1
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Mulder EJ, Moser B, Delgado J, Steinhardt RC, Esser-Kahn AP. Evidence of collective influence in innate sensing using fluidic force microscopy. Front Immunol 2024; 15:1340384. [PMID: 38322261 PMCID: PMC10844469 DOI: 10.3389/fimmu.2024.1340384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 01/05/2024] [Indexed: 02/08/2024] Open
Abstract
The innate immune system initiates early response to infection by sensing molecular patterns of infection through pattern-recognition receptors (PRRs). Previous work on PRR stimulation of macrophages revealed significant heterogeneity in single cell responses, suggesting the importance of individual macrophage stimulation. Current methods either isolate individual macrophages or stimulate a whole culture and measure individual readouts. We probed single cell NF-κB responses to localized stimuli within a naïve culture with Fluidic Force Microscopy (FluidFM). Individual cells stimulated in naïve culture were more sensitive compared to individual cells in uniformly stimulated cultures. In cluster stimulation, NF-κB activation decreased with increased cell density or decreased stimulation time. Our results support the growing body of evidence for cell-to-cell communication in macrophage activation, and limit potential mechanisms. Such a mechanism might be manipulated to tune macrophage sensitivity, and the density-dependent modulation of sensitivity to PRR signals could have relevance to biological situations where macrophage density increases.
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Affiliation(s)
| | | | | | | | - Aaron P. Esser-Kahn
- Esser-Kahn Lab, Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, United States
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2
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Yang H, Tel J. Engineering global and local signal generators for probing temporal and spatial cellular signaling dynamics. Front Bioeng Biotechnol 2023; 11:1239026. [PMID: 37790255 PMCID: PMC10543096 DOI: 10.3389/fbioe.2023.1239026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 08/16/2023] [Indexed: 10/05/2023] Open
Abstract
Cells constantly encounter a wide range of environmental signals and rely on their signaling pathways to initiate reliable responses. Understanding the underlying signaling mechanisms and cellular behaviors requires signal generators capable of providing diverse input signals to deliver to cell systems. Current research efforts are primarily focused on exploring cellular responses to global or local signals, which enable us to understand cellular signaling and behavior in distinct dimensions. This review presents recent advancements in global and local signal generators, highlighting their applications in studying temporal and spatial signaling activity. Global signals can be generated using microfluidic or photochemical approaches. Local signal sources can be created using living or artificial cells in combination with different control methods. We also address the strengths and limitations of each signal generator type, discussing challenges and potential extensions for future research. These approaches are expected to continue to facilitate on-going research to discover novel and intriguing cellular signaling mechanisms.
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Affiliation(s)
- Haowen Yang
- Laboratory of Immunoengineering, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands
- Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven, Netherlands
| | - Jurjen Tel
- Laboratory of Immunoengineering, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands
- Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven, Netherlands
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3
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Yang Y, Luo S, Huang J, Xiao Y, Fu Y, Liu W, Yin H. Photoactivation of Innate Immunity Receptor TLR8 in Live Mammalian Cells by Genetic Encoding of Photocaged Tyrosine. Chembiochem 2021; 23:e202100344. [PMID: 34460982 DOI: 10.1002/cbic.202100344] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 08/10/2021] [Indexed: 11/10/2022]
Abstract
The effectiveness of innate immune responses relies on an intricate balance between activation and regulation. TLR8, a member of the Toll-like receptor (TLR) family, plays a fundamental role in host defense by sensing viral single-stranded RNAs (ssRNAs). However, the molecular recognition and regulatory mechanism of TLR8 is not fully understood, especially in a whole-cell environment. Here, we engineer the first light-controllable TLR8 model by genetically encoding a photocaged tyrosine, NBY, into specific sites of TLR8. In the caged forms, the activity of TLR8 is masked but can be restored upon decaging by exposure to UV light. To explain the mechanism clearly, we divide the sites with light responsiveness into three groups. They can separately block the ligands that bind to the pockets of TLR8, change the interaction modes between two TLR8 protomers, and interfere with the interactions between TLR8 cytosolic domains with its downstream adaptor. Specifically, we use this chemical caging strategy to probe and evaluate the function of several tyrosine sites located at the interface of TLR8 homodimers with a previously unknown regulatory mode, which may provide a new strategy for TLR8 modulator development. Effects on downstream signaling pathways are monitored at the transcriptional and translational levels in various cell lines. By photoactivating specific cells within a larger population, this powerful tool can provide novel mechanistic insights, with potential in biotechnological and pharmaceutical applications.
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Affiliation(s)
- Yi Yang
- Department of Chemistry, School of Pharmaceutical Sciences, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, 100084, P. R. China
| | - Shuchen Luo
- Department of Chemistry, School of Pharmaceutical Sciences, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, 100084, P. R. China
| | - Jian Huang
- Department of Chemistry, School of Pharmaceutical Sciences, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, 100084, P. R. China
| | - Yu Xiao
- Department of Chemistry, School of Pharmaceutical Sciences, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, 100084, P. R. China.,Zhujiang Hospital, Laboratory of Medicine Center, Southern Medical University, Guangzhou, 510282, P. R. China
| | - Yixuan Fu
- Department of Chemistry, School of Pharmaceutical Sciences, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, 100084, P. R. China
| | - Wei Liu
- Department of Chemistry, School of Pharmaceutical Sciences, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, 100084, P. R. China
| | - Hang Yin
- Department of Chemistry, School of Pharmaceutical Sciences, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, 100084, P. R. China
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4
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Parasar B, Chang PV. Engineered Th17 Cell Differentiation Using a Photoactivatable Immune Modulator. J Am Chem Soc 2020; 142:18103-18108. [PMID: 32975936 PMCID: PMC11100974 DOI: 10.1021/jacs.0c07485] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
T helper 17 (Th17) cells, an important subset of CD4+ T cells, help to eliminate extracellular infectious pathogens that have invaded our tissues. Despite the critical roles of Th17 cells in immunity, how the immune system regulates the production and maintenance of this cell type remains poorly understood. In particular, the plasticity of these cells or their dynamic ability to trans-differentiate into other CD4+ T cell subsets remains mostly uncharacterized. Here, we report a synthetic immunology approach using a photoactivatable immune modulator (PIM) to increase Th17 cell differentiation on demand with spatial and temporal precision to help elucidate this important and dynamic process. In this chemical strategy, we developed a latent agonist that upon photochemical activation releases a small-molecule ligand that targets the aryl hydrocarbon receptor (AhR) and ultimately induces Th17 cell differentiation. We used this chemical tool to control AhR activation with spatiotemporal precision within cells and to modulate Th17 cell differentiation on demand using UV light illumination. We envision that this approach will enable an understanding of the dynamic functions and behaviors of Th17 cells in vivo during immune responses and in mouse models of inflammatory disease.
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5
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van de Graaff MJ, Oosenbrug T, Marqvorsen MHS, Nascimento CR, de Geus MAR, Manoury B, Ressing ME, van Kasteren SI. Conditionally Controlling Human TLR2 Activity via Trans-Cyclooctene Caged Ligands. Bioconjug Chem 2020; 31:1685-1692. [PMID: 32510940 PMCID: PMC7303972 DOI: 10.1021/acs.bioconjchem.0c00237] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
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Toll-like
receptors (TLRs) are key pathogen sensors of the immune
system. Their activation results in the production of cytokines, chemokines,
and costimulatory molecules that are crucial for innate and adaptive
immune responses. In recent years, specific (sub)-cellular location
and timing of TLR activation have emerged as parameters for defining
the signaling outcome and magnitude. To study the subtlety of this
signaling, we here report a new molecular tool to control the activation
of TLR2 via “click-to-release”-chemistry. We conjugated
a bioorthogonal trans-cyclooctene (TCO) protecting group via solid
support to a critical position within a synthetic TLR2/6 ligand to
render the compound unable to initiate signaling. The TCO-group could
then be conditionally removed upon addition of a tetrazine, resulting
in restored agonist activity and TLR2 activation. This approach was
validated on RAW264.7 macrophages and various murine primary immune
cells as well as human cell line systems, demonstrating that TCO-caging
constitutes a versatile approach for generating chemically controllable
TLR2 agonists.
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Affiliation(s)
- Michel J van de Graaff
- Department of Bio-Organic Synthesis, Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, Zuid-Holland, The Netherlands
| | - Timo Oosenbrug
- Department of Cell and Chemical Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, Zuid-Holland, The Netherlands
| | - Mikkel H S Marqvorsen
- Department of Bio-Organic Synthesis, Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, Zuid-Holland, The Netherlands
| | - Clarissa R Nascimento
- INEM, INSERM, Unité 1151-CNRS UMR 8253, Université de Paris, Faculté de Médecine, 156 Rue de Vaugirard, 75015 Paris, France
| | - Mark A R de Geus
- Department of Bio-Organic Synthesis, Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, Zuid-Holland, The Netherlands
| | - Bénédicte Manoury
- INEM, INSERM, Unité 1151-CNRS UMR 8253, Université de Paris, Faculté de Médecine, 156 Rue de Vaugirard, 75015 Paris, France
| | - Maaike E Ressing
- Department of Cell and Chemical Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, Zuid-Holland, The Netherlands
| | - Sander I van Kasteren
- Department of Bio-Organic Synthesis, Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, Zuid-Holland, The Netherlands
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6
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Salveson PJ, Haerianardakani S, Thuy-Boun A, Kreutzer AG, Nowick JS. Controlling the Oligomerization State of Aβ-Derived Peptides with Light. J Am Chem Soc 2018; 140:5842-5852. [PMID: 29627987 DOI: 10.1021/jacs.8b02658] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A key challenge in studying the biological and biophysical properties of amyloid-forming peptides is that they assemble to form heterogeneous mixtures of soluble oligomers and insoluble fibrils. Photolabile protecting groups have emerged as tools to control the properties of biomolecules with light. Blocking intermolecular hydrogen bonds that stabilize amyloid oligomers provides a general strategy to control the biological and biophysical properties of amyloid-forming peptides. In this paper we describe the design, synthesis, and characterization of macrocyclic β-hairpin peptides that are derived from amyloidogenic peptides and contain the N-2-nitrobenzyl photolabile protecting group. Each peptide contains two heptapeptide segments from Aβ16-36 or Aβ17-36 constrained into β-hairpins. The N-2-nitrobenzyl group is appended to the amide backbone of Gly33 to disrupt the oligomerization of the peptides by disrupting intermolecular hydrogen bonds. X-ray crystallography reveals that N-2-nitrobenzyl groups can either block assembly into discrete oligomers or permit formation of trimers, hexamers, and dodecamers. Photolysis of the N-2-nitrobenzyl groups with long-wave UV light unmasks the amide backbone and alters the assembly and the biological properties of the macrocyclic β-hairpin peptides. SDS-PAGE studies show that removing the N-2-nitrobenzyl groups alters the assembly of the peptides. MTT conversion and LDH release assays show that decaging the peptides induces cytotoxicity. Circular dichroism studies and dye leakage assays with liposomes reveal that decaging modulates interactions of the peptides with lipid bilayers. Collectively, these studies demonstrate that incorporating N-2-nitrobenzyl groups into macrocyclic β-hairpin peptides provides a new strategy to probe the structures and the biological properties of amyloid oligomers.
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Affiliation(s)
- Patrick J Salveson
- Department of Chemistry , University of California, Irvine , Irvine , California 92697-2025 , United States
| | - Sepehr Haerianardakani
- Department of Chemistry , University of California, Irvine , Irvine , California 92697-2025 , United States
| | - Alexander Thuy-Boun
- Department of Chemistry , University of California, Irvine , Irvine , California 92697-2025 , United States
| | - Adam G Kreutzer
- Department of Chemistry , University of California, Irvine , Irvine , California 92697-2025 , United States
| | - James S Nowick
- Department of Chemistry , University of California, Irvine , Irvine , California 92697-2025 , United States
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7
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Ignacio BJ, Albin TJ, Esser-Kahn AP, Verdoes M. Toll-like Receptor Agonist Conjugation: A Chemical Perspective. Bioconjug Chem 2018; 29:587-603. [PMID: 29378134 PMCID: PMC10642707 DOI: 10.1021/acs.bioconjchem.7b00808] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Toll-like receptors (TLRs) are vital elements of the mammalian immune system that function by recognizing pathogen-associated molecular patterns (PAMPs), bridging innate and adaptive immunity. They have become a prominent therapeutic target for the treatment of infectious diseases, cancer, and allergies, with many TLR agonists currently in clinical trials or approved as immunostimulants. Numerous studies have shown that conjugation of TLR agonists to other molecules can beneficially influence their potency, toxicity, pharmacokinetics, or function. The functional properties of TLR agonist conjugates, however, are highly dependent on the ligation strategy employed. Here, we review the chemical structural requirements for effective functional TLR agonist conjugation. In addition, we provide similar analysis for those that have yet to be conjugated. Moreover, we discuss applications of covalent TLR agonist conjugation and their implications for clinical use.
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Affiliation(s)
- Bob J. Ignacio
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Tyler J. Albin
- Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States
| | - Aaron P. Esser-Kahn
- Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States
- Institute for Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | - Martijn Verdoes
- Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
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8
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Oosenbrug T, van de Graaff MJ, Ressing ME, van Kasteren SI. Chemical Tools for Studying TLR Signaling Dynamics. Cell Chem Biol 2017. [PMID: 28648377 DOI: 10.1016/j.chembiol.2017.05.022] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The detection of infectious pathogens is essential for the induction of antimicrobial immune responses. The innate immune system detects a wide array of microbes using a limited set of pattern-recognition receptors (PRRs). One family of PRRs with a central role in innate immunity are the Toll-like receptors (TLRs). Upon ligation, these receptors initiate signaling pathways culminating in the release of pro-inflammatory cytokines and/or type I interferons (IFN-I). In recent years, it has become evident that the specific subcellular location and timing of TLR activation affect signaling outcome. The subtlety of this signaling has led to a growing demand for chemical tools that provide the ability to conditionally control TLR activation. In this review, we survey current models for TLR signaling in time and space, discuss how chemical tools have contributed to our understanding of TLR ligands, and describe how they can aid further elucidation of the dynamic aspects of TLR signaling.
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Affiliation(s)
- Timo Oosenbrug
- Department of Molecular Cell Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, Zuid-Holland, the Netherlands
| | - Michel J van de Graaff
- Department of Bio-organic Synthesis, Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, Zuid-Holland, the Netherlands
| | - Maaike E Ressing
- Department of Molecular Cell Biology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC Leiden, Zuid-Holland, the Netherlands.
| | - Sander I van Kasteren
- Department of Bio-organic Synthesis, Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, Zuid-Holland, the Netherlands.
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9
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Abstract
Although spatial and temporal elements of immune activation mediate the intensity of the immune response, few tools exist to directly examine these effects. To elucidate the spatiotemporal aspects of innate immune responses, we designed an optogenetic pattern recognition receptor that activates in response to blue light. We demonstrate direct receptor activation, leading to spatial and temporal control of downstream signaling pathways in a variety of relevant cell types. We combined our platform with Bi-molecular Fluorescence Complementation (BiFC), resulting in selective fluorescent labeling of cells in which receptor activation has occurred.
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Affiliation(s)
- Brittany A. Moser
- Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States
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10
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Ross AE, Belanger MC, Woodroof JF, Pompano RR. Spatially resolved microfluidic stimulation of lymphoid tissue ex vivo. Analyst 2017; 142:649-659. [PMID: 27900374 PMCID: PMC7863610 DOI: 10.1039/c6an02042a] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The lymph node is a structurally complex organ of the immune system, whose dynamic cellular arrangements are thought to control much of human health. Currently, no methods exist to precisely stimulate substructures within the lymph node or analyze local stimulus-response behaviors, making it difficult to rationally design therapies for inflammatory disease. Here we describe a novel integration of live lymph node slices with a microfluidic system for local stimulation. Slices maintained the cellular organization of the lymph node while making its core experimentally accessible. The 3-layer polydimethylsiloxane device consisted of a perfusion chamber stacked atop stimulation ports fed by underlying microfluidic channels. Fluorescent dextrans similar in size to common proteins, 40 and 70 kDa, were delivered to live lymph node slices with 284 ± 9 μm and 202 ± 15 μm spatial resolution, respectively, after 5 s, which is sufficient to target functional zones of the lymph node. The spread and quantity of stimulation were controlled by varying the flow rates of delivery; these were predictable using a computational model of isotropic diffusion and convection through the tissue. Delivery to two separate regions simultaneously was demonstrated, to mimic complex intercellular signaling. Delivery of a model therapeutic, glucose-conjugated albumin, to specific regions of the lymph node indicated that retention of the drug was greater in the B-cell zone than in the T-cell zone. Together, this work provides a novel platform, the lymph node slice-on-a-chip, to target and study local events in the lymph node and to inform the development of new immunotherapeutics.
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Affiliation(s)
- Ashley E Ross
- University of Virginia, Dept. of Chemistry, PO Box 400319, McCormick Rd, Charlottesville, VA 22904, USA.
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11
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Moser BA, Steinhardt RC, Esser-Kahn AP. Surface Coating of Nanoparticles Reduces Background Inflammatory Activity while Increasing Particle Uptake and Delivery. ACS Biomater Sci Eng 2017; 3:206-213. [PMID: 28936479 PMCID: PMC5604483 DOI: 10.1021/acsbiomaterials.6b00473] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In the study of host-pathogen interactions, vaccines and drug delivery, particulate delivery system are widely used to mimic pathogen size, pattern recognition receptor agonist presentation, and target cells or organs. However, some of the polymeric systems used in particulate delivery have inherent inflammatory properties that are variable and nonspecific. These properties enhance their adjuvant activity, but confound the analysis of signaling mechanisms. Here, we present a method for particle coating with minimal background immune activation via passivation of the surface with silica-silane. We show herein that a silica-silane shell passivates polymer particles rendering them inert to activation of innate immune cells. The method is broadly applicable and can be used to coat polymeric particles of many different compositions. This method of silica-silane coating also allows conjugation of amine-bearing agonists and provides for controlled variation of agonist loading. Finally, we demonstrate our particles maintain and enhance qualities of known pathogens, making this a potentially general method for improving immune agonist activity.
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Affiliation(s)
| | | | - Aaron P. Esser-Kahn
- Department of Chemistry, Chemical Engineering & Materials Science, Biomedical Engineering, University of California, Irvine, California 92697, United States
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