scholarly journals Preparation of serum capped silver nanoparticles for selective killing of microbial cells sparing host cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rehana Parveen ◽  
Prasanta Kumar Maiti ◽  
Nabendu Murmu ◽  
Alokmay Datta
Keyword(s):  
Silver Nanoparticles ◽  
Mammalian Cells ◽  
Vascular Endothelial Cells ◽  
Host Cells ◽  
Mice Model ◽  
Human Liver Cell ◽  
Wide Range ◽  
Stress Dependent

AbstractFollowing access into the cell, colloidal silver nanoparticles exhibit generalized cytotoxic properties, thus appear as omnipotent microbicidal, but not suitable for systemic use unless are free of toxic effects on host cells. The AgNP-Serum-18 when prepared from silver nitrate, using dextrose as reducing and group-matched homologous serum as a stabilizing agent, selective endocytosis, and oxidative stress-dependent bio-functional damages to the host are mostly eliminated. For their bio-mimicking outer coat, there is the least possibility of internalization into host cells or liberation of excess oxidants in circulation following interaction with erythrocytes or vascular endothelial cells. The presence of infection-specific antibodies in the serum can make such nano-conjugates more selective. A potent antimicrobial action and a wide margin of safety for mammalian cells in comparison with very similar PVA-capped silver nanoparticles have been demonstrated by the in-vitro challenge of such nanoparticles on different microbes, human liver cell-line, and in-vivo study on mice model. This may open up wide-range therapeutic prospects of colloidal nanoparticles.

scholarly journals Preparation of Serum Capped Silver Nanoparticles for Selective Killing of Microbial Cells Sparing Host Cells

2021 ◽  
Author(s):  
Rehana Parveen ◽  
Prasanta Kumar Maiti ◽  
Nabendu Murmu ◽  
Alokmay Datta
Keyword(s):  
Silver Nanoparticles ◽  
Mammalian Cells ◽  
Host Cells ◽  
Mice Model ◽  
Human Liver Cell ◽  
Wide Range ◽  
Margin Of Safety ◽  
Stress Dependent

Abstract Following access into cell, colloidal silver nanoparticles exhibit generalized cytotoxic properties, thus appear as omnipotent microbicidal, but not suitable for systemic use unless are free of toxic effects on host cells. The serum capped silver nanoparticles when prepared from silver nitrate, using dextrose as reducing and group-matched homologous serum as a stabilizing agent, selective endocytosis and oxidative stress dependent bio-functional damages to the host are mostly eliminated. For their bio-mimicking outer coat, there is least possibility of internalization into host-cells or liberation of excess oxidants in circulation following interaction with erythrocytes or vascμμμar endothelial cells. Presence of infection specific antibody in the serum can make such nano-conjugates more selective. A potent antimicrobial action and a wide margin of safety for mammalian cells in comparison with very similar PVA-capped silver nanoparticles have been demonstrated by in-vitro challenge of such nanoparticles on different microbes, human liver cell-line, and in-vivo study on mice model. This may open-up wide-range therapeutic prospects of colloidal nanoparticles.

scholarly journals Neurotrophin Receptor TrkC Is an Entry Receptor for Trypanosoma cruzi in Neural, Glial, and Epithelial Cells

2011 ◽  
Vol 79 (10) ◽  
pp. 4081-4087 ◽  
Author(s):  
Craig Weinkauf ◽  
Ryan Salvador ◽  
Mercio PereiraPerrin
Keyword(s):  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Mammalian Cells ◽  
Chinese Hamster ◽  
Neuronal Cell ◽  
Host Cells ◽  
Neurotrophin Receptor ◽  
Content Type

ABSTRACTTrypanosoma cruzi, the agent of Chagas' disease, infects a variety of mammalian cells in a process that includes multiple cycles of intracellular division and differentiation starting with host receptor recognition by a parasite ligand(s). Earlier work in our laboratory showed that the neurotrophin-3 (NT-3) receptor TrkC is activated byT. cruzisurfacetrans-sialidase, also known as parasite-derived neurotrophic factor (PDNF). However, it has remained unclear whether TrkC is used byT. cruzito enter host cells. Here, we show that a neuronal cell line (PC12-NNR5) relatively resistant toT. cruzibecame highly susceptible to infection when overexpressing human TrkC but not human TrkB. Furthermore,trkCtransfection conferred an ∼3.0-fold intracellular growth advantage. Sialylation-deficient Chinese hamster ovarian (CHO) epithelial cell lines Lec1 and Lec2 also became much more permissive toT. cruziafter transfection with thetrkCgene. Additionally, NT-3 specifically blockedT. cruziinfection of the TrkC-NNR5 transfectants and of naturally permissive TrkC-bearing Schwann cells and astrocytes, as did recombinant PDNF. Two specific inhibitors of Trk autophosphorylation (K252a and AG879) and inhibitors of Trk-induced MAPK/Erk (U0126) and Akt kinase (LY294002) signaling, but not an inhibitor of insulin-like growth factor 1 receptor, abrogated TrkC-mediated cell invasion. Antibody to TrkC blockedT. cruziinfection of the TrkC-NNR5 transfectants and of cells that naturally express TrkC. The TrkC antibody also significantly and specifically reduced cutaneous infection in a mouse model of acute Chagas' disease. TrkC is ubiquitously expressed in the peripheral and central nervous systems, and in nonneural cells infected byT. cruzi, including cardiac and gastrointestinal muscle cells. Thus, TrkC is implicated as a functional PDNF receptor in cell entry, independently of sialic acid recognition, mediating broadT. cruziinfection bothin vitroandin vivo.

scholarly journals SpyAD, a Moonlighting Protein of Group A Streptococcus Contributing to Bacterial Division and Host Cell Adhesion

2014 ◽  
Vol 82 (7) ◽  
pp. 2890-2901 ◽  
Author(s):  
Marilena Gallotta ◽  
Giovanni Gancitano ◽  
Giampiero Pietrocola ◽  
Marirosa Mora ◽  
Alfredo Pezzicoli ◽  
...  
Keyword(s):  
Cell Division ◽  
Mammalian Cells ◽  
Group A Streptococcus ◽  
Host Cells ◽  
Knockout Mutant ◽  
Content Type ◽  
Moonlighting Protein ◽  
Group A

ABSTRACTGroup A streptococcus (GAS) is a human pathogen causing a wide repertoire of mild and severe diseases for which no vaccine is yet available. We recently reported the identification of three protein antigens that in combination conferred wide protection against GAS infection in mice. Here we focused our attention on the characterization of one of these three antigens, Spy0269, a highly conserved, surface-exposed, and immunogenic protein of unknown function. Deletion of thespy0269gene in a GAS M1 isolate resulted in very long bacterial chains, which is indicative of an impaired capacity of the knockout mutant to properly divide. Confocal microscopy and immunoprecipitation experiments demonstrated that the protein was mainly localized at the cell septum and could interactin vitrowith the cell division protein FtsZ, leading us to hypothesize that Spy0269 is a member of the GAS divisome machinery. Predicted structural domains and sequence homologies with known streptococcal adhesins suggested that this antigen could also play a role in mediating GAS interaction with host cells. This hypothesis was confirmed by showing that recombinant Spy0269 could bind to mammalian epithelial cellsin vitroand thatLactococcus lactisexpressing Spy0269 on its cell surface could adhere to mammalian cellsin vitroand to mice nasal mucosain vivo. On the basis of these data, we believe that Spy0269 is involved both in bacterial cell division and in adhesion to host cells and we propose to rename this multifunctional moonlighting protein as SpyAD (StreptococcuspyogenesAdhesion andDivision protein).

scholarly journals Stimulation of Innate Immunity byIn VivoCyclic di-GMP Synthesis Using Adenovirus

2014 ◽  
Vol 21 (11) ◽  
pp. 1550-1559 ◽  
Author(s):  
Benjamin J. Koestler ◽  
Sergey S. Seregin ◽  
David P. W. Rastall ◽  
Yasser A. Aldhamen ◽  
Sarah Godbehere ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Mammalian Cells ◽  
Immune Cell ◽  
Innate Immune ◽  
Host Cells ◽  
Content Type ◽  
Cytokines And Chemokines ◽  
Novel Approach

ABSTRACTThe bacterial second messenger cyclic di-GMP (c-di-GMP) stimulates inflammation by initiating innate immune cell recruitment and triggering the release of proinflammatory cytokines and chemokines. These properties make c-di-GMP a promising candidate for use as a vaccine adjuvant, and numerous studies have demonstrated that administration of purified c-di-GMP with different antigens increases protection against infection in animal models. Here, we have developed a novel approach to produce c-di-GMP inside host cells as an adjuvant to exploit a host-pathogen interaction and initiate an innate immune response. We have demonstrated that c-di-GMP can be synthesizedin vivoby transducing a diguanylate cyclase (DGC) gene into mammalian cells using an adenovirus serotype 5 (Ad5) vector. Expression of DGC led to the production of c-di-GMPin vitroandin vivo, and this was able to alter proinflammatory gene expression in murine tissues and increase the secretion of numerous cytokines and chemokines when administered to animals. Furthermore, coexpression of DGC modestly increased T-cell responses to aClostridium difficileantigen expressed from an adenovirus vaccine, although no significant differences in antibody titers were observed. This adenovirus c-di-GMP delivery system offers a novel method to administer c-di-GMP as an adjuvant to stimulate innate immunity during vaccination.

Infection of mammalian cells with Theileria species

Parasitology ◽  
1983 ◽  
Vol 86 (2) ◽  
pp. 243-254 ◽  
Author(s):  
D. A. Stagg ◽  
A. S. Young ◽  
B. L. Leitch ◽  
J. G. Grootenhuis ◽  
T. T. Dolan
Keyword(s):  
Host Range ◽  
Mammalian Cells ◽  
Mammalian Species ◽  
Rhipicephalus Appendiculatus ◽  
Host Cells ◽  
Transformed Cells ◽  
Theileria Parva ◽  
African Buffalo

SUMMARYExperiments were carried out to determine the susceptibility of mammalian cells to infection with different species of Theileria in vitro. Sporozoites of Theileria parva (parva), Theileria parva (lawrencei) and Theileria taurotragi were isolated from Rhipicephalus appendiculatus ticks by grinding infected ticks in medium, filtering the suspension and concentrating by centrifugation. The sporozoites were used in attempts to infect in vitro peripheral blood leucocytes harvested from 16 different mammalian species which included 12 species of Bovidae from 6 different sub-families. The technique was shown to be both sensitive and reproducible. The sporozoites of T. parva (parva) infected and transformed cells from 2 species of the sub-family Bovinae, the two cattle types and African buffalo. Theileria parva (lawrencei) infected and transformed cells from the two cattle types, African buffalo and Defassa waterbuck. Theileria taurotragi sporozoites infected in vitro cells from 11 different species of Bovidae which were members of 6 sub-families; Bovinae, Tragelaphinae, Reduncinae, Alcelaphinae, Antilopinae and Caprinae. Transformed lymphoblastoid cell lines were established from 7 of the species infected. Sporozoite attachment and infection was not observed with non-susceptible bovid host cells, nor were any of the non-bovid leucocytes infected by the parasites. The host range observed in this study corresponded to the known host range in vivo.

Regulatory Perspective on in Vitro Assays as Predictors of Phototoxicity and Photo Co-Carcinogenicity

1998 ◽  
Vol 17 (5) ◽  
pp. 571-575 ◽  
Author(s):  
Amy L. Ellis
Keyword(s):  
Mammalian Cells ◽  
Hairless Mouse ◽  
In Vitro Assays ◽  
In Vitro Tests ◽  
Drug Products ◽  
Drug Classes ◽  
Wide Range ◽  
Regulatory Perspective

Drugs from a variety of chemical classes used for a wide range of therapeutic indications can be photosensitizers in humans. Several drugs are phototoxic in animal models as well; there are no nonclinical data for many. In vitro tests have been developed as predictors of phototoxicity and although they have been used as screens, none have replaced the in vivo tests done in rodents (usually mice or guinea pigs) since these have been good predictors of clinical phototoxicity. Some phototoxic drug classes are co-carcinogens with ultraviolet radiation (UVA and/or UVB) in hairless mice, specifically psoralens, retinoids, and fluo-roquinolones. Treatment with 8-methoxypsoralen and ultraviolet A radiation for psoriasis is also carcinogenic in humans. It has been suggested that in vitro photogenotoxicity assays using microorganisms or mammalian cells may be predictive of photo co-carcinogenicity. Some attractions of these in vitro assays, compared to the hairless mouse photo co-carcinogenicity assay, are their generally shorter duration and lower cost as well as reducing the number of animals used in research. Currently, personnel at the Food and Drug Administration (FDA) are examining the available data on phototoxicity, photogenotoxicity, and photo co-carcinogenicity to determine how this information can best be used toregulate and label drug products, and considering which assays should be recommended under specific circumstances.

scholarly journals Mitochondria Can Cross Cell Boundaries: An Overview of the Biological Relevance, Pathophysiological Implications and Therapeutic Perspectives of Intercellular Mitochondrial Transfer

2021 ◽  
Vol 22 (15) ◽  
pp. 8312
Author(s):  
Daniela Valenti ◽  
Rosa Anna Vacca ◽  
Loredana Moro ◽  
Anna Atlante
Keyword(s):  
Mammalian Cells ◽  
Therapeutic Potential ◽  
Cell Metabolism ◽  
Immunological Response ◽  
Biological Relevance ◽  
Mitochondrial Transfer ◽  
Response To Chemotherapy ◽  
Wide Range

Mitochondria are complex intracellular organelles traditionally identified as the powerhouses of eukaryotic cells due to their central role in bioenergetic metabolism. In recent decades, the growing interest in mitochondria research has revealed that these multifunctional organelles are more than just the cell powerhouses, playing many other key roles as signaling platforms that regulate cell metabolism, proliferation, death and immunological response. As key regulators, mitochondria, when dysfunctional, are involved in the pathogenesis of a wide range of metabolic, neurodegenerative, immune and neoplastic disorders. Far more recently, mitochondria attracted renewed attention from the scientific community for their ability of intercellular translocation that can involve whole mitochondria, mitochondrial genome or other mitochondrial components. The intercellular transport of mitochondria, defined as horizontal mitochondrial transfer, can occur in mammalian cells both in vitro and in vivo, and in physiological and pathological conditions. Mitochondrial transfer can provide an exogenous mitochondrial source, replenishing dysfunctional mitochondria, thereby improving mitochondrial faults or, as in in the case of tumor cells, changing their functional skills and response to chemotherapy. In this review, we will provide an overview of the state of the art of the up-to-date knowledge on intercellular trafficking of mitochondria by discussing its biological relevance, mode and mechanisms underlying the process and its involvement in different pathophysiological contexts, highlighting its therapeutic potential for diseases with mitochondrial dysfunction primarily involved in their pathogenesis.

scholarly journals MicroRNA-7 Inhibits Rotavirus Replication by Targeting Viral NSP5 In Vivo and In Vitro

Viruses ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 209 ◽  
Author(s):  
Yan Zhou ◽  
Linlin Chen ◽  
Jing Du ◽  
Xiaoqing Hu ◽  
Yuping Xie ◽  
...  
Keyword(s):  
Rna Virus ◽  
Nonstructural Protein ◽  
Antiviral Effect ◽  
Host Cells ◽  
Mice Model ◽  
Live Attenuated Vaccine ◽  
Severe Diarrhea ◽  
Regulation Method

Rotavirus (RV) is the major causes of severe diarrhea in infants and young children under five years of age. There are no effective drugs for the treatment of rotavirus in addition to preventive live attenuated vaccine. Recent evidence demonstrates that microRNAs (miRNAs) can affect RNA virus replication. However, the antiviral effect of miRNAs during rotavirus replication are largely unknown. Here, we determined that miR-7 is upregulated during RV replication and that it targets the RV NSP5 (Nonstructural protein 5). Results suggested that miR-7 affected viroplasm formation and inhibited RV replication by down-regulating RV NSP5 expression. Up-regulation of miR-7 expression is a common regulation method of different G-type RV-infected host cells. Then, we further revealed the antiviral effect of miR-7 in diarrhea suckling mice model. MiR-7 is able to inhibit rotavirus replication in vitro and in vivo. These data provide that understanding the role of cellular miR-7 during rotaviral replication may help in the identification of novel therapeutic small RNA molecule drug for anti-rotavirus.

scholarly journals Insights into the Biosynthesis of Duramycin

2016 ◽  
Vol 83 (3) ◽  
Author(s):  
Liujie Huo ◽  
Ayşe Ökesli ◽  
Ming Zhao ◽  
Wilfred A. van der Donk
Keyword(s):  
Escherichia Coli ◽  
Cystic Fibrosis ◽  
Viral Entry ◽  
Mammalian Cells ◽  
Host Cells ◽  
Molecular Probe ◽  
Content Type ◽  
E Coli

ABSTRACT Lantibiotics are ribosomally synthesized and posttranslationally modified antimicrobial peptides that are characterized by the thioether cross-linked bisamino acids lanthionine (Lan) and methyllanthionine (MeLan). Duramycin contains 19 amino acids, including one Lan and two MeLans, an unusual lysinoalanine (Lal) bridge formed from the ε-amino group of lysine 19 and a serine residue at position 6, and an erythro-3-hydroxy-l-aspartic acid at position 15. These modifications are important for the interactions of duramycin with its biological target, phosphatidylethanolamine (PE). Based on the binding affinity and specificity for PE, duramycin has been investigated as a potential therapeutic, as a molecular probe to investigate the role and localization of PE in biological systems, and to block viral entry into mammalian cells. In this study, we identified the duramycin biosynthetic gene cluster by genome sequencing of Streptomyces cinnamoneus ATCC 12686 and investigated the dur biosynthetic machinery by heterologous expression in Escherichia coli. In addition, the analog duramycin C, containing six amino acid changes compared to duramycin, was successfully generated in E. coli. The substrate recognition motif of DurX, an α-ketoglutarate/iron(II)-dependent hydroxylase that carries out the hydroxylation of aspartate 15 of the precursor peptide DurA, was also investigated using mutagenesis of the DurA peptide. Both in vivo and in vitro results demonstrated that Gly16 is important for DurX activity. IMPORTANCE Duramycin is a natural product produced by certain bacteria that binds to phosphatidylethanolamine (PE). Because PE is involved in many cellular processes, duramycin is an antibiotic that kills bacteria, but it has also been used as a molecular probe to detect PE and monitor its localization in mammalian cells and even whole organisms, and it was recently shown to display broad-spectrum inhibition of viral entry into host cells. In addition, the molecule has been evaluated as treatment for cystic fibrosis. We report here the genes that are involved in duramycin biosynthesis, and we produced duramycin by expressing those genes in Escherichia coli. We show that duramycin analogs can also be produced. The ability to access duramycin and analogs by production in E. coli opens opportunities to improve duramycin as an antibiotic, PE probe, antiviral, or cystic fibrosis therapeutic.

scholarly journals Evolution of Antibacterial Drug Screening Methods: Current Prospects for Mycobacteria

2021 ◽  
Vol 9 (12) ◽  
pp. 2562
Author(s):  
Clara M. Bento ◽  
Maria Salomé Gomes ◽  
Tânia Silva
Keyword(s):  
Rapid Development ◽  
Drug Susceptibility Testing ◽  
New Drugs ◽  
Host Cells ◽  
Screening Methods ◽  
Antibacterial Drug ◽  
Efficient Treatment ◽  
Wide Range

The increasing resistance of infectious agents to available drugs urges the continuous and rapid development of new and more efficient treatment options. This process, in turn, requires accurate and high-throughput techniques for antimicrobials’ testing. Conventional methods of drug susceptibility testing (DST) are reliable and standardized by competent entities and have been thoroughly applied to a wide range of microorganisms. However, they require much manual work and time, especially in the case of slow-growing organisms, such as mycobacteria. Aiming at a better prediction of the clinical efficacy of new drugs, in vitro infection models have evolved to closely mimic the environment that microorganisms experience inside the host. Automated methods allow in vitro DST on a big scale, and they can integrate models that recreate the interactions that the bacteria establish with host cells in vivo. Nonetheless, they are expensive and require a high level of expertise, which makes them still not applicable to routine laboratory work. In this review, we discuss conventional DST methods and how they should be used as a first screen to select active compounds. We also highlight their limitations and how they can be overcome by more complex and sophisticated in vitro models that reflect the dynamics present in the host during infection. Special attention is given to mycobacteria, which are simultaneously difficult to treat and especially challenging to study in the context of DST.

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