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Jalil K, Tahara YO, Miyata M. Visualization of Bacillus subtilis spore structure and germination using quick-freeze deep-etch electron microscopy. Microscopy (Oxf) 2024:dfae023. [PMID: 38819330 DOI: 10.1093/jmicro/dfae023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 04/15/2024] [Accepted: 04/24/2024] [Indexed: 06/01/2024] Open
Abstract
Bacterial spores, known for their complex and resilient structures, have been the focus of visualization using various methodologies. In this study, we applied quick-freeze and replica electron microscopy techniques, allowing observation of Bacillus subtilis spores in high-contrast and three-dimensional detail. This method facilitated visualization of the spore structure with enhanced resolution and provided new insights into the spores and their germination processes. We identified and described five distinct structures: (i) hair-like structures on the spore surface, (ii) spike formation on the surface of lysozyme-treated spores, (iii) the fractured appearance of the spore cortex during germination, (iv) potential connections between small vesicles and the core membrane and (v) the evolving surface structure of nascent vegetative cells during germination.
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Affiliation(s)
- Kiran Jalil
- Graduate School of Science, Osaka Metropolitan University, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - Yuhei O Tahara
- Graduate School of Science, Osaka Metropolitan University, Sumiyoshi-ku, Osaka 558-8585, Japan
- The OCU Advanced Research Institute for Natural Science and Technology (OCARINA), Osaka Metropolitan University, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - Makoto Miyata
- Graduate School of Science, Osaka Metropolitan University, Sumiyoshi-ku, Osaka 558-8585, Japan
- The OCU Advanced Research Institute for Natural Science and Technology (OCARINA), Osaka Metropolitan University, Sumiyoshi-ku, Osaka 558-8585, Japan
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2
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Dailey KM, Small JM, Pullan JE, Winfree S, Vance KE, Orr M, Mallik S, Bayles KW, Hollingsworth MA, Brooks AE. An intravenous pancreatic cancer therapeutic: Characterization of CRISPR/Cas9n-modified Clostridium novyi-Non Toxic. PLoS One 2023; 18:e0289183. [PMID: 37963142 PMCID: PMC10645340 DOI: 10.1371/journal.pone.0289183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 07/12/2023] [Indexed: 11/16/2023] Open
Abstract
Clostridium novyi has demonstrated selective efficacy against solid tumors largely due to the microenvironment contained within dense tumor cores. The core of a solid tumor is typically hypoxic, acidic, and necrotic-impeding the penetration of current therapeutics. C. novyi is attracted to the tumor microenvironment and once there, can both lyse and proliferate while simultaneously re-activating the suppressed immune system. C. novyi systemic toxicity is easily mitigated by knocking out the phage DNA plasmid encoded alpha toxin resulting in C. novyi-NT; but, after intravenous injection spores are quickly cleared by phagocytosis before accomplishing significant tumor localization. C. novyi-NT could be designed to accomplish intravenous delivery with the potential to target all solid tumors and their metastases in a single dose. This study characterizes CRISPR/Cas9 modified C. novyi-NT to insert the gene for RGD, a tumor targeting peptide, expressed within the promoter region of a spore coat protein. Expression of the RGD peptide on the outer spore coat of C. novyi-NT indicates an increased capacity for tumor localization of C. novyi upon intravenous introduction based on the natural binding of RGD with the αvβ3 integrin commonly overexpressed on the epithelial tissue surrounding a tumor, and lead to immune stimulation.
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Affiliation(s)
- Kaitlin M. Dailey
- Eppley Institute for Research in Cancer, University of Nebraska Medical Center, Omaha, NE, United States of America
- Cell and Molecular Biology Program, North Dakota State University, Fargo, ND, United States of America
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, ND, United States of America
| | - James M. Small
- Department of Pathology and Microbiology, Rocky Vista University, Parker, CO, United States of America
| | - Jessica E. Pullan
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, ND, United States of America
- Department of Physical Science, Southern Utah University, Cedar City, UT, United States of America
| | - Seth Winfree
- Eppley Institute for Research in Cancer, University of Nebraska Medical Center, Omaha, NE, United States of America
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, United States of America
| | - Krysten E. Vance
- Eppley Institute for Research in Cancer, University of Nebraska Medical Center, Omaha, NE, United States of America
| | - Megan Orr
- Department of Statistics, North Dakota State University, Fargo, ND, United States of America
- Center for Diagnostics and Therapeutic Strategies in Pancreatic Cancer Biostatistics Core Facility, North Dakota State University, Fargo, ND, United States of America
| | - Sanku Mallik
- Cell and Molecular Biology Program, North Dakota State University, Fargo, ND, United States of America
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, ND, United States of America
| | - Kenneth W. Bayles
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, United States of America
| | - Michael A. Hollingsworth
- Eppley Institute for Research in Cancer, University of Nebraska Medical Center, Omaha, NE, United States of America
| | - Amanda E. Brooks
- Cell and Molecular Biology Program, North Dakota State University, Fargo, ND, United States of America
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, ND, United States of America
- Department of Research and Scholarly Activity, Rocky Vista University, Ivins, UT, United States of America
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3
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Roe JM, Seely K, Bussard CJ, Eischen Martin E, Mouw EG, Bayles KW, Hollingsworth MA, Brooks AE, Dailey KM. Hacking the Immune Response to Solid Tumors: Harnessing the Anti-Cancer Capacities of Oncolytic Bacteria. Pharmaceutics 2023; 15:2004. [PMID: 37514190 PMCID: PMC10384176 DOI: 10.3390/pharmaceutics15072004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 07/13/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023] Open
Abstract
Oncolytic bacteria are a classification of bacteria with a natural ability to specifically target solid tumors and, in the process, stimulate a potent immune response. Currently, these include species of Klebsiella, Listeria, Mycobacteria, Streptococcus/Serratia (Coley's Toxin), Proteus, Salmonella, and Clostridium. Advancements in techniques and methodology, including genetic engineering, create opportunities to "hijack" typical host-pathogen interactions and subsequently harness oncolytic capacities. Engineering, sometimes termed "domestication", of oncolytic bacterial species is especially beneficial when solid tumors are inaccessible or metastasize early in development. This review examines reported oncolytic bacteria-host immune interactions and details the known mechanisms of these interactions to the protein level. A synopsis of the presented membrane surface molecules that elicit particularly promising oncolytic capacities is paired with the stimulated localized and systemic immunogenic effects. In addition, oncolytic bacterial progression toward clinical translation through engineering efforts are discussed, with thorough attention given to strains that have accomplished Phase III clinical trial initiation. In addition to therapeutic mitigation after the tumor has formed, some bacterial species, referred to as "prophylactic", may even be able to prevent or "derail" tumor formation through anti-inflammatory capabilities. These promising species and their particularly favorable characteristics are summarized as well. A complete understanding of the bacteria-host interaction will likely be necessary to assess anti-cancer capacities and unlock the full cancer therapeutic potential of oncolytic bacteria.
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Affiliation(s)
- Jason M Roe
- College of Osteopathic Medicine, Rocky Vista University, Ivins, UT 84738, USA
| | - Kevin Seely
- College of Osteopathic Medicine, Rocky Vista University, Ivins, UT 84738, USA
| | - Caleb J Bussard
- College of Osteopathic Medicine, Rocky Vista University, Parker, CO 80130, USA
| | | | - Elizabeth G Mouw
- College of Osteopathic Medicine, Rocky Vista University, Ivins, UT 84738, USA
| | - Kenneth W Bayles
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Michael A Hollingsworth
- Eppley Institute for Cancer Research, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Amanda E Brooks
- College of Osteopathic Medicine, Rocky Vista University, Ivins, UT 84738, USA
- College of Osteopathic Medicine, Rocky Vista University, Parker, CO 80130, USA
- Office of Research & Scholarly Activity, Rocky Vista University, Ivins, UT 84738, USA
| | - Kaitlin M Dailey
- Eppley Institute for Cancer Research, University of Nebraska Medical Center, Omaha, NE 68198, USA
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Architecture and Self-Assembly of Clostridium sporogenes and Clostridium botulinum Spore Surfaces Illustrate a General Protective Strategy across Spore Formers. mSphere 2020; 5:5/4/e00424-20. [PMID: 32611700 PMCID: PMC7333573 DOI: 10.1128/msphere.00424-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacteria such as those causing botulism and anthrax survive harsh conditions and spread disease as spores. Distantly related species have similar spore architectures with protective proteinaceous layers aiding adhesion and targeting. The structures that confer these common properties are largely unstudied, and the proteins involved can be very dissimilar in sequence. We identify CsxA as a cysteine-rich protein that self-assembles in a two-dimensional lattice enveloping the spores of several Clostridium species. We show that apparently unrelated cysteine-rich proteins from very different species can self-assemble to form remarkably similar and robust structures. We propose that diverse cysteine-rich proteins identified in the genomes of a broad range of spore formers may adopt a similar strategy for assembly. Spores, the infectious agents of many Firmicutes, are remarkably resilient cell forms. Even distant relatives can have similar spore architectures although some display unique features; they all incorporate protective proteinaceous envelopes. We previously found that Bacillus spores can achieve these protective properties through extensive disulfide cross-linking of self-assembled arrays of cysteine-rich proteins. We predicted that this could be a mechanism employed by spore formers in general, even those from other genera. Here, we tested this by revealing in nanometer detail how the outer envelope (exosporium) in Clostridium sporogenes (surrogate for C. botulinum group I), and in other clostridial relatives, forms a hexagonally symmetric semipermeable array. A cysteine-rich protein, CsxA, when expressed in Escherichia coli, self-assembles into a highly thermally stable structure identical to that of the native exosporium. Like the exosporium, CsxA arrays require harsh “reducing” conditions for disassembly. We conclude that in vivo, CsxA self-organizes into a highly resilient, disulfide cross-linked array decorated with additional protein appendages enveloping the forespore. This pattern is remarkably similar to that in Bacillus spores, despite a lack of protein homology. In both cases, intracellular disulfide formation is favored by the high lattice symmetry. We have identified cysteine-rich proteins in many distantly related spore formers and propose that they may adopt a similar strategy for intracellular assembly of robust protective structures. IMPORTANCE Bacteria such as those causing botulism and anthrax survive harsh conditions and spread disease as spores. Distantly related species have similar spore architectures with protective proteinaceous layers aiding adhesion and targeting. The structures that confer these common properties are largely unstudied, and the proteins involved can be very dissimilar in sequence. We identify CsxA as a cysteine-rich protein that self-assembles in a two-dimensional lattice enveloping the spores of several Clostridium species. We show that apparently unrelated cysteine-rich proteins from very different species can self-assemble to form remarkably similar and robust structures. We propose that diverse cysteine-rich proteins identified in the genomes of a broad range of spore formers may adopt a similar strategy for assembly.
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da Silva WL, Yang KT, Pettis GS, Soares NR, Giorno R, Clark CA. Flooding-Associated Soft Rot of Sweetpotato Storage Roots Caused by Distinct Clostridium Isolates. PLANT DISEASE 2019; 103:3050-3056. [PMID: 31642734 DOI: 10.1094/pdis-03-19-0548-re] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Flooding of sweetpotatoes in the field leads to development of soft rot on the storage roots while they remain submerged or on subsequent harvest and storage. Incidences of flooding after periods of intense rainy weather are on the rise in the southeastern United States, which is home to the majority of sweetpotato production in the nation. In an effort to characterize the causative agent(s) of this devastating disease, here we describe two distinct bacterial strains isolated from soft-rotted sweetpotato storage roots retrieved from an intentionally flooded field. Both of these anaerobic spore-forming isolates were identified as members of the genus Clostridium based on sequence similarity of multiple housekeeping genes, and both were confirmed to cause soft rot disease on sweetpotato and other vegetable crops. Despite these common features, the isolates were distinguishable by several phenotypic and biochemical properties, and phylogenetic analysis placed them in separate well-supported clades within the genus. Overall, our results demonstrate that multiple plant-pathogenic Clostridium species can cause soft rot disease on sweetpotato and suggest that a variety of other plant hosts may also be susceptible.
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Affiliation(s)
- Washington L da Silva
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA 70803
- The Connecticut Agricultural Experiment Station, Department of Plant Pathology and Ecology, New Haven, CT 06511
| | - Kuei-Ting Yang
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803
| | - Gregg S Pettis
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA 70803
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803
| | - Natasha R Soares
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803
| | - Rebecca Giorno
- School of Biological Sciences, Louisiana Tech University, Ruston, LA 71272
| | - Christopher A Clark
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA 70803
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Ji J, Park WR, Cho S, Yang Y, Li W, Harris K, Huang X, Gu S, Kim DH, Zhang Z, Larson AC. Iron-Oxide Nanocluster Labeling of Clostridium novyi-NT Spores for MR Imaging-Monitored Locoregional Delivery to Liver Tumors in Rat and Rabbit Models. J Vasc Interv Radiol 2019; 30:1106-1115.e1. [PMID: 30952520 DOI: 10.1016/j.jvir.2018.11.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 11/05/2018] [Accepted: 11/06/2018] [Indexed: 02/06/2023] Open
Abstract
PURPOSE To label Clostridium novyi-NT spores (C. novyi-NT) with iron oxide nanoclusters and track distribution of bacteria during magnetic resonance (MR) imaging-monitored locoregional delivery to liver tumors using intratumoral injection or intra-arterial transcatheter infusion. MATERIALS AND METHODS Vegetative state C. novyi-NT were labeled with iron oxide particles followed by induction of sporulation. Labeling was confirmed with fluorescence microscopy and transmission electron microscopy (TEM). T2 and T2* relaxation times for magnetic clusters and magnetic microspheres were determined using 7T and 1.5T MR imaging scanners. In vitro assays compared labeled bacteria viability and oncolytic potential to unlabeled controls. Labeled spores were either directly injected into N1-S1 rodent liver tumors (n = 24) or selectively infused via the hepatic artery in rabbits with VX2 liver tumors (n = 3). Hematoxylin-eosin, Prussian blue, and gram staining were performed. Statistical comparison methods included paired t-test and ANOVA. RESULTS Both fluorescence microscopy and TEM studies confirmed presence of iron oxide labels within the bacterial spores. Phantom studies demonstrated that the synthesized nanoclusters produce R2 relaxivities comparable to clinical agents. Labeling had no significant impact on overall growth or oncolytic properties (P >.05). Tumor signal-to-noise ratio (SNR) decreased significantly following intratumoral injection and intra-arterial infusion of labeled spores (P <.05). Prussian blue and gram staining confirmed spore delivery. CONCLUSIONS C. novyi-NT spores can be internally labeled with iron oxide nanoparticles to visualize distribution with MR imaging during locoregional bacteriolytic therapy involving direct injection or intra-arterial transcatheter infusion.
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Affiliation(s)
- Jingran Ji
- Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Woo Ram Park
- Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Soojeong Cho
- Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Yihe Yang
- Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Weiguo Li
- Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Kathleen Harris
- Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Xiaoke Huang
- Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Shangzhi Gu
- Department of Interventional Radiology, Hunan Cancer Hospital, Hunan, China
| | - Dong-Hyun Kim
- Department of Radiology, Northwestern University, Chicago, Illinois
| | - Zhuoli Zhang
- Department of Radiology, Northwestern University, Chicago, Illinois
| | - Andrew C Larson
- Department of Radiology, Northwestern University, Chicago, Illinois.
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Structural Characterization of Clostridium sordellii Spores of Diverse Human, Animal, and Environmental Origin and Comparison to Clostridium difficile Spores. mSphere 2017; 2:mSphere00343-17. [PMID: 28989969 PMCID: PMC5628289 DOI: 10.1128/msphere.00343-17] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 09/13/2017] [Indexed: 01/26/2023] Open
Abstract
Clostridium sordellii is a significant pathogen with mortality rates approaching 100%. It is the bacterial spore that is critical in initiating infection and disease. An understanding of spore structures as well as spore morphology across a range of strains may lead to a better understanding of C. sordellii infection and disease. However, the structural characteristics of the C. sordellii spores are limited. In this work, we have addressed this lack of detail and characterized the C. sordellii spore morphology. The use of traditional and advanced microscopy techniques has provided detailed new observations of C. sordellii spore structural features, which serve as a reference point for structural studies of spores from other bacterial species. Clostridium sordellii is an often-lethal bacterium causing human and animal disease. Crucial to the infectious cycle of C. sordellii is its ability to produce spores, which can germinate into toxin-producing vegetative bacteria under favorable conditions. However, structural details of the C. sordellii spore are lacking. Here, we used a range of electron microscopy techniques together with superresolution optical microscopy to characterize the C. sordellii spore morphology with an emphasis on the exosporium. The C. sordellii spore is made up of multiple layers with the exosporium presenting as a smooth balloon-like structure that is open at the spore poles. Focusing on the outer spore layers, we compared the morphologies of C. sordellii spores derived from different strains and determined that there is some variation between the spores, most notably with spores of some strains having tubular appendages. Since Clostridium difficile is a close relative of C. sordellii, their spores were compared by electron microscopy and their exosporia were found to be distinctly different from each other. This study therefore provides new structural details of the C. sordellii spore and offers insights into the physical structure of the exosporium across clostridial species. IMPORTANCEClostridium sordellii is a significant pathogen with mortality rates approaching 100%. It is the bacterial spore that is critical in initiating infection and disease. An understanding of spore structures as well as spore morphology across a range of strains may lead to a better understanding of C. sordellii infection and disease. However, the structural characteristics of the C. sordellii spores are limited. In this work, we have addressed this lack of detail and characterized the C. sordellii spore morphology. The use of traditional and advanced microscopy techniques has provided detailed new observations of C. sordellii spore structural features, which serve as a reference point for structural studies of spores from other bacterial species.
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Park W, Cho S, Huang X, Larson AC, Kim DH. Branched Gold Nanoparticle Coating of Clostridium novyi-NT Spores for CT-Guided Intratumoral Injection. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2017; 13:10.1002/smll.201602722. [PMID: 27862936 PMCID: PMC5288294 DOI: 10.1002/smll.201602722] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 09/26/2016] [Indexed: 05/03/2023]
Abstract
Branched gold nanoparticle (BGNP)-coated Clostridium novyi-NT (C. novyi-NT) spores are developed for computed tomography (CT)-guided bacteriolytic tumor therapy. The BGNP-coated spores are successfully injected into a tumor site under CT image guidance. As a result, a strong antitumor effect is observed in a PC3 prostate tumor-bearing mouse model.
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Affiliation(s)
- Wooram Park
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Soojeong Cho
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Xiaoke Huang
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Andrew C Larson
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
- Robert H. Lurie Comprehensive Cancer Center, Chicago, IL, 60611, USA
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, 60208, USA
- Department of Electrical Engineering and Computer Science, Northwestern University, Evanston, IL, 60208, USA
- International Institute of Nanotechnology (IIN), Northwestern University, Evanston, IL, 60208, USA
| | - Dong-Hyun Kim
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
- Robert H. Lurie Comprehensive Cancer Center, Chicago, IL, 60611, USA
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Nanomechanical Characterization of Bacillus anthracis Spores by Atomic Force Microscopy. Appl Environ Microbiol 2016; 82:2988-2999. [PMID: 26969703 DOI: 10.1128/aem.00431-16] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 03/04/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The study of structures and properties of bacterial spores is important to understanding spore formation and biological responses to environmental stresses. While significant progress has been made over the years in elucidating the multilayer architecture of spores, the mechanical properties of the spore interior are not known. Here, we present a thermal atomic force microscopy (AFM) study of the nanomechanical properties of internal structures of Bacillus anthracis spores. We developed a nanosurgical sectioning method in which a stiff diamond AFM tip was used to cut an individual spore, exposing its internal structure, and a soft AFM tip was used to image and characterize the spore interior on the nanometer scale. We observed that the elastic modulus and adhesion force, including their thermal responses at elevated temperatures, varied significantly in different regions of the spore section. Our AFM images indicated that the peptidoglycan (PG) cortex of Bacillus anthracis spores consisted of rod-like nanometer-sized structures that are oriented in the direction perpendicular to the spore surface. Our findings may shed light on the spore architecture and properties. IMPORTANCE A nanosurgical AFM method was developed that can be used to probe the structure and properties of the spore interior. The previously unknown ultrastructure of the PG cortex of Bacillus anthracis spores was observed to consist of nanometer-sized rod-like structures that are oriented in the direction perpendicular to the spore surface. The variations in the nanomechanical properties of the spore section were largely correlated with its chemical composition. Different components of the spore materials showed different thermal responses at elevated temperatures.
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Staedtke V, Roberts NJ, Bai RY, Zhou S. Clostridium novyi-NT in cancer therapy. Genes Dis 2016; 3:144-152. [PMID: 30258882 PMCID: PMC6150096 DOI: 10.1016/j.gendis.2016.01.003] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 01/25/2016] [Indexed: 12/22/2022] Open
Abstract
The attenuated anaerobic bacterium Clostridium novyi-NT (C. novyi-NT) is known for its ability to precisely germinate in and eradicate treatment-resistant hypoxic tumors in various experimental animal models and spontaneously occurring canine sarcomas. In this article, we review the therapeutic and toxicologic aspects of C. novyi-NT therapy, key challenges and limitations, and promising strategies to optimize its performance via recombinant DNA technology and immunotherapeutic approaches, to establish C. novyi-NT as an essential tool in cancer therapy.
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Affiliation(s)
- Verena Staedtke
- Ludwig Center for Cancer Genetics and Therapeutics, The Johns Hopkins Sidney Kimmel Cancer Center, Baltimore, MD 21287, USA.,Department of Neurology, The Johns Hopkins Medical Institutes, Baltimore, MD 21231, USA
| | - Nicholas J Roberts
- Ludwig Center for Cancer Genetics and Therapeutics, The Johns Hopkins Sidney Kimmel Cancer Center, Baltimore, MD 21287, USA.,Department of Pathology, Sol Goldman Pancreatic Cancer Research Center, Johns Hopkins Medical Institutions, Baltimore, MD 21231, USA
| | - Ren-Yuan Bai
- Department of Neurosurgery, The Johns Hopkins Medical Institutes, Baltimore, MD 21231, USA
| | - Shibin Zhou
- Ludwig Center for Cancer Genetics and Therapeutics, The Johns Hopkins Sidney Kimmel Cancer Center, Baltimore, MD 21287, USA
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El Jaam O, Fliss I, Aider M. Application of electro-activated potassium acetate and potassium citrate solutions combined with moderate heat treatment on the inactivation of Clostridium sporogenes PA 3679 spores. INNOV FOOD SCI EMERG 2016. [DOI: 10.1016/j.ifset.2015.11.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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13
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Formosa C, Dague E. Imaging Living Yeast Cells and Quantifying Their Biophysical Properties by Atomic Force Microscopy. Fungal Biol 2015. [DOI: 10.1007/978-3-319-22437-4_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
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Doona CJ, Feeherry FE, Kustin K, Olinger GG, Setlow P, Malkin AJ, Leighton T. Fighting Ebola with novel spore decontamination technologies for the military. Front Microbiol 2015; 6:663. [PMID: 26322021 PMCID: PMC4533522 DOI: 10.3389/fmicb.2015.00663] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 06/17/2015] [Indexed: 11/13/2022] Open
Abstract
Recently, global public health organizations such as Doctors without Borders (MSF), the World Health Organization (WHO), Public Health Canada, National Institutes of Health (NIH), and the U.S. government developed and deployed Field Decontamination Kits (FDKs), a novel, lightweight, compact, reusable decontamination technology to sterilize Ebola-contaminated medical devices at remote clinical sites lacking infra-structure in crisis-stricken regions of West Africa (medical waste materials are placed in bags and burned). The basis for effectuating sterilization with FDKs is chlorine dioxide (ClO2) produced from a patented invention developed by researchers at the US Army Natick Soldier RD&E Center (NSRDEC) and commercialized as a dry mixed-chemical for bacterial spore decontamination. In fact, the NSRDEC research scientists developed an ensemble of ClO2 technologies designed for different applications in decontaminating fresh produce; food contact and handling surfaces; personal protective equipment; textiles used in clothing, uniforms, tents, and shelters; graywater recycling; airplanes; surgical instruments; and hard surfaces in latrines, laundries, and deployable medical facilities. These examples demonstrate the far-reaching impact, adaptability, and versatility of these innovative technologies. We present herein the unique attributes of NSRDEC's novel decontamination technologies and a Case Study of the development of FDKs that were deployed in West Africa by international public health organizations to sterilize Ebola-contaminated medical equipment. FDKs use bacterial spores as indicators of sterility. We review the properties and structures of spores and the mechanisms of bacterial spore inactivation by ClO2. We also review mechanisms of bacterial spore inactivation by novel, emerging, and established non-thermal technologies for food preservation, such as high pressure processing, irradiation, cold plasma, and chemical sanitizers, using an array of Bacillus subtilis mutants to probe mechanisms of spore germination and inactivation. We employ techniques of high-resolution atomic force microscopy and phase contrast microscopy to examine the effects of γ-irradiation on bacterial spores of Bacillus anthracis, Bacillus thuringiensis, and Bacillus atrophaeus spp. and of ClO2 on B. subtilis spores, and present in detail assays using spore bio-indicators to ensure sterility when decontaminating with ClO2.
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Affiliation(s)
- Christopher J Doona
- U.S. Army Natick - Soldier RD&E Center, Warfighter Directorate, Natick, MA USA
| | - Florence E Feeherry
- U.S. Army Natick - Soldier RD&E Center, Warfighter Directorate, Natick, MA USA
| | - Kenneth Kustin
- Department of Chemistry, Emeritus, Brandeis University, Waltham, MA USA
| | - Gene G Olinger
- National Institute of Allergy and Infectious Diseases, Integrated Research Facility - Division of Clinical Research, Fort Detrick, MD USA
| | - Peter Setlow
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT USA
| | - Alexander J Malkin
- Biosciences and Biotechnology Division, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA USA
| | - Terrance Leighton
- Children's Hospital - Oakland Research Institute, University of California San Francisco - Benioff, Oakland, CA USA
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15
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Apertures in the Clostridium sporogenes spore coat and exosporium align to facilitate emergence of the vegetative cell. Food Microbiol 2015; 51:45-50. [PMID: 26187826 PMCID: PMC4521118 DOI: 10.1016/j.fm.2015.04.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 03/24/2015] [Accepted: 04/28/2015] [Indexed: 11/23/2022]
Abstract
Clostridium sporogenes forms highly heat resistant endospores, enabling this bacterium to survive adverse conditions. Subsequently, spores may germinate, giving rise to vegetative cells that multiply and lead to food spoilage. Electron microscopy was used to visualise changes in spore structures during germination, emergence and outgrowth. C. sporogenes spores were surrounded by an exosporium that was oval in shape and typically 3 μm in length. An aperture of 0.3–0.4 μm was observed at one end of the exosporium. The rupture of the spore coats occurs adjacent to the opening in the exosporium. The germinated cell emerges through this hole in the spore coat and then through the pre-existing aperture in the exosporium, before eventually being released, leaving behind a largely intact exosporium with an enlarged aperture (0.7–1.0 μm) and coat shell. The formation of this aperture, its function and its alignment with the spore coat is discussed. Electron microscopy was used to study structures of Clostridium sporogenes spores. Spore exosporia possessed either a terminal aperture or a lipped protrusion. Cells emerged through the preformed aperture or sporiduct of the spore. Apertures in the spore coat and exosporium were aligned, and may be predetermined.
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16
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Zheng L, Zhang Z, Khazaie K, Saha S, Lewandowski RJ, Zhang G, Larson AC. MRI-monitored intra-tumoral injection of iron-oxide labeled Clostridium novyi-NT anaerobes in pancreatic carcinoma mouse model. PLoS One 2014; 9:e116204. [PMID: 25549324 PMCID: PMC4280207 DOI: 10.1371/journal.pone.0116204] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 12/07/2014] [Indexed: 01/26/2023] Open
Abstract
OBJECTIVES To validate the feasibility of labeling Clostridium novyi-NT (C.novyi-NT) anaerobes with iron-oxide nanoparticles for magnetic resonance imaging (MRI) and demonstrate the potential to use MRI to visualize intra-tumoral delivery of these iron-oxide labeled C.novyi-NT during percutaneous injection procedures. MATERIALS AND METHODS All studies were approved by IACUC. C.novyi-NT were labeled with hybrid iron-oxide Texas red nanoparticles. Growth of labeled and control samples were evaluated with optical density. Labeling was confirmed with confocal fluorescence and transmission electron microscopy (TEM). MRI were performed using a 7 Tesla scanner with T2*-weighted (T2*W) sequence. Contrast-to-noise ratio (CNR) measurements were performed for phantoms and signal-to-noise ratio (SNR) measurements performed in C57BL/6 mice (n = 12) with Panc02 xenografts before and after percutaneous injection of iron-oxide labeled C.novyi-NT. MRI was repeated 3 and 7 days post-injection. Hematoxylin-eosin (HE), Prussian blue and Gram staining of tumor specimens were performed for confirmation of intra-tumoral delivery. RESULTS Iron-oxide labeling had no influence upon C.novyi-NT growth. The signal intensity (SI) within T2*W images was significantly decreased for iron-oxide labeled C.novyi-NT phantoms compared to unlabeled controls. Under confocal fluorescence microscopy, the iron-oxide labeled C.novyi-NT exhibited a uniform red fluorescence consistent with observed regions of DAPI staining and overall labeling efficiency was 100% (all DAPI stained C.novyi-NT exhibited red fluorescence). Within TEM images, a large number iron granules were observed within the iron-oxide labeled C.novyi-NT; these were not observed within unlabeled controls. Intra-procedural MRI measurements permitted in vivo visualization of the intra-tumoral distribution of iron-oxide labeled C.novyi-NT following percutaneous injection (depicted as punctate regions of SI reductions within T2*-weighted images); tumor SNR decreased significantly following intra-tumoral injection of C.novyi-NT (p<0.05); these SNR reductions were maintained at 3 and 7 day follow-up intervals. Prussian blue and Gram staining confirmed presence of the iron-oxide labeled anaerobes. CONCLUSIONS C.novyi-NT can be labeled with iron-oxide nanoparticles for MRI visualization of intra-tumoral deposition following percutaneous injection during bacteriolytic therapy.
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Affiliation(s)
- Linfeng Zheng
- Department of Radiology, First People’s Hospital, Shanghai Jiaotong University, Shanghai, China
- Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
| | - Zhuoli Zhang
- Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
- Robert H. Lurie Comprehensive Cancer Center, Chicago, Illinois, United States of America
| | - Khashayarsha Khazaie
- Department of Immunology, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Saurabh Saha
- BioMed Valley Discoveries, Kansas City, Missouri, United States of America
| | - Robert J. Lewandowski
- Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
| | - Guixiang Zhang
- Department of Radiology, First People’s Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Andrew C. Larson
- Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
- Robert H. Lurie Comprehensive Cancer Center, Chicago, Illinois, United States of America
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17
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Rusciano G, Zito G, Isticato R, Sirec T, Ricca E, Bailo E, Sasso A. Nanoscale chemical imaging of Bacillus subtilis spores by combining tip-enhanced Raman scattering and advanced statistical tools. ACS NANO 2014; 8:12300-12309. [PMID: 25415422 DOI: 10.1021/nn504595k] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Tip-enhanced Raman Scattering (TERS) has recently emerged as a powerful spectroscopic technique capable of providing subdiffraction morphological and chemical information on samples. In this work, we apply TERS spectroscopy for surface analysis of the Bacillus subtilis spore, a very attractive biosystem for a wide range of applications regulated by the spore surface properties. The observed spectra reflect the complex and heterogeneous environment explored by the plasmonic tip, therefore exhibiting significant point-to-point variations at the nanoscale. Herein, we demonstrate that TERS data processing via principal component analysis allows handling such spectral changes, thus enabling an unbiased correlative imaging based on TERS. Our experimental outcomes suggest a denser arrangement of both proteins and carbohydrates on specific spore surface regions simultaneously revealed by AFM phase imaging. Successful TERS analysis of spores' surface is useful for bacterial surface-display systems and drug delivery applications.
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Affiliation(s)
- Giulia Rusciano
- Department of Physics and ‡Department of Biology, University of Naples Federico II , via Cintia, 80126-I Naples, Italy
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18
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Plomp M, Carroll AM, Setlow P, Malkin AJ. Architecture and assembly of the Bacillus subtilis spore coat. PLoS One 2014; 9:e108560. [PMID: 25259857 PMCID: PMC4178626 DOI: 10.1371/journal.pone.0108560] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 08/28/2014] [Indexed: 11/30/2022] Open
Abstract
Bacillus spores are encased in a multilayer, proteinaceous self-assembled coat structure that assists in protecting the bacterial genome from stresses and consists of at least 70 proteins. The elucidation of Bacillus spore coat assembly, architecture, and function is critical to determining mechanisms of spore pathogenesis, environmental resistance, immune response, and physicochemical properties. Recently, genetic, biochemical and microscopy methods have provided new insight into spore coat architecture, assembly, structure and function. However, detailed spore coat architecture and assembly, comprehensive understanding of the proteomic composition of coat layers, and specific roles of coat proteins in coat assembly and their precise localization within the coat remain in question. In this study, atomic force microscopy was used to probe the coat structure of Bacillus subtilis wild type and cotA, cotB, safA, cotH, cotO, cotE, gerE, and cotE gerE spores. This approach provided high-resolution visualization of the various spore coat structures, new insight into the function of specific coat proteins, and enabled the development of a detailed model of spore coat architecture. This model is consistent with a recently reported four-layer coat assembly and further adds several coat layers not reported previously. The coat is organized starting from the outside into an outermost amorphous (crust) layer, a rodlet layer, a honeycomb layer, a fibrous layer, a layer of “nanodot” particles, a multilayer assembly, and finally the undercoat/basement layer. We propose that the assembly of the previously unreported fibrous layer, which we link to the darkly stained outer coat seen by electron microscopy, and the nanodot layer are cotH- and cotE- dependent and cotE-specific respectively. We further propose that the inner coat multilayer structure is crystalline with its apparent two-dimensional (2D) nuclei being the first example of a non-mineral 2D nucleation crystallization pattern in a biological organism.
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Affiliation(s)
- Marco Plomp
- Biosciences and Biotechnology Division, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California, United States of America
| | - Alicia Monroe Carroll
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, Connecticut, United States of America
| | - Peter Setlow
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, Connecticut, United States of America
- * E-mail: (PS); (AJM)
| | - Alexander J. Malkin
- Biosciences and Biotechnology Division, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California, United States of America
- * E-mail: (PS); (AJM)
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19
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Abhyankar W, de Koning LJ, Brul S, de Koster CG. Spore proteomics: the past, present and the future. FEMS Microbiol Lett 2014; 358:137-44. [PMID: 25110127 DOI: 10.1111/1574-6968.12568] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 08/04/2014] [Accepted: 08/05/2014] [Indexed: 11/30/2022] Open
Abstract
Endospores are metabolically dormant, multi-layered cellular structures formed by Gram-positive bacteria belonging to the genera Bacillus, Clostridium and related organisms. Their external layers are composed of proteins which in part play a role in the resistance behaviour of spores to varied chemical and environmental assaults. Thus, protein analysis is of major interest in spore biology. Spore proteomic studies have been carried out previously but these studies have focused on the soluble coat protein fraction. Using gel-based techniques, protein identification and analysis were performed. Mass spectrometry-driven proteomics has opened new avenues to resolve in particular the insoluble part of the spore layer proteomes. Mass spectrometry-based qualitative and quantitative proteomics methods expand the knowledge about both the actual composition and the amount of proteins in their various layers. The techniques can also be used to study the integrity of the layers as well as spore biology in general. This notion is explored concisely in this mini-review.
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Affiliation(s)
- Wishwas Abhyankar
- Department of Mass Spectrometry of BioMacromolecules, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands; Department of Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
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20
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Liu G, Bettegowda C, Qiao Y, Staedtke V, Chan KWY, Bai R, Li Y, Riggins GJ, Kinzler KW, Bulte JWM, McMahon MT, Gilad AA, Vogelstein B, Zhou S, van Zijl PCM. Noninvasive imaging of infection after treatment with tumor-homing bacteria using Chemical Exchange Saturation Transfer (CEST) MRI. Magn Reson Med 2013; 70:1690-8. [PMID: 24123389 DOI: 10.1002/mrm.24955] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 08/12/2013] [Accepted: 08/22/2013] [Indexed: 12/27/2022]
Abstract
PURPOSE To develop a noninvasive MRI method for determining the germination and infection of tumor-homing bacteria in bacteriolytic cancer therapy using endogenous CEST contrast. METHODS The CEST parameters of the anaerobic gram-positive bacterium Clostridium novyi-NT (C. novyi-NT) were first characterized in vitro, then used to detect C. novyi-NT germination and infection in subcutaneous CT26 colorectal tumor-bearing mice (n = 6) after injection of 300 million bacterial spores. Lipopolysacharide (LPS) injected mice were used to exclude that the changes of CEST MRI were due to inflammation. RESULTS CEST contrast was observed over a broad frequency range for bacterial suspensions in vitro, with the maximum contrast around 2.6 ppm from the water resonance. No signal could be detected for bacterial spores, demonstrating the specificity for germination. In vivo, a significant elevation of CEST contrast was identified in C. novyi-NT infected tumors as compared to those before bacterial germination and infection (P < 0.05; n = 6). No significant change was observed in tumors with LPS-induced sterile inflammation (P > 0.05; n = 4). CONCLUSION Endogenous bacterial CEST contrast (bacCEST) can be used to monitor the germination and proliferation of the therapeutic bacterium C. novyi-NT without a need for exogenous cell labeling probes.
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Affiliation(s)
- Guanshu Liu
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA; Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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21
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Li AG, Xing Y, Burggraf LW. Thermal effects on surface structures and properties of Bacillus anthracis spores on nanometer scales. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:8343-8354. [PMID: 23742662 DOI: 10.1021/la400992q] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Bacterial spores, one of the hardiest forms of life known, can survive severe environmental stresses such as high temperature. Using thermal atomic force microscopy (AFM), we show that the surface structures and properties of Bacillus anthracis spores when exposed to elevated temperatures undergo substantial changes on nanometer scales. Thermal-blister-like nanostructures, which grow in size with increasing temperature, are formed on the spore surface when it is heated by a thermal tip. Although thermal damage to the spore surface is persistent upon cooling heat-treated spores to room temperature, thermal effects on surface properties of the spores are complex. The thermally induced nanostructures show a lower surface-tip adhesion and a higher modulus than the surrounding spore surface. The overall trend is for the adhesion to decrease with increasing temperature. However, the adhesion of heat-treated spores may be smaller than, equal to, or larger than that of untreated spores, depending upon the degree of surface damage induced by heat. Although the overall spore dimensions show few changes during and after heat treatment, the size of the spore substructures decreases significantly. In addition, we demonstrate a nanoscratch AFM method for imaging the subsurface structures of spores.
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Affiliation(s)
- Alex G Li
- Department of Engineering Physics, Air Force Institute of Technology, 2950 Hobson Way, Wright-Patterson AFB Ohio 45433-7765, United States.
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22
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Qiao Y, Huang X, Nimmagadda S, Bai R, Staedtke V, Foss CA, Cheong I, Holdhoff M, Kato Y, Pomper MG, Riggins GJ, Kinzler KW, Diaz LA, Vogelstein B, Zhou S. A robust approach to enhance tumor-selective accumulation of nanoparticles. Oncotarget 2011; 2:59-68. [PMID: 21378416 PMCID: PMC3069713 DOI: 10.18632/oncotarget.227] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
While nanoparticles have shown great promise as drug carriers in cancer therapy, their effectiveness is critically dependent on the structural characteristics of the tumor vasculature. Here we demonstrate that several agents capable of inducing vascular responses akin to those observed in inflammatory processes enhance the accumulation of nanoparticles in tumors. The vascular-active agents tested in this study included a bacterium, a pro-inflammatory cytokine, and microtubule-destabilizing drugs. Using radiolabeled nanoparticles, we show that such agents can increase the tumor to blood ratio of radioactivity by more than 20-fold compared to nanoparticles alone. Moreover, vascular-active agents dramatically improved the therapeutic effect of nanoparticles containing radioactive isotopes or chemotherapeutic agents. This resulted in cures of animals with subcutaneous tumors and significantly prolonged the survival of animals with orthotopic brain tumors. In principle, a variety of vascular-active agents and macromolecular anticancer formulations can be combined, which makes this approach broadly applicable and particularly suited for the treatment of patients who have failed standard therapies.
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Affiliation(s)
- Yuan Qiao
- The Ludwig Center for Cancer Genetics and Therapeutics, Howard Hughes Medical Institute and Sidney Kimmel Cancer Center at the Johns Hopkins Medical Institutions, Baltimore, Maryland 21231, USA
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23
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Andreeva N, Bassi D, Cappa F, Cocconcelli P, Parmigiani F, Ferrini G. Nanomechanical analysis of Clostridium tyrobutyricum spores. Micron 2010; 41:945-52. [DOI: 10.1016/j.micron.2010.07.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2010] [Revised: 07/12/2010] [Accepted: 07/12/2010] [Indexed: 10/19/2022]
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24
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Dupres V, Alsteens D, Andre G, Dufrêne YF. Microbial nanoscopy: a closer look at microbial cell surfaces. Trends Microbiol 2010; 18:397-405. [DOI: 10.1016/j.tim.2010.06.004] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2010] [Revised: 06/15/2010] [Accepted: 06/16/2010] [Indexed: 10/19/2022]
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25
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Bassi D, Cappa F, Cocconcelli PS. A combination of a SEM technique and X-ray microanalysis for studying the spore germination process of Clostridium tyrobutyricum. Res Microbiol 2009; 160:322-9. [DOI: 10.1016/j.resmic.2009.04.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2009] [Revised: 04/02/2009] [Accepted: 04/07/2009] [Indexed: 01/13/2023]
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26
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Abstract
At the cross-roads of nanoscience and microbiology, the nanoscale analysis of microbial cells using atomic force microscopy (AFM) is an exciting, rapidly evolving research field. Over the past decade, there has been tremendous progress in our use of AFM to observe membrane proteins and live cells at high resolution. Remarkable advances have also been made in applying force spectroscopy to manipulate single membrane proteins, to map surface properties and receptor sites on cells and to measure cellular interactions at the single-cell and single-molecule levels. In addition, recent developments in cantilever nanosensors have opened up new avenues for the label-free detection of microorganisms and bioanalytes.
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Affiliation(s)
- Yves F Dufrêne
- Unité de chimie des interfaces, Université catholique de Louvain, Croix du Sud 2/18, B-1348 Louvain-la-Neuve, Belgium.
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27
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Plomp M, Malkin AJ. Mapping of proteomic composition on the surfaces of bacillus spores by atomic force microscopy-based immunolabeling. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:403-409. [PMID: 19063625 DOI: 10.1021/la803129r] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Atomic force microscopy (AFM) provides a unique capability to image high-resolution architecture and structural dynamics of pathogens (e.g., viruses, bacteria, and bacterial spores) at near-molecular resolution in native conditions. Further development of atomic force microscopy to enable the correlation of pathogen protein surface structures with specific gene products is essential to understand the mechanisms of the pathogen life cycle. We applied an AFM-based immunolabeling technique for the proteomic mapping of macromolecular structures through the visualization of the binding of antibodies, conjugated with nanogold particles, to specific epitopes on Bacillus spore surfaces. This information is generated while simultaneously acquiring the surface morphology of the pathogen. The immunospecificity of this labeling method was established through the utilization of specific polyclonal and monoclonal antibodies that target spore coat and exosporium epitopes of Bacillus atrophaeus and Bacillus anthracis spores.
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Affiliation(s)
- Marco Plomp
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, L-233, Livermore, California 94551, USA
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28
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Abstract
Spores of Bacillus subtilis have a thick outer layer of relatively insoluble protein called the coat, which protects spores against a number of treatments and may also play roles in spore germination. However, elucidation of precise roles of the coat in spore properties has been hampered by the inability to prepare spores lacking all or most coat material. In this work, we show that spores of a strain with mutations in both the cotE and gerE genes, which encode proteins involved in coat assembly and expression of genes encoding coat proteins, respectively, lack most extractable coat protein as seen by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, as well as the great majority of the coat as seen by atomic force microscopy. However, the cotE gerE spores did retain a thin layer of insoluble coat material that was most easily seen by microscopy following digestion of these spores with lysozyme. These severely coat-deficient spores germinated relatively normally with nutrients and even better with dodecylamine but not with a 1:1 chelate of Ca(2+) and dipicolinic acid. These spores were also quite resistant to wet heat, to mechanical disruption, and to treatment with detergents at an elevated temperature and pH but were exquisitely sensitive to killing by sodium hypochlorite. These results provide new insight into the role of the coat layer in spore properties.
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29
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Protozoal digestion of coat-defective Bacillus subtilis spores produces "rinds" composed of insoluble coat protein. Appl Environ Microbiol 2008; 74:5875-81. [PMID: 18689521 DOI: 10.1128/aem.01228-08] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Bacillus subtilis spore coat is a multilayer, proteinaceous structure that consists of more than 50 proteins. Located on the surface of the spore, the coat provides resistance to potentially toxic molecules as well as to predation by the protozoan Tetrahymena thermophila. When coat-defective spores are fed to Tetrahymena, the spores are readily digested. However, a residue termed a "rind" that looks like coat material remains. As observed with a phase-contrast microscope, the rinds are spherical or hemispherical structures that appear to be devoid of internal contents. Atomic force microscopy and chemical analyses showed that (i) the rinds are composed of insoluble protein largely derived from both outer and inner spore coat layers, (ii) the amorphous layer of the outer coat is largely responsible for providing spore resistance to protozoal digestion, and (iii) the rinds and intact spores do not contain significant levels of silicon.
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Dittrich M, Luttge A. Microorganisms, mineral surfaces, and aquatic environments: learning from the past for future progress. GEOBIOLOGY 2008; 6:201-213. [PMID: 18459966 DOI: 10.1111/j.1472-4669.2008.00159.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The interactions between the geosphere and the biosphere are central questions in environmental and geological research. The relationship between bacteria and their environment is an important example of these interactions. By studying microbial communities in modern environments, it is possible to understand the underlying mechanisms that shape these environments and apply this knowledge to the rock record. Recently, new experimental and theoretical methods, ranging from nano- and biotechnology to mathematical and conceptual modelling, have come into play. Thus, new opportunities for interdisciplinary research in the field of geobiology have emerged. In this paper, we review aspects of state-of-the-art imaging and modelling techniques and propose a research concept linking the experimental and the theoretical approaches.
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Affiliation(s)
- M Dittrich
- Swiss Federal Institute of Aquatic Research, Eawag and Swiss Federal Institute of Technology, ETH, Seestrasse 79, 6047 Kastanienbaum, Switzerland.
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31
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Perspectives on microbes as oncogenic infectious agents and implications for breast cancer. Med Hypotheses 2008; 71:302-6. [PMID: 18445513 DOI: 10.1016/j.mehy.2008.02.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2008] [Revised: 02/05/2008] [Accepted: 02/08/2008] [Indexed: 01/13/2023]
Abstract
Cancer management is partly based on weighing risk factors attributed to noninfectious agents, human genes and epigenetic factors. Infectious disease causation has largely been restricted to genes directly responsible for causing cancer after sustaining damage i.e. oncogenes. Lately, evidence has emerged linking infectious agents to a number of chronic diseases. These studies have recognized the influence that acute, atypical, latent and chronic infections may play in tricking the immune system and affecting disease etiology. Similar evidence is emerging in model systems with respect to the role of infectious agents in gastrointestinal, liver and lung cancers. Although viruses have been found in association with breast cancer, skepticism remains about a role for other infectious agents, notably microbes in the disease etiology. Improved experimental designs employed in different cancer studies and a less rigid definition of infectious causation may aid in confirming or refuting a microbe-breast cancer connection. Cancer recurrence could potentially be minimized and treatment options further tailored on a case by case basis if microbes/microbial components/strain variants associated with breast cancer are identified; probiotics are employed to reduce treatment side-effects and if microbes could effectively be harnessed in immunotherapy.
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