudhry ◽  
Mona Bajaj-Elliott ◽  
Vincent McDonald
Keyword(s):  
Sialic Acid ◽  
Epithelial Cells ◽  
Cell Lines ◽  
Cryptosporidium Parvum ◽  
Diarrheal Disease ◽  
Intestinal Epithelial Cells ◽  
Mammalian Species ◽  
Intestinal Epithelial ◽  
Terminal Sialic Acid ◽  
Pass Through

ABSTRACT The apicomplexan Cryptosporidium parvum reproduces in the intestinal epithelial cells of many mammalian species and is an agent of the important diarrheal disease cryptosporidiosis. Infection is transmitted fecal-orally by oocysts that pass through the stomach and excystation occurs in the intestine, releasing four invasive sporozoites. Some factors involved in inducing excystation have been identified, but the role of the enterocyte is not known. The present study showed that excystation was accelerated in the presence of the three enterocyte cell lines Caco2, HCT8, and CMT93. Epithelial cell lines derived from other organs, including the stomach, had no effect on excystation. No evidence was obtained that factors secreted from enterocytes induced excystation, but an enterocyte membrane preparation promoted sporozoite release. In addition, modification of the enterocyte surface by trypsin digestion or paraformaldehyde fixation abrogated the ability to enhance excystation. Importantly, the level of excystation in the presence of enterocytes decreased after treatment with either sialidase/neuraminidase to deplete surface terminal sialic acid or with lectins that specifically bind to sialic acid. Furthermore, the addition of sialic acid to oocysts in the absence of cells increased the level of excystation. These results suggest that sialic acid on the surface of enterocytes may provide an important local signal for the excystation of C. parvum sporozoites.

scholarly journals Decreased SLC26A3 expression and function in intestinal epithelial cells in response to Cryptosporidium parvum infection

2019 ◽  
Vol 317 (6) ◽  
pp. C1205-C1212 ◽  
Author(s):  
Anoop Kumar ◽  
Dulari Jayawardena ◽  
Arivarasu N. Anbazhagan ◽  
Ishita Chatterjee ◽  
Shubha Priyamvada ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Cryptosporidium Parvum ◽  
Diarrheal Disease ◽  
Intestinal Epithelial Cells ◽  
Ex Vivo ◽  
Jejunal Mucosa ◽  
Intestinal Epithelial ◽  
Chloride Absorption ◽  
And Function

The protozoan parasite Cryptosporidium parvum (CP) causes cryptosporidiosis, a diarrheal disease worldwide. Infection in immunocompetent hosts typically results in acute, self-limiting, or recurrent diarrhea. However, in immunocompromised individuals infection can cause fulminant diarrhea, extraintestinal manifestations, and death. To date, the mechanisms underlying CP-induced diarrheal pathogenesis are poorly understood. Diarrheal diseases most commonly involve increased secretion and/or decreased absorption of fluid and electrolytes. We and others have previously shown impaired chloride absorption in infectious diarrhea due to dysregulation of SLC26A3 [downregulated in adenoma (DRA)], the human intestinal apical membrane Cl−/[Formula: see text] exchanger protein. However, there are no studies on the effects of CP infection on DRA activity. Therefore, we examined the expression and function of DRA in intestinal epithelial cells in response to CP infection in vitro and in vivo. CP infection (0.5 × 106 oocysts/well in 24-well plates, 24 h) of Caco-2 cell monolayers significantly decreased Cl−/[Formula: see text] exchange activity (measured as DIDS-sensitive 125I uptake) as well as DRA mRNA and protein levels. Substantial downregulation of DRA mRNA and protein was also observed following CP infection ex vivo in mouse enteroid-derived monolayers and in vivo in the ileal and jejunal mucosa of C57BL/6 mice for 24 h. However, at 48 h after infection in vivo, the effects on DRA mRNA and protein were attenuated and at 5 days after infection DRA returned to normal levels. Our results suggest that impaired chloride absorption due to downregulation of DRA could be one of the contributing factors to CP-induced acute, self-limiting diarrhea in immunocompetent hosts.

scholarly journals Inhibition of Apoptosis in Cryptosporidium parvum-Infected Intestinal Epithelial Cells Is Dependent on Survivin

2008 ◽  
Vol 76 (8) ◽  
pp. 3784-3792 ◽  
Author(s):  
Jin Liu ◽  
Shinichiro Enomoto ◽  
Cheryl A. Lancto ◽  
Mitchell S. Abrahamsen ◽  
Mark S. Rutherford
Keyword(s):  
Epithelial Cells ◽  
Cryptosporidium Parvum ◽  
Time Course ◽  
Caspase 3 ◽  
Diarrheal Disease ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial ◽  
Genes Encoding ◽  
Infected Cells ◽  
Induced Apoptosis

ABSTRACT Cryptosporidium parvum is an obligate intracellular protozoan capable of causing severe diarrheal disease in a wide variety of mammals, including humans. C. parvum infection has been associated with induction of apoptosis in exposed epithelial cells, and we now demonstrate that apoptosis is restricted to a subset of cells actively infected with C. parvum. Approximately 20% of the infected cells underwent apoptosis within 48 h of infection, suggesting that the majority of the infected cells are rescued from apoptosis. C. parvum infection resulted in low-level activation of multiple members of the caspase family, including caspase-2, -3, -4, -6, -8, and -9. The kinetics of caspase activation correlated with apoptosis over a 48-h time course. Pan caspase inhibitors reduced apoptosis of epithelial cells infected by C. parvum. Furthermore, C. parvum infection inhibited staurosporine-induced apoptosis and caspase-3/7 activation at 24 h and 48 h. Infection with C. parvum led to upregulation of genes encoding inhibitors of apoptosis proteins (IAPs), including c-IAP1, c-IAP2, XIAP, and survivin. Knockdown of survivin gene expression, but not that of c-IAP1, c-IAP2, or XIAP expression, increased caspase-3/7 activity as well as apoptosis of infected cells and decreased C. parvum 18S rRNA levels. These data suggest that the apoptotic response of infected intestinal epithelial cells is actively suppressed by C. parvum via upregulation of survivin, favoring parasite infection.

scholarly journals Cryptosporidium parvum Apical Complex Glycoprotein CSL Contains a Sporozoite Ligand for Intestinal Epithelial Cells

1999 ◽  
Vol 67 (10) ◽  
pp. 5282-5291 ◽  
Author(s):  
Rebecca C. Langer ◽  
Michael W. Riggs
Keyword(s):  
Monoclonal Antibody ◽  
Epithelial Cells ◽  
Cryptosporidium Parvum ◽  
Diarrheal Disease ◽  
Intestinal Epithelial Cells ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Passive Immunization ◽  
Intestinal Epithelial

ABSTRACT Cryptosporidiosis, caused by the apicomplexan parasiteCryptosporidium parvum, has become a well-recognized diarrheal disease of humans and other mammals throughout the world. No approved parasite-specific drugs, vaccines, or immunotherapies for control of the disease are currently available, although passive immunization with C. parvum-specific antibodies has some efficacy in immunocompromised and neonatal hosts. We previously reported that CSL, an ∼1,300-kDa conserved apical glycoprotein of C. parvum sporozoites and merozoites, is the antigenic species mechanistically bound by neutralizing monoclonal antibody 3E2 which elicits the circumsporozoite precipitate (CSP)-like reaction and passively protects against C. parvum infection in vivo. These findings indicated that CSL has a functional role in sporozoite infectivity. Here we report that CSL has properties consistent with being a sporozoite ligand for intestinal epithelial cells. For these studies, native CSL was isolated from whole sporozoites by isoelectric focusing (IEF) following observations that the ∼1,300-kDa region containing CSL as seen by sodium dodecyl sulfate-polyacrylamide gel electrophoresis was comprised of approximately 15 molecular species (pI 3 to 10) when examined by two-dimensional (2-D) electrophoresis and silver staining. A subset of six ∼1,300-kDa species (pI 4.0 to 6.5) was specifically recognized by 3E2 in 2-D Western immunoblots of IEF-isolated CSL. Isolated native CSL bound specifically and with high affinity to permissive human intestinal epithelial Caco-2 cells in a dose-dependent, saturable, and self-displaceable manner. Further, CSL specifically bound to the surface of live Caco-2 cells inhibited sporozoite attachment and invasion. In addition, sporozoites having released CSL after incubation with 3E2 and occurrence of the CSP-like reaction did not attach to and invade Caco-2 cells. These findings indicate that CSL contains a sporozoite ligand which facilitates attachment to and invasion of Caco-2 cells and, further, that ligand function may be disrupted by CSL-reactive monoclonal antibody. We conclude that CSL is a rational target for passive or active immunization against cryptosporidiosis.

scholarly journals A σ28-Regulated Nonflagella Gene Contributes to Virulence of Campylobacter jejuni 81-176

2006 ◽  
Vol 74 (1) ◽  
pp. 769-772 ◽  
Author(s):  
Scarlett Goon ◽  
Cheryl P. Ewing ◽  
Maria Lorenzo ◽  
Dawn Pattarini ◽  
Gary Majam ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Campylobacter Jejuni ◽  
Diarrheal Disease ◽  
Intestinal Epithelial Cells ◽  
Disease Model ◽  
Intestinal Epithelial ◽  
Model Expression

ABSTRACT A Campylobacter jejuni 81-176 mutant in Cj0977 was fully motile but reduced >3 logs compared to the parent in invasion of intestinal epithelial cells in vitro. The mutant was also attenuated in a ferret diarrheal disease model. Expression of Cj0977 protein was dependent on a minimal flagella structure.

scholarly journals The Dual Tropism of Noroviruses

2018 ◽  
Vol 92 (16) ◽  
Author(s):  
Christiane E. Wobus
Keyword(s):  
Epithelial Cells ◽  
Rna Viruses ◽  
Intestinal Epithelial Cells ◽  
Mammalian Species ◽  
Cell Types ◽  
Economic Losses ◽  
Cell Tropism ◽  
Intestinal Epithelial ◽  
Complex Cell ◽  
Significant Morbidity

ABSTRACTNoroviruses are highly prevalent enteric RNA viruses. Human noroviruses (HuNoVs) cause significant morbidity, mortality, and economic losses worldwide. Infections also occur in other mammalian species, including mice. Despite the discovery of the first norovirus in 1972, the viral tropism has long remained an enigma. A long-held assumption was that these viruses infect intestinal epithelial cells. Recent data support a more complex cell tropism of epithelial and nonepithelial cell types.

Induction of endothelin-1 synthesis by IL-2 and its modulation of rat intestinal epithelial cell growth

1998 ◽  
Vol 275 (3) ◽  
pp. G556-G563 ◽  
Author(s):  
Takeharu Shigematsu ◽  
Soichiro Miura ◽  
Masahiko Hirokawa ◽  
Ryota Hokari ◽  
Hajime Higuchi ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Growth ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Cell Lines ◽  
Proliferative Response ◽  
Intestinal Epithelial Cell ◽  
Culture Media ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial

Endothelin (ET), a vasoconstrictive peptide, is known to have a variety of biological actions. Although ET is released by vascular endothelial cells, other cell populations also have been reported to synthesize and release ET. In this study, we examined whether ET is synthesized by intestinal epithelial cells and whether it affects induction of epithelial cell proliferation by interleukin-2 (IL-2). Subconfluent monolayers of intestinal epithelial cells (IEC-6 and IEC-18) were maintained in serum-free medium before addition of rat IL-2. Both IEC-6 and IEC-18 cells released ET-1 into the medium under unstimulated conditions, as determined by a sandwich ELISA. IL-2 significantly enhanced ET-1 release in a time-dependent manner. ET-3 was not detectable in the culture media of either cell line. Expression of ET-1 and ET-3 mRNA in epithelial cells was assessed by competitive PCR. Both cell lines were shown to express ET-1 mRNA, but no ET-3 mRNA was detected. IL-2 treatment enhanced ET-1 mRNA expression by both IEC-6 and IEC-18 cells. Both cell lines also expressed mRNA for ETA and ETB receptor subtypes. When cell proliferation was assessed, exogenous ET-1 induced a slight proliferative response in both types of cells that was consistent and significant at low ET-1 concentrations; cell growth was inhibited at a higher concentration (10−7M). IL-2 produced a significant proliferative response in both cell lines. However, the addition of ET-1 (10−7 M) to culture media attenuated the IL-2-induced increase in cell proliferation. ETA-receptor antagonists significantly enhanced cellular proliferation, suggesting involvement of the ETA receptor in modulation of IL-2-induced intestinal epithelial cell growth.

scholarly journals Simultaneous Exposure to Escherichia coli Heat-Labile and Heat-Stable Enterotoxins Increases Fluid Secretion and Alters Cyclic Nucleotide and Cytokine Production by Intestinal Epithelial Cells

2014 ◽  
Vol 82 (12) ◽  
pp. 5308-5316 ◽  
Author(s):  
Lisa T. Read ◽  
Rachel W. Hahn ◽  
Carli C. Thompson ◽  
David L. Bauer ◽  
Elizabeth B. Norton ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Diarrheal Disease ◽  
Water Movement ◽  
Intestinal Epithelial Cells ◽  
Intestinal Lumen ◽  
Intestinal Epithelial ◽  
Simultaneous Exposure ◽  
Heat Stable ◽  
Heat Labile

ABSTRACTEnterotoxigenicEscherichia coli(ETEC) is a significant cause of diarrheal disease and death, especially in children in developing countries. ETEC causes disease by colonizing the small intestine and producing heat-labile toxin (LT), heat-stable toxin (ST), or both LT and ST (LT+ST). The majority of ETEC strains produce both ST and LT. Despite the prevalence of LT+ST-producing organisms, few studies have examined the physiologic or immunologic consequences of simultaneous exposure to these two potent enterotoxins. In the current report, we demonstrate that when LT and ST are both present, they increase water movement into the intestinal lumen over and above the levels observed with either toxin alone. As expected, cultured intestinal epithelial cells increased their expression of intracellular cyclic GMP (cGMP) when treated with ST and their expression of intracellular cyclic AMP (cAMP) when treated with LT. When both toxins were present, cGMP levels but not cAMP levels were synergistically elevated compared with the levels of expression caused by the corresponding single-toxin treatment. Our data also demonstrate that the levels of inflammatory cytokines produced by intestinal epithelial cells in response to LT are significantly reduced in animals exposed to both enterotoxins. These findings suggest that there may be complex differences between the epithelial cell intoxication and, potentially, secretory outcomes induced by ETEC strains expressing LT+ST compared with strains that express LT or ST only. Our results also reveal a novel mechanism wherein ST production may reduce the hosts' ability to mount an effective innate or adaptive immune response to infecting organisms.

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