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Warr AR, Kuehl CJ, Waldor MK. Shiga toxin remodels the intestinal epithelial transcriptional response to Enterohemorrhagic Escherichia coli. PLoS Pathog 2021; 17:e1009290. [PMID: 33529199 PMCID: PMC7880444 DOI: 10.1371/journal.ppat.1009290] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 02/12/2021] [Accepted: 01/07/2021] [Indexed: 12/22/2022] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) is a food-borne pathogen that causes diarrheal disease and the potentially lethal hemolytic uremic syndrome. We used an infant rabbit model of EHEC infection that recapitulates many aspects of human intestinal disease to comprehensively assess colonic transcriptional responses to this pathogen. Cellular compartment-specific RNA-sequencing of intestinal tissue from animals infected with EHEC strains containing or lacking Shiga toxins (Stx) revealed that EHEC infection elicits a robust response that is dramatically shaped by Stx, particularly in epithelial cells. Many of the differences in the transcriptional responses elicited by these strains were in genes involved in immune signaling pathways, such as IL23A, and coagulation, including F3, the gene encoding Tissue Factor. RNA FISH confirmed that these elevated transcripts were found almost exclusively in epithelial cells. Collectively, these findings suggest that Stx potently remodels the host innate immune response to EHEC. Enterohemorrhagic Escherichia coli (EHEC) is a potentially lethal foodborne pathogen. During infection, EHEC releases a potent toxin, Shiga toxin (Stx), into the intestine, but there is limited knowledge of how this toxin shapes the host response to infection. We used an infant rabbit model of infection that closely mimics human disease to profile intestinal transcriptomic responses to EHEC infection. Comparisons of the transcriptional responses to infection by strains containing or lacking Stx revealed that this toxin markedly remodels how the epithelial cell compartment responds to infection. Our findings suggest that Stx shapes the intestinal innate immune response to EHEC and provide insight into the complex host-pathogen dialogue that underlies disease.
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Affiliation(s)
- Alyson R. Warr
- Division of Infectious Diseases, Brigham & Women’s Hospital, Boston, Massachusetts, United States of America
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Carole J. Kuehl
- Division of Infectious Diseases, Brigham & Women’s Hospital, Boston, Massachusetts, United States of America
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Matthew K. Waldor
- Division of Infectious Diseases, Brigham & Women’s Hospital, Boston, Massachusetts, United States of America
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, United States of America
- Howard Hughes Medical Institute, Boston, Massachusetts, United States of America
- * E-mail:
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2
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Abstract
Shigella species cause diarrheal disease globally. Shigellosis is typically characterized by bloody stools and colitis with mucosal damage and is the leading bacterial cause of diarrheal death worldwide. After the pathogen is orally ingested, it invades and replicates within the colonic epithelium through mechanisms that rely on its type III secretion system (T3SS). Currently, oral infection-based small animal models to study the pathogenesis of shigellosis are lacking. Here, we found that orogastric inoculation of infant rabbits with Shigella flexneri resulted in diarrhea and colonic pathology resembling that found in human shigellosis. Fasting animals prior to S. flexneri inoculation increased the frequency of disease. The pathogen colonized the colon, where both luminal and intraepithelial foci were observed. The intraepithelial foci likely arise through S. flexneri spreading from cell to cell. Robust S. flexneri intestinal colonization, invasion of the colonic epithelium, and epithelial sloughing all required the T3SS as well as IcsA, a factor required for bacterial spreading and adhesion in vitro Expression of the proinflammatory chemokine interleukin 8 (IL-8), detected with in situ mRNA labeling, was higher in animals infected with wild-type S. flexneri versus mutant strains deficient in icsA or T3SS, suggesting that epithelial invasion promotes expression of this chemokine. Collectively, our findings suggest that oral infection of infant rabbits offers a useful experimental model for studies of the pathogenesis of shigellosis and for testing of new therapeutics.IMPORTANCEShigella species are the leading bacterial cause of diarrheal death globally. The pathogen causes bacillary dysentery, a bloody diarrheal disease characterized by damage to the colonic mucosa and is usually spread through the fecal-oral route. Small animal models of shigellosis that rely on the oral route of infection are lacking. Here, we found that orogastric inoculation of infant rabbits with S. flexneri led to a diarrheal disease and colonic pathology reminiscent of human shigellosis. Diarrhea, intestinal colonization, and pathology in this model were dependent on the S. flexneri type III secretion system and IcsA, canonical Shigella virulence factors. Thus, oral infection of infant rabbits offers a feasible model to study the pathogenesis of shigellosis and to develop and test new therapeutics.
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Affiliation(s)
- Carole J Kuehl
- Division of Infectious Diseases, Brigham & Women's Hospital, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Jonathan D D'Gama
- Division of Infectious Diseases, Brigham & Women's Hospital, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Alyson R Warr
- Division of Infectious Diseases, Brigham & Women's Hospital, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Matthew K Waldor
- Division of Infectious Diseases, Brigham & Women's Hospital, Boston, Massachusetts, USA
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
- Howard Hughes Medical Institute, Boston, Massachusetts, USA
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3
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Hubbard TP, Billings G, Dörr T, Sit B, Warr AR, Kuehl CJ, Kim M, Delgado F, Mekalanos JJ, Lewnard JA, Waldor MK. A live vaccine rapidly protects against cholera in an infant rabbit model. Sci Transl Med 2019; 10:10/445/eaap8423. [PMID: 29899024 DOI: 10.1126/scitranslmed.aap8423] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 03/26/2018] [Indexed: 12/17/2022]
Abstract
Outbreaks of cholera, a rapidly fatal diarrheal disease, often spread explosively. The efficacy of reactive vaccination campaigns-deploying Vibrio cholerae vaccines during epidemics-is partially limited by the time required for vaccine recipients to develop adaptive immunity. We created HaitiV, a live attenuated cholera vaccine candidate, by deleting diarrheagenic factors from a recent clinical isolate of V. cholerae and incorporating safeguards against vaccine reversion. We demonstrate that administration of HaitiV 24 hours before lethal challenge with wild-type V. cholerae reduced intestinal colonization by the wild-type strain, slowed disease progression, and reduced mortality in an infant rabbit model of cholera. HaitiV-mediated protection required viable vaccine, and rapid protection kinetics are not consistent with development of adaptive immunity. These features suggest that HaitiV mediates probiotic-like protection from cholera, a mechanism that is not known to be elicited by traditional vaccines. Mathematical modeling indicates that an intervention that works at the speed of HaitiV-mediated protection could improve the public health impact of reactive vaccination.
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Affiliation(s)
- Troy P Hubbard
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA.,Division of Infectious Diseases, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Gabriel Billings
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA.,Division of Infectious Diseases, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Tobias Dörr
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA.,Division of Infectious Diseases, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Brandon Sit
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA.,Division of Infectious Diseases, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Alyson R Warr
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA.,Division of Infectious Diseases, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Carole J Kuehl
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA.,Division of Infectious Diseases, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Minsik Kim
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA.,Division of Infectious Diseases, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Fernanda Delgado
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, MA 02115, USA.,Howard Hughes Medical Institute, Boston, MA 02115, USA
| | - John J Mekalanos
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Joseph A Lewnard
- Center for Communicable Disease Dynamics, Harvard T. H. Chan School of Public Health, Boston, MA 02115, USA
| | - Matthew K Waldor
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA. .,Division of Infectious Diseases, Brigham and Women's Hospital, Boston, MA 02115, USA.,Howard Hughes Medical Institute, Boston, MA 02115, USA.,Department of Immunology and Infectious Disease, Harvard T. H. Chan School of Public Health, Boston, MA 02115, USA
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4
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Blondel CJ, Park JS, Hubbard TP, Pacheco AR, Kuehl CJ, Walsh MJ, Davis BM, Gewurz BE, Doench JG, Waldor MK. CRISPR/Cas9 Screens Reveal Requirements for Host Cell Sulfation and Fucosylation in Bacterial Type III Secretion System-Mediated Cytotoxicity. Cell Host Microbe 2016; 20:226-37. [PMID: 27453484 DOI: 10.1016/j.chom.2016.06.010] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 05/24/2016] [Accepted: 06/17/2016] [Indexed: 12/11/2022]
Abstract
Type III secretion systems (T3SSs) inject bacterial effector proteins into host cells and underlie the virulence of many gram-negative pathogens. Studies have illuminated bacterial factors required for T3SS function, but the required host processes remain largely undefined. We coupled CRISPR/Cas9 genome editing technology with the cytotoxicity of two Vibrio parahaemolyticus T3SSs (T3SS1 and T3SS2) to identify human genome disruptions conferring resistance to T3SS-dependent cytotoxicity. We identity non-overlapping genes required for T3SS1- and T3SS2-mediated cytotoxicity. Genetic ablation of cell surface sulfation reduces bacterial adhesion and thereby alters the kinetics of T3SS1-mediated cytotoxicity. Cell surface fucosylation is required for T3SS2-dependent killing, and genetic inhibition of fucosylation prevents membrane insertion of the T3SS2 translocon complex. These findings reveal the importance of ubiquitous surface modifications for T3SS function, potentially explaining the broad tropism of V. parahaemolyticus, and highlight the utility of genome-wide CRISPR/Cas9 screens to discover processes underlying host-pathogen interactions.
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Affiliation(s)
- Carlos J Blondel
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Joseph S Park
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA; Howard Hughes Medical Institute, Boston, MA 02115, USA; Boston University School of Medicine, Boston, MA 02118, USA
| | - Troy P Hubbard
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Alline R Pacheco
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Carole J Kuehl
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Michael J Walsh
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Brigid M Davis
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Benjamin E Gewurz
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA
| | - John G Doench
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Matthew K Waldor
- Division of Infectious Diseases, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115, USA; Howard Hughes Medical Institute, Boston, MA 02115, USA.
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5
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Kuehl CJ, Dragoi AM, Talman A, Agaisse H. Bacterial spread from cell to cell: beyond actin-based motility. Trends Microbiol 2015; 23:558-66. [PMID: 26021574 DOI: 10.1016/j.tim.2015.04.010] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 04/14/2015] [Accepted: 04/28/2015] [Indexed: 01/01/2023]
Abstract
Several intracellular pathogens display the ability to propagate within host tissues by displaying actin-based motility in the cytosol of infected cells. As motile bacteria reach cell-cell contacts they form plasma membrane protrusions that project into adjacent cells and resolve into vacuoles from which the pathogen escapes, thereby achieving spread from cell to cell. Seminal studies have defined the bacterial and cellular factors that support actin-based motility. By contrast, the mechanisms supporting the formation of protrusions and their resolution into vacuoles have remained elusive. Here, we review recent advances in the field showing that Listeria monocytogenes and Shigella flexneri have evolved pathogen-specific mechanisms of bacterial spread from cell to cell.
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Affiliation(s)
- Carole J Kuehl
- Department of Microbial Pathogenesis, Yale School of Medicine, Boyer Center for Molecular Medicine, New Haven, CT, USA
| | - Ana-Maria Dragoi
- Department of Microbial Pathogenesis, Yale School of Medicine, Boyer Center for Molecular Medicine, New Haven, CT, USA
| | - Arthur Talman
- Department of Microbial Pathogenesis, Yale School of Medicine, Boyer Center for Molecular Medicine, New Haven, CT, USA
| | - Hervé Agaisse
- Department of Microbial Pathogenesis, Yale School of Medicine, Boyer Center for Molecular Medicine, New Haven, CT, USA.
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Kuehl CJ, Dragoi AM, Agaisse H. The Shigella flexneri type 3 secretion system is required for tyrosine kinase-dependent protrusion resolution, and vacuole escape during bacterial dissemination. PLoS One 2014; 9:e112738. [PMID: 25405985 PMCID: PMC4236203 DOI: 10.1371/journal.pone.0112738] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 10/14/2014] [Indexed: 01/29/2023] Open
Abstract
Shigella flexneri is a human pathogen that triggers its own entry into intestinal cells and escapes primary vacuoles to gain access to the cytosolic compartment. As cytosolic and motile bacteria encounter the cell cortex, they spread from cell to cell through formation of membrane protrusions that resolve into secondary vacuoles in adjacent cells. Here, we examined the roles of the Type 3 Secretion System (T3SS) in S. flexneri dissemination in HT-29 intestinal cells infected with the serotype 2a strain 2457T. We generated a 2457T strain defective in the expression of MxiG, a central component of the T3SS needle apparatus. As expected, the ΔmxiG strain was severely affected in its ability to invade HT-29 cells, and expression of mxiG under the control of an arabinose inducible expression system (ΔmxiG/pmxiG) restored full infectivity. In this experimental system, removal of the inducer after the invasion steps (ΔmxiG/pmxiG (Ara withdrawal)) led to normal actin-based motility in the cytosol of HT-29 cells. However, the time spent in protrusions until vacuole formation was significantly increased. Moreover, the number of formed protrusions that failed to resolve into vacuoles was also increased. Accordingly, the ΔmxiG/pmxiG (Ara withdrawal) strain failed to trigger tyrosine phosphorylation in membrane protrusions, a signaling event that is required for the resolution of protrusions into vacuoles. Finally, the ΔmxiG/pmxiG (Ara withdrawal) strain failed to escape from the formed secondary vacuoles, as previously reported in non-intestinal cells. Thus, the T3SS system displays multiple roles in S. flexneri dissemination in intestinal cells, including the tyrosine kinase signaling-dependent resolution of membrane protrusions into secondary vacuoles, and the escape from the formed secondary vacuoles.
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Affiliation(s)
- Carole J. Kuehl
- Department of Microbial Pathogenesis, Yale School of Medicine, Boyer Center for Molecular Medicine, New Haven, Connecticut, United States of America
| | - Ana-Maria Dragoi
- Department of Microbial Pathogenesis, Yale School of Medicine, Boyer Center for Molecular Medicine, New Haven, Connecticut, United States of America
| | - Hervé Agaisse
- Department of Microbial Pathogenesis, Yale School of Medicine, Boyer Center for Molecular Medicine, New Haven, Connecticut, United States of America
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7
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Abstract
Studying the organization and conservation of the TonB systems across the genus Vibrio, we can tease out trends in gene arrangement and function that lead to clues about the evolution and necessity of the proteins in multiple TonB systems. The TonB2 systems, with additional TtpC proteins, are in general more promiscuous regarding their interactions with many different TonB-dependent transporters in the outer membrane. Studies show that the TtpC protein spans the periplasmic space, suggesting that it can be the connection between the energy from the proton motive force and the outer membrane protein receptors, which the shorter TonB2 cannot provide. As an earlier system, the combination of the TtpC protein and a TonB2 system must have been necessary for the function of the smaller TonB2 protein and to transduce energy in a medium that can have osmotic challenges.
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Affiliation(s)
- Carole J Kuehl
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, 97239, USA
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Kuehl CJ, Wood HD, Marsh TL, Schmidt TM, Young VB. Colonization of the cecal mucosa by Helicobacter hepaticus impacts the diversity of the indigenous microbiota. Infect Immun 2005; 73:6952-61. [PMID: 16177375 PMCID: PMC1230902 DOI: 10.1128/iai.73.10.6852-6961.2005] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Establishment of mucosal and/or luminal colonization is the first step in the pathogenesis of many gastrointestinal bacterial pathogens. The pathogen must be able to establish itself in the face of competition from the complex microbial community that is already in place. We used culture-independent methods to monitor the colonization of the cecal mucosa of Helicobacter-free mice following experimental infection with the pathogen Helicobacter hepaticus. Two days after infection, H. hepaticus comprised a minor component of the mucosa-associated microbiota, but within 14 days, it became the dominant member of the community. Colonization of the mucosa by H. hepaticus was associated with a decrease in the overall diversity of the microbial community, in large part due to changes in evenness resulting from the relative dominance of H. hepaticus as a member of the community. Our results demonstrate that invasion of the complex gastrointestinal microbial community by a pathogenic microorganism causes reproducible and significant disturbances in the community structure. The use of non-culture-based methods to monitor these changes should lead to a greater understanding of the ecological principles that govern pathogen invasion and may lead to novel methods for the prevention and control of gastrointestinal pathogens.
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Affiliation(s)
- Carole J Kuehl
- Department of Microbiology and Molecular Genetics, National Food Safety and Toxicology Center, Michigan State University, East Lansing, 48824, USA
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Abstract
Interaction of a predesigned molecular "clip" (4) with rigid dipyridyl bridging ligands, in acetone/water mixtures, leads to the formation of molecular rectangles (5-8) in 92-97% isolated yields via spontaneous self-assembly. Characterization was accomplished with multinuclear NMR and UV-vis spectroscopy, FAB mass spectrometry, and X-ray crystallography. The length of these metallamacrocycles ranges from 2 to 3 nm. Postmodification via non-nucleophilic counterion exchange results in enhanced structural integrity for the assemblies.
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Affiliation(s)
- C J Kuehl
- Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, USA
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10
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Abstract
The combination of linear dipyridyl ligands with a new type of modular building unit, based upon a 1,8-platinum-functionalized anthracene, leads to the self-organization of rectangular frameworks. X-ray crystallography confirms the cyclic structure of the supramolecular cationic complexes. Spectral assignments were provided by 2D NOESY (1)H NMR experiments.
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Affiliation(s)
- C J Kuehl
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, USA
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