scholarly journals IL-22 induced cell extrusion and IL-18-induced pyroptosis prevent and cure rotavirus infection

2019 ◽  
Author(s):  
Zhan Zhang ◽  
Jun Zou ◽  
Zhenda Shi ◽  
Benyue Zhang ◽  
Lucie Etienne-Mesmin ◽  
...  

SummaryAdministration of bacterial flagellin elicits production of TLR5-mediated IL-22 and NLRC4-mediated IL-18 that act in concert to cure and prevent rotavirus (RV) infection. This study investigated the mechanism by which these cytokines act to impede this virus. Although IL-18 and IL-22 induce each other’s expression, we found that IL-18 and IL-22 both impeded RV independently of each other and did so by distinct mechanisms, in both cases via activation of their cognate receptors in intestinal epithelial cells (IEC). IL-22 drove IEC proliferation and migration toward villus tips, which resulted in increased extrusion of highly differentiated IEC that serve as the site of RV replication. In contrast, IL-18 induced pyroptotic death of RV-infected IEC thus directly interrupting the RV replication cycle, resulting in spewing of incompetent virus into the intestinal lumen and causing a rapid drop in levels of RV-infected IEC. Together, these actions resulted in rapid and complete expulsion of RV, even in hosts with severely compromised immune systems. These results suggest that IL-18/22 might be a means of treating viral infections that preferentially target short-lived epithelial cells.


2020 ◽  
Vol 5 (52) ◽  
pp. eabd2876
Author(s):  
Zhan Zhang ◽  
Jun Zou ◽  
Zhenda Shi ◽  
Benyue Zhang ◽  
Lucie Etienne-Mesmin ◽  
...  

Bacterial flagellin can elicit production of TLR5-mediated IL-22 and NLRC4-mediated IL-18 cytokines that act in concert to cure and prevent rotavirus (RV) infection. This study investigated the mechanism by which these cytokines act to impede RV. Although IL-18 and IL-22 induce each other’s expression, we found that IL-18 and IL-22 both impeded RV independently of one another and did so by distinct mechanisms that involved activation of their cognate receptors in intestinal epithelial cells (IEC). IL-22 drove IEC proliferation and migration toward villus tips, which resulted in increased extrusion of highly differentiated IEC that serve as the site of RV replication. In contrast, IL-18 induced cell death of RV-infected IEC thus directly interrupting the RV replication cycle, resulting in spewing of incompetent virus into the intestinal lumen and causing a rapid drop in the number of RV-infected IEC. Together, these actions resulted in rapid and complete expulsion of RV, even in hosts with severely compromised immune systems. These results suggest that a cocktail of IL-18 and IL-22 might be a means of treating viral infections that preferentially target short-lived epithelial cells.





2021 ◽  
pp. 1-8
Author(s):  
Xiaomei Xu ◽  
Guangmang Liu ◽  
Gang Jia ◽  
Hua Zhao ◽  
Xiaoling Chen ◽  
...  


Viruses ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 28
Author(s):  
So-Ri Han ◽  
Hetron M. Munang’andu ◽  
In-Kyu Yeo ◽  
Sung-Hyun Kim

Viral hemorrhagic septicemia virus (VHSV) is a highly pathogenic virus that infects a wide range of host fish species causing high economic losses in aquaculture. Epithelial cells in mucosal organs are target sites for VHSV entry into fish. To protect fish against VHSV infection, there is a need to develop antiviral compounds able to prevent establishment of infection at portals of virus entry into fish. Bacillus subtilis is a probiotic with excellent antiviral properties, of which one of its secretions, surfactin, has been shown to inhibit viral infections in mammals. Herein, we demonstrate its ability to prevent VHSV infection in olive flounder (Paralichthys olivaceus) intestinal epithelial cells (IECs) and infection in internal organs. Our findings show inhibition of VHSV infection in IECs by B. subtilis and surfactin. In addition, our findings showed inhibition of VHSV in Epithelioma Papulosum Cyprini (EPC) cells inoculated with intestinal homogenates from the fish pretreated with B. subtilis by oral exposure, while the untreated fish had cytopathic effects (CPE) caused by VHSV infection in the intestines at 48 h after the VHSV challenge. At 96 h post-challenge, samples from the untreated fish had CPE from head kidney and spleen homogenates and no CPE were observed in the intestinal homogenates, while the B. subtilis-pretreated fish had no CPE in all organs. These findings demonstrate that inhibition of VHSV infection at portals of virus entry in the intestines culminated in prevention of infection in internal organs. In summary, our results show that B. subtilis has the potential to prevent VHSV infection in fish and that its use as a probiotic in aquaculture has the potential to serve as an antiviral therapeutic agent against different viral infections.



1999 ◽  
Vol 277 (1) ◽  
pp. G175-G182 ◽  
Author(s):  
Maryam Varedi ◽  
George H. Greeley ◽  
David N. Herndon ◽  
Ella W. Englander

The effects of a 60% body surface area thermal injury in rats on the morphology and proliferation of the epithelium of the small intestine and the in vitro effects of serum collected from scalded rats on intestinal epithelial cells were investigated. Scald injury caused significant reductions in duodenal villus width and crypt dimensions, villus enterocytes changed in shape from columnar to cuboidal, and the number of goblet cells decreased. The proportion of bromodeoxyuridine-labeled S phase cells in crypts was also diminished. In vitro, incubation of intestinal epithelial cells (IEC-6) with scalded rat serum (SRS) collected at either 12 or 24 h after injury caused a disruption in the integrity of the confluent culture and induced the appearance of large denuded areas. SRS also decreased DNA synthesis and delayed wound closure in an in vitro wound-healing model. The thermal injury-induced changes in intestinal mucosal morphology and epithelial cell growth characteristics described in this study may underlie, in part, the mechanism(s) involved in the diminished absorption of nutrients, increased intestinal permeability, and sepsis in patients with thermal injury.



2001 ◽  
Vol 281 (2) ◽  
pp. G323-G332 ◽  
Author(s):  
M. C. Buresi ◽  
E. Schleihauf ◽  
N. Vergnolle ◽  
A. Buret ◽  
J. L. Wallace ◽  
...  

The thrombin receptor, protease-activated receptor-1 (PAR-1), has wide tissue distribution and is involved in many physiological functions. Because thrombin is in the intestinal lumen and mucosa during inflammation, we sought to determine PAR-1 expression and function in human intestinal epithelial cells. RT-PCR showed PAR-1 mRNA expression in SCBN cells, a nontransformed duodenal epithelial cell line. Confluent SCBN monolayers mounted in Ussing chambers responded to PAR-1 activation with a Cl−-dependent increase in short-circuit current. The secretory effect was blocked by BaCl2and the Ca2+-ATPase inhibitor thapsigargin, but not by the L-type Ca2+channel blocker verapamil or DIDS, the nonselective inhibitor of Ca2+-dependent Cl−transport. Responses to thrombin and PAR-1-activating peptides exhibited auto- and crossdesensitization. Fura 2-loaded SCBN cells had increased fluorescence after PAR-1 activation, indicating increased intracellular Ca2+. RT-PCR showed that SCBN cells expressed mRNA for the cystic fibrosis transmembrane conductance regulator (CFTR) and hypotonicity-activated Cl−channel-2 but not for the Ca2+-dependent Cl−channel-1. PAR-1 activation failed to increase intracellular cAMP, suggesting that the CFTR channel is not involved in the Cl−secretory response. Our data demonstrate that PAR-1 is expressed on human intestinal epithelial cells and regulates a novel Ca2+-dependent Cl−secretory pathway. This may be of clinical significance in inflammatory intestinal diseases with elevated thrombin levels.



1998 ◽  
Vol 274 (5) ◽  
pp. G797-G801 ◽  
Author(s):  
Manabu Nishikawa ◽  
Kenta Takeda ◽  
Eisuke F. Sato ◽  
Tetso Kuroki ◽  
Masayasu Inoue

Nitric oxide (NO) inhibits the respiration of mitochondria and enteric bacteria, particularly under low O2concentration, and induces apoptosis of various types of cells. To gain insight into the molecular role of NO in the intestine, we examined its effects on the respiration, Ca2+status, and expression of Bcl-2 in cultured intestinal epithelial cells (IEC-6). NO reversibly inhibited the respiration of IEC-6 cells, especially under physiologically low O2concentration. Although NO elevated cytosolic Ca2+as determined by the fura 2 method, the cells were fairly resistant to NO. Kinetic analysis revealed that prolonged exposure to NO elevated the levels of Bcl-2 and suppressed the NO-induced changes in Ca2+status of the cells. Because Bcl-2 possesses antiapoptotic function, toxic NO effects might appear minimally in enterocytes enriched with Bcl-2. Thus NO might effectively exhibit its antibacterial action in anaerobic intestinal lumen without inducing apoptosis of Bcl-2-enriched mucosal 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 ◽  
...  

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.



2016 ◽  
Vol 311 (3) ◽  
pp. G458-G465 ◽  
Author(s):  
Jason D. Matthews ◽  
Ronen Sumagin ◽  
Benjamin Hinrichs ◽  
Asma Nusrat ◽  
Charles A. Parkos ◽  
...  

Intestinal wounds often occur during inflammatory and ischemic disorders of the gut. To repair damage, intestinal epithelial cells must rapidly spread and migrate to cover exposed lamina propria, events that involve redox signaling. Wounds are subject to extensive redox alterations, particularly resulting from H2O2 produced in the adjacent tissue by both the epithelium and emigrating leukocytes. The mechanisms governing these processes are not fully understood, particularly at the level of protein signaling. Crk-associated substrate, or Cas, is an important signaling protein known to modulate focal adhesion and actin cytoskeletal dynamics, whose association with Crk is regulated by Abl kinase, a ubiquitously expressed tyrosine kinase. We sought to evaluate the role of Abl regulation of Cas at the level of cell spreading and migration during wound closure. As a model, we used intestinal epithelial cells exposed to H2O2 or scratch wounded to assess the Abl-Cas signaling pathway. We characterized the localization of phosphorylated Cas in mouse colonic epithelium under baseline conditions and after biopsy wounding the mucosa. Analysis of actin and focal adhesion dynamics by microscopy or biochemical analysis after manipulating Abl kinase revealed that Abl controls redox-dependent Cas phosphorylation and localization to influence cell spreading and migration. Collectively, our data shed new light on redox-sensitive protein signaling modules controlling intestinal wound healing.



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