Chemico-Physical Properties of Some 1,1'-Bis-alkyl-2,2'-hexane-1,6-diyl-bispyridinium Chlorides Hydrogenated and Partially Fluorinated for Gene Delivery.

The development of very efficient and safe non-viral vectors, constituted mainly by cationic lipids bearing multiple charges, is a landmark for in vivo gene-based medicine. To understand the effect of the hydrophobic chain's length, we here report the synthesis, and the chemico-physical and biological characterization, of a new term of the homologous series of hydrogenated gemini bispyridinium surfactants, the 1,1'-bis-dodecyl-2,2'-hexane-1,6-diyl-bispyridinium chloride (GP12_6). Moreover, we have collected and compared the thermodynamic micellization parameters (cmc, changes in enthalpy, free energy, and entropy of micellization) obtained by isothermal titration calorimetry (ITC) experiments for hydrogenated surfactants GP12_6 and GP16_6, and for the partially fluorinated ones, FGPn (where n is the spacer length). The data obtained for GP12_6 by EMSA, MTT, transient transfection assays, and AFM imaging show that in this class of compounds, the gene delivery ability strictly depends on the spacer length but barely on the hydrophobic tail length. CD spectra have been shown to be a useful tool to verify the formation of lipoplexes due to the presence of a "tail" in the 288-320 nm region attributed to a chiroptical feature named ψ-phase. Ellipsometric measurements suggest that FGP6 and FGP8 (showing a very interesting gene delivery activity, when formulated with DOPE) act in a very similar way, and dissimilar from FGP4, exactly as in the case of transfection, and confirm the hypothesis suggested by previously obtained thermodynamic data about the requirement of a proper length of the spacer to allow the molecule to form a sort of molecular tong able to intercalate DNA.

Gene-Delivery Ability of New Hydrogenated and Partially Fluorinated Gemini bispyridinium Surfactants with Six Methylene Spacers.

The pandemic emergency determined by the spreading worldwide of the SARS-CoV-2 virus has focused the scientific and economic efforts of the pharmaceutical industry and governments on the possibility to fight the virus by genetic immunization. The genetic material must be delivered inside the cells by means of vectors. Due to the risk of adverse or immunogenic reaction or replication connected with the more efficient viral vectors, non-viral vectors are in many cases considered as a preferred strategy for gene delivery into eukaryotic cells. This paper is devoted to the evaluation of the gene delivery ability of new synthesized gemini bis-pyridinium surfactants with six methylene spacers, both hydrogenated and fluorinated, in comparison with compounds with spacers of different lengths, previously studied. Results from MTT proliferation assay, electrophoresis mobility shift assay (EMSA), transient transfection assay tests and atomic force microscopy (AFM) imaging confirm that pyridinium gemini surfactants could be a valuable tool for gene delivery purposes, but their performance is highly dependent on the spacer length and strictly related to their structure in solution. All the fluorinated compounds are unable to transfect RD-4 cells, if used alone, but they are all able to deliver a plasmid carrying an enhanced green fluorescent protein (EGFP) expression cassette, when co-formulated with 1,2-dioleyl-sn-glycero-3-phosphoethanolamine (DOPE) in a 1:2 ratio. The fluorinated compounds with spacers formed by six (FGP6) and eight carbon atoms (FGP8) give rise to a very interesting gene delivery activity, greater to that of the commercial reagent, when formulated with DOPE. The hydrogenated compound GP16_6 is unable to sufficiently compact the DNA, as shown by AFM images.

Visual illusions via neural dynamics: Wilson-Cowan-type models and the efficient representation principle.

We reproduce suprathreshold perception phenomena, specifically visual illusions, by Wilson-Cowan (WC)-type models of neuronal dynamics. Our findings show that the ability to replicate the illusions considered is related to how well the neural activity equations comply with the efficient representation principle. Our first contribution consists in showing that the WC equations can reproduce a number of brightness and orientation-dependent illusions. Then we formally prove that there cannot be an energy functional that the WC dynamics are minimizing. This leads us to consider an alternative, variational modeling, which has been previously employed for local histogram equalization (LHE) tasks. To adapt our model to the architecture of V1, we perform an extension that has an explicit dependence on local image orientation. Finally, we report several numerical experiments showing that LHE provides a better reproduction of visual illusions than the original WC formulation, and that its cortical extension is capable also to reproduce complex orientation-dependent illusions.NEW & NOTEWORTHY We show that the Wilson-Cowan equations can reproduce a number of brightness and orientation-dependent illusions. Then we formally prove that there cannot be an energy functional that the Wilson-Cowan equations are minimizing, making them suboptimal with respect to the efficient representation principle. We thus propose a slight modification that is consistent with such principle and show that this provides a better reproduction of visual illusions than the original Wilson-Cowan formulation. We also consider the cortical extension of both models to deal with more complex orientation-dependent illusions.

BoHV-4-based vector delivering Ebola virus surface glycoprotein.

BACKGROUND: Ebola virus (EBOV) is a Category A pathogen that is a member of Filoviridae family that causes hemorrhagic fever in humans and non-human primates. Unpredictable and devastating outbreaks of disease have recently occurred in Africa and current immunoprophylaxis and therapies are limited. The main limitation of working with pathogens like EBOV is the need for costly containment. To potentiate further and wider opportunity for EBOV prophylactics and therapies development, innovative approaches are necessary. METHODS: In the present study, an antigen delivery platform based on a recombinant bovine herpesvirus 4 (BoHV-4), delivering a synthetic EBOV glycoprotein (GP) gene sequence, BoHV-4-syEBOVgD106ΔTK, was generated. RESULTS: EBOV GP was abundantly expressed by BoHV-4-syEBOVgD106ΔTK transduced cells without decreasing viral replication. BoHV-4-syEBOVgD106ΔTK immunized goats produced high titers of anti-EBOV GP antibodies and conferred a long lasting (up to 6 months), detectable antibody response. Furthermore, no evidence of BoHV-4-syEBOVgD106ΔTK viremia and secondary localization was detected in any of the immunized animals. CONCLUSIONS: The BoHV-4-based vector approach described here, represents: an alternative antigen delivery system for vaccination and a proof of principle study for anti-EBOV antibodies generation in goats for potential immunotherapy applications.

Cyclodextrin- and calixarene-based polycationic amphiphiles as gene delivery systems: a structure-activity relationship study.

Multi-head/multi-tail facial amphiphiles built on cyclodextrin (CD) and calixarene (CA) scaffolds are paradigmatic examples of monodisperse gene delivery systems. The possibility to precisely control the architectural features at the molecular level offers unprecedented opportunities for conducting structure-activity relationship studies. A major requirement for those channels is the design of a sufficiently diverse ensemble of compounds for parallel evaluation of their capabilities to condense DNA into transfection nanoparticles where the gene material is protected from the environment. Here we have undertaken the preparation of an oriented library of ß-cyclodextrin (ßCD) and calix[4]arene (CA4) vectors with facial amphiphilic character designed to ascertain the effect of the cationic head nature (aminothiourea-, arginine- or guanidine-type groups) and the macrocyclic platform on the abilities to complex plasmid DNA (pDNA) and in the efficiency of the resulting nanocomplexes to transfect cells in vitro. The hydrophobic domain, formed by hexanoyl or hexyl chains, remains constant in each series, matching the overall structure found to be optimal in previous studies. DLS, TEM and AFM data support that all the compounds self-assemble in the presence of pDNA through a process that involves initially electrostatic interactions followed by formation of ßCD or CA4 bilayers between the oligonucleotide filaments. Spherical transfectious nanoparticles that are monomolecular in DNA are thus obtained. Evaluation in epithelial COS-7 and human rhabdomyosarcoma RD-4 cells evidenced the importance of having primary amino groups in the vector to warrant high levels of transfection, probably because of their buffering capacity. The results indicate that the optimal cationic head depends on the macrocyclic core, aminothiourea groups being preferred in the ßCD series and arginine groups in the CA4 series. Whereas the transfection efficiency relationships remain essentially unchanged within each series, irrespective of the cell type, the optimal platform (ßD or CA4) strongly depends on the cell type. The results illustrate the potential of monodisperse vector prototypes and diversity-oriented strategies on identifying the optimal candidates for gene therapy applications.

BoHV-4 immediate early 1 gene is a dispensable gene and its product is not a bone marrow stromal cell antigen 2 counteracting factor.

BACKGROUND: Bovine herpesvirus 4 (BoHV-4) is a gammaherpesvirus whose genome was cloned as Bacterial Artificial Chromosome (BAC) and exploited as a gene delivery vector for vaccine purposes. Although BoHV-4 genome has been completely sequenced and its open reading frames (ORFs) structurally defined in silico, most of them are not functionally characterized. In BoHV-4 genome two major immediate early genes (IE) are present, IE1 and IE2. IE2 is an essential gene because its removal from the viral genome renders the virus unable to replicate, whereas for IE1 no many functional information are available. RESULTS: In this work, IE1 contribution in initiating and maintaining BoHV-4 lytic replication was assessed generating a recombinant BoHV-4 genome lacking of IE1 gene, BoHV-4ΔIE1. In contrast to BoHV-4IE2 deleted mutant, BoHV-4ΔIE1 infectious replicating viral particles (IRVPs) could be reconstituted following viral DNA electroporation in permissive cells. However the titer of BoHV-4ΔIE1 IRVPs produced into the cell supernatant and BoHV-4ΔIE1 plaques size were reduced respect to BoHV-4 undeleted control. Further the impaired BoHV-4ΔIE1 IRVPs produced into the cell supernatant could be rescued by expressing IE1 gene product in trans, confirming the implication of IE1 in BoHV-4 lytic replication. Next, the possible role of BoHV-4IE1 as bone marrow stromal cell antigen 2 (BST-2) counteracting factor, as hypothesized by IE1 amino-terminal gene product homology with Kaposi Sarcoma Associated Herpesvirus (KSHV) K5, was excluded too. CONCLUSIONS: Although the real function of BoHV-4IE1 is still elusive, a new BoHV-4 genome gene locus as a target site for the insertion of foreign DNA and resulting in the attenuation of the virus has been revealed. These data can be considered of relevance to improve BoHV-4 gene delivery properties.

Interferon gamma-mediated BoHV-4 replication restriction in bovine endometrial stromal cells is host IDO1 gene expression independent and BoHV-4 IE2 gene expression dependent.

In the present work the interaction between bovine herpesvirus 4 (BoHV-4)-infected bovine endometrial stromal cells (BESCs) and interferon gamma (IFNG) was investigated. Starting from the particular tropism of BoHV-4 toward BESCs, a pure population of these cells, free of CD45-positive cells, was prepared and proven to have a bona fide mesenchymal derivation as shown by vimentin-positive and cytokeratin-negative staining. BESCs expressed functional IFNG receptors (IFNGR) 1 and 2 but not IFNG ligand. BESCs transfected with a new reporter construct made by cloning the bovine indoleamine 2, 3-dioxygenase 1 (IDO1) promoter in front of the luciferase reporter gene responded to exogenous IFNG treatment. Further, IFNG-treated or constitutively secreting IFNG BESCs strongly restricted BoHV-4 replication and consequent cytopathic effect. IDO1 expression in BESCs was tightly induced by IFNG and IDO1 was previously shown to be the mediator for some of the IFNG pathogenostatic effects. However, IDO1 inhibitors and IDO1 constitutive expression could not respectively abrogate or recapitulate IFNG effect on BoHV-4-infected BESCs, whereas BoHV-4 immediate early (IE2) gene expression was transcriptionally depressed by IFNG axis activation independently from IDO1 expression; this was further confirmed by revealing a BoHV-4 IE2 gene promoter area containing potential responsive elements interacting with inhibitory transcription factors induced by IFNG in BESCs. The data achieved in this work highlight at least two issues: first, the role of BESCs as target/effector cells for the IFNG; second, the importance of uterine IFNG integrity to control BoHV-4 infection recrudescence from a persistent/latent state to a chronic disease, endometritis.

Enlightened Mannhemia haemolytica lung inflammation in bovinized mice.

Polymorphonuclear cells diapedesis has an important contribution to the induced Mannhemia haemolytica (M. haemolytica) infection lung inflammation and IL-8 is the primary polymorphonuclear chemoattractant. Using a bovine IL-8/luciferase transiently transgenized mouse model, the orchestration among M. haemolytica, IL-8 promoter activation and neutrophilia was followed in real time by in vivo image analysis.

Bovine endometrial stromal cells support tumor necrosis factor alpha-induced bovine herpesvirus type 4 enhanced replication.

Bovine uterine infections are the most important cause of economic losses in the cattle industry. Although the etiology of uterine diseases is mainly ascribed to bacterial infection, they can also be associated with viral infection, such as bovine herpesvirus 4 (BoHV-4), which is often a secondary agent following bacteria. Besides microbial infection, many inflammatory molecules belonging to the innate immune response orchestrate the outcome of the infection. In the present study, the interaction between BoHV-4-infected bovine endometrial stromal cells and tumor necrosis factor alpha (TNF-alpha) was investigated. Bovine herpesvirus 4 possesses a special tropism toward endometrial stromal cells. For this reason, a simian virus 40 (SV40) immortalized endometrial stromal cell line (SV40BESC) was established; it was proven that it was stable, it expressed toll-like receptors (TLRs; from 1 to 10) and TNF-alpha receptors I and II, and it was responsive to exogenous TNF-alpha. Further, an increase of BoHV-4 replication and cytopathic effect was observed in BoHV-4-infected and TNF-alpha-treated SV40BESCs. This increase of viral replication was associated with BoHV-4 immediate early 2 (IE2) gene promoter trans-activation through the interaction of the nuclear factor KB (NFKB) with the putative NFKB-responsive elements found within BoHV-4 IE2 gene promoter, and this interaction was abolished when NFKB-responsive elements were deleted. These data shed light on two important and rather controversial issues: the role of TNF-alpha receptor, which is weakly expressed in the stromal layer of the bovine uterus, as well as the possible interactions between proinflammatory molecules, viral replication, and chronic uterine disease.

Bovine herpesvirus 4 glycoprotein B is indispensable for lytic replication and irreplaceable by VSVg.

BACKGROUND: Bovine herpesvirus 4 (BoHV-4) is a gammaherpesvirus, belonging to Rhadinovirus genus, with no clear association with disease. However, there is increasing evidence of its secondary pathogenic role in cases of post-partum metritis in cattle. BoHV-4 Open Reading Frame 8 (ORF8) codifies for glycoprotein B (gB) that shows a heterodimeric structure, composed of two subunits and covalently linked by disulfide bonds and responsible for host cell adhesion through binding to heparan sulfates associated with cellular proteoglycans. Here we describe the generation of several tagged soluble forms of gB ectodomain, in order to test their ability to neutralize BoHV-4 infection. RESULTS: The results show, however, that none of these soluble forms are able to block viral infectivity. To better understand the role of gB during BoHV-4 lytic replication, a recombinant BoHV-4 was generated by homologous recombination from a BoHV-4 cloned as a Bacterial artificial chromosome (BAC) (pBAC-BoHV-4-A), in which most of the BoHV-4 gB ORF was substituted by the insertion of a DNA stuffer selectable cassette. The resulting recombinant BoHV-4 genome (pBAC-BoHV-4-AΔgB-KanaGalK) was completely unable to reconstitute infectious replicating viral particles (Infectious Replicating Viral Particles, IRVPs) and to replicate when transfected in permissive cell lines in comparison to its revertant clone (pBAC-BoHV-4-ΔgB-Rev) or pBAC-BoHV-4-A parental clone. CONCLUSION: This demonstrates that the BoHV-4 replicating cycle is dependent on gB. Moreover, when gB was deleted from a recombinant BoHV-4 genome delivering an heterologous glycoprotein, Vesicular Stomatitis Virus Glycoprotein (VSVg), VSVg was unable to complement gB. This study provides direct evidence that gB is necessary for BoHV-4 lytic replication.

Characterization of BoHV-4 ORF45.

Bovine herpesvirus 4 (BoHV-4) is a Gammaherpesvirus belonging to the Rhadinovirus genus. The bovine is BoHV-4's natural host, and the African buffalo is BoHV-4's natural reservoir. In any case, BoHV-4 infection is not associated with a specific disease. Genome structure and genes are well-conserved in Gammaherpesvirus, and the orf 45 gene and its product, ORF45, are one of those. BoHV-4 ORF45 has been suggested to be a tegument protein; however, its structure and function have not yet been experimentally characterized. The present study shows that BoHV-4 ORF45, despite its poor homology with other characterized Rhadinovirus ORF45s, is structurally related to Kaposi's sarcoma-associated herpesvirus (KSHV), is a phosphoprotein, and localizes in the host cell nuclei. Through the generation of an ORF45-null mutant BoHV-4 and its pararevertant, it was possible to demonstrate that ORF45 is essential for BoHV-4 lytic replication and is associated with the viral particles, as for the other characterized Rhadinovirus ORF45s. Finally, the impact of BoHV-4 ORF45 on cellular transcriptome was investigated, an aspect poorly explored or not at all for other Gammaherpesvirus. Many cellular transcriptional pathways were found to be altered, mainly those involving p90 ribosomal S6 kinase (RSK) and signal-regulated kinase (ERK) complex (RSK/ERK). It was concluded that BoHV-4 ORF45 has similar characteristics to those of KSHV ORF45, and its unique and incisive impact on the cell transcriptome paves the way for further investigations.

Assessment of BoHV-4-based vector vaccine intranasally administered in a hamster challenge model of lung disease.

Introduction: Bovine herpesvirus 4 (BoHV-4) is a bovine Rhadinovirus not associated with a specific pathological lesion or disease and experimentally employed as a viral vector vaccine. BoHV-4-based vector (BoHV-4-BV) has been shown to be effective in immunizing and protecting several animal species when systemically administrated through intramuscular, subcutaneous, intravenous, or intraperitoneal routes. However, whether BoHV-4-BV affords respiratory disease protection when administered intranasally has never been tested. Methods: In the present study, recombinant BoHV-4, BoHV-4-A-S-ΔRS-HA-ΔTK, was constructed to deliver an expression cassette for the SARS-CoV-2 spike glycoprotein, and its immunogenicity, as well as its capability to transduce cells of the respiratory tract, were tested in mice. The well-established COVID-19/Syrian hamster model was adopted to test the efficacy of intranasally administered BoHV-4-A-S-ΔRS-HA-ΔTK in protecting against a SARS-CoV-2 challenge. Results: The intranasal administration of BoHV-4-A-S-ΔRS-HA-ΔTK elicited protection against SARS-CoV-2, with improved clinical signs, including significant reductions in body weight loss, significant reductions in viral load in the trachea and lungs, and significant reductions in histopathologic lung lesions compared to BoHV-4-A-S-ΔRS-HA-ΔTK administered intramuscularly. Discussion: These results suggested that intranasal immunization with BoHV-4-BV induced protective immunity and that BoHV-4-BV could be a potential vaccine platform for the protection of other animal species against respiratory diseases.

A dry powder formulation for peripheral lung delivery and absorption of an anti-SARS-CoV-2 ACE2 decoy polypeptide.

One of the strategies proposed for the neutralization of SARS-CoV-2 has been to synthetize small proteins able to act as a decoy towards the virus spike protein, preventing it from entering the host cells. In this work, the incorporation of one of these proteins, LCB1, within a spray-dried formulation for inhalation was investigated. A design of experiments approach was applied to investigate the optimal condition for the manufacturing of an inhalable powder. The lead formulation, containing 6% w/w of LCB1 as well as trehalose and L-leucine as excipients, preserved the physical stability of the protein and its ability to neutralize the virus. In addition, the powder had a fine particle fraction of 58.6% and a very high extra-fine particle fraction (31.3%) which could allow a peripheral deposition in the lung. The in vivo administration of the LCB1 inhalation powder showed no significant difference in the pharmacokinetic from the liquid formulation, indicating the rapid dissolution of the microparticles and the protein capability to translocate into the plasma. Moreover, LCB1 in plasma samples still maintained the ability to neutralize the virus. In conclusion, the optimized spray drying conditions allowed to obtain an inhalation powder able to preserve the protein biological activity, rendering it suitable for a systemic prevention of the viral infection via pulmonary administration.

Lower rim guanidinocalix[4]arenes: macrocyclic nonviral vectors for cell transfection.

Guanidinium groups were introduced through a spacer at the lower rim of calix[4]arenes in the cone conformation to give new potential nonviral vectors for gene delivery. Several structural modifications were explored, such as the presence or absence of a macrocyclic scaffold, lipophilicity of the backbone, length of the spacer, and nature of the charged groups, in order to better understand the factors which affect the DNA condensation ability and transfection efficiency of these derivatives. The most interesting compound was a calix[4]arene unsubstituted at the upper rim and having four guanidinium groups linked at the lower rim through a three carbon atom spacer. This compound, when formulated with DOPE, showed low toxicity and transfection efficiency higher than the commercially available lipofectamine LTX in the treatment of human Rhabdomiosarcoma and Vero cells. Most of the investigated compounds showed a tendency to self-aggregate in pure water or in the presence of salts, as evidenced by NMR and AFM studies, and it was found that the ability to condense DNA plasmids in nanometric globules is a necessary but not sufficient condition for transfection. The superiority of macrocyclic vectors over linear Gemini-type analogues and of guanidinium compared to other ammonium head groups in determining the biological activity of the vectors was also ascertained.

Enhanced immunogenicity of a positively supercharged archaeon thioredoxin scaffold as a cell-penetrating antigen carrier for peptide vaccines.

Polycationic resurfaced proteins hold great promise as cell-penetrating bioreagents but their use as carriers for the intracellular delivery of peptide immuno-epitopes has not thus far been explored. Here, we report on the construction and functional characterization of a positively supercharged derivative of Pyrococcus furiosus thioredoxin (PfTrx), a thermally hyperstable protein we have previously validated as a peptide epitope display and immunogenicity enhancing scaffold. Genetic conversion of 13 selected amino acids to lysine residues conferred to PfTrx a net charge of +21 (starting from the -1 charge of the wild-type protein), along with the ability to bind nucleic acids. In its unfused form, +21 PfTrx was readily internalized by HeLa cells and displayed a predominantly cytosolic localization. A different intracellular distribution was observed for a +21 PfTrx-eGFP fusion protein, which although still capable of cell penetration was predominantly localized within endosomes. A mixed cytosolic/endosomal partitioning was observed for a +21 PfTrx derivative harboring three tandemly repeated copies of a previously validated HPV16-L2 (aa 20-38) B-cell epitope grafted to the display site of thioredoxin. Compared to its wild-type counterpart, the positively supercharged antigen induced a faster immune response and displayed an overall superior immunogenicity, including a substantial degree of self-adjuvancy. Altogether, the present data point to +21 PfTrx as a promising novel carrier for intracellular antigen delivery and the construction of potentiated recombinant subunit vaccines.

Immune response to SARS-CoV-2 mRNA vaccination and booster dose in patients with multiple myeloma and monoclonal gammopathies: impact of Omicron variant on the humoral response.

The humoral and cellular response to SARS-CoV-2 mRNA full vaccination and booster dose as well as the impact of the spike variants, including Omicron, are still unclear in patients with multiple myeloma (MM) and those with pre-malignant monoclonal gammopathies. In this study, involving 40 patients, we found that MM patients with relapsed-refractory disease (MMR) had reduced spike-specific antibody levels and neutralizing titers after SARS-CoV-2 vaccination. The five analyzed variants, remarkably Omicron, had a significant negative impact on the neutralizing ability of the vaccine-induced antibodies in all patients with MM and smoldering MM. Moreover, lower spike-specific IL-2-producing CD4+ T cells and reduced cytotoxic spike-specific IFN-γ and TNF-α-producing CD8+ T cells were found in MM patients as compared to patients with monoclonal gammopathy of undetermined significance. We found that a heterologous booster immunization improved SARS-CoV-2 spike humoral and cellular responses in newly diagnosed MM (MMD) patients and in most, but not all, MMR patients. After the booster dose, a significant increase of the neutralizing antibody titers against almost all the analyzed variants was achieved in MMD. However, in MMR patients, Omicron retained a negative impact on neutralizing ability, suggesting further approaches to potentiating the effectiveness of SARS-CoV-2 vaccination in these patients.

A Cortical-Inspired Sub-Riemannian Model for Poggendorff-Type Visual Illusions.

We consider Wilson-Cowan-type models for the mathematical description of orientation-dependent Poggendorff-like illusions. Our modelling improves two previously proposed cortical-inspired approaches, embedding the sub-Riemannian heat kernel into the neuronal interaction term, in agreement with the intrinsically anisotropic functional architecture of V1 based on both local and lateral connections. For the numerical realisation of both models, we consider standard gradient descent algorithms combined with Fourier-based approaches for the efficient computation of the sub-Laplacian evolution. Our numerical results show that the use of the sub-Riemannian kernel allows us to reproduce numerically visual misperceptions and inpainting-type biases in a stronger way in comparison with the previous approaches.

Immunization With Bovine Herpesvirus-4-Based Vector Delivering PPRV-H Protein Protects Sheep From PPRV Challenge.

The Morbillivirus peste des petits ruminants virus (PPRV) is the causal agent of a highly contagious disease that mostly affects sheep and goats and produces considerable losses in developing countries. Current PPRV control strategies rely on live-attenuated vaccines, which are not ideal, as they cannot differentiate infected from vaccinated animals (DIVA). Recombinant vector-based vaccines expressing viral subunits can provide an alternative to conventional vaccines, as they can be easily paired with DIVA diagnostic tools. In the present work, we used the bovine herpesvirus-4-based vector (BoHV-4-A) to deliver PPRV hemagglutinin H antigen (BoHV-4-A-PPRV-H-ΔTK). Vaccination with BoHV-4-A-PPRV-H-ΔTK protected sheep from virulent PPRV challenge and prevented virus shedding. Protection correlated with anti-PPRV IgGs, neutralizing antibodies and IFN-γ-producing cells induced by the vaccine. Detection of antibodies exclusively against H-PPRV in animal sera and not against other PPRV viral proteins such as F or N could serve as a DIVA diagnostic test when using BoHV-4-A-PPRV-H-ΔTK as vaccine. Our data indicate that BoHV-4-A-PPRV-H-ΔTK could be a promising new approach for PPRV eradication programs.

Persistency of Mesenchymal Stromal/Stem Cells in Lungs.

Mesenchymal stromal/stem cells (MSCs) are a fibroblast-like cell population with high regenerative potential that can be isolated from many different tissues. Several data suggest MSCs as a therapeutic tool capable of migrating to a site of injury and guide tissue regeneration mainly through their secretome. Pulmonary first-pass effect occurs during intravenous administration of MSCs, where 50 to 80% of the cells tend to localize in the lungs. This phenomenon has been exploited to study MSC potential therapeutic effects in several preclinical models of lung diseases. Data demonstrated that, regardless of the lung disease severity and the delivery route, MSCs were not able to survive longer than 24 h in the respiratory tract but still surprisingly determined a therapeutic effect. In this work, two different mouse bone marrow-derived mesenchymal stromal/stem cell (mBM-MSC) lines, stably transduced with a third-generation lentiviral vector expressing luciferase and green fluorescent protein reporter genes tracking MSCs in vivo biodistribution and persistency, have been generated. Cells within the engrafted lung were in vivo traced using the high-throughput bioluminescence imaging (BLI) technique, with no invasiveness on animal, minimizing biological variations and costs. In vivo BLI analysis allowed the detection and monitoring of the mBM-MSC clones up to 28 days after implantation independently from the delivery route. This longer persistency than previously observed (24 h) could have a strong impact in terms of pharmacokinetics and pharmacodynamics of MSCs as a therapeutic tool.