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Silva LDD, Pinheiro JLS, Rodrigues LHM, Santos VMRD, Borges JLF, Oliveira RRD, Maciel LG, Araújo TDSL, Martins CDS, Gomes DA, Lira EC, Souza MHLP, Medeiros JVR, Damasceno ROS. Crucial role of carbon monoxide as a regulator of diarrhea caused by cholera toxin: Evidence of direct interaction with toxin. Biochem Pharmacol 2023; 216:115791. [PMID: 37689274 DOI: 10.1016/j.bcp.2023.115791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 09/01/2023] [Accepted: 09/06/2023] [Indexed: 09/11/2023]
Abstract
The present study evaluated the role of heme oxygenase 1 (HO-1)/carbon monoxide (CO) pathway in the cholera toxin-induced diarrhea and its possible action mechanism. The pharmacological modulation with CORM-2 (a CO donor) or Hemin (a HO-1 inducer) decreased the intestinal fluid secretion and Cl- efflux, altered by cholera toxin. In contrast, ZnPP (a HO-1 inhibitor) reversed the antisecretory effect of Hemin and potentiated cholera toxin-induced intestinal secretion. Moreover, CORM-2 also prevented the alteration of intestinal epithelial architecture and local vascular permeability promoted by cholera toxin. The intestinal absorption was not altered by any of the pharmacological modulators. Cholera toxin inoculation also increased HO-1 immunoreactivity and bilirubin levels, a possible protective physiological response. Finally, using fluorometric technique, ELISA assay and molecular docking simulations, we show evidence that CO directly interacts with cholera toxin, forming a complex that affects its binding to GM1 receptor, which help explain the antisecretory effect. Thus, CO is an essential molecule for protection against choleric diarrhea and suggests its use as a possible therapeutic tool.
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Affiliation(s)
- Lorena Duarte da Silva
- Department of Physiology and Pharmacology, Federal University of Pernambuco, Recife, PE, Brazil
| | | | | | | | | | | | | | | | | | - Dayane Aparecida Gomes
- Department of Physiology and Pharmacology, Federal University of Pernambuco, Recife, PE, Brazil
| | - Eduardo Carvalho Lira
- Department of Physiology and Pharmacology, Federal University of Pernambuco, Recife, PE, Brazil
| | | | - Jand Venes Rolim Medeiros
- Biotechnology and Biodiversity Center Research, Parnaíba Delta Federal University, Parnaíba, PI, Brazil
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Susnik E, Balog S, Taladriz-Blanco P, Petri-Fink A, Rothen-Rutishauser B. The Functions of Cholera Toxin Subunit B as a Modulator of Silica Nanoparticle Endocytosis. Toxins (Basel) 2023; 15:482. [PMID: 37624239 PMCID: PMC10467089 DOI: 10.3390/toxins15080482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 07/15/2023] [Accepted: 07/27/2023] [Indexed: 08/26/2023] Open
Abstract
The gastrointestinal tract is the main target of orally ingested nanoparticles (NPs) and at the same time is exposed to noxious substances, such as bacterial components. We investigated the interaction of 59 nm silica (SiO2) NPs with differentiated Caco-2 intestinal epithelial cells in the presence of cholera toxin subunit B (CTxB) and compared the effects to J774A.1 macrophages. CTxB can affect cellular functions and modulate endocytosis via binding to the monosialoganglioside (GM1) receptor, expressed on both cell lines. After stimulating macrophages with CTxB, we observed notable changes in the membrane structure but not in Caco-2 cells, and no secretion of the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) was detected. Cells were then exposed to 59 nm SiO2 NPs and CtxB sequentially and simultaneously, resulting in a high NP uptake in J774A.1 cells, but no uptake in Caco-2 cells was detected. Flow cytometry analysis revealed that the exposure of J774A.1 cells to CTxB resulted in a significant reduction in the uptake of SiO2 NPs. In contrast, the uptake of NPs by highly selective Caco-2 cells remained unaffected following CTxB exposure. Based on colocalization studies, CTxB and NPs might enter cells via shared endocytic pathways, followed by their sorting into different intracellular compartments. Our findings provide new insights into CTxB's function of modulating SiO2 NP uptake in phagocytic but not in differentiated intestine cells.
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Affiliation(s)
- Eva Susnik
- Adolphe Merkle Institute, University of Fribourg, 1700 Fribourg, Switzerland; (E.S.); (S.B.); (A.P.-F.)
| | - Sandor Balog
- Adolphe Merkle Institute, University of Fribourg, 1700 Fribourg, Switzerland; (E.S.); (S.B.); (A.P.-F.)
| | | | - Alke Petri-Fink
- Adolphe Merkle Institute, University of Fribourg, 1700 Fribourg, Switzerland; (E.S.); (S.B.); (A.P.-F.)
- Department of Chemistry, University of Fribourg, 1700 Fribourg, Switzerland
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3
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Zhang Y, Li X, Shan B, Zhang H, Zhao L. Perspectives from recent advances of Helicobacter pylori vaccines research. Helicobacter 2022; 27:e12926. [PMID: 36134470 DOI: 10.1111/hel.12926] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 07/25/2022] [Accepted: 08/17/2022] [Indexed: 12/09/2022]
Abstract
BACKGROUND Helicobacter pylori (H. pylori) infection is the main factor leading to some gastric diseases. Currently, H. pylori infection is primarily treated with antibiotics. However, with the widespread application of antibiotics, H. pylori resistance to antibiotics has also gradually increased year by year. Vaccines may be an alternative solution to clear H. pylori. AIMS By reviewing the recent progress on H. pylori vaccines, we expected it to lead to more research efforts to accelerate breakthroughs in this field. MATERIALS & METHODS We searched the research on H. pylori vaccine in recent years through PubMed®, and then classified and summarized these studies. RESULTS The study of the pathogenic mechanism of H. pylori has led to the development of vaccines using some antigens, such as urease, catalase, and heat shock protein (Hsp). Based on these antigens, whole-cell, subunit, nucleic acid, vector, and H. pylori exosome vaccines have been tested. DISCUSSION At present, researchers have developed many types of vaccines, such as whole cell vaccines, subunit vaccines, vector vaccines, etc. However, although some of these vaccines induced protective immunity in mouse models, only a few were able to move into human trials. We propose that mRNA vaccine may play an important role in preventing or treating H. pylori infection. The current study shows that we have developed various types of vaccines based on the virulence factors of H. pylori. However, only a few vaccines have entered human clinical trials. In order to improve the efficacy of vaccines, it is necessary to enhance T-cell immunity. CONCLUSION We should fully understand the pathogenic mechanism of H. pylori and find its core antigen as a vaccine target.
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Affiliation(s)
- Ying Zhang
- Research Center, The Fourth Hospital of Hebei Medical University, Shijiazhuang, China
| | - Xiaoya Li
- Research Center, The Fourth Hospital of Hebei Medical University, Shijiazhuang, China
| | - Baoen Shan
- Research Center, The Fourth Hospital of Hebei Medical University, Shijiazhuang, China
| | - Hongtao Zhang
- University of Pennsylvania School of Medicine Philadelphia, Philadelphia, Pennsylvania, USA
| | - Lianmei Zhao
- Research Center, The Fourth Hospital of Hebei Medical University, Shijiazhuang, China
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4
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Wu HJ, Singla A, Weatherston JD. Nanocube-Based Fluidic Glycan Array. Methods Mol Biol 2022; 2460:45-63. [PMID: 34972930 DOI: 10.1007/978-1-0716-2148-6_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The nature of cell membrane fluidity permits glycans, which are attached to membrane proteins and lipids, to freely diffuse on cell surfaces. Through such two-dimensional motion, some weakly binding glycans can participate in lectin binding processes, eventually changing lectin binding behaviors. This chapter discusses a plasmonic nanocube sensor that allows users to detect lectin binding kinetics in a cell membrane mimicking environment. This assay only requires standard laboratory spectrometers, including microplate readers. We describe the basics of the technology in detail, including sensor fabrication, sensor calibration, data processing, a general protocol for detecting lectin-glycan interactions, and a troubleshooting guide.
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Affiliation(s)
- Hung-Jen Wu
- Department of Chemical Engineering, Texas A&M University, College Station, TX, USA.
| | - Akshi Singla
- Department of Chemical Engineering, Texas A&M University, College Station, TX, USA
| | - Joshua D Weatherston
- Department of Chemical Engineering, Texas A&M University, College Station, TX, USA
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Verma A, Zhu P, Xu K, Du T, Liao S, Liang Z, Raizada MK, Li Q. Angiotensin-(1-7) Expressed From Lactobacillus Bacteria Protect Diabetic Retina in Mice. Transl Vis Sci Technol 2020; 9:20. [PMID: 33344064 PMCID: PMC7735952 DOI: 10.1167/tvst.9.13.20] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 11/03/2020] [Indexed: 01/04/2023] Open
Abstract
Purpose A multitude of animal studies substantiates the beneficial effects of Ang-(1–7), a peptide hormone in the protective axis of the renin angiotensin system, in diabetes and its associated complications including diabetic retinopathy (DR). However, the clinical application of Ang-(1–7) is limited due to unfavorable pharmacological properties. As emerging evidence implicates gut dysbiosis in pathogenesis of diabetes and supports beneficial effects of probiotics, we sought to develop probiotics-based expression and delivery system to enhance Ang-(1–7) and evaluate the efficacy of engineered probiotics expressing Ang-(1–7) in attenuation of DR in animal models. Methods Ang-(1–7) was expressed in the Lactobacillus species as a secreted fusion protein with a trans-epithelial carrier to allow uptake into circulation. To evaluate the effects of Ang-(1–7) expressed from Lactobacillus paracasei (LP), adult diabetic eNOS−/− and Akita mice were orally gavaged with either 1 × 109 CFU of LP secreting Ang-(1–7) (LP-A), LP alone or vehicle, 3 times/week, for 8 and 12 weeks, respectively. Results Ang-(1–7) is efficiently expressed from different Lactobacillus species and secreted into circulation in mice fed with LP-A. Oral administration of LP-A significantly reduced diabetes-induced loss of retinal vascular capillaries. LP-A treatment also prevented loss of retinal ganglion cells, and significantly decreased retinal inflammatory cytokine expression in both diabetic eNOS−/− and Akita mice. Conclusions These results provide proof-of-concept for feasibility and efficacy of using engineered probiotic species as live vector for delivery of Ang-(1–7) with enhanced bioavailability. Translational Relevance Probiotics-based delivery of Ang-(1–7) may hold important therapeutic potential for the treatment of DR and other diabetic complications.
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Affiliation(s)
- Amrisha Verma
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Ping Zhu
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Kang Xu
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Tao Du
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Shengquan Liao
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Zhibing Liang
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Mohan K Raizada
- Physiology & Functional Genomics, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Qiuhong Li
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida, USA
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Miller MC, Nesmelova IV, Daragan VA, Ippel H, Michalak M, Dregni A, Kaltner H, Kopitz J, Gabius HJ, Mayo KH. Pro4 prolyl peptide bond isomerization in human galectin-7 modulates the monomer-dimer equilibrum to affect function. Biochem J 2020; 477:3147-3165. [PMID: 32766716 PMCID: PMC7473712 DOI: 10.1042/bcj20200499] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 08/03/2020] [Accepted: 08/06/2020] [Indexed: 02/06/2023]
Abstract
Human galectin-7 (Gal-7; also termed p53-induced gene 1 product) is a multifunctional effector by productive pairing with distinct glycoconjugates and protein counter-receptors in the cytoplasm and nucleus, as well as on the cell surface. Its structural analysis by NMR spectroscopy detected doubling of a set of particular resonances, an indicator of Gal-7 existing in two conformational states in slow exchange on the chemical shift time scale. Structural positioning of this set of amino acids around the P4 residue and loss of this phenomenon in the bioactive P4L mutant indicated cis-trans isomerization at this site. Respective resonance assignments confirmed our proposal of two Gal-7 conformers. Mapping hydrogen bonds and considering van der Waals interactions in molecular dynamics simulations revealed a structural difference for the N-terminal peptide, with the trans-state being more exposed to solvent and more mobile than the cis-state. Affinity for lactose or glycan-inhibitable neuroblastoma cell surface contact formation was not affected, because both conformers associated with an overall increase in order parameters (S2). At low µM concentrations, homodimer dissociation is more favored for the cis-state of the protein than its trans-state. These findings give direction to mapping binding sites for protein counter-receptors of Gal-7, such as Bcl-2, JNK1, p53 or Smad3, and to run functional assays at low concentration to test the hypothesis that this isomerization process provides a (patho)physiologically important molecular switch for Gal-7.
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Affiliation(s)
- Michelle C. Miller
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455 U.S.A
| | - Irina V. Nesmelova
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455 U.S.A
| | - Vladimir A. Daragan
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455 U.S.A
| | - Hans Ippel
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455 U.S.A
- Department of Biochemistry, CARIM, University of Maastricht, Maastricht, The Netherlands
| | - Malwina Michalak
- Department of Applied Tumor Biology, Institute of Pathology, Medical School of the Ruprecht-Karls-University Heidelberg, Heidelberg, Germany
| | - Aurelio Dregni
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455 U.S.A
| | - Herbert Kaltner
- Institute of Physiological Chemistry, Faculty of Veterinary Medicine, Ludwig-Maximillians-University Munich, Munich, Germany
| | - Jürgen Kopitz
- Department of Applied Tumor Biology, Institute of Pathology, Medical School of the Ruprecht-Karls-University Heidelberg, Heidelberg, Germany
| | - Hans-Joachim Gabius
- Institute of Physiological Chemistry, Faculty of Veterinary Medicine, Ludwig-Maximillians-University Munich, Munich, Germany
| | - Kevin H. Mayo
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455 U.S.A
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Erratum: Expression of Human ACE2 in Lactobacillus and Beneficial Effects in Diabetic Retinopathy in Mice. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2020; 17:400. [PMID: 32128344 PMCID: PMC7044497 DOI: 10.1016/j.omtm.2020.02.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
[This corrects the article DOI: 10.1016/j.omtm.2019.06.007.].
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Hu X, Yang G, Chen S, Luo S, Zhang J. Biomimetic and bioinspired strategies for oral drug delivery. Biomater Sci 2019; 8:1020-1044. [PMID: 31621709 DOI: 10.1039/c9bm01378d] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Oral drug delivery remains the most preferred approach due to its multiple advantages. Recently there has been increasing interest in the development of advanced vehicles for oral delivery of different therapeutics. Among them, biomimetic and bioinspired strategies are emerging as novel approaches that are promising for addressing biological barriers encountered by traditional drug delivery systems. Herein we provide a state-of-the-art review on the current progress of biomimetic particulate oral delivery systems. Different biomimetic nanoparticles used for oral drug delivery are first discussed, mainly including ligand/antibody-functionalized nanoparticles, transporter-mediated nanoplatforms, and nanoscale extracellular vesicles. Then we describe bacteria-derived biomimetic systems, with respect to oral delivery of therapeutic proteins or antigens. Subsequently, yeast-derived oral delivery systems, based on either chemical engineering or bioengineering approaches are discussed, with emphasis on the treatment of inflammatory diseases and cancer as well as oral vaccination. Finally, bioengineered plant cells are introduced for oral delivery of biological agents. A future perspective is also provided to highlight the existing challenges and possible resolution toward clinical translation of currently developed biomimetic oral therapies.
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Affiliation(s)
- Xiankang Hu
- Department of Cardiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China. and Department of Pharmaceutics, College of Pharmacy, Third Military Medical University, Chongqing 400038, China.
| | - Guoyu Yang
- Department of Cardiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China. and Department of Pharmaceutics, College of Pharmacy, Third Military Medical University, Chongqing 400038, China. and The First Clinical College, Chongqing Medical University, Chongqing 400016, China
| | - Sheng Chen
- Department of Pediatrics, Southwest Hospital, Third Military Medical University, Chongqing 400038, China.
| | - Suxin Luo
- Department of Cardiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China.
| | - Jianxiang Zhang
- Department of Pharmaceutics, College of Pharmacy, Third Military Medical University, Chongqing 400038, China.
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Verma A, Xu K, Du T, Zhu P, Liang Z, Liao S, Zhang J, Raizada MK, Grant MB, Li Q. Expression of Human ACE2 in Lactobacillus and Beneficial Effects in Diabetic Retinopathy in Mice. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2019; 14:161-170. [PMID: 31380462 PMCID: PMC6661465 DOI: 10.1016/j.omtm.2019.06.007] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 06/25/2019] [Indexed: 02/06/2023]
Abstract
The angiotensin converting enzyme 2 (ACE2) catalyzes the degradation of Angiotensin II (Ang II) to generate Angiotensin-(1-7), which reduces inflammation and oxidative stress stimulated by Ang II. ACE2 has been shown to be protective in cardiovascular and metabolic diseases including diabetes and its complications. However, the challenge for its clinical application is large-scale production of high-quality ACE2 with sufficient target tissue bioavailability. We developed an expression and delivery system based on the use of probiotic species Lactobacillus paracasei (LP) to serve as a live vector for oral delivery of human ACE2. We show that codon-optimized ACE2 can be efficiently expressed in LP. Mice treated with the recombinant LP expressing the secreted ACE2 in fusion with the non-toxic subunit B of cholera toxin, which acts as a carrier to facilitate transmucosal transport, showed increased ACE2 activities in serum and tissues. ACE2-LP administration reduced the number of acellular capillaries, blocked retinal ganglion cell loss, and decreased retinal inflammatory cytokine expression in two mouse models of diabetic retinopathy. These results provide proof of concept for feasibility of using engineered probiotic species as live vector for delivery of human ACE2 with enhanced tissue bioavailability for treating diabetic retinopathy, as well as other diabetic complications.
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Affiliation(s)
- Amrisha Verma
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, FL 32610-0284, USA
| | - Kang Xu
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, FL 32610-0284, USA
| | - Tao Du
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, FL 32610-0284, USA
| | - Ping Zhu
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, FL 32610-0284, USA
| | - Zhibing Liang
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, FL 32610-0284, USA
| | - Shengquan Liao
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, FL 32610-0284, USA
| | - Juantao Zhang
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, FL 32610-0284, USA
| | - Mohan K Raizada
- Department of Physiology & Functional Genomics, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - Maria B Grant
- Department of Ophthalmology & Visual Sciences, University of Alabama, Birmingham, AL 35294, USA
| | - Qiuhong Li
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, FL 32610-0284, USA
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10
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Multiple Pleomorphic Tetramers of Thermostable Direct Hemolysin from Grimontia hollisae in Exerting Hemolysis and Membrane Binding. Sci Rep 2019; 9:9833. [PMID: 31285470 PMCID: PMC6614540 DOI: 10.1038/s41598-019-46354-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 06/18/2019] [Indexed: 11/20/2022] Open
Abstract
Oligomerization of protein into specific quaternary structures plays important biological functions, including regulation of gene expression, enzymes activity, and cell–cell interactions. Here, we report the determination of two crystal structures of the Grimontia hollisae (formally described as Vibrio hollisae) thermostable direct hemolysin (Gh–TDH), a pore-forming toxin. The toxin crystalized in the same space group of P21212, but with two different crystal packing patterns, each revealing three consistent tetrameric oligomerization forms called Oligomer–I, –II, and –III. A central pore with comparable depth of ~50 Å but differing in shape and size was observed in all determined toxin tetrameric oligomers. A common motif of a toxin dimer was found in all determined structures, suggesting a plausible minimum functional unit within the tetrameric structure in cell membrane binding and possible hemolytic activity. Our results show that bacterial toxins may form a single or highly symmetric oligomerization state when exerting their biological functions. The dynamic nature of multiple symmetric oligomers formed upon release of the toxin may open a niche for bacteria survival in harsh living environments.
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11
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Ermini L, Morganti E, Post A, Yeganeh B, Caniggia I, Leadley M, Faria CC, Rutka JT, Post M. Imaging mass spectrometry identifies prognostic ganglioside species in rodent intracranial transplants of glioma and medulloblastoma. PLoS One 2017; 12:e0176254. [PMID: 28463983 PMCID: PMC5413052 DOI: 10.1371/journal.pone.0176254] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 04/08/2017] [Indexed: 11/30/2022] Open
Abstract
Matrix-assisted laser desorption ionization (MALDI) imaging mass spectrometry (MALDI-MSI) allows us to investigate the distribution of lipid molecules within tissues. We used MALDI-MSI to identify prognostic gangliosides in tissue sections of rat intracranial allografts of rat glioma and mouse intracranial xenografts of human medulloblastoma. In the healthy adult rodent brain, GM1 and GD1 were the main types of glycolipids. Both gangliosides were absent in both intracranial transplants. The ganglioside GM3 was not present in the healthy adult brain but was highly expressed in rat glioma allografts. In combination with tandem mass spectrometry GM3 (d18:1/C24:0) was identified as the most abundant ganglioside species in the glioma allotransplant. By contrast, mouse xenografts of human medulloblastoma were characterized by prominent expression of the ganglioside GM2 (d18:0/C18:0). Together, these data demonstrate that tissue-based MALDI-MSI of gangliosides is able to discriminate between different brain tumors and may be a useful clinical tool for their classification and grading.
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Affiliation(s)
- Leonardo Ermini
- Program in Physiology and Experimental Medicine, Peter Gilgan Centre for Research and Learning, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Elena Morganti
- Program in Physiology and Experimental Medicine, Peter Gilgan Centre for Research and Learning, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Alexander Post
- Program in Physiology and Experimental Medicine, Peter Gilgan Centre for Research and Learning, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Behzad Yeganeh
- Program in Physiology and Experimental Medicine, Peter Gilgan Centre for Research and Learning, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Isabella Caniggia
- The Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
- Institute of Medical Science, University of Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Ontario, Canada
| | - Michael Leadley
- Program in Physiology and Experimental Medicine, Peter Gilgan Centre for Research and Learning, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Claudia C. Faria
- Division of Neurosurgery, Arthur and Sonia Labatt Brain Tumour Research Centre, Hospital for Sick Children, Toronto, Ontario, Canada
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - James T. Rutka
- Division of Neurosurgery, Arthur and Sonia Labatt Brain Tumour Research Centre, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Martin Post
- Program in Physiology and Experimental Medicine, Peter Gilgan Centre for Research and Learning, Hospital for Sick Children, Toronto, Ontario, Canada
- Institute of Medical Science, University of Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Ontario, Canada
- * E-mail:
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12
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Mercier V, Laporte MH, Destaing O, Blot B, Blouin CM, Pernet-Gallay K, Chatellard C, Saoudi Y, Albiges-Rizo C, Lamaze C, Fraboulet S, Petiot A, Sadoul R. ALG-2 interacting protein-X (Alix) is essential for clathrin-independent endocytosis and signaling. Sci Rep 2016; 6:26986. [PMID: 27244115 PMCID: PMC4886688 DOI: 10.1038/srep26986] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 05/09/2016] [Indexed: 12/22/2022] Open
Abstract
The molecular mechanisms and the biological functions of clathrin independent endocytosis (CIE) remain largely elusive. Alix (ALG-2 interacting protein X), has been assigned roles in membrane deformation and fission both in endosomes and at the plasma membrane. Using Alix ko cells, we show for the first time that Alix regulates fluid phase endocytosis and internalization of cargoes entering cells via CIE, but has no apparent effect on clathrin mediated endocytosis or downstream endosomal trafficking. We show that Alix acts with endophilin-A to promote CIE of cholera toxin and to regulate cell migration. We also found that Alix is required for fast endocytosis and downstream signaling of the interleukin-2 receptor giving a first indication that CIE is necessary for activation of at least some surface receptors. In addition to characterizing a new function for Alix, our results highlight Alix ko cells as a unique tool to unravel the biological consequences of CIE.
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Affiliation(s)
- Vincent Mercier
- Institut National de la Santé et de la Recherche Médicale (INSERM), Unité 1216, F-38042 Grenoble, France.,Université Grenoble Alpes, Institut des Neurosciences, F-38042 Grenoble, France
| | - Marine H Laporte
- Institut National de la Santé et de la Recherche Médicale (INSERM), Unité 1216, F-38042 Grenoble, France.,Université Grenoble Alpes, Institut des Neurosciences, F-38042 Grenoble, France
| | - Olivier Destaing
- INSERM U1209, Grenoble, F-38042, France.,Université Grenoble Alpes, Institut Albert Bonniot, F-38000 Grenoble, France.,CNRS UMR 5309, F-38000 Grenoble, France
| | - Béatrice Blot
- Institut National de la Santé et de la Recherche Médicale (INSERM), Unité 1216, F-38042 Grenoble, France.,Université Grenoble Alpes, Institut des Neurosciences, F-38042 Grenoble, France
| | - Cédric M Blouin
- Institut Curie, PSL Research University, Membrane Dynamics and Mechanics of Intracellular Signaling Laboratory, Paris, France.,INSERM, U1143, Paris, France.,CNRS, UMR 3666, Paris, France
| | - Karin Pernet-Gallay
- Institut National de la Santé et de la Recherche Médicale (INSERM), Unité 1216, F-38042 Grenoble, France.,Université Grenoble Alpes, Institut des Neurosciences, F-38042 Grenoble, France
| | - Christine Chatellard
- Institut National de la Santé et de la Recherche Médicale (INSERM), Unité 1216, F-38042 Grenoble, France.,Université Grenoble Alpes, Institut des Neurosciences, F-38042 Grenoble, France
| | - Yasmina Saoudi
- Institut National de la Santé et de la Recherche Médicale (INSERM), Unité 1216, F-38042 Grenoble, France.,Université Grenoble Alpes, Institut des Neurosciences, F-38042 Grenoble, France
| | - Corinne Albiges-Rizo
- INSERM U1209, Grenoble, F-38042, France.,Université Grenoble Alpes, Institut Albert Bonniot, F-38000 Grenoble, France.,CNRS UMR 5309, F-38000 Grenoble, France
| | - Christophe Lamaze
- Institut Curie, PSL Research University, Membrane Dynamics and Mechanics of Intracellular Signaling Laboratory, Paris, France.,INSERM, U1143, Paris, France.,CNRS, UMR 3666, Paris, France
| | - Sandrine Fraboulet
- Institut National de la Santé et de la Recherche Médicale (INSERM), Unité 1216, F-38042 Grenoble, France.,Université Grenoble Alpes, Institut des Neurosciences, F-38042 Grenoble, France
| | - Anne Petiot
- Institut National de la Santé et de la Recherche Médicale (INSERM), Unité 1216, F-38042 Grenoble, France.,Université Grenoble Alpes, Institut des Neurosciences, F-38042 Grenoble, France
| | - Rémy Sadoul
- Institut National de la Santé et de la Recherche Médicale (INSERM), Unité 1216, F-38042 Grenoble, France.,Université Grenoble Alpes, Institut des Neurosciences, F-38042 Grenoble, France
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13
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Abstract
Heat-labile enterotoxins (LTs) of Escherichia coli are closely related to cholera toxin (CT), which was originally discovered in 1959 in culture filtrates of the gram-negative bacterium Vibrio cholerae. Several other gram-negative bacteria also produce enterotoxins related to CT and LTs, and together these toxins form the V. cholerae-E. coli family of LTs. Strains of E. coli causing a cholera-like disease were designated enterotoxigenic E. coli (ETEC) strains. The majority of LTI genes (elt) are located on large, self-transmissible or mobilizable plasmids, although there are instances of LTI genes being located on chromosomes or carried by a lysogenic phage. The stoichiometry of A and B subunits in holotoxin requires the production of five B monomers for every A subunit. One proposed mechanism is a more efficient ribosome binding site for the B gene than for the A gene, increasing the rate of initiation of translation of the B gene independently from A gene translation. The three-dimensional crystal structures of representative members of the LT family (CT, LTpI, and LTIIb) have all been determined by X-ray crystallography and found to be highly similar. Site-directed mutagenesis has identified many residues in the CT and LT A subunits, including His44, Val53, Ser63, Val97, Glu110, and Glu112, that are critical for the structures and enzymatic activities of these enterotoxins. For the enzymatically active A1 fragment to reach its substrate, receptor-bound holotoxin must gain access to the cytosol of target cells.
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14
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Huang J, Li F, Wu J, Yang F. White spot syndrome virus enters crayfish hematopoietic tissue cells via clathrin-mediated endocytosis. Virology 2015; 486:35-43. [PMID: 26397221 DOI: 10.1016/j.virol.2015.08.034] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Revised: 08/21/2015] [Accepted: 08/31/2015] [Indexed: 12/20/2022]
Abstract
White spot syndrome virus (WSSV) is a major pathogen of aquacultured shrimp. However, the mechanism of its entry remains poorly understood. In this study, by analyzing the internalization of WSSV using crayfish hematopoietic tissue (HPT) cells, we showed that WSSV virions were engulfed by cell membrane invaginations sharing the features of clathrin-coated pits and then internalized into coated cytoplasmic vesicles. Further investigation indicated that WSSV internalization was significantly inhibited by chlorpromazine (CPZ) but not genistein. The internalized virions were colocalized with endogenous clathrin as well as transferrin which undergoes clathrin-dependent uptake. Preventing endosome acidification by ammonium chloride (NH4Cl) or chloroquine (CQ) dramatically reduced WSSV entry as well. Moreover, disturbance of dynamin activity or depletion of membrane cholesterol also blocked WSSV uptake. These data indicate that WSSV enters crayfish HPT cells via clathrin-mediated endocytosis in a pH-dependent manner, and membrane cholesterol as well as dynamin is critical for efficient viral entry.
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Affiliation(s)
- Jiajun Huang
- Key Laboratory of Marine Genetic Resources, South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Third Institute of Oceanography, State Oceanic Administration, Xiamen 361005, China
| | - Fang Li
- Key Laboratory of Marine Genetic Resources, South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Third Institute of Oceanography, State Oceanic Administration, Xiamen 361005, China.
| | - Junjun Wu
- Key Laboratory of Marine Genetic Resources, South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Third Institute of Oceanography, State Oceanic Administration, Xiamen 361005, China
| | - Feng Yang
- Key Laboratory of Marine Genetic Resources, South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Third Institute of Oceanography, State Oceanic Administration, Xiamen 361005, China.
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15
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Lige B, Romano JD, Sampels V, Sonda S, Joiner KA, Coppens I. Introduction of caveolae structural proteins into the protozoan Toxoplasma results in the formation of heterologous caveolae but not caveolar endocytosis. PLoS One 2012; 7:e51773. [PMID: 23272165 PMCID: PMC3522706 DOI: 10.1371/journal.pone.0051773] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Accepted: 11/08/2012] [Indexed: 11/30/2022] Open
Abstract
Present on the plasma membrane of most metazoans, caveolae are specialized microdomains implicated in several endocytic and trafficking mechanisms. Caveolins and the more recently discovered cavins are the major protein components of caveolae. Previous studies reported that caveolar invaginations can be induced de novo on the surface of caveolae-negative mammalian cells upon heterologous expression of caveolin-1. However, it remains undocumented whether other components in the transfected cells participate in caveolae formation. To address this issue, we have exploited the protozoan Toxoplasma as a heterologous expression system to provide insights into the minimal requirements for caveogenesis and caveolar endocytosis. Upon expression of caveolin-1, Toxoplasma accumulates prototypical exocytic caveolae 'precursors' in the cytoplasm. Toxoplasma expressing caveolin-1 alone, or in conjunction with cavin-1, neither develops surface-located caveolae nor internalizes caveolar ligands. These data suggest that the formation of functional caveolae at the plasma membrane in Toxoplasma and, by inference in all non-mammalian cells, requires effectors other than caveolin-1 and cavin-1. Interestingly, Toxoplasma co-expressing caveolin-1 and cavin-1 displays an impressive spiraled network of membranes containing the two proteins, in the cytoplasm. This suggests a synergistic activity of caveolin-1 and cavin-1 in the morphogenesis and remodeling of membranes, as illustrated for Toxoplasma.
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Affiliation(s)
- Bao Lige
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health Baltimore, Maryland, United States of America
| | - Julia D. Romano
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health Baltimore, Maryland, United States of America
| | - Vera Sampels
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health Baltimore, Maryland, United States of America
| | - Sabrina Sonda
- Institute of Parasitology, University of Zurich, Zurich, Switzerland
| | - Keith A. Joiner
- Arizona Health Science Center, University of Arizona College of Medicine, Tucson, Arizona, United States of America
| | - Isabelle Coppens
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health Baltimore, Maryland, United States of America
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16
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Cholera toxin induces a shift from inactive to active cyclooxygenase 2 in alveolar macrophages activated by Mycobacterium bovis BCG. Infect Immun 2012; 81:373-80. [PMID: 23147035 DOI: 10.1128/iai.01031-12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Intranasal vaccination stimulates formation of cyclooxygenases (COX) and release of prostaglandin E(2) (PGE(2)) by lung cells, including alveolar macrophages. PGE(2) plays complex pro- or anti-inflammatory roles in facilitating mucosal immune responses, but the relative contributions of COX-1 and COX-2 remain unclear. Previously, we found that Mycobacterium bovis BCG, a human tuberculosis vaccine, stimulated increased release of PGE(2) by macrophages activated in vitro; in contrast, intranasal BCG activated no PGE(2) release in the lungs, because COX-1 and COX-2 in alveolar macrophages were subcellularly dissociated from the nuclear envelope (NE) and catalytically inactive. This study tested the hypothesis that intranasal administration of BCG with cholera toxin (CT), a mucosal vaccine component, would shift the inactive, NE-dissociated COX-1/COX-2 to active, NE-associated forms. The results showed increased PGE(2) release in the lungs and NE-associated COX-2 in the majority of COX-2(+) macrophages. These COX-2(+) macrophages were the primary source of PGE(2) release in the lungs, since there was only slight enhancement of NE-associated COX-1 and there was no change in COX-1/COX-2 levels in alveolar epithelial cells following treatment with CT and/or BCG. To further understand the effect of CT, we investigated the timing of BCG versus CT administration for in vivo and in vitro macrophage activations. When CT followed BCG treatment, macrophages in vitro had elevated COX-2-mediated PGE(2) release, but macrophages in vivo exhibited less activation of NE-associated COX-2. Our results indicate that inclusion of CT in the intranasal BCG vaccination enhances COX-2-mediated PGE(2) release by alveolar macrophages and further suggest that the effect of CT in vivo is mediated by other lung cells.
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17
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Kato T, Kawaguchi A, Nagata K, Hatanaka K. Development of tetraphenylethylene-based fluorescent oligosaccharide probes for detection of influenza virus. Biochem Biophys Res Commun 2010; 394:200-4. [PMID: 20188703 PMCID: PMC7117542 DOI: 10.1016/j.bbrc.2010.02.155] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2010] [Accepted: 02/23/2010] [Indexed: 11/30/2022]
Abstract
Tetraphenylethylene (TPE) derivatives have strong fluorescence in aggregated state. We designed and synthesized a tetraphenylethylene derivative bearing alkyne groups which were used for combination by click chemistry. The new TPE compound bearing alkyne groups was used to synthesize fluorescence oligosaccharide probes which have lactosyl and 6′-sialyllactosyl moieties as ligands. We found that the TPE compounds bearing lactosyl and 6′-sialyllactosyl moieties were useful for detection of RCA120 and SSA lectins, respectively. Moreover, we have shown that TPE-based fluorescent oligosaccharide probe bearing 6′-sialyllactose moiety can be utilized as a “turn-on” fluorescent sensor for detection of influenza virus.
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Affiliation(s)
- Tomohisa Kato
- Japan Chemical Innovation Institute, 1-3-5 Jimbocho, Chiyoda-ku, Tokyo 101-0051, Japan.
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18
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Little heterogeneity among genes encoding heat-labile and heat-stable toxins of enterotoxigenic Escherichia coli strains isolated from diarrheal pigs. Appl Environ Microbiol 2009; 75:6402-5. [PMID: 19684170 DOI: 10.1128/aem.00952-09] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
To examine whether the heat-labile enterotoxin gene in porcine enterotoxigenic Escherichia coli (ETEC) strains is as divergent as in human ETEC strains, we sequenced the heat-labile and heat-stable toxin genes from 52 and 33 porcine ETEC strains, respectively. We found that the STa gene is identical, that the LT gene has only two mutations in 4 (of 52) strains, and that both mutations cause a reduction in GM1 binding and toxicity.
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19
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De Haan L, Hirst TR. Cholera toxin: A paradigm for multi-functional engagement of cellular mechanisms (Review). Mol Membr Biol 2009; 21:77-92. [PMID: 15204437 DOI: 10.1080/09687680410001663267] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Cholera toxin (Ctx) from Vibrio cholerae and its closely related homologue, heat-labile enterotoxin (Etx) from Escherichia coli have become superb tools for illuminating pathways of cellular trafficking and immune cell function. These bacterial protein toxins should be viewed as conglomerates of highly evolved, multi-functional elements equipped to engage the trafficking and signalling machineries of cells. Ctx and Etx are members of a larger family of A-B toxins of bacterial (and plant) origin that are comprised of structurally and functionally distinct enzymatically active A and receptor-binding B sub-units or domains. Intoxication of mammalian cells by Ctx and Etx involves B pentamer-mediated receptor binding and entry into a vesicular pathway, followed by translocation of the enzymatic A1 domain of the A sub-unit into the target cell cytosol, where covalent modification of intracellular targets leads to activation of adenylate cyclase and a sequence of events culminating in life-threatening diarrhoeal disease. Importantly, Ctx and Etx also have the capacity to induce a wide spectrum of remarkable immunological processes. With respect to the latter, it has been found that these toxins activate signalling pathways that modulate the immune system. This review explores the complexities of the cellular interactions that are engaged by these bacterial protein toxins, and highlights some of the new insights to have recently emerged.
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Affiliation(s)
- Lolke De Haan
- Department of Pathology and Microbiology, School of Medical Sciences, University of Bristol, United Kingdom
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20
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Terrell J, Yadava P, Castro C, Hughes J. Liposome fluidity alters interactions between the ganglioside GM1 and cholera toxin B subunit. J Liposome Res 2008; 18:21-9. [PMID: 18348069 DOI: 10.1080/08982100801893929] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Cholera toxin is a complex protein with a biologically active protein (A subunit) and a cell targeting portion (B subunit). The B subunit is responsible for specific cell binding and entry of the A subunit. One way to limit potential toxicity of the toxin after exposure is to introduce cellular decoys to bind the toxin before it can enter cells. In this study the ganglioside GM1, a natural ligand for cholera toxin, was incorporated into liposomes and the interaction between fluorescent B subunit and the liposome determined. Liposome membrane fluidity was determined to play a major role in the binding between liposomes and the cholera toxin B subunit. Liposomes with lower fluidity demonstrated greater binding with the B subunit. The findings from this study could have important implications on formulation strategies for liposome decoys of toxins.
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Affiliation(s)
- James Terrell
- Department of Pharmaceutics, University of Florida, Gainesville, FL 32611, USA
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21
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Part I: an x-ray scattering study of cholera toxin penetration and induced phase transformations in lipid membranes. Biophys J 2008; 95:629-40. [PMID: 18359802 DOI: 10.1529/biophysj.107.120725] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cholera toxin is a highly efficient biotoxin, which is frequently used as a tool to investigate protein-membrane interactions and as a reporter for membrane rafts. Cholera toxin binds selectively to gangliosides with highest affinity to GM(1). However, the mechanism by which cholera toxin crosses the membrane remains unresolved. Using x-ray reflectivity and grazing incidence diffraction, we have been able to monitor the binding and penetration of cholera toxin into a model lipid monolayer containing the receptor GM(1) at the air-water interface. Very high toxin coverage was obtained allowing precise measurements of how toxin binding alters lipid packing. Grazing incidence x-ray diffraction revealed the coexistence of two monolayer phases after toxin binding. The first was identical to the monolayer before toxin binding. In regions where toxin was bound, a second membrane phase exhibited a decrease in order as evidenced by a larger area per molecule and tilt angle with concomitant thinning of the monolayer. These results demonstrate that cholera toxin binding induces the formation of structurally distinct, less ordered domains in gel phases. Furthermore, the largest decrease in lateral order to the monolayer occurred at low pH, supporting a low endosomal pH in the infection pathway. Surprisingly, at pH = 8 toxin penetration by the binding portion of the toxin, the B(5) pentamer, was also observed.
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22
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Attenuated endocytosis and toxicity of a mutant cholera toxin with decreased ability to cluster ganglioside GM1 molecules. Infect Immun 2008; 76:1476-84. [PMID: 18212085 DOI: 10.1128/iai.01286-07] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cholera toxin (CT) moves from the plasma membrane (PM) of host cells to the endoplasmic reticulum (ER) by binding to the lipid raft ganglioside GM(1). The homopentomeric B-subunit of the toxin can bind up to five GM(1) molecules at once. Here, we examined the role of polyvalent binding of GM(1) in CT action by producing chimeric CTs that had B-subunits with only one or two normal binding pockets for GM(1). The chimeric toxins had attenuated affinity for binding to host cell PM, as expected. Nevertheless, like wild-type (wt) CT, the CT chimeras induced toxicity, fractionated with detergent-resistant membranes extracted from toxin-treated cells, displayed restricted diffusion in the plane of the PM in intact cells, and remained bound to GM(1) when they were immunoprecipitated. Thus, binding normally to two or perhaps only one GM(1) molecule is sufficient for association with lipid rafts in the PM and toxin action. The chimeric toxins, however, were much less potent than wt toxin, and they entered the cell by endocytosis more slowly, suggesting that clustering of GM(1) molecules by the B-subunit enhances the efficiency of toxin uptake and perhaps also trafficking to the ER.
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23
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Cholera toxin, E. coli heat-labile toxin, and non-toxic derivatives induce dendritic cell migration into the follicle-associated epithelium of Peyer's patches. Mucosal Immunol 2008; 1:59-67. [PMID: 19079161 PMCID: PMC2614317 DOI: 10.1038/mi.2007.7] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The follicle-associated epithelium (FAE) of Peyer's patches (PPs) transports antigens and microorganisms into mucosal lymphoid tissues where they are captured by subepithelial dendritic cells (DCs). Feeding of cholera toxin (CT) induced migration of subepithelial DCs to interfollicular T-cell areas within 24 h. This study investigated short-term effects of CT, Escherichia coli heat-labile toxin, and non-toxic derivatives on DC migration. CT or CTB injected into ligated intestinal loops induced significant increase in CD11c+ DCs within the FAE within 90 min. In mice fed CT intragastrically, DC numbers in the FAE increased by 1 h, were maximal by 2 h, declined between 8 and 12 h, and were reversed by 24 h. Feeding of native LT, recombinant CTB, dibutyryl cyclic AMP, and to a lesser extent mutated CT(E29H) or mutated LT(R192G) had the same effect. Thus, both A and B subunits of enterotoxins, presumably acting through distinct signaling pathways, may promote capture of incoming antigens and pathogens by PP DCs.
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24
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Sillence DJ. New insights into glycosphingolipid functions--storage, lipid rafts, and translocators. INTERNATIONAL REVIEW OF CYTOLOGY 2007; 262:151-89. [PMID: 17631188 DOI: 10.1016/s0074-7696(07)62003-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Glycosphingolipids are key components of eukaryotic cellular membranes. Through their propensity to form lipid rafts, they are important in membrane transport and signaling. At the cell surface, they are required for caveolar-mediated endocytosis, a process required for the action of many glycosphingolipid-binding toxins. Glycosphingolipids also exist intracellularly, on both leaflets of organelle membranes. It is expected that dissecting the mechanisms of cell pathology seen in the glycosphingolipid storage diseases, where lysosomal glycosphingolipid degradation is defective, will reveal their functions. Disrupted cation gradients in Mucolipidosis type IV disease are interlinked with glycosphingolipid storage, defective rab 7 function, and the activation of autophagy. Relationships between drug translocators and glycosphingolipid synthesis are also discussed. Mass spectrometry of cell lines defective in drug transporters reveal clear differences in glycosphingolipid mass and fatty acid composition. The potential roles of glycosphingolipids in lipid raft formation, endocytosis, and cationic gradients are discussed.
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Affiliation(s)
- Dan J Sillence
- Leicester School of Pharmacy, Hawthorne Building, De Montfort University, Leicester, LE1 9BH, United Kingdom
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25
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Nuzzi PA, Senetar MA, Huttenlocher A. Asymmetric localization of calpain 2 during neutrophil chemotaxis. Mol Biol Cell 2006; 18:795-805. [PMID: 17192410 PMCID: PMC1805107 DOI: 10.1091/mbc.e06-09-0876] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Chemoattractants induce neutrophil polarization through localized polymerization of F-actin at the leading edge. The suppression of rear and lateral protrusions is required for efficient chemotaxis and involves the temporal and spatial segregation of signaling molecules. We have previously shown that the intracellular calcium-dependent protease calpain is required for cell migration and is involved in regulating neutrophil chemotaxis. Here, we show that primary neutrophils and neutrophil-like HL-60 cells express both calpain 1 and calpain 2 and that chemoattractants induce the asymmetric recruitment of calpain 2, but not calpain 1, to the leading edge of polarized neutrophils and differentiated HL-60 cells. Using time-lapse microscopy, we show that enrichment of calpain 2 at the leading edge occurs during early pseudopod formation and that its localization is sensitive to changes in the chemotactic gradient. We demonstrate that calpain 2 is recruited to lipid rafts and that cholesterol depletion perturbs calpain 2 localization, suggesting that its enrichment at the front requires proper membrane organization. Finally, we show that catalytic activity of calpain is required to limit pseudopod formation in the direction of chemoattractant and for efficient chemotaxis. Together, our findings identify calpain 2 as a novel component of the frontness signal that promotes polarization during chemotaxis.
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Affiliation(s)
| | | | - Anna Huttenlocher
- Departments of *Pharmacology and
- Pediatrics, University of Wisconsin, Madison, WI 53706
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26
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Smith DC, Sillence DJ, Falguières T, Jarvis RM, Johannes L, Lord JM, Platt FM, Roberts LM. The association of Shiga-like toxin with detergent-resistant membranes is modulated by glucosylceramide and is an essential requirement in the endoplasmic reticulum for a cytotoxic effect. Mol Biol Cell 2005; 17:1375-87. [PMID: 16381816 PMCID: PMC1382325 DOI: 10.1091/mbc.e05-11-1035] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Receptor-mediated internalization to the endoplasmic reticulum (ER) and subsequent retro-translocation to the cytosol are essential sequential processes required for the productive intoxication of susceptible mammalian cells by Shiga-like toxin-1 (SLTx). Recently, it has been proposed that the observed association of certain ER-directed toxins and viruses with detergent-resistant membranes (DRM) may provide a general mechanism for their retrograde transport to endoplasmic reticulum (ER). Here, we show that DRM recruitment of SLTx bound to its globotriosylceramide (Gb(3)) receptor is mediated by the availability of other glycosphingolipids. Reduction in glucosylceramide (GlcCer) levels led to complete protection against SLTx and a reduced cell surface association of bound toxin with DRM. This reduction still allowed efficient binding and transport of the toxin to the ER. However, toxin sequestration within DRM of the ER was abolished under reduced GlcCer conditions, suggesting that an association of toxin with lipid microdomains or rafts in the ER (where these are defined by detergent insolubility) is essential for a later step leading to or involving retro-translocation of SLTx across the ER membrane. In support of this, we show that a number of ER residents, proteins intimately involved in the process of ER dislocation of misfolded proteins, are present in DRM.
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Affiliation(s)
- Daniel C Smith
- Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK
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27
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Nawar HF, Arce S, Russell MW, Connell TD. Mucosal adjuvant properties of mutant LT-IIa and LT-IIb enterotoxins that exhibit altered ganglioside-binding activities. Infect Immun 2005; 73:1330-42. [PMID: 15731030 PMCID: PMC1064923 DOI: 10.1128/iai.73.3.1330-1342.2005] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
LT-IIa and LT-IIb, the type II heat-labile enterotoxins of Escherichia coli, are closely related in structure and function to cholera toxin and LT-I, the type I heat-labile enterotoxins of Vibrio cholerae and E. coli, respectively. Recent studies from our group demonstrated that LT-IIa and LT-IIb are potent systemic and mucosal adjuvants. To determine whether binding of LT-IIa and LT-IIb to their specific ganglioside receptors is essential for adjuvant activity, LT-IIa and LT-IIb enterotoxins were compared with their respective single-point substitution mutants which have no detectable binding activity for their major ganglioside receptors [e.g., LT-IIa(T34I) and LT-IIb(T13I)]. Both mutant enterotoxins exhibited an extremely low capacity for intoxicating mouse Y1 adrenal cells and for inducing production of cyclic AMP in a macrophage cell line. BALB/c female mice were immunized by the intranasal route with the surface adhesin protein AgI/II of Streptococcus mutans alone or in combination with LT-IIa, LT-IIa(T34I), LT-IIb, or LT-IIb(T13I). Both LT-IIa and LT-IIb potentiated strong mucosal and systemic immune responses against AgI/II. Of the two mutant enterotoxins, only LT-IIb(T13I) had the capacity to strongly potentiate mucosal anti-AgI/II and systemic anti-AgI/II antibody responses. Upon boosting with AgI/II, however, both LT-IIa(T34I) and LT-IIb(T13I) enhanced humoral memory responses to AgI/II. Flow cytometry demonstrated that LT-IIa(T34I) had no affinity for cervical lymph node lymphocytes. In contrast, LT-IIb(T13I) retained binding activity for T cells, B cells, and macrophages, indicating that this immunostimulatory mutant enterotoxin interacts with one or more unknown lymphoid cell receptors.
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Affiliation(s)
- Hesham F Nawar
- Department of Microbiology and Immunology, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, 138 Farber Hall, 3435 Main St., Buffalo, NY 14214, USA
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28
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Badizadegan K, Wheeler HE, Fujinaga Y, Lencer WI. Trafficking of cholera toxin-ganglioside GM1 complex into Golgi and induction of toxicity depend on actin cytoskeleton. Am J Physiol Cell Physiol 2004; 287:C1453-62. [PMID: 15294854 DOI: 10.1152/ajpcell.00189.2004] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Intestinal epithelial lipid rafts contain ganglioside GM1 that is the receptor for cholera toxin (CT). The ganglioside binds CT at the plasma membrane (PM) and carries the toxin through the trans-Golgi network (TGN) to the endoplasmic reticulum (ER). In the ER, a portion of the toxin unfolds and translocates to the cytosol to activate adenylyl cyclase. Activation of the cyclase leads to an increase in intracellular cAMP, which results in apical chloride secretion. Here, we find that an intact actin cytoskeleton is necessary for the efficient transport of CT to the Golgi and for subsequent activation of adenylyl cyclase. CT bound to GM1 on the cell membrane fractionates with a heterogeneous population of lipid rafts, a portion of which is enriched in actin and other cytoskeletal proteins. In this actin-rich fraction of lipid rafts, CT and actin colocalize on the same membrane microdomains, suggesting a possible functional association. Depolymerization or stabilization of actin filaments interferes with transport of CT from the PM to the Golgi and reduces the levels of cAMP generated in the cytosol. Depletion of membrane cholesterol, which also inhibits CT trafficking to the TGN, causes displacement of actin from the lipid rafts while CT remains stably raft associated. On the basis of these observations, we propose that the CT-GM1 complex is associated with the actin cytoskeleton via the lipid rafts and that the actin cytoskeleton plays a role in trafficking of CT from the PM to the Golgi/ER and the subsequent activation of adenylyl cyclase.
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Affiliation(s)
- Kamran Badizadegan
- Department of Pathology, Massachusetts General Hospital, Boston 02114, USA.
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Kopitz J, André S, von Reitzenstein C, Versluis K, Kaltner H, Pieters RJ, Wasano K, Kuwabara I, Liu FT, Cantz M, Heck AJR, Gabius HJ. Homodimeric galectin-7 (p53-induced gene 1) is a negative growth regulator for human neuroblastoma cells. Oncogene 2003; 22:6277-88. [PMID: 13679866 DOI: 10.1038/sj.onc.1206631] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The extracellular functions of galectin-7 (p53-induced gene 1) are largely unknown. On the surface of neuroblastoma cells (SK-N-MC), the increased GM1 density, a result of upregulated ganglioside sialidase activity, is a key factor for the switch from proliferation to differentiation. We show by solid-phase and cell assays that the sugar chain of this ganglioside is a ligand for galectin-7. In serum-supplemented proliferation assays, galectin-7 reduced neuroblastoma cell growth without the appearance of features characteristic for classical apoptosis. The presence of galectin-3 blocked this effect, which mechanistically resembles that of galectin-1. By virtue of carbohydrate binding, galectin-7 thus exerts neuroblastoma growth control similar to galectin-1 despite their structural differences. In addition to p53-linked proapoptotic activity intracellularly, galectin-7, acting as a lectin on the cell surface, appears to be capable of reducing cancer cell proliferation in susceptible systems.
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Affiliation(s)
- Jürgen Kopitz
- Institut für Molekulare Pathologie, Klinikum der Ruprecht-Karls-Universtiät, Im Neuenheimer Feld 220, 69120 Heidelberg, Germany.
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30
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Abstract
Studying human diseases can help us to uncover important processes in normal cells. Cell biologists have recently focused on inherited sphingolipid-storage diseases. Eukaryotic life is characterized by internal membranes of various compositions, and sphingolipids are a small but important part of these membranes. Compositional differences between cellular membranes are maintained by sorting and sphingolipids are thought to organize this process by forming ordered domains of increased thickness in the bilayer. Here, we describe the impact of sphingolipid accumulation on the sorting of endocytic membranes and discuss the proposed basis for the pathology of these diseases at the cellular level.
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Affiliation(s)
- Dan J Sillence
- Glycobiology Institute, Dept Biochemistry, University of Oxford, South Parks Road, UK.
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Fraser SA, de Haan L, Hearn AR, Bone HK, Salmond RJ, Rivett AJ, Williams NA, Hirst TR. Mutant Escherichia coli heat-labile toxin B subunit that separates toxoid-mediated signaling and immunomodulatory action from trafficking and delivery functions. Infect Immun 2003; 71:1527-37. [PMID: 12595472 PMCID: PMC148879 DOI: 10.1128/iai.71.3.1527-1537.2003] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The homopentameric B-subunit components of Escherichia coli heat-labile enterotoxin (EtxB) and cholera toxin (CtxB) possess the capacity to enter mammalian cells and to activate cell-signaling events in leukocytes that modulate immune cell function. Both properties have been attributed to the ability of the B subunits to bind to GM1-ganglioside receptors, a ubiquitous glycosphingolipid found in the plasma membrane. Here we describe the properties of EtxB(H57S), a mutant B subunit with a His-->Ser substitution at position 57. The mutant was found to be severely defective in inducing leukocyte signaling, as shown by failure to (i) trigger caspase 3-mediated CD8(+)-T-cell apoptosis, (ii) activate nuclear translocation of NF-kappaB in Jurkat T cells, (iii) induce a potent anti-B-subunit response in mice, or (iv) serve as a mucosal adjuvant. However, its GM1 binding, cellular uptake, and delivery functions remained intact. This was further validated by the finding that EtxB(H57S) was as effective as EtxB in delivering a conjugated model class I epitope into the major histocompatibility complex class I pathway of a dendritic cell line. These observations imply that GM1 binding alone is not sufficient to trigger the signaling events responsible for the potent immunomodulatory properties of EtxB. Moreover, they demonstrate that its signaling properties play no role in EtxB uptake and trafficking. Thus, EtxB(H57S) represents a novel tool for evaluating the complex cellular interactions and signaling events occurring after receptor interaction, as well as offering an alternative means of delivering attached peptides in the absence of the potent immunomodulatory signals induced by wild-type B subunits.
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Affiliation(s)
- Sylvia A Fraser
- Department of Pathology & Microbiology, School of Medical Sciences, University of Bristol, University Walk, Bristol BS8 1TD, United Kingdom
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Wolf AA, Fujinaga Y, Lencer WI. Uncoupling of the cholera toxin-G(M1) ganglioside receptor complex from endocytosis, retrograde Golgi trafficking, and downstream signal transduction by depletion of membrane cholesterol. J Biol Chem 2002; 277:16249-56. [PMID: 11859071 DOI: 10.1074/jbc.m109834200] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
To induce toxicity, cholera toxin (CT) must first bind ganglioside G(M1) at the plasma membrane, enter the cell by endocytosis, and then traffic retrograde into the endoplasmic reticulum. We recently proposed that G(M1) provides the sorting motif necessary for retrograde trafficking into the biosynthetic/secretory pathway of host cells, and that such trafficking depends on association with lipid rafts and lipid raft function. To test this idea, we examined whether CT action in human intestinal T84 cells depends on membrane cholesterol. Chelation of cholesterol with 2-hydroxypropyl beta-cyclodextrin or methyl beta-cyclodextrin reversibly inhibited CT-induced chloride secretion and prolonged the time required for CT to enter the cell and induce toxicity. These effects were specific to CT, as identical conditions did not alter the potency or toxicity of anthrax edema toxin that enters the cell by another mechanism. We found that endocytosis and trafficking of CT into the Golgi apparatus depended on membrane cholesterol. Cholesterol depletion also changed the density and specific protein content of CT-associated lipid raft fractions but did not entirely displace the CT-G(M1) complex from these lipid raft microdomains. Taken together these data imply that cholesterol may function to couple the CT-G(M1) complex with raft domains and with other membrane components of the lipid raft required for CT entry into the cell.
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Affiliation(s)
- Anne A Wolf
- Gastrointestinal Cell Biology, Department of Pediatrics, Children's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
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