Publications
2026
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Testing the safety of nature-based microbial exposure in atopic dermatitis patients: a randomized, placebo-controlled, double-blinded pilot trial
The biodiversity hypothesis posits that contact with microbial biodiversity is beneficial for human health, and that the loss of such contact may contribute to immune-mediated diseases such as atopy. Based on this hypothesis, we aimed to investigate whether a lotion containing a highly diverse mixture of inactivated natural microbes is a safe and feasible method to administer nature-based microbial exposure to humans, and to assess its effects on healthy and atopic skin. Participants with atopic... -
Competitive protein adsorption on silicate bioactive glasses
Recent studies have highlighted a poor correlation between the outcomes of in vitro and in vivo characterization of biomaterials. This highlights the poor reliability of the current in vitro models, caused by the lack of knowledge concerning the early-stage interactions between the implanted material and its surrounding tissue, which is largely regulated by protein adsorption on implant. This study investigates the adsorption kinetics of human serum albumin (HSA), immunoglobulin G (IgG), and... -
Avidin is evolutionarily conserved in fish but dispensable for development and resistance against Streptococcus agalactiae in zebrafish
Biotin is a vital cofactor in cellular carboxylation reactions and avidins are biotin-binding proteins that are produced by bacteria and fungi but also by egg-laying vertebrates, including avian species and zebrafish (Danio rerio). Although avidins have proposed roles in embryonic development and immunity, their biological significance is poorly characterized. Moreover, besides zebrafish, the presence of avidins in other fish species has not been explored. Here, we cataloged avidins in fish... -
Response to the Comment "On Determination of Force on Bead-Surface Linker Proteins" by Rasool Dezhkam and Cheng Zhu (smll.202510363)
A recently published comment challenges the data analysis we employed to quantify nanomechanical properties in our force spectroscopy experiments. In the corresponding measurements, sub-µm-sized fluorescent beads are linked via nm-sized macromolecules ("linker") to the bottom of a microfluidic channel. Application of a flow through the channel generates a well-defined shear force acting on the bead, which deforms the linker and can be followed with nm spatial and sub-pN force resolution and high... -
Red-to-Near-Infrared Fluorescence Resonance Energy Transfer Reporters for Dual Imaging Applications
Fluorescence resonance energy transfer (FRET) biosensors enable quantitative visualization of protein interactions and signaling dynamics in living cells. However, most fluorescent protein (FP) FRET pairs occupy overlapping spectral regions, limiting multiplexing and simultaneous imaging of multiple pathways. In particular, the limited availability of well-characterized near-infrared (NIR) acceptors has constrained robust dual-FRET measurements within single cells. Here, we characterize a... -
Janus kinase 2 activation loop as a regulator of catalysis and trans-activation
Protein kinases regulate essential cellular processes such as apoptosis, proliferation, and growth. Precise regulation of kinase activity is critical for proper signal transduction and is often mediated by activation-loop phosphorylation. Janus kinases (JAKs) employ a unique regulatory mechanism: they remain autoinhibited by their pseudokinase domains until cytokine stimulation triggers dimerization and trans-phosphorylation of two activation-loop tyrosines. Despite its relevance for JAK... -
Discovering Age- and Sex-Specific Genetic Risk Factors in Sensorineural Hearing Loss: Genome-Wide Evidence from Large-Scale Biobanks
CONCLUSIONS: Previously unreported SNHL risk loci and differences in effect sizes found in this study provide additional insight into the genetic underpinnings of SNHL. Our results validate the role of mechano-transduction and genetic components affecting the structure of the inner ear in the background of SNHL. Our study contributes to our understanding of the genetic causes of SNHL and may open the door for further translational research. -
Acidosis Regulates Microtubule Dynamics via the β1 Integrin/RhoA/CRMP-2 Axis
Microtubules are dynamic cytoskeletal filaments that have important organizing roles in all eukaryotic cells. Early in vitro studies on the effect of pH on microtubule stability focused on microtubules isolated from whole cell lysates, which can only replicate changes in intracellular pH. However, how extracellular pH can affect microtubule dynamics remains unclear. Here, we report that acidosis activates β1 integrin by increasing its affinity for RGD-containing ligands through the displacement... -
Coxsackie B1 virus-like particle that lacks VP4 protein demonstrates improved vaccine scalability, stability and immunogenicity
CONCLUSIONS: VLPΔVP4 represents a promising next-generation CVB vaccine candidate with broad applicability against enteroviruses. Removal of VP4 may mitigate the risk for non-beneficial immune imprinting while enabling high purity, long-term stability, and improved manufacturing efficiency. -
Reprogramming Immunogenicity of Iron Oxide Nanoparticles through Sulfated Glycan Presentation
Heparin (HP) and dextran sulfate (DS) are well-known for their anti-thrombotic and immunomodulatory properties; however, a direct comparison of their immunological responses when used in drug delivery applications is lacking. This study addresses this gap by evaluating the immunological behavior of superparamagnetic iron oxide nanoparticles (SPIONs) coated with HP or DS in human whole blood, primary immune cells, endothelial cells, and in vivo. Both HP-SPIONs and DS-SPIONs effectively suppressed...
2025
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De novo talin-1 variant L353F connects multifaceted clinical symptoms to alterations in talin-1 function
Talin-1 is a central integrin adapter protein connecting cytoplasmic domains of integrins to the cytoskeleton. These talin-1-mediated mechanical linkages are crucial for cellular functions such as cell movement and connections with other cells. Here, we report a patient carrying a missense variant, L353F, in the talin-1 head which is associated with a complex set of symptoms, including skin lesions, blood cell abnormalities, and congenital cataracts. We conducted structural and cellular...
2024
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Structural insight into rabies virus neutralization revealed by an engineered antibody scaffold
Host-cell entry of the highly pathogenic rabies virus (RABV) is mediated by glycoprotein (G) spikes, which also comprise the primary target for the humoral immune response. RABV glycoprotein (RABV-G) displays several antigenic sites that are targeted by neutralizing monoclonal antibodies (mAbs). In this study, we determined the epitope of a potently neutralizing human mAb, CR57, which we engineered into a diabody format to facilitate crystallization. We report the crystal structure of the CR57... -
Experimental VLP vaccine displaying a furin antigen elicits production of autoantibodies and is well tolerated in mice
Proprotein convertase (PCSK) enzymes serve a wide range of regulatory roles in mammals, for example in metabolism and immunity, and altered activity of PCSKs is associated with disorders, such as cardiovascular disease and cancer. Inhibition of PCSK9 activity with therapeutic antibodies or small interfering RNAs is used in the clinic to lower blood cholesterol, and RNA interference -based silencing of FURIN (PCSK3) is being evaluated in clinical trials as a cancer treatment. Inhibiting these... -
Talin2 binds to non-muscle myosin IIa and regulates cell attachment and fibronectin secretion
Talin2 is localized to large focal adhesions and is indispensable for traction force generation, invadopodium formation, cell invasion as well as metastasis. Talin2 has a higher affinity toward β-integrin tails than talin1. Moreover, disruption of the talin2-β-integrin interaction inhibits traction force generation, invadopodium formation and cell invasion, indicating that a strong talin2-β-integrin interaction is required for talin2 to fulfill these functions. Nevertheless, the role of talin2... -
Tensin-2 interactomics reveals interaction with GAPDH and a phosphorylation-mediated regulatory role in glycolysis
Integrin adaptor proteins, like tensin-2, are crucial for cell adhesion and signaling. However, the function of tensin-2 beyond localizing to focal adhesions remain poorly understood. We utilized proximity-dependent biotinylation and Strep-tag affinity proteomics to identify interaction partners of tensin-2 in Flp-In 293 T-REx cells. Interactomics linked tensin-2 to known focal adhesion proteins and the dystrophin glycoprotein complex, while also uncovering novel interaction with the glycolytic... -
Talin-1 variants associated with spontaneous coronary artery dissection (SCAD) highlight how even subtle changes in multi-functional scaffold proteins can manifest in disease
Variants of talin-1 (TLN1) have recently been linked with spontaneous coronary artery dissection (SCAD) a condition where a tear can form in the wall of a heart artery necessitating immediate medical care. One talin-1 variant, A2013T, has an extensive familial pedigree of SCAD, which led to the screening for, and identification of, further talin-1 variants in SCAD patients. Here we evaluated these variants with commonly used pathogenicity prediction tools and found it challenging to reliably... -
Molecular dynamics simulations reveal how vinculin refolds partially unfolded talin rod helices to stabilize them against mechanical force
Vinculin binds to specific sites of mechanically unfolded talin rod domains to reinforce the coupling of the cell's exterior to its force generation machinery. Force-dependent vinculin-talin complexation and dissociation was previously observed as contraction or extension of the unfolded talin domains respectively using magnetic tweezers. However, the structural mechanism underlying vinculin recognition of unfolded vinculin binding sites (VBSs) in talin remains unknown. Using molecular dynamics... -
Genome-wide association study indicates novel associations of annexin A13 to secretory and GAS2L2 with mucous otitis media
To evaluate the genetics of chronic nonsuppurative otitis media (OM). We performed a genome-wide association study of 429,599 individuals included in the FinnGen study using three different case definitions: combined chronic nonsuppurative OM (7034 cases) (included serous and mucous chronic OM), mucous chronic OM (5953 cases), and secretory chronic OM (1689 cases). Individuals without otitis media were used as controls (417,745 controls). We used immunohistochemistry (IHC) of the murine middle... -
Production of norovirus-, rotavirus-, and enterovirus-like particles in insect cells is simplified by plasmid-based expression
Insect cells have long been the main expression host of many virus-like particles (VLP). VLPs resemble the respective viruses but are non-infectious. They are important in vaccine development and serve as safe model systems in virus research. Commonly, baculovirus expression vector system (BEVS) is used for VLP production. Here, we present an alternative, plasmid-based system for VLP expression, which offers distinct advantages: in contrast to BEVS, it avoids contamination by baculoviral... -
Acetyl-NPKY of integrin-β1 binds KINDLIN2 to control endothelial cell proliferation and junctional integrity
Integrin-dependent crosstalk between cell-matrix adhesions and cell-cell junctions is critical for controlling endothelial permeability and proliferation in cancer and inflammatory diseases but remains poorly understood. Here, we investigated how acetylation of the distal NPKY-motif of Integrin-β1 influences endothelial cell physiology and barrier function. Expression of an acetylation-mimetic β1-K794Q-GFP mutant led to the accumulation of immature cell-matrix adhesions accompanied by a... -
Progression of herpesvirus infection remodels mitochondrial organization and metabolism
Viruses target mitochondria to promote their replication, and infection-induced stress during the progression of infection leads to the regulation of antiviral defenses and mitochondrial metabolism which are opposed by counteracting viral factors. The precise structural and functional changes that underlie how mitochondria react to the infection remain largely unclear. Here we show extensive transcriptional remodeling of protein-encoding host genes involved in the respiratory chain, apoptosis,...
2023
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Visible Light-Induced Specific Protein Reaction Delineates Early Stages of Cell Adhesion
Light is well-established for control of bond breakage but not for control of specific bond formation in complex environments. We previously engineered the diffusion-limited reactivity of the SpyTag003 peptide with its protein partner SpyCatcher003 through spontaneous isopeptide bond formation. This system enables precise and irreversible assembly of biological building blocks with applications from biomaterials to vaccines. Here we establish a system for the rapid control of this amide bond... -
Thrombus Aspirates From Patients With Acute Ischemic Stroke Are Infiltrated by Viridans Streptococci
CONCLUSIONS: Oral streptococci were found in aspirated thrombi of patients with acute ischemic stroke as well as in carotid artery samples. Our results suggest that viridans streptococci group bacteria may play a role in the pathophysiology of ischemic stroke. -
Visible light-induced specific protein reaction delineates early stages of cell adhesion
Light is well established for control of bond breakage, but not for control of specific bond formation in complex environments. We previously engineered diffusion-limited reactivity of SpyTag003 peptide with its protein partner SpyCatcher003 through spontaneous transamidation. This system enables precise and irreversible assembly of biological building blocks, with applications from biomaterials to vaccines. Here, we establish a system for rapid control of this amide bond formation with visible... -
DNA-origami-directed virus capsid polymorphism
Viral capsids can adopt various geometries, most iconically characterized by icosahedral or helical symmetries. Importantly, precise control over the size and shape of virus capsids would have advantages in the development of new vaccines and delivery systems. However, current tools to direct the assembly process in a programmable manner are exceedingly elusive. Here we introduce a modular approach by demonstrating DNA-origami-directed polymorphism of single-protein subunit capsids. We achieve... -
SpyTag/SpyCatcher display of influenza M2e peptide on norovirus-like particle provides stronger immunization than direct genetic fusion
INTRODUCTION: Virus-like particles (VLPs) are similar in size and shape to their respective viruses, but free of viral genetic material. This makes VLP-based vaccines incapable of causing infection, but still effective in mounting immune responses. Noro-VLPs consist of 180 copies of the VP1 capsid protein. The particle tolerates C-terminal fusion partners, and VP1 fused with a C-terminal SpyTag self-assembles into a VLP with SpyTag protruding from its surface, enabling conjugation of antigens... -
ConFERMing the role of talin in integrin activation and mechanosignaling
Talin (herein referring to the talin-1 form), is a cytoskeletal adapter protein that binds integrin receptors and F-actin, and is a key factor in the formation and regulation of integrin-dependent cell-matrix adhesions. Talin forms the mechanical link between the cytoplasmic domain of integrins and the actin cytoskeleton. Through this linkage, talin is at the origin of mechanosignaling occurring at the plasma membrane-cytoskeleton interface. Despite its central position, talin is not able to... -
Structural mechanism for inhibition of PP2A-B56α and oncogenicity by CIP2A
The protein phosphatase 2A (PP2A) heterotrimer PP2A-B56α is a human tumour suppressor. However, the molecular mechanisms inhibiting PP2A-B56α in cancer are poorly understood. Here, we report molecular level details and structural mechanisms of PP2A-B56α inhibition by an oncoprotein CIP2A. Upon direct binding to PP2A-B56α trimer, CIP2A displaces the PP2A-A subunit and thereby hijacks both the B56α, and the catalytic PP2Ac subunit to form a CIP2A-B56α-PP2Ac pseudotrimer. Further, CIP2A competes... -
Microfluidics-Based Force Spectroscopy Enables High-Throughput Force Experiments with Sub-Nanometer Resolution and Sub-Piconewton Sensitivity
Several techniques have been established to quantify the mechanicals of single molecules. However, most of them show only limited capabilities of parallelizing the measurement by performing many individual measurements simultaneously. Herein, a microfluidics-based single-molecule force spectroscopy method, which achieves sub-nanometer spatial resolution and sub-piconewton sensitivity and is capable of simultaneously quantifying hundreds of single-molecule targets in parallel, is presented. It...
2022
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Discovering Age- and Sex-Specific Genetic Risk Factors in Sensorineural Hearing Loss: Genome-Wide Evidence from Large-Scale Biobanks
CONCLUSIONS: Previously unreported SNHL risk loci and differences in effect sizes found in this study provide additional insight into the genetic underpinnings of SNHL. Our results validate the role of mechano-transduction and genetic components affecting the structure of the inner ear in the background of SNHL. Our study contributes to our understanding of the genetic causes of SNHL and may open the door for further translational research. -
The mechanical cell - the role of force dependencies in synchronising protein interaction networks
The role of mechanical signals in the proper functioning of organisms is increasingly recognised, and every cell senses physical forces and responds to them. These forces are generated both from outside the cell or via the sophisticated force-generation machinery of the cell, the cytoskeleton. All regions of the cell are connected via mechanical linkages, enabling the whole cell to function as a mechanical system. In this Review, we define some of the key concepts of how this machinery... -
Coxsackievirus B infections are common in Cystic Fibrosis and experimental evidence supports protection by vaccination
Viral respiratory tract infections exacerbate airway disease and facilitate life-threatening bacterial colonization in cystic fibrosis (CF). Annual influenza vaccination is recommended and vaccines against other common respiratory viruses may further reduce pulmonary morbidity risk. Enteroviruses have been found in nasopharyngeal samples from CF patients experiencing pulmonary exacerbations. Using serology tests, we found that infections by a group of enteroviruses, Coxsackievirus Bs (CVBs), are... -
Biochemical and Biophysical Characterization of Carbonic Anhydrase VI from Human Milk and Saliva
Carbonic anhydrases (CA, EC 4.2.1.1) catalyze the hydration of carbon dioxide and take part in many essential physiological processes. In humans, 15 CAs are characterized, including the only secreted isoenzyme CA VI. CA VI has been linked to specific processes in the mouth, namely bitter taste perception, dental caries, and maintenance of enamel pellicle, and implicated in several immunity-related phenomena. However, little is known of the mechanisms of the above. In this study, we characterized... -
Talin variant P229S compromises integrin activation and associates with multifaceted clinical symptoms
Adhesion of cells to the extracellular matrix (ECM) must be exquisitely coordinated to enable development and tissue homeostasis. Cell-ECM interactions are regulated by multiple signalling pathways that coordinate the activation state of the integrin family of ECM receptors. The protein talin is pivotal in this process, and talin's simultaneous interactions with the cytoplasmic tails of the integrins and the plasma membrane are essential to enable robust, dynamic control of integrin activation... -
A reverse vaccinology approach on transmembrane carbonic anhydrases from Plasmodium species as vaccine candidates for malaria prevention
CONCLUSIONS: The predicted results revealed that tmCAs from Plasmodium spp. can be potential targets for vaccination against malaria. -
The production and biochemical characterization of α-carbonic anhydrase from Lactobacillus rhamnosus GG
We report the production and biochemical characterization of an α-carbonic anhydrase (LrhCA) from gram-positive probiotic bacteria Lactobacillus rhamnosus GG. CAs form a family of metalloenzymes that catalyze hydration of CO(2)/interconversion between CO(2) and water to bicarbonate ions and protons. They are divided into eight independent gene families (α, β, γ, δ, ζ, η, θ, and ι). Interestingly, many pathogens have been identified with only β- and/or γ-CAs, which can be targeted with... -
Rapid high-throughput compatible label-free virus particle quantification method based on time-resolved luminescence
Viruses play a major role in modern society and create risks from global pandemics and bioterrorism to challenges in agriculture. Virus infectivity assays and genome copy number determination methods are often used to obtain information on virus preparations used in diagnostics and vaccine development. However, these methods do not provide information on virus particle count. Current methods to measure the number of viral particles are often cumbersome and require highly purified virus... -
Hepcidin is potential regulator for renin activity
An association between genetic variants in the genes HFE, HJV, BMP4 and arterial hypertension has been shown earlier. Proteins encoded by these genes participate in the signalling routes leading eventually to the production of the peptide hormone hepcidin. Mutations in these genes have been associated with the abnormal production of hepcidin in the body. This finding led to studies exploring the possible role of hepcidin in regulating the activity of blood pressure related renin-angiotensin... -
Detection of cultured breast cancer cells from human tumor-derived matrix by differential ion mobility spectrometry
The primary treatment of breast cancer is the surgical removal of the tumor with an adequate healthy tissue margin. An intraoperative method for assessing surgical margins could optimize tumor resection. Differential ion mobility spectrometry (DMS) is applicable for tissue analysis and allows for the differentiation of malignant and benign tissues. However, the number of cancer cells necessary for detection remains unknown. We studied the detection threshold of DMS for cancer cell identification... -
Antigenicity and immunogenicity of HA2 and M2e influenza virus antigens conjugated to norovirus-like, VP1 capsid-based particles by the SpyTag/SpyCatcher technology
Virus-like particles (VLPs) modified through different molecular technologies are employed as delivery vehicles or platforms for heterologous antigen display. We have recently created a norovirus (NoV) VLP platform, where two influenza antigens, the extracellular domain of matrix protein M2 (M2e) or the stem domain of the major envelope glycoprotein hemagglutinin (HA2) are displayed on the surface of the NoV VLPs by SpyTag/SpyCatcher conjugation. To demonstrate the feasibility of the platform to... -
Biochemical and structural characterization of beta-carbonic anhydrase from the parasite Trichomonas vaginalis
Trichomonas vaginalis is a unicellular parasite and responsible for one of the most common sexually transmittable infections worldwide, trichomoniasis. Carbonic anhydrases (CAs) are enzymes found in all lifeforms and are known to play a vital role in many biochemical processes in organisms including the maintenance of acid-base homeostasis. To date, eight evolutionarily divergent but functionally convergent forms of CAs (α, β, γ, δ, ζ, η, θ, and ι) have been discovered. The human genome contains...
2021
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Discovering Age- and Sex-Specific Genetic Risk Factors in Sensorineural Hearing Loss: Genome-Wide Evidence from Large-Scale Biobanks
CONCLUSIONS: Previously unreported SNHL risk loci and differences in effect sizes found in this study provide additional insight into the genetic underpinnings of SNHL. Our results validate the role of mechano-transduction and genetic components affecting the structure of the inner ear in the background of SNHL. Our study contributes to our understanding of the genetic causes of SNHL and may open the door for further translational research. -
Coxsackie B1 virus-like particle that lacks VP4 protein demonstrates improved vaccine scalability, stability and immunogenicity
CONCLUSIONS: VLPΔVP4 represents a promising next-generation CVB vaccine candidate with broad applicability against enteroviruses. Removal of VP4 may mitigate the risk for non-beneficial immune imprinting while enabling high purity, long-term stability, and improved manufacturing efficiency. -
Reprogramming Immunogenicity of Iron Oxide Nanoparticles through Sulfated Glycan Presentation
Heparin (HP) and dextran sulfate (DS) are well-known for their anti-thrombotic and immunomodulatory properties; however, a direct comparison of their immunological responses when used in drug delivery applications is lacking. This study addresses this gap by evaluating the immunological behavior of superparamagnetic iron oxide nanoparticles (SPIONs) coated with HP or DS in human whole blood, primary immune cells, endothelial cells, and in vivo. Both HP-SPIONs and DS-SPIONs effectively suppressed... -
Antigenicity and immunogenicity of HA2 and M2e influenza virus antigens conjugated to norovirus-like, VP1 capsid-based particles by the SpyTag/SpyCatcher technology
Virus-like particles (VLPs) modified through different molecular technologies are employed as delivery vehicles or platforms for heterologous antigen display. We have recently created a norovirus (NoV) VLP platform, where two influenza antigens, the extracellular domain of matrix protein M2 (M2e) or the stem domain of the major envelope glycoprotein hemagglutinin (HA2) are displayed on the surface of the NoV VLPs by SpyTag/SpyCatcher conjugation. To demonstrate the feasibility of the platform to... -
Biochemical and structural characterization of beta-carbonic anhydrase from the parasite Trichomonas vaginalis
Trichomonas vaginalis is a unicellular parasite and responsible for one of the most common sexually transmittable infections worldwide, trichomoniasis. Carbonic anhydrases (CAs) are enzymes found in all lifeforms and are known to play a vital role in many biochemical processes in organisms including the maintenance of acid-base homeostasis. To date, eight evolutionarily divergent but functionally convergent forms of CAs (α, β, γ, δ, ζ, η, θ, and ι) have been discovered. The human genome contains... -
Avidin-Conjugated Nanofibrillar Cellulose Hydrogel Functionalized with Biotinylated Fibronectin and Vitronectin Promotes 3D Culture of Fibroblasts
The future success of physiologically relevant three-dimensional (3D) cell/tissue models is dependent on the development of functional biomaterials, which can provide a well-defined 3D environment instructing cellular behavior. To establish a platform to produce tailored hydrogels, we conjugated avidin (Avd) to anionic nanofibrillar cellulose (aNFC) and demonstrated the use of the resulting Avd-NFC hydrogel for 3D cell culture, where Avd-NFC allows easy functionalization via biotinylated... -
Surface Modification of Bioactive Glass Promotes Cell Attachment and Spreading
Phosphate glasses have several advantages over traditional silicate-based bioglasses but are inferior in the crucial step of cell attachment to their surface. Here, as a proof of concept, we analyze fibroblast attachment to the phosphate glass surface subjected to basic treatment and silanization. Silicate (S53P4)- and phosphate (Sr50)-based bioactive glasses were either untreated or surface-treated with basic buffer and functionalized with silane. The surface-treated samples were studied as... -
Coxsackievirus B Vaccines Prevent Infection-Accelerated Diabetes in NOD Mice and Have No Disease-Inducing Effect
Enteroviruses, including the Coxsackievirus Bs (CVB), have been implicated as causal agents in human type 1 diabetes. Immunization of at-risk individuals with a CVB vaccine provides an attractive strategy for elucidating the role of CVBs in the disease etiology. Previously, we have shown that an inactivated whole-virus vaccine covering all CVB serotypes (CVB1-6) is safe to administer and highly immunogenic in preclinical models, including nonhuman primates. Before initiating clinical trials with... -
Polyphenols Epigallocatechin Gallate and Resveratrol, and Polyphenol-Functionalized Nanoparticles Prevent Enterovirus Infection through Clustering and Stabilization of the Viruses
To efficiently lower virus infectivity and combat virus epidemics or pandemics, it is important to discover broadly acting antivirals. Here, we investigated two naturally occurring polyphenols, Epigallocatechin gallate (EGCG) and Resveratrol (RES), and polyphenol-functionalized nanoparticles for their antiviral efficacy. Concentrations in the low micromolar range permanently inhibited the infectivity of high doses of enteroviruses (10⁷ PFU/mL). Sucrose gradient separation of radiolabeled... -
Surface Modification of Bioresorbable Phosphate Glasses for Controlled Protein Adsorption
The traditional silicate bioactive glasses exhibit poor thermal processability, which inhibits fiber drawing or sintering into scaffolds. The composition of the silicate glasses has been modified to enable hot processing. However, the hot forming ability is generally at the expense of bioactivity. Metaphosphate glasses, on the other hand, possess excellent thermal processability, congruent dissolution, and a tailorable degradation rate. However, due to the layer-by-layer dissolution mechanism,... -
Comparative analysis of two paradigm bacteriophytochromes reveals opposite functionalities in two-component signaling
Bacterial phytochrome photoreceptors usually belong to two-component signaling systems which transmit environmental stimuli to a response regulator through a histidine kinase domain. Phytochromes switch between red light-absorbing and far-red light-absorbing states. Despite exhibiting extensive structural responses during this transition, the model bacteriophytochrome from Deinococcus radiodurans (DrBphP) lacks detectable kinase activity. Here, we resolve this long-standing conundrum by... -
Bacterial avidins are a widely distributed protein family in Actinobacteria, Proteobacteria and Bacteroidetes
CONCLUSIONS: Bacterial avidins are a taxonomically and ecologically diverse group mainly found in Actinobacteria, Proteobacteria and Bacteroidetes, associated often with plant invasiveness. Avidin encoding genes in plasmids hint that avidins may be horizontally transferred. The current survey may be used as a basis in attempts to understand the ecological significance of biotin-binding capacity. -
Structural and functional analysis of LIM domain-dependent recruitment of paxillin to αvβ3 integrin-positive focal adhesions
The LIM domain-dependent localization of the adapter protein paxillin to β3 integrin-positive focal adhesions (FAs) is not mechanistically understood. Here, by combining molecular biology, photoactivation and FA-isolation experiments, we demonstrate specific contributions of each LIM domain of paxillin and reveal multiple paxillin interactions in adhesion-complexes. Mutation of β3 integrin at a putative paxillin binding site (β3^(VE/YA)) leads to rapidly inward-sliding FAs, correlating with... -
Activation of the β-carbonic anhydrase from the protozoan pathogen <em>Trichomonas vaginalis</em> with amines and amino acids
We report the first activation study of the β-class carbonic anhydrase (CA, EC 4.2.1.1) encoded in the genome of the protozoan pathogen Trichomonas vaginalis, TvaCA1. Among 24 amino acid and amine activators investigated, derivatives incorporating a second carboxylic moiety, such as L-Asp, L- and D-Glu, were devoid of activating effects up to concentrations of 50 µM within the assay system, whereas the corresponding compounds with a CONH(2) moiety, i.e. L-Gln and L-Asn showed modest activating... -
Modular vaccine platform based on the norovirus-like particle
CONCLUSIONS: The modular noro-VLP vaccine platform presented here offers a rapid, convenient and safe method to present various soluble protein antigens to the immune system for vaccination and antibody production purposes. -
Extrusion-Based Bioprinting of Multilayered Nanocellulose Constructs for Cell Cultivation Using <em>In Situ</em> Freezing and Preprint CaCl<sub>2</sub> Cross-Linking
Extrusion-based bioprinting with a preprint cross-linking agent and an in situ cooling stage provides a versatile method for the fabrication of 3D structures for cell culture. We added varying amounts of calcium chloride as a precross-linker into native nanofibrillated cellulose (NFC) hydrogel prior to 3D bioprinting to fabricate structurally stable multilayered constructs without the need for a separate cross-linking bath. To further enhance their stability, we bioprinted the multilayered... -
Cancer associated talin point mutations disorganise cell adhesion and migration
Talin-1 is a key component of the multiprotein adhesion complexes which mediate cell migration, adhesion and integrin signalling and has been linked to cancer in several studies. We analysed talin-1 mutations reported in the Catalogue of Somatic Mutations in Cancer database and developed a bioinformatics pipeline to predict the severity of each mutation. These predictions were then assessed using biochemistry and cell biology experiments. With this approach we were able to identify several... -
Inhibition of the β-carbonic anhydrase from the protozoan pathogen <em>Trichomonas vaginalis</em> with sulphonamides
Sulphonamides and their isosteres are classical inhibitors of the carbonic anhydrase (CAs, EC 4.2.1.1) metalloenzymes. The protozoan pathogen Trichomonas vaginalis encodes two such enzymes belonging to the β-class, TvaCA1 and TvaCA2. Here we report the first sulphonamide inhibition study of TvaCA1, with a series of simple aromatic/heterocyclic primary sulphonamides as well as with clinically approved/investigational drugs for a range of pathologies (diuretics, antiglaucoma, antiepileptic,... -
Regenerable Biosensors for Small-Molecule Kinetic Characterization Using SPR
A key activity in small-molecule drug discovery is the characterization of compound-target interactions. Surface plasmon resonance (SPR) is a flexible technique for this purpose, with a wide affinity range (micromoles to picomoles), low protein requirements, and the ability to characterize the kinetics of compound binding. However, a key requirement of SPR is the immobilization of the target protein to the surface of the sensor chip. The most commonly used immobilization techniques (covalent...
2020
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Discovering Age- and Sex-Specific Genetic Risk Factors in Sensorineural Hearing Loss: Genome-Wide Evidence from Large-Scale Biobanks
CONCLUSIONS: Previously unreported SNHL risk loci and differences in effect sizes found in this study provide additional insight into the genetic underpinnings of SNHL. Our results validate the role of mechano-transduction and genetic components affecting the structure of the inner ear in the background of SNHL. Our study contributes to our understanding of the genetic causes of SNHL and may open the door for further translational research. -
Extrusion-Based Bioprinting of Multilayered Nanocellulose Constructs for Cell Cultivation Using <em>In Situ</em> Freezing and Preprint CaCl<sub>2</sub> Cross-Linking
Extrusion-based bioprinting with a preprint cross-linking agent and an in situ cooling stage provides a versatile method for the fabrication of 3D structures for cell culture. We added varying amounts of calcium chloride as a precross-linker into native nanofibrillated cellulose (NFC) hydrogel prior to 3D bioprinting to fabricate structurally stable multilayered constructs without the need for a separate cross-linking bath. To further enhance their stability, we bioprinted the multilayered... -
Crystal structure of the FERM-folded talin head reveals the determinants for integrin binding
Binding of the intracellular adapter proteins talin and its cofactor, kindlin, to the integrin receptors induces integrin activation and clustering. These processes are essential for cell adhesion, migration, and organ development. Although the talin head, the integrin-binding segment in talin, possesses a typical FERM-domain sequence, a truncated form has been crystallized in an unexpected, elongated form. This form, however, lacks a C-terminal fragment and possesses reduced β3-integrin... -
Regenerable Biosensors for Small-Molecule Kinetic Characterization Using SPR
A key activity in small-molecule drug discovery is the characterization of compound-target interactions. Surface plasmon resonance (SPR) is a flexible technique for this purpose, with a wide affinity range (micromoles to picomoles), low protein requirements, and the ability to characterize the kinetics of compound binding. However, a key requirement of SPR is the immobilization of the target protein to the surface of the sensor chip. The most commonly used immobilization techniques (covalent... -
Inhibition of the newly discovered β‑carbonic anhydrase from the protozoan pathogen Trichomonas vaginalis with inorganic anions and small molecules
The protozoan pathogen Trichomonas vaginalis encodes two carbonic anhydrases (CAs, EC 4.2.1.1) belonging to the β-class. One of these enzymes, T. vaginalis carbonic anhydrase 1 (TvaCA1), was recently cloned and characterized by our group, and its X-ray crystal structure reported. No inhibitors of this enzyme were reported up until now. Here we investigated the inhibition of TvaCA1 with inorganic anions and small molecules and observed that thiocyanate, cyanide, selenite, selenocyanate and... -
The F1 loop of the talin head domain acts as a gatekeeper in integrin activation and clustering
Integrin activation and clustering by talin are early steps of cell adhesion. Membrane-bound talin head domain and kindlin bind to the β integrin cytoplasmic tail, cooperating to activate the heterodimeric integrin, and the talin head domain induces integrin clustering in the presence of Mn^(2+) Here we show that kindlin-1 can replace Mn^(2+) to mediate β3 integrin clustering induced by the talin head, but not that induced by the F2-F3 fragment of talin. Integrin clustering mediated by kindlin-1... -
Sulphonamide inhibition profile of <em>Staphylococcus aureus</em> β-carbonic anhydrase
This paper presents the production and kinetic and inhibitory characterisation of β-carbonic anhydrase from the opportunistic bacterium Staphylococcus aureus (SauBCA). From the eight different carbonic anhydrase (CA) families known to date, humans have only the α-form, whereas many clinically relevant pathogens have β- and/or γ-form(s). Based on this discovery, β- and γ-CAs have been introduced as promising new anti-infective targets. The results of this study revealed that recombinant SauBCA... -
Correction: Saarinen, N.V.V., et al. Multiplexed High-Throughput Serological Assay for Human Enteroviruses. Microorganismis 2020, 8, 963
The authors wish to make the following corrections to this paper [...]. -
Structural Insight into CVB3-VLP Non-Adjuvanted Vaccine
Coxsackievirus B (CVB) enteroviruses are common pathogens that can cause acute and chronic myocarditis, dilated cardiomyopathy, aseptic meningitis, and they are hypothesized to be a causal factor in type 1 diabetes. The licensed enterovirus vaccines and those currently in clinical development are traditional inactivated or live attenuated vaccines. Even though these vaccines work well in the prevention of enterovirus diseases, new vaccine technologies, like virus-like particles (VLPs), can offer... -
Mechanical Unfolding of Proteins-A Comparative Nonequilibrium Molecular Dynamics Study
Mechanical signals regulate functions of mechanosensitive proteins by inducing structural changes that are determinant for force-dependent interactions. Talin is a focal adhesion protein that is known to extend under mechanical load, and it has been shown to unfold via intermediate states. Here, we compared different nonequilibrium molecular dynamics (MD) simulations to study unfolding of the talin rod. We combined boxed MD (BXD), steered MD, and umbrella sampling (US) techniques and provide... -
Modern Tools for Rapid Diagnostics of Antimicrobial Resistance
Fast, robust, and affordable antimicrobial susceptibility testing (AST) is required, as roughly 50% of antibiotic treatments are started with wrong antibiotics and without a proper diagnosis of the pathogen. Validated growth-based AST according to EUCAST or CLSI (European Committee on Antimicrobial Susceptibility Testing, Clinical Laboratory Standards Institute) recommendations is currently suggested to guide the antimicrobial therapy. Any new AST should be validated against these standard... -
Rotavirus Inner Capsid VP6 Acts as an Adjuvant in Formulations with Particulate Antigens Only
Novel adjuvants present a concern for adverse effects, generating a need for alternatives. Rotavirus inner capsid VP6 protein could be considered a potential candidate, due to its ability to self-assemble into highly immunogenic nanospheres and nanotubes. These nanostructures exhibit immunostimulatory properties, which resemble those of traditional adjuvants, promoting the uptake and immunogenicity of the co-administered antigens. We have previously elucidated an adjuvant effect of VP6 on... -
Multiplexed High-Throughput Serological Assay for Human Enteroviruses
Immunological assays detecting antibodies against enteroviruses typically use a single enterovirus serotype as antigen. This limits the ability of such assays to detect antibodies against different enterovirus types and to detect possible type-specific variation in antibody responses. We set out to develop a multiplexed assay for simultaneous detection of antibodies against multiple enterovirus and rhinovirus types encompassing all human infecting species. Seven recombinant VP1 proteins from... -
Biochemical and structural characterisation of a protozoan beta-carbonic anhydrase from <em>Trichomonas vaginalis</em>
We report the biochemical and structural characterisation of a beta-carbonic anhydrase (β-CA) from Trichomonas vaginalis, a unicellular parasite responsible for one of the world's leading sexually transmitted infections, trichomoniasis. CAs are ubiquitous metalloenzymes belonging to eight evolutionarily divergent groups (α, β, γ, δ, ζ, η, θ, and ι); humans express only α-CAs, whereas many clinically significant pathogens express only β- and/or γ-CAs. For this reason, the latter two groups of CAs... -
Induction of ligand promiscuity of αVβ3 integrin by mechanical force
αVβ3 integrin can bind to multiple extracellular matrix proteins, including vitronectin (Vn) and fibronectin (Fn), which are often presented to cells in culture as homogenous substrates. However, in tissues, cells experience highly complex and changing environments. To better understand integrin ligand selection in such complex environments, we employed binary-choice substrates of Fn and Vn to dissect αVβ3 integrin-mediated binding to different ligands on the subcellular scale. Super-resolution... -
Competitive binding assay for biotin and biotin derivatives, based on avidin and biotin-4-fluorescein
Biotinylated molecules are extensively employed in bioanalytics and biotechnology. The currently available assays for quantification of biotin groups suffer from low sensitivity, low accuracy, or provide highly variable responses for different biotin derivatives. We developed a competitive binding assay in which avidin was pre-blocked to different extents by the biotinylated analyte and a constant amount of biotin-4-fluorescein (B4F) was added, resulting in strong quenching of the B4F. The assay... -
(Strept)avidin as a template for ligands other than biotin: An overview
Chicken avidin and bacterial streptavidin are workhorses in biotechnology. We have used avidin as a scaffold protein to develop avidin variants with novel ligand-binding affinity, so-called antidins. This article covers the strategy applied in the development of antidins. Using a phage display developed for avidin, immobilized ligands were used to select binders from a phage pool displaying avidin variants with randomized sequence in the protein loops. Antidins binding various ligands with... -
Antibody Responses against Enterovirus Proteases are Potential Markers for an Acute Infection
CONCLUSIONS: Antibody responses against enterovirus proteases are shorter-lived than against structural proteins and can differentiate between IgM positive and negative patients, and therefore they are a potential marker for acute infections. -
Cyanidin-3-glucoside binds to talin and modulates colon cancer cell adhesions and 3D growth
Cyanidin-3-glucoside (C3G) is a natural pigment, found in many colorful fruits and vegetables. It has many health benefits, including anti-inflammation, cancer prevention, and anti-diabetes. Although C3G is assumed to be an antioxidant, it has been reported to affect cell-matrix adhesions. However, the underlying molecular mechanism is unknown. Here, we show that the expression of talin1, a key regulator of integrins and cell adhesions, negatively correlated with the survival rate of colon... -
Syndecan-4 tunes cell mechanics by activating the kindlin-integrin-RhoA pathway
Extensive research over the past decades has identified integrins to be the primary transmembrane receptors that enable cells to respond to external mechanical cues. We reveal here a mechanism whereby syndecan-4 tunes cell mechanics in response to localized tension via a coordinated mechanochemical signalling response that involves activation of two other receptors: epidermal growth factor receptor and β1 integrin. Tension on syndecan-4 induces cell-wide activation of the kindlin-2/β1...
2019
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Discovering Age- and Sex-Specific Genetic Risk Factors in Sensorineural Hearing Loss: Genome-Wide Evidence from Large-Scale Biobanks
CONCLUSIONS: Previously unreported SNHL risk loci and differences in effect sizes found in this study provide additional insight into the genetic underpinnings of SNHL. Our results validate the role of mechano-transduction and genetic components affecting the structure of the inner ear in the background of SNHL. Our study contributes to our understanding of the genetic causes of SNHL and may open the door for further translational research. -
Competitive binding assay for biotin and biotin derivatives, based on avidin and biotin-4-fluorescein
Biotinylated molecules are extensively employed in bioanalytics and biotechnology. The currently available assays for quantification of biotin groups suffer from low sensitivity, low accuracy, or provide highly variable responses for different biotin derivatives. We developed a competitive binding assay in which avidin was pre-blocked to different extents by the biotinylated analyte and a constant amount of biotin-4-fluorescein (B4F) was added, resulting in strong quenching of the B4F. The assay... -
(Strept)avidin as a template for ligands other than biotin: An overview
Chicken avidin and bacterial streptavidin are workhorses in biotechnology. We have used avidin as a scaffold protein to develop avidin variants with novel ligand-binding affinity, so-called antidins. This article covers the strategy applied in the development of antidins. Using a phage display developed for avidin, immobilized ligands were used to select binders from a phage pool displaying avidin variants with randomized sequence in the protein loops. Antidins binding various ligands with... -
Approaching infinite affinity through engineering of peptide-protein interaction
Much of life's complexity depends upon contacts between proteins with precise affinity and specificity. The successful application of engineered proteins often depends on high-stability binding to their target. In recent years, various approaches have enabled proteins to form irreversible covalent interactions with protein targets. However, the rate of such reactions is a major limitation to their use. Infinite affinity refers to the ideal where such covalent interaction occurs at the diffusion... -
Host Cell Calpains Can Cleave Structural Proteins from the Enterovirus Polyprotein
Enteroviruses are small RNA viruses that cause diseases with various symptoms ranging from mild to severe. Enterovirus proteins are translated as a single polyprotein, which is cleaved by viral proteases to release capsid and nonstructural proteins. Here, we show that also cellular calpains have a potential role in the processing of the enteroviral polyprotein. Using purified calpains 1 and 2 in an in vitro assay, we show that addition of calpains leads to an increase in the release of VP1 and... -
Combination of three virus-derived nanoparticles as a vaccine against enteric pathogens; enterovirus, norovirus and rotavirus
Enteric viruses cause diverse infections with substantial morbidity and mortality in children, rotavirus (RV) and norovirus (NoV) being the leading agents of severe pediatric gastroenteritis. Coxsackie B viruses (CVB) are common enteroviruses (EV), associated with increased incidence of severe neonatal CVB disease with potentially fatal consequences. To prevent majority of childhood gastroenteritis, we have developed a non-live NoV-RV combination vaccine consisting of NoV virus-like particles... -
Competition for Membrane Receptors: Norovirus Detachment via Lectin Attachment
Virus internalization into the host cells occurs via multivalent interactions, in which a single virus binds to multiple receptors in parallel. Because of analytical and experimental limitations this complex type of interaction is still poorly understood and quantified. Herein, the multivalent interaction of norovirus-like particles (noroVLPs) with H or B type 1 glycosphingolipids (GSLs), embedded in a supported phospholipid bilayer, is investigated by following the competition between noroVLPs... -
Formalin treatment increases the stability and immunogenicity of coxsackievirus B1 VLP vaccine
Type B Coxsackieviruses (CVBs) are a common cause of acute and chronic myocarditis, dilated cardiomyopathy and aseptic meningitis. However, no CVB-vaccines are available for human use. We have previously produced virus-like particles (VLPs) for CVB3 with a baculovirus-insect cell production system. Here we have explored the potential of a VLP-based vaccine targeting CVB1 and describe the production of CVB1-VLPs with a scalable VLP purification method. The developed purification method consisting... -
A comparative study of the effect of UV and formalin inactivation on the stability and immunogenicity of a Coxsackievirus B1 vaccine
Type B Coxsackieviruses (CVBs) belong to the enterovirus genus, and they cause both acute and chronic diseases in humans. CVB infections usually lead to flu-like symptoms but can also result in more serious diseases such as myocarditis, aseptic meningitis and life-threatening multi-organ infections in young infants. Thus, CVBs have long been considered as important targets of future vaccines. We have previously observed CVB1 capsid disintegration and virus concentration decrease with 12-day long... -
Design of modular gellan gum hydrogel functionalized with avidin and biotinylated adhesive ligands for cell culture applications
This article proposes the coupling of the recombinant protein avidin to the polysaccharide gellan gum to create a modular hydrogel substrate for 3D cell culture and tissue engineering. Avidin is capable of binding biotin, and thus biotinylated compounds can be tethered to the polymer network to improve cell response. The avidin is successfully conjugated to gellan gum and remains functional as shown with fluorescence titration and electrophoresis (SDS-PAGE). Self-standing hydrogels were formed... -
Cell Adhesion by Integrins
Integrins are heterodimeric cell surface receptors ensuring the mechanical connection between cells and the extracellular matrix. In addition to the anchorage of cells to the extracellular matrix, these receptors have critical functions in intracellular signaling, but are also taking center stage in many physiological and pathological conditions. In this review, we provide some historical, structural, and physiological notes so that the diverse functions of these receptors can be appreciated and... -
Identifying yeasts using surface enhanced Raman spectroscopy
The molecular fingerprints of yeasts Saccharomyces cerevisiae, Dekkera bruxellensis, and Wickerhamomyces anomalus (former name Pichia anomala) have been examined using surface-enhanced Raman spectroscopy (SERS) and helium ion microscopy (HIM). The SERS spectra obtained from cell cultures (lysate and non-treated cells) distinguish between these very closely related fungal species. Highly SERS active silver nano-particles suitable for detecting complex biomolecules were fabricated using a simple... -
β1D integrin splice variant stabilizes integrin dynamics and reduces integrin signaling by limiting paxillin recruitment
Heterodimeric integrin receptors control cell adhesion, migration and extracellular matrix assembly. While the α integrin subunit determines extracellular ligand specificity, the β integrin chain binds to an acidic residue of the ligand, and cytoplasmic adapter protein families such as talins, kindlins and paxillin, to form mechanosensing cell matrix adhesions. Alternative splicing of the β1 integrin cytoplasmic tail creates ubiquitously expressed β1A, and the heart and skeletal muscle-specific... -
Talin-mediated force transmission and talin rod domain unfolding independently regulate adhesion signaling
Talin protein is one of the key components in integrin-mediated adhesion complexes. Talins transmit mechanical forces between β-integrin and actin, and regulate adhesion complex composition and signaling through the force-regulated unfolding of talin rod domain. Using modified talin proteins, we demonstrate that these functions contribute to different cellular processes and can be dissected. The transmission of mechanical forces regulates adhesion complex composition and phosphotyrosine... -
Molecular features of steroid-binding antidins and their use for assaying serum progesterone
Chicken avidin (Avd) and streptavidin from Streptomyces avidinii are extensively used in bionanotechnology due to their extremely tight binding to biotin (Kd ~ 10-15 M for chicken Avd). We previously reported engineered Avds known as antidins, which have micro- to nanomolar affinities for steroids, non-natural ligands of Avd. Here, we report the 2.8 Å X-ray structure of the sbAvd-2 (I117Y) antidin co-crystallized with progesterone. We describe the creation of new synthetic phage display... -
Intelectin 3 is dispensable for resistance against a mycobacterial infection in zebrafish (Danio rerio)
Tuberculosis is a multifactorial bacterial disease, which can be modeled in the zebrafish (Danio rerio). Abdominal cavity infection with Mycobacterium marinum, a close relative of Mycobacterium tuberculosis, leads to a granulomatous disease in adult zebrafish, which replicates the different phases of human tuberculosis, including primary infection, latency and spontaneous reactivation. Here, we have carried out a transcriptional analysis of zebrafish challenged with low-dose of M. marinum, and...