scholarly journals Aptamers: Novel Molecules as Diagnostic Markers in Bacterial and Viral Infections?

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Flávia M. Zimbres ◽  
Attila Tárnok ◽  
Henning Ulrich ◽  
Carsten Wrenger
Keyword(s):  
Viral Infections ◽  
High Specificity ◽  
Current Status ◽  
Virus Infections ◽  
Pathogenic Factors ◽  
Therapeutic Tools ◽  
Pathogenic Agents ◽  
Exponential Enrichment ◽  
High Degree

Worldwide the entire human population is at risk of infectious diseases of which a high degree is caused by pathogenic protozoans, worms, bacteria, and virus infections. Moreover the current medications against pathogenic agents are losing their efficacy due to increasing and even further spreading drug resistance. Therefore, there is an urgent need to discover novel diagnostic as well as therapeutic tools against infectious agents. In view of that, the Systematic Evolution of Ligands by Exponential Enrichment (SELEX) represents a powerful technology to target selectively pathogenic factors as well as entire bacteria or viruses. SELEX uses a large combinatorial oligonucleic acid library (DNA or RNA) which is processed a by high-fluxin vitroscreen of iterative cycles. The selected ligands, termed aptamers, are characterized by high specificity and affinity to their target molecule, which are already exploited in diagnostic and therapeutic applications. In this minireview we will discuss the current status of the SELEX technique applied on bacterial and viral pathogens.

scholarly journals Identification and characterization of RNA aptamers: A long aptamer blocks the AMPA receptor and a short aptamer blocks both AMPA and kainate receptors

2017 ◽  
Vol 292 (18) ◽  
pp. 7338-7347 ◽  
Author(s):  
William J. Jaremko ◽  
Zhen Huang ◽  
Wei Wen ◽  
Andrew Wu ◽  
Nicholas Karl ◽  
...  
Keyword(s):  
Ampa Receptor ◽  
Neurological Diseases ◽  
Rna Aptamers ◽  
Kainate Receptors ◽  
Single Receptor ◽  
Cell Recording ◽  
Exponential Enrichment ◽  
High Degree

AMPA and kainate receptors, along with NMDA receptors, represent different subtypes of glutamate ion channels. AMPA and kainate receptors share a high degree of sequence and structural similarities, and excessive activity of these receptors has been implicated in neurological diseases such as epilepsy. Therefore, blocking detrimental activity of both receptor types could be therapeutically beneficial. Here, we report the use of an in vitro evolution approach involving systematic evolution of ligands by exponential enrichment with a single AMPA receptor target (i.e. GluA1/2R) to isolate RNA aptamers that can potentially inhibit both AMPA and kainate receptors. A full-length or 101-nucleotide (nt) aptamer selectively inhibited GluA1/2R with a KI of ∼5 μm, along with GluA1 and GluA2 AMPA receptor subunits. Of note, its shorter version (55 nt) inhibited both AMPA and kainate receptors. In particular, this shorter aptamer blocked equally potently the activity of both the GluK1 and GluK2 kainate receptors. Using homologous binding and whole-cell recording assays, we found that an RNA aptamer most likely binds to the receptor's regulatory site and inhibits it noncompetitively. Our results suggest the potential of using a single receptor target to develop RNA aptamers with dual activity for effectively blocking both AMPA and kainate receptors.

Telomerase-based Cancer Therapeutics: A Review on their Clinical Trials

2020 ◽  
Vol 20 (6) ◽  
pp. 433-457 ◽  
Author(s):  
Nicola Relitti ◽  
Akella P. Saraswati ◽  
Stefano Federico ◽  
Tuhina Khan ◽  
Margherita Brindisi ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Small Molecules ◽  
Tandem Repeats ◽  
Cancer Therapeutics ◽  
High Specificity ◽  
Telomerase Activity ◽  
Current Status ◽  
Anti Cancer ◽  
Therapeutic Tools ◽  
Made In

Telomeres are protective chromosomal ends that shield the chromosomes from DNA damage, exonucleolytic degradation, recombination, and end-to-end fusion. Telomerase is a ribonucleoprotein that adds TTAGGG tandem repeats to the telomeric ends. It has been observed that 85 to 90% of human tumors express high levels of telomerase, playing a crucial role in the development of cancers. Interestingly, the telomerase activity is generally absent in normal somatic cells. This selective telomerase expression has driven scientists to develop novel anti-cancer therapeutics with high specificity and potency. Several advancements have been made in this area, which is reflected by the enormous success of the anticancer agent Imetelstat. Since the discovery of Imetelstat, several research groups have contributed to enrich the therapeutic arsenal against cancer. Such contributions include the application of new classes of small molecules, peptides, and hTERT-based immunotherapeutic agents (p540, GV1001, GRNVAC1 or combinations of these such as Vx-001). Many of these therapeutic tools are under different stages of clinical trials and have shown promising outcomes. In this review, we highlight the current status of telomerase-based cancer therapeutics and the outcome of these investigations.

Xylo-oligosaccharides and lactitol promote the growth of Bifidobacterium lactis and Lactobacillus species in pure cultures

2010 ◽  
Vol 1 (2) ◽  
pp. 139-148 ◽  
Author(s):  
H. Mäkeläinen ◽  
M. Saarinen ◽  
J. Stowell ◽  
N. Rautonen ◽  
A. Ouwehand
Keyword(s):  
High Specificity ◽  
Lactobacillus Species ◽  
Limited Extent ◽  
Bifidobacterium Lactis ◽  
Screening Study ◽  
Pure Cultures ◽  
Pathogenic Microbes ◽  
High Degree ◽  
Current Screening

The current screening study aimed at identifying promising prebiotic and synbiotic candidates. The fermentation of xylo-oligosaccharides, xylan, galacto-oligosaccharide, fructo-oligosaccharide, polydextrose, lactitol, gentiobiose and pullulan was investigated in vitro. The ability of these established and potential prebiotic candidates to function as a sole carbon source for probiotic (Bifidobacterium and Lactobacillus), intestinal and potential pathogenic microbes (Eubacterium, Bacteroides, Clostridium, Escherichia coli, Salmonella, and Staphylococcus) was assessed in pure cultures. Xylo-oligosaccharides were fermented with high specificity by the tested Bifidobacterium lactis strains and lactitol by lactobacilli, whereas galacto-oligosaccharides, fructo-oligosaccharides and gentiobiose were utilised by a larger group of microbes. Xylan, polydextrose and pullulan were utilised to a limited extent by only a few of the tested microbes. The results of this screening study indicate that xylo-oligosaccharides and lactitol support the growth of a limited number of beneficial microbes in pure cultures. Such a high degree of specificity has not been previously reported for established prebiotics. Based on these results, the most promising prebiotics and synbiotic combinations can be selected for further testing.

scholarly journals Probiotic Effects against Virus Infections: New Weapons for an Old War

Foods ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 130
Author(s):  
Aroa Lopez-Santamarina ◽  
Alexandre Lamas ◽  
Alicia del Carmen Mondragón ◽  
Alejandra Cardelle-Cobas ◽  
Patricia Regal ◽  
...  
Keyword(s):  
Viral Infections ◽  
Lactobacillus Species ◽  
Virus Infections ◽  
Probiotic Supplementation ◽  
Immunodeficiency Virus ◽  
Probiotic Strains ◽  
Respiratory Tract Viruses ◽  
Simplex Virus

This review aimed to gather the available literature investigating the effects of probiotics against the most common viral infections using in vitro trials in cell lines and in vivo clinical trials in both experimental animals and humans. Probiotics were employed to prevent and reduce symptoms of infections caused by common viruses, especially respiratory tract viruses, but also for viral digestive infections (such as rotavirus, coronavirus, or norovirus) and other viral infections (such as viruses that cause hepatitis, human papillomavirus, human immunodeficiency virus, and herpes simplex virus). Different probiotics have been studied to see their possible effect against the abovementioned viruses, among which different Lactobacillus species, Bifidobacterium, Clostridium, Enterococcus, and Streptococcus can be highlighted. In many cases, mixtures of various probiotic strains were used. Although the results obtained did not show similar results, in most cases, probiotic supplementation improved both barrier and biochemical immune responses, decreased susceptibility to viral infections, and enhanced the effects of concomitant vaccines. Works collected in this review show a beneficial effect of probiotics in the prevention and treatment of different viral infections. We found interesting results related to the prevention of viral infections, reduction of the duration of diseases, and decrease of symptoms.

scholarly journals Gamma Delta T Cells and Their Involvement in COVID-19 Virus Infections

2021 ◽  
Vol 12 ◽  
Author(s):  
Georg von Massow ◽  
Steve Oh ◽  
Alan Lam ◽  
Kenth Gustafsson
Keyword(s):  
T Cells ◽  
Viral Infections ◽  
Cell Subset ◽  
Γδ T Cells ◽  
Common Symptom ◽  
Virus Infections ◽  
Infected Cells ◽  
The Relationship

The global outbreak of the SARS-Cov-2 virus in 2020 has killed millions of people worldwide and forced large parts of the world into lockdowns. While multiple vaccine programs are starting to immunize the global population, there is no direct cure for COVID-19, the disease caused by the SARS-Cov-2 infection. A common symptom in patients is a decrease in T cells, called lymphopenia. It is as of yet unclear what the exact role of T cells are in the immune response to COVID-19. The research so far has mainly focused on the involvement of classical αβ T cells. However, another subset of T cells called γδ T cells could have an important role to play. As part of the innate immune system, γδ T cells respond to inflammation and stressed or infected cells. The γδ T cell subset appears to be particularly affected by lymphopenia in COVID-19 patients and commonly express activation and exhaustion markers. Particularly in children, this subset of T cells seems to be most affected. This is interesting and relevant because γδ T cells are more prominent and active in early life. Their specific involvement in this group of patients could indicate a significant role for γδ T cells in this disease. Furthermore, they seem to be involved in other viral infections and were able to kill SARS infected cells in vitro. γδ T cells can take up, process and present antigens from microbes and human cells. As e.g. tumour-associated antigens are presented by MHC on γδ T cells to classical T-cells, we argue here that it stands to reason that also viral antigens, such as SARS-Cov-2-derived peptides, can be presented in the same way. γδ T cells are already used for medical purposes in oncology and have potential in cancer therapy. As γδ T cells are not necessarily able to distinguish between a transformed and a virally infected cell it could therefore be of great interest to investigate further the relationship between COVID-19 and γδ T cells.

scholarly journals Resveratrol, Rapamycin and Metformin as Modulators of Antiviral Pathways

Viruses ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1458
Author(s):  
Francesca Benedetti ◽  
Vincenzo Sorrenti ◽  
Alessandro Buriani ◽  
Stefano Fortinguerra ◽  
Giovanni Scapagnini ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Viral Infections ◽  
Small Animal ◽  
Current Status ◽  
Dietary Interventions ◽  
Antiviral Immune Response ◽  
Small Animal Models ◽  
Cellular Pathways

Balanced nutrition and appropriate dietary interventions are fundamental in the prevention and management of viral infections. Additionally, accurate modulation of the inflammatory response is necessary to achieve an adequate antiviral immune response. Many studies, both in vitro with mammalian cells and in vivo with small animal models, have highlighted the antiviral properties of resveratrol, rapamycin and metformin. The current review outlines the mechanisms of action of these three important compounds on the cellular pathways involved with viral replication and the mechanisms of virus-related diseases, as well as the current status of their clinical use.

scholarly journals Carrageenans as Broad-Spectrum Microbicides: Current Status and Challenges

Marine Drugs ◽  
2020 ◽  
Vol 18 (9) ◽  
pp. 435
Author(s):  
Choongho Lee
Keyword(s):  
Broad Spectrum ◽  
Red Algae ◽  
Viral Infections ◽  
Ex Vivo ◽  
Antimicrobial Activities ◽  
Current Status ◽  
Sulfated Polysaccharides ◽  
Future Research

Different kinds of red algae are enriched with chemically diverse carbohydrates. In particular, a group of sulfated polysaccharides, which were isolated from the cell walls of red algae, gained a large amount of attention due to their broad-spectrum antimicrobial activities. Within that group, carrageenans (CGs) were expected to be the first clinically applicable microbicides that could prevent various viral infections due to their superior antiviral potency and desirable safety profiles in subclinical studies. However, their anticipated beneficial effects could not be validated in human studies. To assess the value of a second attempt at pharmacologically developing CGs as a new class of preventive microbicides, all preclinical and clinical development processes of CG-based microbicides need to be thoroughly re-evaluated. In this review, the in vitro toxicities; in vivo safety profiles; and in vitro, ex vivo, and in vivo antiviral activities of CGs are summarized according to the study volume of their target viruses, which include human immunodeficiency virus, herpesviruses, respiratory viruses, human papillomavirus, dengue virus, and other viruses along with a description of their antiviral modes of action and development of antiviral resistance. This evaluation of the strengths and weaknesses of CGs will help provide future research directions that may lead to the successful development of CG-based antimicrobial prophylactics.

scholarly journals Three-Dimensional Cell Culture Models to Study Respiratory Virus Infections Including COVID-19

Biomimetics ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 3
Author(s):  
Aya Harb ◽  
Mohammad Fakhreddine ◽  
Hassan Zaraket ◽  
Fatima A. Saleh
Keyword(s):  
Viral Infections ◽  
Three Dimensional ◽  
3D Culture ◽  
3D Models ◽  
Respiratory Viruses ◽  
Model Systems ◽  
Virus Infections ◽  
Culture Models ◽  
Syncytial Virus

Respiratory viral infections, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), are among the most common illnesses and a leading cause of morbidity and mortality worldwide. Due to the severe effects on health, the need of new tools to study the pathogenesis of respiratory viruses as well as to test for new antiviral drugs and vaccines is urgent. In vitro culture model systems, such as three-dimensional (3D) cultures, are emerging as a desirable approach to understand the virus host interactions and to identify novel therapeutic agents. In the first part of the article, we address the various scaffold-free and scaffold-based 3D culture models such as hydrogels, bioreactors, spheroids and 3D bioprinting as well as present their properties and advantages over conventional 2D methods. Then, we review the 3D models that have been used to study the most common respiratory viruses including influenza, parainfluenza, respiratory syncytial virus (RSV) and coronaviruses. Herein, we also explain how 3D models have been applied to understand the novel SARS-CoV-2 infectivity and to develop potential therapies.

scholarly journals Cultivar and Phenological Stage Effects on the Success of In Vitro Meristem Culture and GLRaV-3 Elimination of Croatian Autochthonous Grapevine Cultivars

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1395
Author(s):  
Zvjezdana Marković ◽  
Anđela Zrilić ◽  
Iva Šikuten ◽  
Petra Štambuk ◽  
Ivana Tomaz ◽  
...  
Keyword(s):  
In Vitro Culture ◽  
Culture Medium ◽  
Viral Infections ◽  
Meristem Culture ◽  
Phenological Stages ◽  
Planting Material ◽  
In Vitro Establishment ◽  
Meristem Explants ◽  
High Degree

The population of Croatian autochthonous cultivars has a high degree of infection with economically important viruses, so it is necessary to carry out the elimination of the viruses in some cultivars to obtain healthy planting material. In this research, we tested in vitro meristem culture establishment on 18 autochthonous cultivars with different viral infections and the possibility of GLRaV-3 elimination through in vitro meristem culture. Plant material was sampled in a vineyard in two phenological stages, 10 days before flowering and 10 days after flowering of the grapevine. Apical meristem explants (1 mm) were placed into the MS culture medium supplemented with 0.5 mg/L benzyl adenine (BA) and 0.05 mg/L indol-3-acetic acid (IAA), and their survival, regeneration, and rooting were monitored. The results showed that the cultivar and the growth phase have a significant impact on the success of in vitro culture. In all cultivars studied higher success of in vitro culture establishment parameters (survival, regeneration, and rooting) was obtained in the case of explants sampled after flowering, with the exception of one cultivar for explants survival. Contrary to expectations, genotypes infected with three viruses (GLRaV-1, GLRaV-3, and GFLV) showed better results than genotypes infected with one or two viruses. The results showed successful in vitro establishment of Croatian autochthonous cultivar and GRLaV-3 elimination in one cultivar. However, due to the significant effect of cultivar, for routine application of this in vitro protocol on more than 100 autochthonous cultivars in need of sanitation, further studies should be conducted.

A Physiologic Regulator of Collagen-Induced Platelet Aggregation: Inhibition by Clq

1981 ◽  
Vol 45 (02) ◽  
pp. 110-115 ◽  
Author(s):  
György Csákó ◽  
Eva A Suba
Keyword(s):  
Platelet Aggregation ◽  
Human Platelet ◽  
Platelet Reactivity ◽  
High Specificity ◽  
Turbidimetric Method ◽  
Specific Manner ◽  
Aggregation Inhibition ◽  
Different Tissues

SummaryPlatelet aggregations were studied by a turbidimetric method in citrated human platelet-rich plasmas (PRP) in vitro. Human Clq inhibited the aggregations caused by collagens derived from different tissues and species. Clq was needed by weight in comparable quantities to collagen for neutralizing the aggregating effect. The dependence of the inhibitory reaction on the preincubation of platelets with Clq and the differences in the occurrence of aggregating substances in supernatants of PRP triggered with collagen in the presence or absence of Clq, confirmed that Clq exerts its effect by preventing fixation of collagen to platelets. In addition, the high specificity of the inhibitory action of Clq for collagen-induced platelet aggregation was demonstrated by results obtained for testing a variety of aggregating agents in combination with Clq and/or collagen.Since normal concentrations of Clq in the blood are in the range of inhibitory doses of Clq for collagen-induced platelet aggregations in vitro and upon activation of complement Clq is known to dissociate from Cl, it is proposed that Clq may participate in a highly specific manner in regulating platelet reactivity to collagen in vivo.

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