scholarly journals Adhesion to the host cell surface is sufficient to mediateListeria monocytogenesentry into epithelial cells

2017 ◽  
Vol 28 (22) ◽  
pp. 2945-2957 ◽  
Author(s):  
Fabian E. Ortega ◽  
Michelle Rengarajan ◽  
Natalie Chavez ◽  
Prathima Radhakrishnan ◽  
Martijn Gloerich ◽  
...  

The intestinal epithelium is the first physiological barrier breached by the Gram-positive facultative pathogen Listeria monocytogenes during an in vivo infection. Listeria monocytogenes binds to the epithelial host cell receptor E-cadherin, which mediates a physical link between the bacterium and filamentous actin (F-actin). However, the importance of anchoring the bacterium to F-actin through E-cadherin for bacterial invasion has not been tested directly in epithelial cells. Here we demonstrate that depleting αE-catenin, which indirectly links E-cadherin to F-actin, did not decrease L. monocytogenes invasion of epithelial cells in tissue culture. Instead, invasion increased due to increased bacterial adhesion to epithelial monolayers with compromised cell–cell junctions. Furthermore, expression of a mutant E-cadherin lacking the intracellular domain was sufficient for efficient L. monocytogenes invasion of epithelial cells. Importantly, direct biotin-mediated binding of bacteria to surface lipids in the plasma membrane of host epithelial cells was sufficient for uptake. Our results indicate that the only requirement for L. monocytogenes invasion of epithelial cells is adhesion to the host cell surface, and that E-cadherin–mediated coupling of the bacterium to F-actin is not required.

1998 ◽  
Vol 111 (9) ◽  
pp. 1305-1318 ◽  
Author(s):  
S.M. Norvell ◽  
K.J. Green

The integrity of cell-cell junctions in epithelial cells depends on functional interactions of both extracellular and intracellular domains of cadherins with other junction proteins. To examine the roles of the different domains of E-cadherin and desmoglein in epithelial junctions, we stably expressed full length desmoglein 1 and chimeras of E-cadherin and desmoglein 1 in A431 epithelial cells. Full length desmoglein 1 was able to incorporate into or disrupt endogenous desmosomes depending on expression level. Each of the chimeric cadherin molecules exhibited distinct localization patterns at the cell surface. A chimera of the desmoglein 1 extracellular domain and the E-cadherin intracellular domain was distributed diffusely at the cell surface while the reverse chimera, comprising the E-cadherin extracellular domain and the desmoglein 1 intracellular domain, localized in large, sometimes contiguous patches at cell-cell interfaces. Nevertheless, both constructs disrupted desmosome assembly. Expression of constructs containing the desmoglein 1 cytoplasmic domain resulted in approximately a 3-fold decrease in E-cadherin bound to plakoglobin and a 5- to 10-fold reduction in the steady-state levels of the endogenous desmosomal cadherins, desmoglein 2 and desmocollin 2, possibly contributing to the dominant negative effect of the desmoglein 1 tail. In addition, biochemical analysis of protein complexes in the stable lines revealed novel in vivo protein interactions. Complexes containing beta-catenin and desmoglein 1 were identified in cells expressing constructs containing the desmoglein 1 tail. Furthermore, interactions were identified between endogenous E-cadherin and the chimera containing the E-cadherin extracellular domain and the desmoglein 1 intracellular domain providing in vivo evidence for previously predicted lateral interactions of E-cadherin extracellular domains.


2005 ◽  
Vol 73 (4) ◽  
pp. 1917-1926 ◽  
Author(s):  
Kimberly J. Mueller ◽  
Nancy E. Freitag

ABSTRACT Listeria monocytogenes is a facultative intracellular bacterial pathogen that causes serious disease in immunocompromised individuals, pregnant women, and neonates. Bacterial virulence is mediated by the expression of specific gene products that facilitate entry into host cells and enable bacterial replication; the majority of these gene products are regulated by a transcriptional activator known as PrfA. L. monocytogenes strains containing prfA E77K or prfA G155S mutations exhibit increased expression of virulence genes in broth culture and are hypervirulent in mice. To define the scope of the influences of the prfA E77K and prfA G155S mutations on L. monocytogenes pathogenesis, multiple aspects of bacterial invasion and intracellular growth were examined. Enhanced bacterial invasion of host epithelial cells was dependent on the expression of a number of surface proteins previously associated with invasion, including InlA, InlB, and ActA. In addition to these surface proteins, increased production of the hly-encoded secreted hemolysin listeriolysin O (LLO) was also found to significantly enhance bacterial invasion into epithelial cell lines for both prfA mutant strains. Although prfA E77K and prfA G155S strains were similar in their invasive phenotypes, the infection of epithelial cells with prfA E77K strains resulted in host cell plasma membrane damage, whereas prfA G155S strains did not alter plasma membrane integrity. Bacterial infection of human epithelial cells, in which the production of LLO is not required for bacterial entry into the cytosol, indicated that prfA E77K cytotoxic effects were mediated via LLO. Both prfA E77K and prfA G155S strains were more efficient than wild-type bacteria in gaining access to the host cell cytosol and in initiating the polymerization of host cell actin, and both were capable of mediating LLO-independent lysis of host cell vacuoles in cell lines for which L. monocytogenes vacuole disruption normally requires LLO activity. These experiments illuminate the diverse facets of L. monocytogenes pathogenesis that are significantly enhanced by the constitutive activation of PrfA via prfA mutations and underscore the critical role of this protein in promoting L. monocytogenes virulence.


2021 ◽  
Vol 9 (5) ◽  
pp. 1015
Author(s):  
Tianyu Zhang ◽  
Xin Gao ◽  
Dongqiang Wang ◽  
Jixue Zhao ◽  
Nan Zhang ◽  
...  

Cryptosporidium parvum is a globally recognized zoonotic parasite of medical and veterinary importance. This parasite mainly infects intestinal epithelial cells and causes mild to severe watery diarrhea that could be deadly in patients with weakened or defect immunity. However, its molecular interactions with hosts and pathogenesis, an important part in adaptation of parasitic lifestyle, remain poorly understood. Here we report the identification and characterization of a C. parvum T-cell immunomodulatory protein homolog (CpTIPH). CpTIPH is a 901-aa single-pass type I membrane protein encoded by cgd5_830 gene that also contains a short Vibrio, Colwellia, Bradyrhizobium and Shewanella (VCBS) repeat and relatively long integrin alpha (ITGA) N-terminus domain. Immunofluorescence assay confirmed the location of CpTIPH on the cell surface of C. parvum sporozoites. In congruence with the presence of VCBS repeat and ITGA domain, CpTIPH displayed high, nanomolar binding affinity to host cell surface (i.e., Kd(App) at 16.2 to 44.7 nM on fixed HCT-8 and CHO-K1 cells, respectively). The involvement of CpTIPH in the parasite invasion is partly supported by experiments showing that an anti-CpTIPH antibody could partially block the invasion of C. parvum sporozoites into host cells. These observations provide a strong basis for further investigation of the roles of CpTIPH in parasite-host cell interactions.


2009 ◽  
Vol 5 (2) ◽  
pp. e1000314 ◽  
Author(s):  
Guillain Mikaty ◽  
Magali Soyer ◽  
Emilie Mairey ◽  
Nelly Henry ◽  
Dave Dyer ◽  
...  

2021 ◽  
Vol 8 ◽  
Author(s):  
Jingwen Yue ◽  
Weihua Jin ◽  
Hua Yang ◽  
John Faulkner ◽  
Xuehong Song ◽  
...  

The severe acute respiratory syndrome (SARS)-like coronavirus disease (COVID-19) is caused by SARS-CoV-2 and has been a serious threat to global public health with limited treatment. Cellular heparan sulfate (HS) has been found to bind SARS-CoV-2 spike protein (SV2-S) and co-operate with cell surface receptor angiotensin-converting enzyme 2 (ACE2) to mediate SARS-CoV-2 infection of host cells. In this study, we determined that host cell surface SV2-S binding depends on and correlates with host cell surface HS expression. This binding is required for SARS-Cov-2 virus to infect host cells and can be blocked by heparin lyase, HS antagonist surfen, heparin, and heparin derivatives. The binding of heparin/HS to SV2-S is mainly determined by its overall sulfation with potential, minor contribution of specific SV2-S binding motifs. The higher binding affinity of SV2-S G614 mutant to heparin and upregulated HS expression may be one of the mechanisms underlying the higher infectivity of the SARS-CoV-2 G614 variant and the high vulnerability of lung cancer patients to SARS-CoV-2 infection, respectively. The higher host cell infection by SARS-CoV-2 G614 variant pseudovirus and the increased infection caused by upregulated HS expression both can be effectively blocked by heparin lyase and heparin, and possibly surfen and heparin derivatives too. Our findings support blocking HS-SV2-S interaction may provide one addition to achieve effective prevention and/treatment of COVID-19.


2021 ◽  
Vol 72 (3) ◽  
pp. 30-36
Author(s):  
Tatjana Simić

Studies of the molecular mechanisms regarding interaction of different viruses with receptors on the host cell surface have shown that the viral entry depends on the specific relationship between free thiol (SH) groups and disulfides on the virus surface, as well as the thiol disulfide balance on the host cell surface. The presence of oxidizing compounds or alkylating agents, which disturb the thiol-disulfide balance on the surface of the virus, can also affect its infectious potential. Disturbed thiol-disulfide balance may also influence protein-protein interactions between SARS-CoV-2 protein S and ACE2 receptors of the host cell. This review presents the basic mechanisms of maintaining intracellular and extracellular thiol disulfide balance and previous experimental and clinical evidence in favor of impaired balance in SARS-CoV-2 infection. Besides, the results of the clinical application or experimental analysis of compounds that induce changes in the thiol disulfide balance towards reduction of disulfide bridges in proteins of interest in COVID-19 infection are presented.


mBio ◽  
2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Pallab Ghosh ◽  
Elizabeth M. Halvorsen ◽  
Dustin A. Ammendolia ◽  
Nirit Mor-Vaknin ◽  
Mary X. D. O’Riordan ◽  
...  

ABSTRACTListeria monocytogenesis a facultative intracellular bacterial pathogen that is frequently associated with food-borne infection. Of particular concern is the ability ofL. monocytogenesto breach the blood-brain barrier, leading to life-threatening meningitis and encephalitis. The mechanisms used by bacterial pathogens to infect the brain are not fully understood. Here we show thatL. monocytogenesis able to utilize vimentin for invasion of host cells. Vimentin is a type III intermediate filament protein within the cytosol but is also expressed on the host cell surface. We found thatL. monocytogenesinteraction with surface-localized vimentin promoted bacterial uptake. Furthermore, in the absence of vimentin,L. monocytogenescolonization of the brain was severely compromised in mice. TheL. monocytogenesvirulence factor InlF was found to bind vimentin and was necessary for optimal bacterial colonization of the brain. These studies reveal a novel receptor-ligand interaction that enhances infection of the brain byL. monocytogenesand highlights the importance of surface vimentin in host-pathogen interactions.IMPORTANCEListeria monocytogenesis an intracellular bacterial pathogen that is capable of invading numerous host cells during infection.L. monocytogenescan cross the blood-brain barrier, leading to life-threatening meningitis. Here we show that anL. monocytogenessurface protein, InlF, is necessary for optimal colonization of the brain in mice. Furthermore, in the absence of vimentin, a cytosolic intermediate filament protein that is also present on the surface of brain endothelial cells, colonization of the brain was significantly impaired. We further show that InlF binds vimentin to mediate invasion of host cells. This work identifies InlF as a bacterial surface protein with specific relevance for infection of the brain and underscores the significance of host cell surface vimentin interactions in microbial pathogenesis.


2021 ◽  
Author(s):  
Yanmei Hu ◽  
Hyunil Jo ◽  
William DeGrado ◽  
Jun Wang

Brilacidin, a mimetic of host defense peptides (HDPs), is currently in phase 2 clinical trial as an antibiotic drug candidate. A recent study reported that brilacidin has antiviral activity against SARS-CoV-2 by inactivating the virus. In this work, we discovered an additional mechanism of action of brilacidin by targeting heparan sulfate proteoglycans (HSPGs) on host cell surface. Brilacidin, but not acetyl brilacidin, inhibits the entry of SARS-CoV-2 pseudovirus into multiple cell lines, and heparin, a HSPG mimetic, abolishes the inhibitory activity of brilacidin on SARS-CoV-2 pseudovirus cell entry. In addition, we found that brilacidin has broad-spectrum antiviral activity against multiple human coronaviruses (HCoVs) including HCoV-229E, HCoV-OC43, and HCoV-NL63. Mechanistic studies revealed that brilacidin has a dual antiviral mechanism of action including virucidal activity and binding to coronavirus attachment factor HSPGs on host cell surface. Brilacidin partially loses its antiviral activity when heparin was included in the cell cultures, supporting the host-targeting mechanism. Drug combination therapy showed that brilacidin has a strong synergistic effect with remdesivir against HCoV-OC43 in cell culture. Taken together, this study provides appealing findings for the translational potential of brilacidin as a broad-spectrum antiviral for coronaviruses including SARS-CoV-2.


2020 ◽  
Vol 125 (12) ◽  
Author(s):  
Michael C. DeSantis ◽  
Chunjuan Tian ◽  
Jin H. Kim ◽  
Jamie L. Austin ◽  
Wei Cheng

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