Ales Berlec

Ales Berlec
Jožef Stefan Institute | IJS · Department of Biotechnology

PhD

About

57
Publications
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1,536
Citations

Publications

Publications (57)
Article
Full-text available
Background Dysregulated production of interleukin (IL)-6 is implicated in the pathology of inflammatory bowel disease (IBD). Neutralization of IL-6 in the gut by safe probiotic bacteria may help alleviate intestinal inflammation. Here, we developed Lactococcus lactis with potent and selective IL-6 binding activity by displaying IL-6-specific affibo...
Article
Full-text available
The lack of appropriate delivery systems hinders the use of probiotics in the treatment of vaginal infections. Therefore, the development of a new delivery system for the local administration of vaginal probiotics is necessary. In this study, we selected three vaginal lactobacilli, i.e., Lactobacillus crispatus, Lactobacillus gasseri, and Lactobaci...
Article
Biofilms serve as a bacterial survival strategy, allowing bacteria to persist under adverse environmental conditions. The non-pathogenic Listeria innocua is used as a surrogate organism for the foodborne pathogen Listeria monocytogenes, because they share genetic and physiological similarities and can be used in a Biosafety Level 1 laboratory. Seve...
Article
Full-text available
Pro-inflammatory cytokines play an important role in the development and progression of colorectal cancer (CRC). Tumor-targeting bacteria that can capture pro-inflammatory cytokines in the tumor microenvironment and thus block their tumor-promoting effects might provide clinical benefits in inflammation-associated CRC. The aim of this study was to...
Article
Full-text available
Lactobacilli are a promising natural tool against vaginal dysbiosis and infections. However, new local delivery systems and additional knowledge about their distribution and mechanism of action would contribute to the development of effective medicine. This will be facilitated by the introduction of the techniques for effective, inexpensive, and re...
Article
Full-text available
Genetic modification of lactic acid bacteria is an evolving and highly relevant field of research that allows the engineered bacteria to be equipped with the desired functions through the controlled expression of the recombinant protein. Novel genetic engineering techniques offer the advantage of being faster, easier and more efficient in incorpora...
Article
Full-text available
Development of targeted treatment for colorectal cancer is crucial to avoid side effects. To harness the possibilities offered by microbiome engineering, we prepared safe multifunctional cancer cell‐targeting bacteria Lactococcus lactis. They displayed, on their surface, binding proteins for cancer‐associated transmembrane receptors epithelial cell...
Article
Full-text available
Studies of biofilm formation by bacteria are crucial for understanding bacterial resistance and for development of novel antibacterial strategies. We have developed a new bioluminescence biofilm assay for Listeria innocua, which is considered a non-pathogenic surrogate for Listeria monocytogenes. L. innocua was transformed with a plasmid for induci...
Article
Full-text available
Lectins have been increasingly utilized as carriers for targeted drug delivery based on their specific binding to glycans located on mammalian cells. This study employed two lectins, B subunit of bacterial Shiga holotoxin (Stx1B) and fungal Clitocybe nebularis lectin (CNL), for surface display on the lactic acid bacterium Lactococcus lactis. The sp...
Article
Full-text available
The two most important bacterial phyla in the gastrointestinal tract, Firmicutes and Bacteroidetes, have gained much attention in recent years. The Firmicutes/Bacteroidetes (F/B) ratio is widely accepted to have an important influence in maintaining normal intestinal homeostasis. Increased or decreased F/B ratio is regarded as dysbiosis, whereby th...
Article
Full-text available
Lactic acid bacteria (LAB) have a long history of use in the food industry. Some species are part of the normal human microbiota and have beneficial properties for human health. Their long-standing use and considerable biotechnological potential have led to the development of various systems for their engineering. Together with novel approaches suc...
Article
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Electrospinning is a technique that uses polymer solutions and strong electric fields to produce nano-sized fibers that have wide-ranging applications. We present here an overview of the use of electrospinning to incorporate biological products into nanofibers, including microorganisms, cells, proteins, and nucleic acids. Although the conditions us...
Article
Full-text available
Lactic acid bacteria can have beneficial health effects and be used for the treatment of various diseases. However, there remains the challenge of encapsulating probiotics into delivery systems with a high viability and encapsulation efficacy. The electrospinning of bacteria is a novel and little-studied method, and further investigation of its pro...
Article
Full-text available
The display of recombinant proteins on bacterial surfaces is a developing research area with a wide range of potential biotechnological applications. The lactic acid bacterium Lactococcus lactis is an attractive host for such surface display, and a promising vector for in vivo delivery of bioactive proteins. Surface-displayed recombinant proteins a...
Article
Full-text available
Lactococcus lactis, a probiotic bacterium of food origin, has recently been demonstrated as a suitable strain for the production and in vivo delivery of therapeutically important proteins into the gut. We aimed to engineer recombinant L. lactis cells producing/secreting REX binding proteins that have been described as IL-23 receptor (IL-23R) blocke...
Article
The interest in probiotics has grown in recent years due to increased awareness of the importance of microbiota for human health. We present the development of monolithic poly(ethylene oxide) and composite poly(ethylene oxide)/lyoprotectant nanofibers loaded with the probiotic Lactobacillus plantarum ATCC 8014. High loading was achieved for L. plan...
Article
Full-text available
Lactic acid bacteria (LAB) have a long-term history of use in food industry and are becoming attractive for use in therapy on account of their safety, intrinsic beneficial health effects, and considerable biotechnological potential. The established systems for engineering are combined with novel approaches, such as CRISPR-Cas, to enable the use of...
Article
Dysbiosis of intestinal microbiota and aberrant inflammatory responses in gastrointestinal mucosa plays important roles in the development of inflammatory bowel disease (IBD). The purpose of this study was to demonstrate the probiotic activity of Lactococcus lactis and the ability of TNF-α-binding by recombinant L. lactis bearing TNF-α-binding affi...
Article
Full-text available
Display of recombinant proteins on the bacterial surface is an emerging research area with wide range of potential biotechnological applications. Because of its GRAS (generally recognized as safe) status, lactic acid bacterium Lactococcus lactis represents an attractive host for surface display and promising vector for in situ delivery of bioactive...
Article
Full-text available
Lactic acid bacteria (LAB) are attractive hosts for the expression of heterologous proteins and can be engineered to deliver therapeutic proteins or peptides to mucosal surfaces. The gastric stable pentadecapeptide BPC-157 is able to prevent and treat gastrointestinal inflammation by reducing the production of reactive oxygen species (ROS). In this...
Article
Full-text available
IL-23-mediated Th-17 cell activation and stimulation of IL-17-driven pro-inflammatory axis has been associated with autoimmunity disorders such as Inflammatory Bowel Disease (IBD) or Crohn’s Disease (CD). Recently we developed a unique class of IL-23-specific protein blockers, called ILP binding proteins that inhibit binding of IL-23 to its cognate...
Article
Full-text available
Lactococcus lactis is a food-grade lactic acid bacterium that is used in the dairy industry as a cell factory and as a host for recombinant protein expression. The nisin-controlled inducible expression (NICE) system is frequently applied in L. lactis; however new tools for its genetic modification are highly desirable. In this work NICE was adapted...
Data
Table S1. Strains, plasmids and primers used in the study. Fig. S1. Shift in fluorescence intensity. Fig. S2. ELISA‐determined percentage of CCL3, CCL5 and CXCL8 removed after incubation with 6 × 108 (white bars), 3 × 109 (gray bars), or 6 × 109 (black bars) cells/mL of recombinant L. lactis NZ9000 cells that displayed evasin‐1 (pSDEva1), evasin‐...
Article
Full-text available
Chemokines are key signals in the immune system and play an important role as proinflammatory mediators in the pathology of inflammatory bowel disease and colorectal cancer, making them an important target for therapy. Recombinant lactic acid bacteria (LAB) were engineered to bind CC and CXC chemokines by displaying chemokine-binding proteins evasi...
Article
Background: Neutralization of proinflammatory cytokines is an established strategy in the treatment of inflammatory bowel disease (IBD). Systemic anti-TNFα antibodies have been used in the clinics for several years, while anti-IL-17/IL-23 antibodies have been less successful so far. We report the development of safe lactic acid bacterium Lb. saliv...
Article
TNFα has a well-established role in inflammatory bowel disease that affects the gastrointestinal tract and is usually manifested as Crohn's disease or ulcerative colitis. We have compared Lactococcus lactis NZ9000 displaying TNFα-binding affibody with control Lactococcus lactis and with anti-TNFα antibody infliximab for the treatment of mice with d...
Article
Full-text available
Infections with shiga toxin-producing bacteria, like enterohemorrhagic Escherichia coli and Shigella dysenteriae, represent a serious medical problem. No specific and effective treatment is available for patients with these infections, creating a need for the development of new therapies. Recombinant lactic acid bacterium Lactococcus lactis was eng...
Conference Paper
Current treatment of inflammatory bowel disease (IBD) is largely symptomatic and consists of anti-inflammatory agents, immune-suppressives or antibiotics, whereby local luminal action is preferred to minimize systemic side-effects. Recently, anti-TNFα therapy has shown considerable success and is now being routinely used. Here we present a novel ap...
Article
Full-text available
Background: In vivo imaging of orally administered lactic acid bacteria (LAB) and commensal bacteria in mice is shown to provide information on the spatial and temporal distribution of bacteria in the gastrointestinal tract. The bacteria can be detected and monitored using bioluminescence or near-infrared fluorescence. Results: Fluorescence imag...
Article
Non-immunoglobulin (non-Ig) scaffolds are, in contrast to antibodies, small single-domain proteins that require no post-translational modification, often lack disulfide bonds, and can undergo straightforward multimerization. Among the 20 different types of non-Ig scaffolds, Adhirons, Alphabodies, Centyrins, Pronectins, Repebodies, Affimers, and Obo...
Article
Lactic acid bacteria (LAB) are food-grade hosts for surface display with potential applications in food and therapy. Alternative approaches to surface display on LAB would avoid the use of recombinant DNA technology and genetically-modified organism (GMO)-related regulatory requirements. Non-covalent surface display of proteins can be achieved by f...
Article
Safety and probiotic properties make Lactic Acid Bacteria (LAB) attractive hosts for surface display of heterologous proteins. Their display on non-recombinant microorganisms is preferred for therapeutic and food applications due to regulatory requirements. We have displayed two designed ankyrin repeat proteins (DARPins), each possessing affinity f...
Article
Biliverdin is an intermediate of heme degradation with an established role in veterinary clinical diagnostics of liver-related diseases. The need for chromatographic assays has so far prevented its wider use in diagnostic laboratories. The current report describes a simple, fast, high-throughput, and inexpensive assay, based on the interaction of b...
Article
Full-text available
Basic membrane protein A (BmpA) is a potential carrier protein for surface display of the IgG-binding domain on Lactococcus lactis. We have shown that it can increase the adhesion of bacteria to the intestinal cell model by 1.3-fold and have improved BmpA-based surface display by engineering the BmpA molecule. The bulk of the BmpA molecule was show...
Article
Asthma is a chronic inflammation of respiratory tract and affects more than 300 million people around the world. Of those, 5-10% suffer from the form of asthma, which is hard to control with standard corticosteroid and β2-agonist therapy, and are therefore appropriate candidates for the tretament with biologicals. Omalizumab is a monoclonal antibod...
Article
Almost all of the 200 or so approved biopharmaceuticals have been produced in one of three host systems: the bacterium Escherichia coli, yeasts (Saccharomyces cerevisiae, Pichia pastoris) and mammalian cells. We describe the most widely used methods for the expression of recombinant proteins in the cytoplasm or periplasm of E. coli, as well as stra...
Article
An epidemic shift in Hepatitis A virus (HAV) infection has been observed in recent years in rapidly developing countries, with increasing numbers of severe adult cases which has led to renewed interest in vaccination. Our approach in vaccine development uses recombinant expression of the highly immunogenic HAV antigen VP1-P2a in food-grade lactic a...
Article
Lactic acid bacteria (LAB) have become increasingly studied over the last two decades as potential delivery systems for various biological molecules to the gastrointestinal tract. This article presents an overview of characteristics of LAB as delivery systems and of the applications which have already been developed. The majority of LAB strains are...
Article
Plants live in intimate relationships with numerous microorganisms present inside or outside plant tissues. The plant exterior provides two distinct ecosystems, the rhizosphere (below ground) and the phyllosphere (above ground), both populated by microbial communities. Most studies on plant microbiota deal with pathogens or mutualists. This review...
Article
Full-text available
The growing popularity of the lactic acid bacterium Lactococcus lactis has increased demand for novel high-throughput cloning methods. Here we describe a general TA-cloning methodology and demonstrate its feasibility using the plasmid pNZ8148. PCR products were directly ligated into a linear, PCR-amplified and XcmI-digested pNZ8148 derivative that...
Article
Full-text available
Lactococcus lactis is a lactic acid bacterium of proven safety for use in human oral applications. For this purpose, surface display of recombinant proteins is important, and new approaches for it are being sought. Analysis of the bacterial surface proteome is essential in identifying new candidate carrier proteins for surface display. We have made...
Article
Full-text available
The aim of our study was to determine the genetic characterization and classification of Lb. gasseri K7 bacteriocins, comparison with bacteriocins of the Lb. gasseri LF221 strain and other related strains. Bacteriocin-encoding genes were amplified by PCR, subjected to DNA sequencing, and BLAST sequence analysis was performed to search the database...
Article
Full-text available
We have optimized the display of the B domain of staphylococcal protein A on the surface of Lactococcus lactis. The maximum binding capacity was estimated at 0.146 μg of antibody per 108 cells and was sustained at 86% after treatment with simulated gastric juice. A tumor necrosis factor alpha (TNF-α)-binding affibody was also displayed and bound TN...
Article
Determination of the nucleotide sequence of individual's genome could contribute to the establishment of personalized medicine. High price of the nucleotide sequencing represented the biggest hurdle in the past; however the next generation sequencing techniques have caused the prices to drop. New techniques enable high-throughput parallel sequencin...
Article
To evaluate brazzein production in Lactococcus lactis using the nisin-controlled expression (NICE) system. The approach is through analysis of different plasmid/strain combinations. Two plasmid/strain combinations of the NICE system were used in brazzein expression: L. lactis NZ9000 harbouring plasmid pNZ8148, and L. lactis IL1403 harbouring plasmi...
Article
Lactic acid bacteria (LAB) are gaining importance due to their "generally recognized as safe" status, long-term use in food and beneficial, probiotic properties. They can acquire new, desirable traits by the incorporation of genes that allow the expression of heterologous proteins, and several patents and patent applications describe the use of rec...
Article
Lactic acid bacteria have been a part of human diet for centuries and their safety is therefore generally recognised. Apart from that, the techniques that enable recombinant protein expression in lactic acid bacteria have recently developed. This is why lactic acid bacteria could serve as a cheap and efficient delivery system for recombinant protei...
Article
Calcipotriol is a potent drug for topical treatment of psoriasis because it manages to inhibit keratinocyte proliferation. In the present study we investigated the effects of calcipotriol on gene expression in human keratinocytes in terms of mechanism of how calcipotriol decreases proliferation. Cell proliferation was analyzed by MTT assay. The dif...
Article
Aims: To improve the production of sweet-tasting protein brazzein in Lactococcus lactis using controlled fermentation conditions. Methods and results: The nisin-controlled expression system was used for brazzein expression. The concentration of nisin for induction and the optical density (OD) at induction were therefore optimized, together with...
Article
Full-text available
Brazzein is an intensely sweet-tasting plant protein with good stability, which makes it an attractive alternative to sucrose. A brazzein gene has been designed, synthesized, and expressed in Escherichia coli at 30 degrees C to yield brazzein in a soluble form and in considerable quantity. Antibodies have been produced using brazzein fused to His-t...
Article
Inhibitory peptide of papain-like cysteine proteases, affinity selected from a random disulfide constrained phage-displayed peptide library, was grafted to staphylococcal protein A's B domain. Scaffold protein was additionally modified in order to allow solvent exposed display of peptide loop. Correct folding of fusion proteins was confirmed by CD-...

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Projects (2)
Project
The aim is to expand the substrate range for the production of medium-chain carboxylates by anaerobic fermentation with bacterial consortia. Tools and strategies will be developed to unlock the full potential of microbial communities facilitating bioconversion processes with lignocellulosic feedstock. Details are available on www.cell4chem.eu
Project
CA19123 - PHOENIX: Protection, Resilience, Rehabilitation of damaged environment European Cooperation in Science and Technology (COST) Action - Horizon 2020 Framework Programme (H2020) Visit us at: https://www.cost.eu/actions/CA19123/ https://www.cost-phoenix.eu/ https://en-gb.facebook.com/phoenix.cost https://twitter.com/PHOENIX_COST https://www.instagram.com/phoenix_cost/ https://www.linkedin.com/groups/8992578/