Cell-penetrating peptide and cationic liposomes mediated siRNA delivery to arrest growth of chronic myeloid leukemia cells in vitro.

Gene silencing through RNA interference (RNAi) is a promising therapeutic approach for a wide range of disorders, including cancer. Non-viral gene therapy, using specific siRNAs against BCR-ABL1, can be a supportive or alternative measure to traditional chronic myeloid leukemia (CML) tyrosine kinase inhibitor (TKIs) therapies, given the prevalence of clinical TKI resistance. The main challenge for such approaches remains the development of the effective delivery system for siRNA tailored to the specific disease model. The purpose of this study was to examine and compare the efficiency of endosomolytic cell penetrating peptide (CPP) EB1 and PEG2000-decorated cationic liposomes composed of polycationic lipid 1,26-bis(cholest-5-en-3-yloxycarbonylamino)-7,11,16,20-tetraazahexacosane tetrahydrochloride (2Ð¥3) and helper lipid 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) for anti-bcr-abl siRNA delivery into the K562 human CML cell line. We show that both EB1 and 2Ð¥3-DOPE-DSPE-PEG2000 (0.62 % mol.) liposomes effectively deliver siRNA into K562 cells by endocytic mechanisms, and the use of liposomes leads to more effective inhibition of expression of the targeted gene (BCR-ABL1) and cancer cell proliferation. Taken together, these findings suggest that PEG-decorated cationic liposomes mediated siRNA delivery allows an effective antisense suppression of certain oncogenes, and represents a promising new class of therapies for CML.

Fluorescence of the Retinal Chromophore in Microbial and Animal Rhodopsins.

Fluorescence of the vast majority of natural opsin-based photoactive proteins is extremely low, in accordance with their functions that depend on efficient transduction of absorbed light energy. However, several recently proposed classes of engineered rhodopsins with enhanced fluorescence, along with the discovery of a new natural highly fluorescent rhodopsin, NeoR, opened a way to exploit these transmembrane proteins as fluorescent sensors and draw more attention to studies on this untypical rhodopsin property. Here, we review the available data on the fluorescence of the retinal chromophore in microbial and animal rhodopsins and their photocycle intermediates, as well as different isomers of the protonated retinal Schiff base in various solvents and the gas phase.

IgGκ Signal Peptide Enhances the Efficacy of an Influenza Vector Vaccine against Respiratory Syncytial Virus Infection in Mice.

Intranasal vaccination using influenza vectors is a promising approach to developing vaccines against respiratory pathogens due to the activation of the mucosa-associated immune response. However, there is no clear evidence of a vector design that could be considered preferable. To find the optimal structure of an influenza vector with a modified NS genomic segment, we constructed four vector expressing identical transgene sequences inherited from the F protein of the respiratory syncytial virus (RSV). Two vectors were designed aiming at transgene accumulation in the cytosol. Another two were supplemented with an IgGκ signal peptide prior to the transgene for its extracellular delivery. Surprisingly, adding the IgGκ substantially enhanced the T-cell immune response to the CD8 epitope of the transgene. Moreover, this strategy allowed us to obtain a better protection of mice from the RSV challenge after a single intranasal immunization. Protection was achieved without antibodies, mediated by a balanced T-cell immune response including the formation of the RSV specific effector CD8+ IFNγ+/IL10+-producing cells and the accumulation of Treg cells preventing immunopathology in the lungs of infected mice. In addition to the presented method for optimizing the influenza vector, our results highlight the possibility of achieving protection against RSV through a respiratory-associated T-cell immune response alone.

Non-invasive transcutaneous influenza immunization using vaccine-loaded vaterite particles.

Transcutaneous immunization receives much attention due to the recognition of a complex network of immunoregulatory cells in various layers of the skin. The elaboration of non-invasive needle-free approaches towards antigen delivery holds especially great potential here while searching for a hygienically optimal vaccination strategy. Here, we report on a novel protocol for transfollicular immunization aiming at delivery of an inactivated influenza vaccine to perifollicular antigen presenting cells without disrupting the stratum corneum integrity. Porous calcium carbonate (vaterite) submicron carriers and sonophoresis were utilized for this purpose. Transportation of the vaccine-loaded particles into hair follicles of mice was assessed in vivo via optical coherence tomography monitoring. The effectiveness of the designed immunization protocol was further demonstrated in an animal model by means of micro-neutralization and enzyme-linked immunosorbent assays. The titers of secreted virus-specific IgGs were compared to those obtained in response to intramuscular immunization using conventional influenza vaccine formulation demonstrating no statistically significant differences in antibody levels between the groups. The findings of our pilot study render the intra-follicular delivery of the inactivated influenza vaccine by means of vaterite carriers a promising alternative to invasive immunization.

Kinetics of interferon-λ and receptor expression in response to in vitro respiratory viral infection.

The major protective immune response against viruses is the production of type I and III interferons (IFNs). IFNs induce the expression of hundreds of IFN-stimulated genes (ISGs) that block viral replication and further viral spread. In this report, we analyzed the expression of IFNs and some ISGs (MxA, PKR, OAS-1, IFIT-1, RIG-1, MDA5, SOCS-1) in alveolar epithelial cells (A549) in response to infection with influenza A viruses (A/California/07/09 (H1N1pdm); A/Texas/50/12 (H3N2)); influenza B virus (B/Phuket/3073/13); adenovirus type 5 and 6; or respiratory syncytial virus (strain A2). Influenza B virus had the ability to most rapidly induce IFNs and ISGs as well as to stimulate excessive IFN-α, IFN-ß and IFN-λ secretion. It seems curious that IAV H1N1pdm did not induce IFN-λ secretion, but enhanced type I IFN and interleukin (IL)-6 production. We emphasized the importance of the negative regulation of virus-triggered signaling and cellular IFN response. We showed a decrease in IFNLR1 mRNA in the case of IBV infection. The attenuation of SOCS-1 expression in IAV H1N1pdm can be considered as the inability of the system to restore the immune status. Presumably, the lack of negative feedback loop regulation of proinflammatory immune response may be a factor contributing to the particular pathogenicity of several strains of influenza. Keywords: lambda interferons; MxA; influenza; respiratory syncytial virus; A549 cells.

Uncertainty Estimation for Quantitative Agarose Gel Electrophoresis of Nucleic Acids.

This paper considers the evaluation of uncertainty of quantitative gel electrophoresis. To date, such uncertainty estimation presented in the literature are based on the multiple measurements performed for assessing the intra- and interlaboratory reproducibility using standard samples. This paper shows how to estimate the uncertainty in cases where we cannot study scattering components of the results. The first point is dedicated to a case where we have standard samples (the direct expressions are shown). The second point considers the situation when standard samples are absent (the algorithm for estimating the lower bound for uncertainty is discussed). The role of the data processing algorithm is demonstrated.

Fluorescence Imaging of Cell Membrane Potential: From Relative Changes to Absolute Values.

Membrane potential is a fundamental property of biological cells. Changes in membrane potential characterize a vast number of vital biological processes, such as the activity of neurons and cardiomyocytes, tumorogenesis, cell-cycle progression, etc. A common strategy to record membrane potential changes that occur in the process of interest is to utilize organic dyes or genetically-encoded voltage indicators with voltage-dependent fluorescence. Sensors are introduced into target cells, and alterations of fluorescence intensity are recorded with optical methods. Techniques that allow recording relative changes of membrane potential and do not take into account fluorescence alterations due to factors other than membrane voltage are already widely used in modern biological and biomedical studies. Such techniques have been reviewed previously in many works. However, in order to investigate a number of processes, especially long-term processes, the measured signal must be corrected to exclude the contribution from voltage-independent factors or even absolute values of cell membrane potential have to be evaluated. Techniques that enable such measurements are the subject of this review.

Exosomes Released by Influenza-Virus-Infected Cells Carry Factors Capable of Suppressing Immune Defense Genes in Naïve Cells.

Background: Exosomes are involved in intercellular communication and can transfer regulatory molecules between cells. Consequently, they can participate in host immune response regulation. For the influenza A virus (IAV), there is very limited information on changes in exosome composition during cell infection shedding light on the potential role of these extracellular membrane vesicles. Thus, the aim of our work was to study changes in exosomal composition following IAV infection of cells, as well as to evaluate their effect on uninfected cells. Methods: To characterize changes in the composition of cellular miRNAs and mRNAs of exosomes during IAV infection of A549 cells, NGS was used, as well as PCR to identify viral genes. Naïve A549 cells were stimulated with infected-cell-secreted exosomes for studying their activity. Changes in the expression of genes associated with the cell's immune response were shown using PCR. The effect of exosomes on IAV replication was shown in MDCK cells using In-Cell ELISA and PCR of the supernatants. Results: A change in the miRNA composition (miR-21-3p, miR-26a-5p, miR-23a-5p, miR-548c-5p) and mRNA composition (RPL13A, MKNK2, TRIB3) of exosomes under the influence of the IAV was shown. Many RNAs were involved in the regulation of the immune response of the cell, mainly by suppressing it. After exosome stimulation of naïve cells, a significant decrease in the expression of genes involved in the immune response was shown (RIG1, IFIT1, MDA5, COX2, NFκB, AnxA1, PKR, IL6, IL18). When infecting MDCK cells, a significant decrease in nucleoprotein levels was observed in the presence of exosomes secreted by mock-infected cells. Viral levels in supernatants also decreased. Conclusions: Exosomes secreted by IAV-infected cells could reduce the immune response of neighboring intact cells, leading to more effective IAV replication. This may be associated both with regulatory functions of cellular miRNAs and mRNAs carried by exosomes, or with the presence of viral mRNAs encoding proteins with an immunosuppressive function.

Simultaneous Detection of RIG-1, MDA5, and IFIT-1 Expression Is a Convenient Tool for Evaluation of the Interferon-Mediated Response.

In this study, we developed a novel, multiplex qPCR assay for simultaneous detection of RIG-1, MDA5, and IFIT-1 at the mRNA level. The assay was validated in A549 cells transfected with in vitro transcribed RNAs. Both exogenous RNA-GFP and self-amplifying (saRNA-GFP) induced significant expression of RIG-1, MDA5, IFIT-1, as well as type I and III interferons. In contrast, native RNA from intact A549 cells did not upregulate expression of these genes. Next, we evaluated RIG-1, MDA5, and IFIT-1 mRNA levels in the white blood cells of patients with influenza A virus (H3N2) or SARS-CoV-2. In acute phase (about 4 days after disease onset) both viruses induced these genes expression. Clinical observations of SARS-CoV-2 typically describe a two-step disease progression, starting with a mild-to-moderate presentation followed by a secondary respiratory worsening 9 to 12 days after the first onset of symptoms. It revealed that the expression of RIG-1, MDA5, and MxA was not increased after 2 and 3 weeks from the onset the disease, while for IFIT-1 it was observed the second peak at 21 day post infection. It is well known that RIG-1, MDA5, and IFIT-1 expression is induced by the action of interferons. Due to the ability of SOCS-1 to inhibit interferon-dependent signaling, and the distinct antagonism of SARS-CoV-2 in relation to interferon-stimulated genes expression, we assessed SOCS-1 mRNA levels in white blood cells. SARS-CoV-2 patients had increased SOCS-1 expression, while the influenza-infected group did not differ from heathy donors. Moreover, SOCS-1 mRNA expression remained stably elevated during the course of the disease. It can be assumed that augmented SOCS-1 expression is one of multiple mechanisms that allow SARS-CoV-2 to escape from the interferon-mediated immune response. Our results implicate SOCS-1 involvement in the pathogenesis of SARS-CoV-2.

Influenza B: Prospects for the Development of Cross-Protective Vaccines.

In this review, we analyze the epidemiological and ecological features of influenza B, one of the most common and severe respiratory infections. The review presents various strategies for cross-protective influenza B vaccine development, including recombinant viruses, virus-like particles, and recombinant proteins. We provide an overview of viral proteins as cross-protective vaccine targets, along with other updated broadly protective vaccine strategies. The importance of developing such vaccines lies not only in influenza B prevention, but also in the very attractive prospect of eradicating the influenza B virus in the human population.

Exosomes as Natural Nanocarriers for RNA-Based Therapy and Prophylaxis.

Exosomes are natural nanocontainers actively secreted by the body's cells and transmitting molecular signals of various types to recipient cells. Cellular mechanisms of exosomes' biogenesis involve specific sorting of RNA for incorporation into them. As a result, the molecular composition of exosomes is closely related to the donor cell's functional state, and this makes exosomes an important diagnostic and prognostic marker in a number of diseases (primarily oncological). The ability of exosomes to transport biologically active molecules and to protect the cargo from degradation makes them nearly ideal candidates as delivery carriers of RNA in therapeutic or prophylactic regimes. Potential of exosomal surface functionalization enables improved targeting to specific organs, tissues and cells. However, the development of an effective technology for RNA's loading into exosomes cannot be considered resolved. This review is focused on experimental data on the use of exosomes as vehicles for the delivery of therapeutic and prophylactic RNAs. We briefly consider the biogenesis and functions of exosomes, focusing on those biological properties that make them formidable candidates in the race to develop effective delivery carriers. Furthermore, we describe various techniques of cargo loading into exosomes. Prospects of exosomes application as therapeutic delivery system for siRNAs, miRNAs, and long RNAs are considered.

A novel method for multiplex protein biomarker analysis of human serum using quantitative MALDI mass spectrometry.

In this work, we have extended our previously proposed approach for determining protein concentrations in human serum (using MALDI-TOF mass spectrometry) to include simultaneous analysis of several proteins associated with acute inflammation (alpha-2-macroglobulin, fetuin-A, serum amyloid A1). This technique can be used to diagnose systemic inflammation and provides results in 4-5 h. The developed approach was verified using standard immunological methods (ELISA). Samples from 87 individuals, in specific groups, were used for testing and validation: control; inflammatory soft tissue disease accompanied by sepsis; influenza A infection; or COVID-19. The feasibility of differentiating patient groups with the aforementioned conditions was analyzed using a combination of the inflammatory markers described. For fetuin-A and serum amyloid A1, diagnostically significant concentration ranges were established.

Influence of Lipid Composition of Cationic Liposomes 2X3-DOPE on mRNA Delivery into Eukaryotic Cells.

The design of cationic liposomes for efficient mRNA delivery can significantly improve mRNA-based therapies. Lipoplexes based on polycationic lipid 1,26-bis(cholest-5-en-3ß-yloxycarbonylamino)-7,11,16,20-tetraazahexacosane tetrahydrochloride (2X3) and helper lipid 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) were formulated in different molar ratios (1:1, 1:2, 1:3) to efficiently deliver model mRNAs to BHK-21 and A549. The objective of this study was to examine the effect of 2X3-DOPE composition as well as lipid-to-mRNA ratio (amino-to-phosphate group ratio, N/P) on mRNA transfection. We found that lipoplex-mediated transfection efficiency depends on both liposome composition and the N/P ratio. Lipoplexes with an N/P ratio of 10/1 showed nanometric hydrodynamic size, positive ζ potential, maximum loading, and transfection efficiency. Liposomes 2X3-DOPE (1:3) provided the superior delivery of both mRNA coding firefly luciferase and mRNA-eGFP into BHK-21 cells and A549 cells, compared with commercial Lipofectamine MessengerMax.

Peripheral Blood Mononuclear Cell Cytokine mRNA Profiles in Acute Respiratory Infection Patients.

Introduction: Respiratory infections, collectively, are one of the World's most common and serious illness groups. As recent observations have shown, the most severe courses of acute respiratory infection, often leading to death, are due to uncontrolled cytokine production (hypercytokinemia). Methods: The study involved 364 patients with respiratory illness being treated in clinics in St. Petersburg (Russia) in 2018-2019 and 30 healthy controls. Cytokine analysis was carried out in the acute phase of illness (2-3 days from onset of initial symptoms) and in the stage of recovery (days 9-10). The research presented is devoted to the assessment of mRNA expression of specific cytokines (interleukin [IL]-1b, IL-2, IL-4, IL-6, IL-8, IL-10, IL-18, tumor necrosis factor-α [TNF-α], and interferon-λ) and MxA in whole blood leukocytes, by means of real-time polymerase chain reaction. Results: In 70% of patients, bacterial or viral pathogens were identified, with influenza viral infections (types A and B) prevailing. Significant increases in the expression of IL-18, TNF, and IL-10 were observed, relative to controls, only with influenza viral infections. We have shown a difference in IL-6 mRNA expression in patients with bacterial or viral pathogens. No statistically significant difference was found in white blood cells IL-4 expression levels between patients and healthy controls. Conclusion: Investigation of the nuances of systemic cytokine production, in response to specific viral and bacterial pathogens, makes it possible to assess the risks of developing hypercytokinemia during respiratory infection with agents circulating in the human population and to predict the pathogenicity and virulence of circulating threats.

Azobenzene/Tetraethyl Ammonium Photochromic Potassium Channel Blockers: Scope and Limitations for Design of Para-Substituted Derivatives with Specific Absorption Band Maxima and Thermal Isomerization Rate.

Azobenzene/tetraethyl ammonium photochromic ligands (ATPLs) are photoactive compounds with a large variety of photopharmacological applications such as nociception control or vision restoration. Absorption band maximum and lifetime of the less stable isomer are important characteristics that determine the applicability of ATPLs. Substituents allow to adjust these characteristics in a range limited by the azobenzene/tetraethyl ammonium scaffold. The aim of the current study is to find the scope and limitations for the design of ATPLs with specific spectral and kinetic properties by introducing para substituents with different electronic effects. To perform this task we synthesized ATPLs with various electron acceptor and electron donor functional groups and studied their spectral and kinetic properties using flash photolysis and conventional spectroscopy techniques as well as quantum chemical modeling. As a result, we obtained diagrams that describe correlations between spectral and kinetic properties of ATPLs (absorption maxima of E and Z isomers of ATPLs, the thermal lifetime of their Z form) and both the electronic effect of substituents described by Hammett constants and structural parameters obtained from quantum chemical calculations. The provided results can be used for the design of ATPLs with properties that are optimal for photopharmacological applications.

Clean and folded: Production of active, high quality recombinant human interferon-λ1.

Type III interferons exhibit antiviral activity against influenza viruses, coronaviruses, rotaviruses, and others. In addition, this type of interferon theoretically has therapeutic advantages, in comparison with type I interferons, due to its ability to activate a narrower group of genes in a relatively small group of target cells. Hence, it can elicit more targeted antiviral or immunomodulatory responses. Obtaining biologically-active interferon lambda (hIFN-λ1) is fraught with difficulties at the stage of expression in soluble form or, in the case of expression in the form of inclusion bodies, at the stage of refolding. In this work, hIFN-λ1 was expressed in the form of inclusion bodies, and a simple, effective refolding method was developed. Efficient and scalable methods for chromatographic purification of recombinant hIFN-λ1 were also developed. High-yield, high-purity product was obtained through optimization of several processes including: recombinant protein expression; metal affinity chromatography; cation exchange chromatography; and an intermediate protein refolding stage. The obtained protein was shown to feature expected specific biological activity in line with published effects: induction of MxA gene expression in A549 cells and antiviral activity against influenza A virus.

IFN-λ1 Displays Various Levels of Antiviral Activity In Vitro in a Select Panel of RNA Viruses.

Type III interferons (lambda IFNs) are a quite new, small family of three closely related cytokines with interferon-like activity. Attention to IFN-λ is mainly focused on direct antiviral activity in which, as with IFN-α, viral genome replication is inhibited without the participation of immune system cells. The heterodimeric receptor for lambda interferons is exposed mainly on epithelial cells, which limits its possible action on other cells, thus reducing the likelihood of developing undesirable side effects compared to type I IFN. In this study, we examined the antiviral potential of exogenous human IFN-λ1 in cellular models of viral infection. To study the protective effects of IFN-λ1, three administration schemes were used: 'preventive' (pretreatment); 'preventive/therapeutic' (pre/post); and 'therapeutic' (post). Three IFN-λ1 concentrations (from 10 to 500 ng/mL) were used. We have shown that human IFN-λ1 restricts SARS-CoV-2 replication in Vero cells with all three treatment schemes. In addition, we have shown a decrease in the viral loads of CHIKV and IVA with the 'preventive' and 'preventive/therapeutic' regimes. No significant antiviral effect of IFN-λ1 against AdV was detected. Our study highlights the potential for using IFN-λ as a broad-spectrum therapeutic agent against respiratory RNA viruses.

Laser-Assisted Surface Modification of Ni Microstructures with Au and Pt toward Cell Biocompatibility and High Enzyme-Free Glucose Sensing.

We investigated the influence of morphology of Ni microstructures modified with Au and Pt on their cell biocompatibility and electrocatalytic activity toward non-enzymatic glucose detection. Synthesis and modification were carried out using a simple and inexpensive approach based on the method of laser-induced deposition of metal microstructures from a solution on the surface of various dielectrics. Morphological analysis of the fabricated materials demonstrated that the surface of the Ni electrode has a hierarchical structure with large-scale 10 µm pores and small-scale 10 nm irregularities. In turn, the Ni-Pt surface has large-scale cavities, small-scale pores (1-1.5 µm), and a few tens of nanometer particles opposite to Ni-Au that reveals no obvious hierarchical structure. These observations were supported by impedance spectroscopy confirming the hierarchy of the surface topography of Ni and Ni-Pt structures. We tested the biocompatibility of the fabricated Ni-based electrodes with the HeLa cells. It was shown that the Ni-Au electrode has a much better cell adhesion than Ni-Pt with a more complex morphology. On the contrary, porous Ni and Ni-Pt electrodes with a more developed surface area than that of Ni-Au have better catalytic performance toward enzymeless glucose sensing, revealing greater sensitivity, selectivity, and stability. In this regard, modification of Ni with Pt led to the most prominent results providing rather good glucose detection limits (0.14 and 0.19 µA) and linear ranges (10-300 and 300-1500 µA) as well as the highest sensitivities of 18,570 and 2929 µA mM-1 cm-2. We also proposed some ideas to clarify the observed behavior and explain the influence of morphology of the fabricated electrodes on their electrocatalytic activity and biocompatibility.

Antigenic and Genetic Characterization of Swine Influenza Viruses Identified in the European Region of Russia, 2014-2020.

Pigs have long been recognized as "mixing vessels" in which new viruses are formed by reassortment involving various influenza virus lineages (avian, animal, human). However, surveillance of swine influenza viruses only gained real significance after the 2009 pandemic. A fundamentally important point is the fact that there is still no regular surveillance of swine flu in Russia, and the role of swine viruses is underestimated since, as a rule, they do not cause serious disease in animals. Since the pig population in Russia is large, it is obvious that the lack of monitoring and insufficient study of swine influenza evolution constitutes a gap in animal influenza surveillance, not only for Russia, but globally. A 6 year joint effort enabled identification of SIV subtypes that circulate in the pig population of Russia's European geographic region. The swine influenza viruses isolated were antigenically and genetically diverse. Some were similar to human influenza viruses of A(H1N1)pdm09 and A(H3N2) subtype, while others were reassortant A(H1pdm09N2) and A(H1avN2) and were antigenically distinct from human H1N1 and H1N1pdm09 strains. Analysis of swine serum samples collected throughout the seasons showed that the number of sera positive for influenza viruses has increased in recent years. This indicates that swine populations are highly susceptible to infection with human influenza viruses. It also stresses the need for regular SIV surveillance, monitoring of viral evolution, and strengthening of pandemic preparedness.