Virus-cell Interactions Research Articles

Structure and properties of polysaccharides from tetrasporophytes of Mazzaella parksii.

The structure and anti-SARS-CoV-2 activity of sulfated polysaccharides (Mzpt) obtained in high yield (60 %) from tetrasporophytes of Mazzaella parksii were studied. Stepwise fractionation with KCl showed that Mzpt consisted of eight (MzptF1-MzptF8) carrageenans fractions, differing in structure and molecular weight. The yield of non-gelling MzptF8 was 58.1 % of the original Mzpt. According to IR and NMR spectroscopies, gelling MzptF1 and MzptF2 were mainly kappa/iota/nu-carrageenans. MzptF7 included mainly lambda-carrageenan and in smaller quantities kappa-, iota-, mu- and nu-carrageenans. MzptF8 had a complex composition and included gamma-carrageenan, unsulfated carrageenan, probably, delta-carrageenan and also structural elements of xi-, psi- and omicron-carrageenans. According to atomic force microscopy data, MzptF8 involved several polymer chains associated with each other in a disordered structure, in contrast to MzptF2, which formed three-dimensional networks. Unlike ribavirin and remdesivir, Mzpt was not cytotoxic to Vero E6 cells at concentrations >2000 μg mL-1. Mzpt was shown to inhibit SARS-CoV-2 replication in a dose-dependent manner in CPE inhibition and RT-PCR assays. IC50 was 92.0 μg mL-1, SI - 22. At concentration 250 μg mL-1, Mzpt caused the highest reduction in viral RNA levels with an inhibition coefficient of 31.1 % and exhibited significant inhibition of the early stages of virus-cell interaction.

Pseudotyped Viruses: A Useful Platform for Pre-Clinical Studies Conducted in a BSL-2 Laboratory Setting.

The study of pathogenic viruses has always posed significant biosafety challenges. In particular, the study of highly pathogenic viruses requires methods with low biological risk but relatively high sensitivity and convenience in detection. In recent years, pseudoviruses, which consist of a backbone of one virus and envelope proteins of another virus, have become one of the most widely used tools for exploring the mechanisms of viruses binding to cells, membrane fusion and viral entry, as well as for screening the libraries of antiviral substances, evaluating the potential of neutralizing monoclonal antibodies, developing neutralization tests, and therapeutic platforms. During the outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), pseudotyped virus-based assays played a pivotal role in advancing our understanding of virus-cell interactions and the role of its proteins in disease pathogenesis. Such tools facilitated the search for potential therapeutic agents and accelerated epidemiological studies on post-infection and post-vaccination humoral immunity. This review focuses on the use of pseudoviruses as a model for large-scale applications to study enveloped viruses.

The Haemagglutinin Gene of Bovine-Origin H5N1 Influenza Viruses Currently Retains Receptor-binding and pH-fusion Characteristics of Avian Host Phenotype.

Clade 2.3.4.4b H5N1 high pathogenicity avian influenza virus (HPAIV) has caused a panzootic affecting all continents except Australia, expanding its host range to several mammalian species. In March 2024, H5N1 HPAIV was first detected in dairy cattle and goats in the United States. Over 891 dairy farms across 16 states have tested positive until 25th December 2024, with zoonotic infections reported among dairy workers. This raises concerns about the virus undergoing evolutionary changes in cattle that could enhance its zoonotic potential. The Influenza glycoprotein haemagglutinin (HA) facilitates entry into host cells through receptor binding and pH-induced fusion with cellular membranes. Adaptive changes in HA modulate virus-host cell interactions. This study compared the HA genes of cattle and goat H5N1 viruses with the dominant avian-origin clade 2.3.4.4b H5N1 in the United Kingdom, focusing on receptor binding, pH fusion, and thermostability. All the tested H5N1 viruses showed binding exclusively to avian-like receptors, with a pH fusion of 5.9, outside the pH range associated with efficient human airborne transmissibility (pH 5.0 to 5.5). We further investigated the impact of emerging HA substitutions seen in the ongoing cattle outbreaks, but saw little phenotypic difference, with continued exclusive binding to avian-like receptor analogues and pHs of fusion above 5.8. This suggests that the HA genes from the cattle and goat outbreaks do not pose an enhanced threat compared to circulating avian viruses. However, given the rapid evolution of H5 viruses, continuous monitoring and updated risk assessments remain essential to understanding virus zoonotic and pandemic risks.

Genome-wide characterization of structure variations in the Xiang pig for genetic resistance to African swine fever

ABSTRACT African swine fever (ASF) is a rapidly fatal viral haemorrhagic fever in Chinese domestic pigs. Although very high mortality is observed in pig farms after an ASF outbreak, clinically healthy and antibody-positive pigs are found in those farms, and viral detection is rare from these pigs. The ability of pigs to resist ASF viral infection may be modulated by host genetic variations. However, the genetic basis of the resistance of domestic pigs against ASF remains unclear. We generated a comprehensive set of structural variations (SVs) in a Chinese indigenous Xiang pig with ASF-resistant (Xiang-R) and ASF-susceptible (Xiang-S) phenotypes using whole-genome resequencing method. A total of 53,589 nonredundant SVs were identified, with an average of 25,656 SVs per individual in the Xiang pig genome, including insertion, deletion, inversion and duplication variations. The Xiang-R group harboured more SVs than the Xiang-S group. The F-statistics (F ST) was carried out to reveal genetic differences between two populations using the resequencing data at each SV locus. We identified 2,414 population-stratified SVs and annotated 1,152 Ensembl genes (including 986 protein-coding genes), in which 1,326 SVs might disturb the structure and expression of the Ensembl genes. Those protein-coding genes were mainly enriched in the Wnt, Hippo, and calcium signalling pathways. Other important pathways associated with the ASF viral infection were also identified, such as the endocytosis, apoptosis, focal adhesion, Fc gamma R-mediated phagocytosis, junction, NOD-like receptor, PI3K-Akt, and c-type lectin receptor signalling pathways. Finally, we identified 135 candidate adaptive genes overlapping 166 SVs that were involved in the virus entry and virus-host cell interactions. The fact that some of population-stratified SVs regions detected as selective sweep signals gave another support for the genetic variations affecting pig resistance against ASF. The research indicates that SVs play an important role in the evolutionary processes of Xiang pig adaptation to ASF infection.

Biostatistical Analysis of Microarray Data to Decipher Viral Pathogenesis

Background: Zika virus, Kunjin virus, Yellow Fever virus, & Sindbis virus belong to Flaviviridae family and are involved in derailing various biological pathways which are not yet elucidated. Aim: Understanding the gene as well as miRNA interplay which plays a vital role in pathogenesis in the diagnosis and prognosis of the disease is of utmost significance. Materials and Methods: By leveraging microarray data from the Gene Expression Omnibus GSE232504 dataset, we meticulously examined the differentially expressed genes & micro RNAs (miRNAs) induced by viral infections. Results: Our analysis revealed 60 statistically significant and differentially expressed genes (DEGs) out of a total of 18,725, with SESN2 (SESTRIN 2) and GADD45A (Growth Arrest and DNA Damage-Inducible Alpha) standing out as highly significant players in the host cell response to these viruses. hsa-miR-148b-3p, hsa-miR-148a-3p, hsa-miR-607 & hsa-miR-5582-3p were the highly expressed micro RNAs (miRNAs). Through functional enrichment analyses, we unveiled significant pathways, including Type 1 Diabetes Mellitus and NF-kappa B Signaling, shedding light on the potential mechanisms underlying these virus-host cell interactions. Furthermore, our PPI (protein-protein interaction) network analysis highlighted key hub genes, while our exploration of miRNA-gene targeting relationships offered valuable insights into post-transcriptional regulation. Conclusion: This study provides a robust foundation for understanding the molecular intricacies of virus-host cell interactions, offering potential targets for further experimental validation and paving the way for innovative therapeutic approaches in combatting viral infections and associated diseases.

Electrostatic Interaction between SARS-CoV-2 and Charged Surfaces: Spike Protein Evolution Changed the Game.

Previous works show the key role of electrostatics in the SARS-CoV-2 virus in aspects such as virus-cell interactions or virus inactivation by ionic surfactants. Electrostatic interactions depend strongly on the variant since the charge of the Spike protein (responsible for virus-environment interactions) evolved across the variants from the highly negative Wild Type (WT) to the highly positive Omicron variant. The distribution of the charge also evolved from diffuse to highly localized. These facts suggest that SARS-CoV-2 should interact strongly with charged surfaces in a way that changed during the virus evolution. This question is studied here by computing the electrostatic interaction between WT, Delta and Omicron Spike proteins with charged surfaces using a new method (based on Debye-Hückel theory) that provides efficiently general results as a function of the surface charge density σ. We found that the interaction of the WT and Delta variant spikes with charged surfaces is dominated by repulsive image forces proportional to σ2 originating at the protein/water interface. On the contrary, the Omicron variant shows a distinct behavior, being strongly attracted to negatively charged surfaces and repelled from positively charged ones. Therefore, the SARS-CoV-2 virus has evolved from being repelled by charged surfaces to being efficiently adsorbing to negatively charged ones.

Potential role of Mappain, a prenylated stilbene, in reducing SARS-CoV-2 envelope protein-induced inflammation

As of right now, more than 776 million people have contracted the COVID-19-causing SARS-CoV-2 virus, which has also resulted in over 7 million deaths. A dysregulated host's innate immune response to the virus exacerbates clinical outcomes and leads to cytokine storm. Developing a drug targeting the multiple aspects of the SARS-CoV-2 virus-host cell interactions is essential for effective treatment. The 75 amino acid-long SARS-CoV-2 envelope (2E) protein is a small structural transmembrane protein that plays a crucial role in the viral life cycle and pathogenesis. Mappain is a plant-derived stilbene from Macaranga species that previously demonstrated antiviral potential against enteroviruses in tissue culture. This study aims to assess the inhibitory potential of Mappain against SARS-CoV-2 key proteins and induced hyperinflammation using computational and in-vitro approaches. Autodock Vina was used to evaluate mappain interaction with SARS- CoV-2 antiviral targets including Spike, Envelope, Membrane, 3CLPro, PLpro, Nucleocapsid N and C termini, RdRP, and host receptors—TLR2, TLR3, TLR7, and TLR8. Afterwards, mappain was subjected to in-vitro bioassay testing using inhibition 2E-induced cytokines (IL-6 and TNF-α) in human peripheral blood mononuclear cells, measured by ELISA; Amantadine as control. KEGG pathway enrichment analysis was further performed using network pharmacology to elucidate the mechanism. Mappain demonstrated a high binding score with all the targets, especially with the envelope protein (− 9.6 kcal/mol) and TLR2 (− 9.7 kcal/mol) compared to Amantadine (− 6.1 kcal/mol and − 5.5 kcal/mol, respectively). Mappain also significantly reduced the expression of 2E-induced Interleukin 6 (p ≤ 0.001) and tumour necrosis factor-alpha (p ≤ 0.01) in the PBMCs, when compared to Amantadine HCl. The KEGG Pathway enrichment analysis supports the anti-inflammatory potential of mappain in the virus-induced cytokine storm by specifically targeting TLR signalling and COVID-19 pathways.

Viral N protein hijacks deaminase-containing RNA granules to enhance SARS-CoV-2 mutagenesis

Host cell-encoded deaminases act as antiviral restriction factors to impair viral replication and production through introducing mutations in the viral genome. We sought to understand whether deaminases are involved in SARS-CoV-2 mutation and replication, and how the viral factors interact with deaminases to trigger these processes. Here, we show that APOBEC and ADAR deaminases act as the driving forces for SARS-CoV-2 mutagenesis, thereby blocking viral infection and production. Mechanistically, SARS-CoV-2 nucleocapsid (N) protein, which is responsible for packaging viral genomic RNA, interacts with host deaminases and co-localizes with them at stress granules to facilitate viral RNA mutagenesis. N proteins from several coronaviruses interact with host deaminases at RNA granules in a manner dependent on its F17 residue, suggesting a conserved role in modulation of viral mutagenesis in other coronaviruses. Furthermore, mutant N protein bearing a F17A substitution cannot localize to deaminase-containing RNA granules and leads to reduced mutagenesis of viral RNA, providing support for its function in enhancing deaminase-dependent viral RNA editing. Our study thus provides further insight into virus-host cell interactions mediating SARS-CoV-2 evolution.

The potential of lactoferrin as antiviral and immune-modulating agent in viral infectious diseases.

Emerging infectious diseases are caused by unpredictable viruses with the dangerous potential to trigger global pandemics. These viruses typically initiate infection by utilizing the anionic structures of host cell surface receptors to gain entry. Lactoferrin (Lf) is a multifunctional glycoprotein with multiple properties such as antiviral, anti-inflammatory and antioxidant activities. Due to its cationic structure, Lf naturally interacts with certain host cell receptors, such as heparan sulfate proteoglycans, as well as viral particles and other receptors that are targeted by viruses. Therefore, Lf may interfere with virus-host cell interactions by acting as a receptor competitor for viruses. Herein we summarize studies in which this competition was investigated with SARS-CoV-2, Zika, Dengue, Hepatitis and Influenza viruses in vitro. These studies have demonstrated not only Lf's competitive properties, but also its potential intracellular impact on host cells, such as enhancing cell survival and reducing infection efficiency by inhibiting certain viral enzymes. In addition, the immunomodulatory effect of Lf is highlighted, as it can influence the activity of specific immune cells and regulate cytokine release, thereby enhancing the host's response to viral infections. Collectively, these properties promote the potential of Lf as a promising candidate for research in viral infectious diseases.

Enhanced lentiviral gene delivery to mammalian cells via paired cell surface and viral envelope engineering.

Lentiviral vectors that facilitate gene delivery to desired cell types have been widely used in routine laboratory research and therapeutic cell engineering. However, the lack of proper entry receptors on many cell types often results in poor gene delivery. Here, we present a simple paired virus-cell engineering approach that promotes lentiviral gene delivery into mammalian cells. Lentiviruses are dual-pseudotyped with VSV-G and a chimeric envelope protein specifically recognizing a small molecule fluorescein (αFITC-Env), and target cells are transiently labelled with FITC to create surrogate receptors for lentivirus attachment. The synthetic interaction between FITC-labeled cells and FITC-binding LVs enables efficient LV docking, viral entry and stable transgene expression in a range of mammalian cell lines and primary T cells. We showed that this approach enabled efficient delivery of a CD19-targeted chimeric antigen receptor (CAR) into naïve human T cells that are naturally refractory to conventional VSV-G LVs, which upon activation rapidly eradicated CD19 + leukemic cells. This paired cell surface and virus envelope engineering approach may serve as a universal method for engineering synthetic virus-cell interactions to improve lentiviral gene delivery to mammalian cells.

Physiological oxygen concentration during sympathetic primary neuron culture improves neuronal health and reduces HSV-1 reactivation.

Herpes simplex virus-1 (HSV-1) establishes a latent infection in peripheral neurons and periodically reactivates in response to a stimulus to permit transmission. In vitro models using primary neurons are invaluable to studying latent infection because they use bona fide neurons that have undergone differentiation and maturation in vivo. However, culture conditions in vitro should remain as close to those in vivo as possible. This is especially important when considering minimizing cell stress, as it is a well-known trigger of HSV reactivation. We recently developed an HSV-1 model system that requires neurons to be cultured for extended lengths of time. Therefore, we sought to refine culture conditions to optimize neuronal health and minimize secondary effects on latency and reactivation. Here, we demonstrate that culturing primary neurons under conditions closer to physiological oxygen concentrations (5% oxygen) results in cultures with features consistent with reduced stress. Furthermore, culture in these lower oxygen conditions diminishes the progression to full HSV-1 reactivation despite minimal impacts on latency establishment and earlier stages of HSV-1 reactivation. We anticipate that our findings will be useful for the broader microbiology community as they highlight the importance of considering physiological oxygen concentration in studying host-pathogen interactions.IMPORTANCEEstablishing models to investigate host-pathogen interactions requires mimicking physiological conditions as closely as possible. One consideration is the oxygen concentration used for in vitro tissue culture experiments. Standard incubators do not regulate oxygen levels, exposing cells to oxygen concentrations of approximately 18%. However, cells within the body are exposed to much lower oxygen concentrations, with physiological oxygen concentrations in the brain being 0.55%-8% oxygen. Here, we describe a model for herpes simplex virus 1 (HSV-1) latent infection using neurons cultured in 5% oxygen. We show that culturing neurons in more physiological oxygen concentrations improves neuronal health to permit long-term studies of virus-cell interactions and the impact on reactivation.

Temperature Interference on ZIKV and CHIKV Cycles in Mosquitoes and Mammalian Cells.

Temperature is a determining factor for the viral cycle. In this study, we investigate the effect of different temperatures on the cycles of two important arboviruses-Zika (ZIKV) and Chikungunya (CHIKV)-in Vero (mammalian) and C6/36 (mosquito) cells. We compare genome quantification to infectivity at 28 °C and 37 °C in both cell types. Virus-cell interaction was also examined by transmission electron microscopy, allowing the observation of phenomena such as virus-surfing and giant forms for CHIKV, as well as the the scarcity of ZIKV in C6/36 cells compared to its cycle in mammalian cells.

Dual Role of Extracellular Vesicles as Orchestrators of Emerging and Reemerging Virus Infections.

Current decade witnessed the emergence and re-emergence of many viruses, which affected public health significantly. Viruses mainly utilize host cell machinery to promote its growth, and spread of these diseases. Numerous factors influence virus-host cell interactions, of which extracellular vesicles play an important role, where they transfer information both locally and distally by enclosing viral and host-derived proteins and RNAs as their cargo. Thus, they play a dual role in mediating virus infections by promoting virus dissemination and evoking immune responses in host organisms. Moreover, it acts as a double-edged sword during these infections. Advances in extracellular vesicles regulating emerging and reemerging virus infections, particularly in the context of SARS-CoV-2, Dengue, Ebola, Zika, Chikungunya, West Nile, and Japanese Encephalitis viruses are discussed in this review.

Parvovirus B19 in Rheumatic Diseases.

Parvovirus B19 (B19V) is a human pathogen belonging to the Parvoviridae family. It is widely diffused in the population and responsible for a wide range of diseases, diverse in pathogenetic mechanisms, clinical course, and severity. B19V infects and replicates in erythroid progenitor cells (EPCs) in the bone marrow leading to their apoptosis. Moreover, it can also infect, in an abortive manner, a wide set of different cell types, normally non-permissive, and modify their normal physiology. Differences in the characteristics of virus-cell interaction may translate into different pathogenetic mechanisms and clinical outcomes. Joint involvement is a typical manifestation of B19V infection in adults. Moreover, several reports suggest, that B19V could be involved in the pathogenesis of some autoimmune rheumatologic diseases such as rheumatoid arthritis (RA), juvenile idiopathic arthritis (JIA), systemic sclerosis (SSc), systemic lupus erythematosus (SLE), or vasculitis. This review provides basic information on the B19 virus, highlights characteristics of viral infection in permissive and non-permissive systems, and focuses on recent findings concerning the pathogenic role of B19V in rheumatologic diseases.

3D CELL CULTURES: PROSPECTS FOR USE IN VIROLOGY

Abstract As a rule, traditional methods of cell cultivation invitro using monolayer cell lines (2Dcultivation) are unable to simulate the structural organization of a three-dimensional (3D) cell network invivo and are insufficient for modeling living tissues to study intercellular signaling, proliferation, differentiation, gene and protein expression, reactions to various stimuli and drug metabolism. Using 2Dcultivation, it is impossible to adequately reproduce a virus-host cell interaction and disease pathogenesis at the level of individual tissues. The technological platform for obtaining the most reliable results is 3Dcell cultivation. Based on the analysis of scientific literature contained in the main databases (Web of Science, PubMed, Scopus, Elsevier, Google Scholar and RSCI), our review provides a brief description of various types of 3Dcultures, as well as methods for their production and viability maintenance. The modern prospects of their use in virological research are discussed. The main aspects for application of 3D-cultures are analyzed: isolation, cultivation and study of mechanisms for virus reproduction, virus-host interaction, the study of immunopathogenesis and epidemiological prognosis of viral infections. The possibilities of 3Dcultures for production and testing of vaccines, antiviral drugs, and, generally, for choosing a treatment strategy of viral infections are analyzed. In addition to the advantages and prospects of using 3D-cell cultures in virology, their disadvantages are also assessed. Special attention is devoted to such exvivo 3D systems, as organoids and "organ on a chip", which largely meet the requirements of laboratory models in virological research. The hallmark characteristics of organoids is imitation of tissue organization, functionality and genetic specificity in a specific tissue or part of an organ. This approach allows to markedly increase model sensitivity for virus isolation. The review analyzes the data from numerous studies concerning the use of organoids to examine human and animal viruses, which display affinity for certain tissues and the data on assessing the features of immunopathogenesis behind respiratory viral infections.

In Vitro Anti-HIV-1 Activity of Fucoidans from Brown Algae.

Due to the developing resistance and intolerance to antiretroviral drugs, there is an urgent demand for alternative agents that can suppress the viral load in people living with human immunodeficiency virus (HIV). Recently, there has been increased interest in agents of marine origin such as, in particular, fucoidans to suppress HIV replication. In the present study, the anti-HIV-1 activity of fucoidans from the brown algae Alaria marginata, Alaria ochotensis, Laminaria longipes, Saccharina cichorioides, Saccharina gurianovae, and Tauya basicrassa was studied in vitro. The studied compounds were found to be able to inhibit HIV-1 replication at different stages of the virus life cycle. Herewith, all fucoidans exhibited significant antiviral activity by affecting the early stages of the virus-cell interaction. The fucoidan from Saccharina cichorioides showed the highest virus-inhibitory activity by blocking the virus' attachment to and entry into the host's cell, with a selectivity index (SI) > 160.

Significance of Artificial Intelligence in the Study of Virus-Host Cell Interactions.

A highly critical event in a virus's life cycle is successfully entering a given host. This process begins when a viral glycoprotein interacts with a target cell receptor, which provides the molecular basis for target virus-host cell interactions for novel drug discovery. Over the years, extensive research has been carried out in the field of virus-host cell interaction, generating a massive number of genetic and molecular data sources. These datasets are an asset for predicting virus-host interactions at the molecular level using machine learning (ML), a subset of artificial intelligence (AI). In this direction, ML tools are now being applied to recognize patterns in these massive datasets to predict critical interactions between virus and host cells at the protein-protein and protein-sugar levels, as well as to perform transcriptional and translational analysis. On the other end, deep learning (DL) algorithms-a subfield of ML-can extract high-level features from very large datasets to recognize the hidden patterns within genomic sequences and images to develop models for rapid drug discovery predictions that address pathogenic viruses displaying heightened affinity for receptor docking and enhanced cell entry. ML and DL are pivotal forces, driving innovation with their ability to perform analysis of enormous datasets in a highly efficient, cost-effective, accurate, and high-throughput manner. This review focuses on the complexity of virus-host cell interactions at the molecular level in light of the current advances of ML and AI in viral pathogenesis to improve new treatments and prevention strategies.

Conformational analysis of a new peptide derived from feline immunodeficiency virus gp36 in SDS micelles: An NMR-MD based investigation.

Feline immunodeficiency virus (FIV) shares structural similarities with human immunodeficiency virus (HIV): the surface glycoprotein gp36 corresponds to the HIV gp41, which drives virus-host cell interactions and is targeted by the peptide entry inhibitor enfuvirtide. Following a similar drug design strategy for the development of an anti-FIV therapy, the present study investigates 627-646gp36 NHR, a peptide sequence derived from a region of gp36 that was previously found to interfere with the antiviral activity of the peptide C8, which instead derives from the gp36 MPER. CD, NMR, and MD simulations were employed to probe the conformational characteristics of 627-646gp36 NHR in the membrane-mimicking environment of SDS micelles. Our data show that 627-646gp36 NHR is characterized by three dynamic helix structures. MD simulations involving 627-646gp36 NHR, C8, and a larger protein, including the CHR and MPER regions, suggest that the interaction of C8 with the MPER region, the origin of the antiviral activity of C8, is disfavored in the presence of 627-646gp36 NHR in the simulation. This evidence can be useful for interpreting the molecular mechanism that leads to interference with the activity of C8, providing information on the folding/unfolding mechanism of the viral glycoprotein to design new strategies to inhibit viral entry.

Surface-modified injectable poly(ethylene-glycol) diacrylate-based cryogels for localized gene delivery

Lentiviral transduction is widely used in research, has shown promise in clinical trials involving gene therapy and has been approved for CAR-T cell immunotherapy. However, most modifications are done ex vivo and rely on systemic administration of large numbers of transduced cells for clinical applications. A novel approach utilizing in situ biomaterial-based gene delivery can reduce off-target side effects while enhancing effectiveness of the manipulation process. In this study, poly(ethylene glycol) diacrylate (PEGDA)-based scaffolds were developed to enable in situ lentivirus-mediated transduction. Compared to other widely popular biomaterials, PEGDA stands out due to its robustness and cost-effectiveness. These scaffolds, prepared via cryogelation, are capable of flowing through surgical needles in both in vitro and in vivo conditions, and promptly regain their original shape. Modification with poly(L-lysine) (PLL) enables lentivirus immobilization while interconnected macroporous structure allows cell infiltration into these matrices, thereby facilitating cell-virus interaction over a large surface area for efficient transduction. Notably, these preformed injectable scaffolds demonstrate hemocompatibility, cell viability and minimally inflammatory response as shown by our in vitro and in vivo studies involving histology and immunophenotyping of infiltrating cells. This study marks the first instance of using preformed injectable scaffolds for delivery of lentivectors, which offers a non-invasive and localized approach for delivery of factors enabling in situ lentiviral transduction suitable for both tissue engineering and immunotherapeutic applications.

Differential gene expression and immune cell infiltration in maedi-visna virus-infected lung tissues

BackgroundMaedi-visna virus (MVV) is a lentivirus that infects monocyte/macrophage lineage cells in sheep, goats, and wild ruminants and causes pneumonia, mastitis, arthritis, and encephalitis. The immune response to MVV infection is complex, and a complete understanding of its infection and pathogenesis is lacking. This study investigated the in vivo transcriptomic patterns of lung tissues in sheep exposed to MVV using the RNA sequencing technology.ResultThe results indicated that 2,739 genes were significantly differentially expressed, with 1,643 downregulated genes and 1,096 upregulated genes. Many variables that could be unique to MVV infections were discovered. Gene Ontology analysis revealed that a significant proportion of genes was enriched in terms directly related to the immune system and biological responses to viral infections. Kyoto Encyclopedia of Genes and Genomes analysis revealed that the most enriched pathways were related to virus-host cell interactions and inflammatory responses. Numerous immune-related genes, including those encoding several cytokines and interferon regulatory factors, were identified in the protein-protein interaction network of differentially expressed genes (DEGs). The expression of DEGs was evaluated using real-time polymerase chain reaction and western blot analysis. CXCL13, CXCL6, CXCL11, CCR1, CXCL8, CXCL9, CXCL10, TNFSF8, TNFRSF8, IL7R, IFN-γ, CCL2, and MMP9 were upregulated. Immunohistochemical analysis was performed to identify the types of immune cells that infiltrated MVV-infected tissues. B cells, CD4+ and CD8+ T cells, and macrophages were the most prevalent immune cells correlated with MVV infection in the lungs.ConclusionOverall, the findings of this study provide a comprehensive understanding of the in vivo host response to MVV infection and offer new perspectives on the gene regulatory networks that underlie pathogenesis in natural hosts.