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Endosomal lysis

Loganathan Rangasamy, Venkatesh Chelvam, Ananda Kumar Kanduluru, Madduri Srinivasarao, Achini N Bandara, Fei You, Esteban Orellana, Andrea L Kasinski, Philip S Low
Although peptides, antibodies/antibody fragments, siRNAs, antisense DNAs, enzymes and aptamers are all under development as possible therapeutic agents, the breadth of their applications has been severely compromised by their inability to reach intracellular targets. Thus, while macromolecules can often enter cells by receptor-mediated endocytosis, their missions frequently fail due to an inability to escape their entrapping endosomes. In this paper, we describe a general method for promoting release of any biologic material from any entrapping endosome...
February 15, 2018: Bioconjugate Chemistry
Dominic W Malcolm, Jomy J Varghese, Janet E Sorrells, Catherine E Ovitt, Danielle S W Benoit
Nanoparticles (NPs) interact with complex protein milieus in biological fluids, and these interactions have profound effects on NP physicochemical properties and function. Surprisingly, most studies neglect the impact of these interactions, especially with respect to NP-mediated siRNA delivery. Here, the effects of serum on colloidal stability and siRNA delivery of a pH-responsive micellar NP delivery system were characterized. Results show cationic NP-siRNA complexes aggregate in ≥2% serum in buffer, but are stable in serum-free media...
January 23, 2018: ACS Nano
Sunil Kumar Dogga, Budhaditya Mukherjee, Damien Jacot, Tobias Kockmann, Luca Molino, Pierre-Mehdi Hammoudi, Ruben C Hartkoorn, Adrian B Hehl, Dominique Soldati-Favre
Micronemes and rhoptries are specialized secretory organelles that deploy their contents at the apical tip of apicomplexan parasites in a regulated manner. The secretory proteins participate in motility, invasion, and egress and are subjected to proteolytic maturation prior to organellar storage and discharge. Here we establish that Toxoplasma gondii aspartyl protease 3 (ASP3) resides in the endosomal-like compartment and is crucially associated to rhoptry discharge during invasion and to host cell plasma membrane lysis during egress...
September 12, 2017: ELife
Philipp Heller, Dominika Hobernik, Ulrich Lächelt, Meike Schinnerer, Benjamin Weber, Manfred Schmidt, Ernst Wagner, Matthias Bros, Matthias Barz
Therapeutic nucleic acids such as pDNA hold great promise for the treatment of multiple diseases. These therapeutic interventions are, however, compromised by the lack of efficient and safe non-viral delivery systems, which guarantee stability during blood circulation together with high transfection efficiency. To provide these desired properties within one system, we propose the use of reactive triblock copolypept(o)ides, which include a stealth-like block for efficient shielding, a hydrophobic block based on reactive disulfides for cross-linking and a cationic block for complexation of pDNA...
July 28, 2017: Journal of Controlled Release: Official Journal of the Controlled Release Society
Shi-Kun Zhang, Jin-Wen Song, Su-Bo Li, Hong-Wei Gao, Hong-Yu Chang, Li-Li Jia, Feng Gong, Ying-Xia Tan, Shou-Ping Ji
BACKGROUND: Poor endosomal release is a major barrier of polyplex-mediated gene transfection. Antimicrobial peptides (AMPs) are commonly used to improve polyethylenimine (PEI)-mediated gene transfection by increasing endosomal release. In the present study, we designed novel pH-sensitive peptides that highly enhance transfection efficiency compared to their parent peptides. METHODS: Two analogues of melittin (Mel) and RV-23 (RV) were synthesized by replacing the positively-charged residues in their sequences with glutamic acid residues...
May 2017: Journal of Gene Medicine
Zhan Yuin Ong, Chuan Yang, Wei Cheng, Zhi Xiang Voo, Willy Chin, James L Hedrick, Yi Yan Yang
The degree of hydrophobicity in cationic polymers plays an important but often underappreciated role in the safety and efficacy of gene delivery processes. In order to further elucidate structure-activity relationships of biodegradable cationic poly(carbonate) gene carriers, we synthesized a series of narrowly dispersed homo-polymers via metal-free organocatalytic living ring-opening polymerization (ROP) of cyclic carbonate monomers bearing either alkyl (propyl, hexyl or nonyl) or 4-methyl benzyl halide side chains...
March 18, 2017: Acta Biomaterialia
Charlotte Montespan, Shauna A Marvin, Sisley Austin, Andrew M Burrage, Benoit Roger, Fabienne Rayne, Muriel Faure, Edward M Campell, Carola Schneider, Rudolph Reimer, Kay Grünewald, Christopher M Wiethoff, Harald Wodrich
Cells employ active measures to restrict infection by pathogens, even prior to responses from the innate and humoral immune defenses. In this context selective autophagy is activated upon pathogen induced membrane rupture to sequester and deliver membrane fragments and their pathogen contents for lysosomal degradation. Adenoviruses, which breach the endosome upon entry, escape this fate by penetrating into the cytosol prior to autophagosome sequestration of the ruptured endosome. We show that virus induced membrane damage is recognized through Galectin-8 and sequesters the autophagy receptors NDP52 and p62...
February 2017: PLoS Pathogens
Bonggoo Park, Gayoung Park, Jiyoung Kim, Seon Ah Lim, Kyung-Mi Lee
Legionella pneumophila is an etiological agent of the severe pneumonia known as Legionnaires' disease (LD). This gram-negative bacterium is thought to replicate naturally in various freshwater amoebae, but also replicates in human alveolar macrophages. Inside host cells, legionella induce the production of non-endosomal replicative phagosomes by injecting effector proteins into the cytosol. Innate immune responses are first line defenses against legionella during early phases of infection, and distinguish between legionella and host cells using germline-encoded pattern recognition receptors such as Toll-like receptors , NOD-like receptors, and RIG-I-like receptors, which sense pathogen-associated molecular patterns that are absent in host cells...
February 2017: Archives of Pharmacal Research
Valérie Poirier, Yossef Av-Gay
The ability of intracellular pathogens to subvert the host response, to facilitate invasion and subsequent infection, is the hallmark of microbial pathogenesis. Bacterial pathogens produce and secrete a variety of effector proteins, which are the primary means by which they exert control over the host cell. Secreted effectors work independently, yet in concert with each other, to facilitate microbial invasion, replication, and intracellular survival in host cells. In this review we focus on defined host cell processes targeted by bacterial pathogens...
December 2015: Microbiology Spectrum
A Kashiwada, M Mizuno, J Hashimoto
We developed a membrane-lytic peptide (LP) having 26 amino acid residues composed of a helix-promoting hydrophobic segment (Leu-Ala repetitive sequence) and a cationic segment from melittin. In the presence of liposomes, LP interacts with liposomal surfaces to form a hydrophobic helix in the lipid bilayer in a wide pH range. In order to provide LP with a weakly acidic (endosomal) pH-controlled membrane-lytic activity, we have designed an LPE peptide series (a typical peptide, LPE3-1) with a hydrophobic segment in which Leu (L) residues are replaced by acidic Glu (E) residues...
July 14, 2016: Organic & Biomolecular Chemistry
Innocenzo Caruso, Salvatore Santandrea, Mariarita Gismondo, Alessandra Lombardi, Franco Montrone, Enzo Massimo Caruso, Piercarlo Sarzi Puttini
BACKGROUND: Our previous results showed that intrasynovial Rifamycin SV caused the lysis of synoviocites and freed the autoantigens which in turn stimulated the immunoregulatory rather than autoreactive T cell response in rheumatoid patients. Here, we hypothesize that disruption in vitro of peripheral blood mononuclear cells, by freeze/thawing or by lytic action of Rifamycin SV, would induce the release of endosomal pathogenic autoantigens from APCs present in the circulation, which could then be isolated from degrading enzymes by ultrafiltration...
June 7, 2016: Journal of Translational Medicine
Qixin Leng, A James Mixson
BACKGROUND: Promising plasmid-based treatments have limited value without an effective delivery system. Recently, the linear H2K with a repeating -KHHK- pattern was determined to be an effective plasmid carrier to tumor xenografts in vivo. Although unpacking of the H2K polyplex within the tumor may have a role, the mechanism for the enhanced efficacy remains unclear. METHODS: After solid-phase synthesis of linear and branched histidine-lysine (HK) peptide carriers of plasmids, the peptides were compared for their ability to lyse endosomes with a red blood cell model and to transfect MDA-MB-435 xenografts in the presence or absence of neuropilin-1 receptor (NRP-1) antibodies...
July 2016: Journal of Gene Medicine
Raphael Wolfisberg, Christoph Kempf, Carlos Ros
UNLABELLED: Although the mechanism is not well understood, growing evidence indicates that the nonenveloped parvovirus minute virus of mice (MVM) may actively egress before passive release through cell lysis. We have dissected the late maturation steps of the intranuclear progeny with the aims of confirming the existence of active prelytic egress and identifying critical capsid rearrangements required to initiate the process. By performing anion-exchange chromatography (AEX), we separated intranuclear progeny particles by their net surface charges...
June 1, 2016: Journal of Virology
Masashi Maekawa, Yanbo Yang, Gregory D Fairn
Cholesterol is an essential structural component of cellular membranes in eukaryotes. Cholesterol in the exofacial leaflet of the plasma membrane is thought to form membrane nanodomains with sphingolipids and specific proteins. Additionally, cholesterol is found in the intracellular membranes of endosomes and has crucial functions in membrane trafficking. Furthermore, cellular cholesterol homeostasis and regulation of de novo synthesis rely on transport via both vesicular and non-vesicular pathways. Thus, the ability to visualize and detect intracellular cholesterol, especially in the plasma membrane, is critical to understanding the complex biology associated with cholesterol and the nanodomains...
March 8, 2016: Toxins
Hiroshi Nakashima, Johanna K Kaufmann, Pin-Yi Wang, Tran Nguyen, Maria-Carmela Speranza, Kazue Kasai, Kazuo Okemoto, Akihiro Otsuki, Ichiro Nakano, Soledad Fernandez, William F Goins, Paola Grandi, Joseph C Glorioso, Sean Lawler, Timothy P Cripe, E Antonio Chiocca
Oncolytic viral (OV) therapy, which uses genetically engineered tumor-targeting viruses, is being increasingly used in cancer clinical trials due to the direct cytolytic effects of this treatment that appear to provoke a robust immune response against the tumor. As OVs enter tumor cells, intrinsic host defenses have the potential to hinder viral replication and spread within the tumor mass. In this report, we show that histone deacetylase 6 (HDAC6) in tumor cells appears to alter the trafficking of post-entry OVs from the nucleus toward lysosomes...
November 2, 2015: Journal of Clinical Investigation
Daniele R Nogueira, Laís E Scheeren, M Pilar Vinardell, Montserrat Mitjans, M Rosa Infante, Clarice M B Rolim
The pH-responsive delivery systems have brought new advances in the field of functional nanodevices and might allow more accurate and controllable delivery of specific cargoes, which is expected to result in promising applications in different clinical therapies. Here we describe a family of chitosan-TPP (tripolyphosphate) nanoparticles (NPs) for intracellular drug delivery, which were designed using two pH-sensitive amino acid-based surfactants from the family N(α),N(ε)-dioctanoyl lysine as bioactive compounds...
December 1, 2015: Materials Science & Engineering. C, Materials for Biological Applications
Špela Magister, Han-Ching Tseng, Vickie T Bui, Janko Kos, Anahid Jewett
Freshly isolated human primary NK cells induce preferential lysis of Oral Squamous Carcinoma Stem Cells (OSCSCs) when compared to differentiated Oral Squamous Carcinoma Cells (OSCCs), while anti-CD16 antibody and monocytes induce functional split anergy in primary NK cells by decreasing the cytotoxic function of NK cells and increasing the release of IFN-γ. Since NK92 cells have relatively lower levels of cytotoxicity when compared to primary NK cells, and have the ability to increase secretion of regulatory cytokines IL-10 and IL-6, we used these cells as a model of NK cell anergy to identify and to study the upstream regulators of anergy...
September 8, 2015: Oncotarget
Gareth L Evans, Laura G Caller, Victoria Foster, Colin M Crump
BK polyomavirus (BKPyV) is a member of a family of potentially oncogenic viruses, whose reactivation can cause severe pathological conditions in transplant patients, leading to graft rejection. As with many non-enveloped viruses, it is assumed that virus release occurs through lysis of the host cell. We now show the first evidence for a non-lytic release pathway for BKPyV and that this pathway can be blocked by the anion channel inhibitor DIDS. Our data show a dose-dependent effect of DIDS on the release of BKPyV virions...
August 2015: Open Biology
Jean-Mathieu Bart, Carlos Cordon-Obras, Isabel Vidal, Jennifer Reed, Esperanza Perez-Pastrana, Laureano Cuevas, Mark C Field, Mark Carrington, Miguel Navarro
African trypanosomes infect a broad range of mammals, but humans and some higher primates are protected by serum trypanosome lytic factors that contain apolipoprotein L1 (ApoL1). In the human-infective subspecies of Trypanosoma brucei, Trypanosoma brucei rhodesiense, a gene product derived from the variant surface glycoprotein gene family member, serum resistance-associated protein (SRA protein), protects against ApoL1-mediated lysis. Protection against trypanosome lytic factor requires the direct interaction between SRA protein and ApoL1 within the endocytic apparatus of the trypanosome, but some uncertainty remains as to the precise mechanism and location of this interaction...
October 2015: Cellular Microbiology
Russell Thomson, Alan Finkelstein
Apolipoprotein L-1 (APOL1), the trypanolytic factor of human serum, can lyse several African trypanosome species including Trypanosoma brucei brucei, but not the human-infective pathogens T. brucei rhodesiense and T. brucei gambiense, which are resistant to lysis by human serum. Lysis follows the uptake of APOL1 into acidic endosomes and is apparently caused by colloid-osmotic swelling due to an increased ion permeability of the plasma membrane. Here we demonstrate that nanogram quantities of full-length recombinant APOL1 induce ideally cation-selective macroscopic conductances in planar lipid bilayers...
March 3, 2015: Proceedings of the National Academy of Sciences of the United States of America
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