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Quantum Entanglement has been hypothesized to mediate non-local consciousness, underlying which, empirically, is the force of gravity. Upon further reflection, the case can be made for 'the breath' as the physiologic trait that binds all of these properties together, offering further opportunity for hypothesis testing experimentation. Humans have inexplicably made extraordinary intellectual and technical advances within a relatively very short period of time, referred to as the 'great leap forward'. It would be of great value if we could identify how and why we have evolved so rapidly. There is a holotropism that begins with the Big Bang that is centered on the homeostatic control of energy, perpetually referencing the First Principles of Physiology. "The Breath" is how and why our physiology has managed to perpetuate our species, and perhaps why the lung has been 'over-engineered' in order to facilitate the role of breathing in consciousness. [ABSTRACT FROM AUTHOR]

Proteinaceous receptors bind distinct sites of the alphavirus glycoprotein to mediate efficient cellular entry. The cleft formed by E1–E2 heterodimers is utilized by the mammalian MXRA8 to bind Chikungunya virus (CHIKV) and LDLRAD3 to bind Venezuelan equine encephalitis virus (VEEV). VLDLR binds Semliki forest virus (SFV) outside of the cleft at the fivefold and twofold icosahedral vertices, resulting in an avid interaction involving multiple lipoprotein A (LA) domains with E1-DIII. Avian MXRA8 binds specifically to the Western equine encephalitis (WEE) complex in a 'flipped' orientation compared with mammalian MXRA8 and CHIKV. The interactions of VLDLR and ApoER2 with Eastern equine encephalitis virus (EEEV) and Sindbis virus (SINV) remain to be fully characterized but likely do not involve E1-DIII. Additional sites on the alphavirus glycoprotein, apart from the cleft and vertices formed by E1, likely bind host receptors and mediate entry. With these new structural data, we hypothesize that alphaviruses evolved distinct strategies to engage multiple host cell receptors. Alphaviruses are mosquito-transmitted RNA viruses with epidemic potential. The alphavirus family is phylogenetically grouped into distinct complexes, which can utilize different receptors to mediate entry into host cells. Structural characterization has revealed key sites on the envelope glycoproteins that mediate interaction with host receptors. However, the receptors and binding sites identified so far do not account for the entry of all alphaviruses from different complexes, suggesting the existence of additional receptors. A more complete characterization of alphavirus host receptor interactions will inform our understanding of species tropism, evolution, and pathogenesis, and may facilitate the development of broad-spectrum receptor-based therapeutics. Only a subset of viruses can productively infect many different host species. Some arthropod-transmitted viruses, such as alphaviruses, can infect invertebrate and vertebrate species including insects, reptiles, birds, and mammals. This broad tropism may be explained by their ability to engage receptors that are conserved across vertebrate and invertebrate classes. Through several genome-wide loss-of-function screens, new alphavirus receptors have been identified, some of which bind to multiple related viruses in different antigenic complexes. Structural analysis has revealed that distinct sites on the alphavirus glycoprotein can mediate receptor binding, which opposes the idea that a single receptor-binding site mediates viral entry. Here, we discuss how different paradigms of receptor engagement on cells might explain the promiscuity of alphaviruses for multiple hosts. [ABSTRACT FROM AUTHOR]

[Display omitted] • Meronts and megalomeronts of five co-infecting Haemoproteus spp. were described. • In situ hybridization combined with laser microdissection are effective in merogony research. • Lineage-specific tools revealed different tissue tropism in co-infecting parasites. • New pathologies during haemoproteosis were reported. • Haemoproteus magnus was molecularly characterized. Avian haemosporidians of the genera Plasmodium , Haemoproteus, and Leucocytozoon are common blood parasites in wild birds all over the world. Despite their importance as pathogens potentially compromising host fitness and health, little is known about the exo-erythrocytic development of these parasites, particularly during co-infections which predominate in wildlife. This study aimed to address this issue using Haemoproteus parasites of Fringilla coelebs , a common bird species of the Western Palearctic and host to a variety of haemosporidian parasite lineages. Blood and tissue samples of 20 F. coelebs, positive for haemosporidians by blood film microscopy, were analysed by PCR and sequencing to determine cytochrome b lineages of the parasites. Tissue sections were examined for exo-erythrocytic stages by histology and in situ hybridization applying genus-, species-, and lineage-specific probes which target the 18S rRNA of the parasites. In addition, laser microdissection of tissue stages was performed to identify parasite lineages. Combined molecular results of PCR, laser microdissection, and in situ hybridization showed a high rate of co-infections, with Haemoproteus lineages dominating. Exo-erythrocytic meronts of five Haemoproteus spp. were described for the first known time, including Haemoproteus magnus hCCF6 , Haemoproteus fringillae hCCF3, Haemoproteus majoris hCCF5, Haemoproteus sp. hROFI1, and Haemoproteus sp. hCCF2. Merogonic stages were observed in the vascular system, presenting a formerly unknown mode of exo-erythrocytic development in Haemoproteus parasites. Meronts and megalomeronts of these species were distinct regarding their morphology and organ distribution, indicating species-specific patterns of merogony and different host tissue tropism. New pathological aspects of haemoproteosis were reported. Furthermore, phylogenetic analysis of Haemoproteus spp. with regard to their exo-erythrocytic stages points towards separation of non-megalomeront-forming species from megalomeront-forming species, calling for further studies on exo-erythrocytic development of haemosporidian parasites to explore the phylogenetic character of this trait. [ABSTRACT FROM AUTHOR]

The pseudorabies virus (PRV) TJ strain, a variant of PRV, induces more severe neurological symptoms and higher mortality in piglets and mice than the PRV SC strain isolated in 1980. However, the mechanism underlying responsible for the discrepancy in virulence between these strains remains unclear. Our study investigated the differences in neurotropism between PRV TJ and PRV SC using both in vitro and in vivo models. We discovered that PRV TJ enters neural cells more efficiently than PRV SC. Furthermore, we found that PRV TJ has indistinguishable genomic DNA replication capability and axonal retrograde transport dynamics compared to the PRV SC. To gain deeper insights into the mechanisms underlying these differences, we constructed gene-interchanged chimeric virus constructs and assessed the affinity between envelope glycoprotein B, C, and D (gD) and corresponding receptors. Our findings confirmed that mutations in these envelope proteins, particularly gD, significantly contributed to the heightened attachment and penetration capabilities of PRV TJ. Our study revealed the critical importance of the gDΔR278/P279 and gDV338A in facilitating viral invasion. Furthermore, our observations indicated that mutations in envelope proteins have a more significant impact on viral invasion than on virulence in the mouse model. Our findings provide valuable insights into the roles of natural mutations on the PRV envelope glycoproteins in cell tropism, which sheds light on the relationship between cell tropism and clinical symptoms and offers clues about viral evolution. [ABSTRACT FROM AUTHOR]

Tumor recurrence mainly triggered by tumor residual cells significantly contributes to mortality following breast tumor resection, and meanwhile post-surgical bacterial wound infections may accelerate tumor recurrence due to a series of infection-related complications. In this study, a nano-sensor system, Van-ICG@PLT, is constructed by a membrane camouflage and small molecule drug self-assembly strategy. This nano-sensor harnesses the innate tropism of platelets (PLT) to deliver vancomycin (Van) and indocyanine green (ICG) to surgical incisions, effectively eliminating both residual tumor cells and bacterial infections. Our findings demonstrate that Van-ICG@PLT preferentially accumulates at surgical wound. Under near-infrared (NIR) laser irradiation, Van-ICG@PLT exhibits significant cytotoxicity against 4T1 cells. Additionally, it is found to significantly promote ROS production thus inhibiting Staphylococcus aureus (S. aureus) growth, underscoring the synergistic benefits of phototherapy in combination with antibiotic treatment. In the 4T1 post-surgery recurrence mice model, Van-ICG@PLT is shown to efficiently ablate tumors in tumor-bearing mice (tumor inhibition rate of about 83%), and it demonstrates an excellent anti-infective effect in mice abscess models. Taken together, Van-ICG@PLT represents a promising paradigm in post-surgical adjuvant therapy (PAT). Its dual benefit in inhibiting cancer growth and promoting antibacterial activity makes Van-ICG@PLT a valuable addition to the existing arsenal of therapeutic options available for breast cancer patients. PLT membrane-coated Van-ICG nanodrug cascade targets tumor cells and bacteria in post-operative tumor incisions microenvironment. This system utilizes phototherapy and antibiotics to complement each other, synchronously inhibiting residual tumor regeneration and wound bacterial infection. [Display omitted] • Van-ICG@PLT nano-assemblies are specifically accumulated at the surgical incision. • ROS produced by phototherapy kills post-surgery residual tumor cells and infected bacteria in parallel. • Co-delivery of Van and ICG demonstrates a strong additive advantage against bacterial wound infection. • Potent regulation of tumor recurrence and infection provides a supplement to postoperative adjuvant therapy. [ABSTRACT FROM AUTHOR]

Mesenchymal stem cells (MSCs) exhibited remarkable therapeutic potential in ischemic stroke due to their exceptional immunomodulatory ability and paracrine effect; they have also been regarded as excellent neuroprotectant delivery vehicles with inflammatory tropism. However, the presence of high levels of reactive oxygen species (ROS) and an oxidative stress environment at the lesion site inhibits cell survival and further therapeutic effects. Using bioorthogonal click chemistry, ROS-responsive luteolin-loaded micelles were tethered to the surface of MSCs. As MSCs migrated to the ischemic brain, the micelles would achieve ROS-responsive release of luteolin to protect MSCs from excessive oxidative damage while inhibiting neuroinflammation and scavenging ROS to ameliorate ischemic stroke. This study provided an effective and prospective therapeutic strategy for ischemic stroke and a framework for a stem cell-based therapeutic system to treat inflammatory cerebral diseases. [Display omitted] [ABSTRACT FROM AUTHOR]

Interferon-γ (IFN-γ) is well known to reduce the infectivity of viral pathogens by altering their tissue tropism. This effect is induced by upregulation of cholesterol 25-hydroxylase (CH25H). Given the similarity of viral pathogens and ligand-functionalized nanoparticles in the underlying strategy of receptor-mediated cell recognition, it appears conceivable that IFN-γ exceeds similar effects on nanoparticles. Concretely, IFN-γ-induced activation of CH25H could decrease nanoparticle avidity for target cells via depletion of clathrin-coated pits. We hypothesized that this effect would cause deterioration of target-cell specific accumulation of nanoparticles. To prove our hypothesis, we investigated the cell tropism of angiotensin II functionalized nanoparticles (NP Lys-Ang II) in a co-culture system of angiotensin II subtype 1 receptor (AT 1 R) positive rat mesangial target cells (rMCs) and AT 1 R-negative HeLa off-target cells. In the presence of IFN-γ we observed an up to 5-fold loss of target cell preference for NP Lys-Ang II. Thus, our in vitro results suggest a strong influence of IFN-γ on nanoparticle distribution, which is relevant in the context of nanotherapeutic approaches to cancer treatment, as IFN-γ is strongly expressed in tumors. For the target cell tropism of viruses, our results provide a conclusive hypothesis for the underlying mechanism behind non-directed viral distribution in the presence of IFN-γ. [Display omitted] • IFN-γ impaired performance of ligand-decorated NPs in target/off-target cell co-culture. • Target cell-specific NP uptake, recognition, and directed accumulation were reduced. • Loss in NP performance was correlated with an increase in CH25H concentration. • Unsupervised-learning algorithm found subpopulations in cell co-culture NP distribution. [ABSTRACT FROM AUTHOR]

Extracellular vesicles (EVs) work as communication vehicles, allowing the exchange of bioactive molecules (microRNAs, mRNAs, proteins, etc) between neighbouring and distant cells in the organism. EVs are thus important players in several physiological and pathological processes. Thus, it is critical to understand their role in cellular/organ communication to fully evaluate their biological, diagnosis and therapeutic potential. In addition, recent studies have explored the controlled release of EVs for regenerative medicine applications and thus the evaluation of their release profile is important to correlate with biological activity. Here, we give a brief introduction about EV imaging platforms in terms of their sensitivity, penetration depth, cost, and operational simplicity, followed by a discussion of different EV labelling processes with their advantages and limitations. Next, we cover the relevance of these imaging platforms to dissect the tropism and biological role of endogenous EVs. We also cover the relevance of imaging platforms to monitor the accumulation of exogenous EVs and their potential cellular targets. Finally, we highlight the importance of imaging platforms to investigate the release profile of EVs from different controlled systems. [Display omitted] [ABSTRACT FROM AUTHOR]

Metabolic dysregulation contributes not only to cancer development but also to a tumor immune microenvironment (TIME), which poses great challenges to chemo- and immunotherapy. Targeting metabolic reprogramming has recently emerged as a promising strategy for cancer treatment, but the lethality against solid tumors appears to be fairly restricted, partially due to the poor solubility of small molecule drugs. Herein, we construct a versatile biomimetic nanoplatform (referred to as HM-BPT) employing pH-sensitive tumor-tropism hybrid membrane-coated Manganese oxide (MnO 2) nanoparticles for the delivery of BPTES, a glutamine metabolism inhibitor. Basically, hybrid membranes consisting of mesenchymal stem cell membranes (MSCm) and pH-sensitive liposomes (pSL) enable the biomimetic nanoplatform to target TME and escape from endo/lysosomes after endocytosis. The results reveal that HM-BPT treatment leads to remarkable tumor inhibition, cytotoxic T lymphocyte (CTL) infiltration, as well as M1 phenotype repolarization and stimulator of IFN genes (STING) pathway activation in macrophages in a 4T1 xenograft model. Furthermore, glutathione (GSH) depletion and oxygen (O 2) supply synergistically ameliorate the immunosuppressive status of the TME, boosting potent antitumor immune responses. Overall, our study explores an integrated therapeutic platform for TME reprogramming and immune activation, offering tremendous promise for cancer combination therapy. Metabolic abnormalities and the tumor immune microenvironment (TIME) lead to hyporesponsiveness to conventional therapies, ultimately resulting in refractory malignancies. In the current work, a biomimetic nanoplatform (HM-BPT) was developed for TME metabolic reprogramming in favor of immunotherapy. Particularly, hybrid membrane camouflage endowed the nanoplatform with TME targeting, endo/lysosomal escape, and sensitive release properties. The impact of hybrid membrane fusion ratio on cellular uptake and cell viability was explored, yielding beneficial references for the future development of bioactive nanomaterials. Intravenous administration of HM-BPT substantially relieved tumor burden and restored innate and acquired immune activation in 4T1 xenograft models. In conclusion, the created HM-BPT system has the potential to be a promising nanoplatform for combining cancer therapies. [Display omitted] [ABSTRACT FROM AUTHOR]

Since the nineteenth century, several reports in the historical medical literature emphasized that, occasionally, cancer patients showed a clinical remission, called "Saint Peregrine tumor" as a result of natural infections. Moreover, additional evidence indicated that viruses show a tropism toward cancer cells, leading to the discovery of oncolytic activity of several viruses, called oncolytic viruses (OVs). With the technological and scientific advancements, the advent of rodent models, the establishment of in vitro cell lines, the introduction of methods for virus propagation, several attempts through the 1950s and 1970s have been made to increase OVs specificity, efficacy and safety; however, inconclusive/negative results have been reached and many researchers abandoned the field. Only in the later 1990s, the genetic engineering and the recombinant DNA techniques that allowed the generation of potent, specific and safe OVs and a better understanding of cancer cells renewed the interest in virotherapy. Currently, virotherapy represents a cancer therapeutic strategy based on the use of OVs that selectively infect and lyse cancer cells, without harming normal cells. Over the past years, several "natural" and "genetic engineered" viruses, have been investigated in clinical studies and some of them revealed encouraging results. Recently, the clinical use of OVs has also been supported by the immune stimulatory property of OVs against tumor cells. Here, we analyze the early oncolytic virotherapy before genetic engineering to highlight the relevant progresses reached, and the mechanism to stimulate host immune response, a significant challenge in current virotherapy field. • Occurrence of cancer remission concomitantly with naturally viral infections. • Modern molecular biology techniques allowed generation of new oncolytic viruses. • Clinical trials guided the approval of oncolytic viruses for cancer treatment. • Beyond cancer cell lysis, oncolytic viruses display immune-stimulatory properties. [ABSTRACT FROM AUTHOR]

Adeno-associated viruses (AAVs) are one of the leading gene therapy vectors for clinical applications. However, AAV serotypes are limited by their inherent tropisms to specific tissues, and the presence of neutralizing antibodies (NAbs) in a patient's bloodstream can prevent efficient biodistribution of AAVs and make repeated treatment challenging. A small proportion of the AAVs incorporate into extracellular vesicles (EVs) to evade immune detection. These EV-AAVs have several advantages over standard AAVs including protection from NAbs, improved transduction efficiency and ability to co-package additional molecules for improved targeting or immunomodulation. Nonetheless, EV-AAV candidacy for clinical therapy is limited by low levels of natural incorporation into vesicles. It is the goal of this study to characterize EVs that naturally incorporate AAVs, to inform future engineering strategies in increasing EV-AAV yield. Using a flow nanoanalyzer and two independent staining methods, we show that the % of EVs that incorporate AAVs is less than 2%, highlighting the need for the development of engineering strategies to increase the incorporation of AAVs inside EVs. Evaluation of three different serotypes – serotypes 2, 8 and 9 – demonstrates similar (low) percentages of AAVs being secreted in association with EVs. Ultracentrifugation separation of large (20k pellet) and small (100k pellet) EVs, reveals that larger vesicles incorporate AAVs more efficiently. The biogenesis pathway of EV-AAVs was investigated using chemical inhibition of exosome and microvesicle release pathways. To investigate AAVs' potential incorporation into EVs through interactions with common EV markers, we overexpressed 12 markers in HEK293T producer cells. TSPAN2, CD63, and PTTG1IP overexpression significantly increased EV-AAV yield. Pulldown experiments reveal that EV-AAVs are enriched in phosphatidylserine, but surprisingly devoid of tetraspanin markers. One way of overcoming the challenging unknowns of endogenous loading is to instead use exogenous loading and bind AAVs at the surface of EVs. AAV Receptor (AAVR) engineered EVs were able to bind AAVs efficiently and showed protection from NAbs in vitro. When comparing luminal and surface loading strategies in vivo , the former exhibited superior transduction and better protection against NAbs. These findings contribute valuable insights for future advancement of EV-AAV candidacy for clinical gene therapy applications. [ABSTRACT FROM AUTHOR]

Nanocarriers (NCs) have shown potential in delivering hydrophobic cytotoxic drugs and tumor-specific targeting. However, the inability to penetrate the tumor microenvironment and entrapment by macrophages has limited their clinical translation. Various cell-based drug delivery systems have been explored for their ability to improve circulation half-life and tumor accumulation capabilities. Tumors are characterized by high inflammation, which aids in tumor progression and metastasis. Immune cells show natural tumor tropism and penetration inside the tumor microenvironment (TME) and are a topic of great interest in cancer drug delivery. However, the TME is immunosuppressive and can polarize immune cells to pro-tumor. Thus, the use of immune cell membrane-coated NCs has gained popularity. Such carriers display immune cell-specific surface receptors for tumor-specific accumulation but lack cell machinery. The lack of immune cell machinery makes them unaffected by the immunosuppressive TME, meanwhile maintaining the inherent tumor tropism. In this review, we discuss the molecular mechanism behind the movement of various immune cells toward TME, the preparation and characterization of membrane-coated NCs, and the efficacy of immune cell-mimicking NCs in tumor therapy. Regulatory guidelines and the bottlenecks in clinical translation are also highlighted. Nanocarriers have been explored for the site-specific delivery of chemotherapeutics. However, low systemic circulation half-life, extensive entrapment by macrophages, and poor accumulation inside the tumor microenvironment prevent the clinical translation of conventional nanotherapeutics. Immune cells possess the natural tropism towards the tumor along the chemokine gradient. Hence, coating the nanocarriers with immune cell-derived membranes can improve the accumulation of nanocarriers inside the tumor. Moreover, coating with membranes derived autologous immune cells will prevent engulfment by the macrophages. [Display omitted] [ABSTRACT FROM AUTHOR]

• Lack of efficient HEV-1 cell culture systems hinders research. • Comparison of revere genetics approaches for the generation of HEV-1 and HEV-3. • HEV-1 strain Sar55 replicates efficiently in colon-derived Caco-2 cells. • Robust reverse genetics system enables investigation of many aspects of HEV-1. The hepatitis E virus (HEV) is infecting over 20 million people annually with a high morbidity especially in pregnant women and immune-suppressed individuals. While HEV genotype 1 (HEV-1) infects only humans, genotype 3 (HEV-3) is zoonotic and commonly transmitted from infected animals to humans. Whereas a few reverse genetics systems enabling targeted genome manipulations exist for HEV-3, those for HEV-1 are still very limited, mainly because of inefficient cell culture replication. Here, the generation of HEV-1 strain Sar55 and HEV-3 strain 47832mc by transfecting in vitro -transcribed and capped virus genomes into different cell lines was attempted. Culture supernatants of colon-derived colorectal adenocarcinoma cell line Caco-2 contained HEV-1 and HEV-3 capable of infecting Caco-2 cells. Density gradient centrifugation analyses of culture supernatants confirmed that HEV-1 particles were quasi-enveloped in analogy to HEV-3 and that non-virion-associated capsid protein was secreted from cells. Following transfection or infection of Caco-2 cells, HEV-1 consistently reached higher titers than HEV-3 in culture supernatants, but HEV-1 generated by transfection of Caco-2 cells was unable to efficiently infect hepatoma cell lines PLC/PRF/5 or HuH7-Lunet BLR. Taken together, our results indicate that HEV-1 is able to exert a complete replication cycle in Caco-2 cells. An efficient cell culture system for this genotype will be useful for studying species tropism, but further research is required to determine the significance of HEV-1 replication in colon-derived cells. [ABSTRACT FROM AUTHOR]

Human adenovirus type 41 (HAdV-F41) usually causes pediatrics gastroenteritis. However, it was reported to be associated with the outbreaks of severe acute hepatitis of unknown aetiology (SAHUA) in pediatrics during COVID-19 pandemic. In this study, we investigated the prevalence of enteric HAdV-F41 in 37,920 paediatric gastroenteritis cases from 2017 to 2022 in Guangzhou, China. All children presented were tested negative for SARS-CoV-2 during the "zero-COVID" period. The main clinical symptom of the children was diarrhea (96.5%). No fatalities nor liver abnormal symptoms was found. In 2021, one year since the pandemic of COVID-19, the prevalence of HAdV-F41 abruptly increased from 3.71% to 8.64% (P < 0.001). All of HAdV-F41 circulating worldwide were classified into eight different subtypes (G1-G8) based on the phylogenetic clustering permutation of the four capsid genes of HAdV-F41. G3 was the predominant subtype (56.2%; 77/137). CRV5 isolates from SAHUA cases belong to this subtype, in which N312D and H335D mutations in the short fiber knob were identified in both Guangzhou and CRV5 isolates, presumably changing the virus tropism by directly interacting with the heparin sulfate (HS) receptor. Additionally, a novel recombinant G6 subtype, which is unique and only circulating in China was first identified in this study. This is the first study highlighting the prevalence of HAdV-F41 in paediatric cases of gastroenteritis during COVID-19 pandemic in China. The clinical and viral evolution finding of HAdV-F41 provide insight into the clinical characteristics of children with HAdV-F41 infections as well as the uncertain role of HAdV-F41 in the cause of SAHUA. • We investigated the epidemiology of human adenovirus type 41 (HAdV-F41) in children. • We reported a HAdV-F41 circulation peak during 2021. No fatalities nor reported liver abnormal symptoms was associated with these cases during SARS-CoV-2 pandemic. • We identified eight different HAdV-F41 subtypes (G1-G8) circulating worldwide; G3 was the predominant subtype that have been isolated from children with severe acute hepatitis of unknown aetiology. • We identified a novel recombinant subtype (G6). [ABSTRACT FROM AUTHOR]

• Eight coxsackievirus A24 variant (CVA24v) genotypes were divided, and two novel genotypes were reported first. • Five genotypes of CVA24v circulated previously in mainland China. • Special ocular tropism might impact the variation of CVA24v. • Residue 146T could contribute to the CVA24v outbreaks and its pathogenicity. • CVA24v possesses a potential neuroinvasion capability besides causing acute hemorrhagic conjunctivitis. The coxsackievirus A24 variant (CVA24v) has raised a remarkable concern because of its main etiological role in acute hemorrhagic conjunctivitis. We conducted a retrospective study to summarize CVA24v isolated from acute hemorrhagic conjunctivitis outbreaks and acute flaccid paralysis surveillance in Shandong province, China during 1988-2020. Phylogenetic and phylogeographic methods based on the VP1 coding region were used to determine the CVA24v origin, spatiotemporal dynamics, and evolution. Also, the positive selection sites in the VP1 gene were identified and exhibited in the tertiary structure. The global CVA24vs were classified into eight genotypes (GⅠ-GⅧ). Here, 12 CVA24v isolates were detected, of which five strains were typed as two novel genotypes (GⅦ and GⅧ) and reported first in the world. The time to the most recent common ancestor of the global CVA24v was estimated around March 1965 and evolved with 5.573 × 10−3 substitutions/site/year. Four residues under positive selection were detected, and residue 146T might be adapted in the CVA24v pandemic. Phylogeographic analysis indicated that China was the main source sink for CVA24v dispersion in a long-lasting global pattern. Our study updated the epidemiological characteristics of CVA24v and enabled a better understanding of the molecular mechanism underlying different genotypes. The results provided new insights into the CVA24v origin, spatiotemporal dynamics, and possibly, the determinants of viral tropism and pathogenicity. [Display omitted] [ABSTRACT FROM AUTHOR]

In recent years, Coxsackievirus A2 (CV-A2) has become one of the main serotypes of enterovirus species A associated with hand, foot and mouth disease (HFMD) in China. It has also caused HFMD epidemics in many countries all over the world. Currently, there are no effective, preventive vaccines against it. A CV-A2 strain was isolated in RD cells and then adapted to grow in Vero cells. This is in compliance with guidelines for cell substrates allowed for human vaccines by the Chinese regulatory authority. Groups of newborn Kunming mice were inoculated on day 3 and day 9 using two formulations of candidate vaccines, empty particles and full particles. They were then challenged on day 14 at a lethal dose with a mouse-adapted strain. The mice in the control group all died within 14 days post-challenge whereas most of the mice in the candidate vaccine groups survived. It was found that the titers of neutralizing antibodies was dose-dependent in sera of immunized mice. The results also showed that the vaccine candidates stimulated a strong humoral immune response and protected the mice from disease and death. The virus loads in tissues or organs were significantly reduced and pathological changes were either weak or not observed in the immunized groups compared with those in Al(OH) 3 control group. Preliminary mapping of the nucleotide and amino acid residues potentially related to cell tropism of the vaccine strain and virulence of the challenge strain was performed. The results showed that the RD cell-isolated and Vero cell-adapted CV-A2 strain is a promising vaccine candidate. This active immunization-challenge mouse model mimics the vaccination and then exposure to wildtype viruses, compared with passive immunization-challenge model, and is invaluable for efficacy evaluation in studies on multivalent vaccines containing CV-A2 against HFMD. [ABSTRACT FROM AUTHOR]

Pancreatic cancer is a highly lethal cancer characterized by local invasiveness, early metastasis, recurrence and high resistance to current therapies. Extensive stroma or desmoplasia is a key histological feature of the disease, and interactions between cancer and stromal cells are critical for pancreatic cancer development and progression. Mesenchymal stromal cells [MSCs] exhibit preferential tropism to primary and metastatic tumor sites and may either suppress or support tumor growth. Although MSCs represent a potential source of pancreatic cancer stroma, their contribution to pancreatic tumor growth remains poorly known. Here, we show that bone marrow MSCs significantly contribute to pancreatic cancer growth in vitro and in vivo. Furthermore, MSCs create a pro-carcinogenic microenvironment through the release of key factors mediating growth and angiogenesis, including interleukin (IL)-6, IL-8, vascular endothelial growth factor and activation of STAT3 signaling in tumor cells. IL-6 released by MSCs was largely responsible for the pro-tumorigenic effects of MSCs. Knockdown of IL-6 expression in MSCs by small interfering RNA (siRNA) abolished the MSC growth-promoting effect in vitro, reducing tumor cell proliferation and clonogenic potential. In addition, in a heterotopic nude mouse model of human pancreatic tumor xenografts, blockade of IL-6 with the anti-IL-6 receptor antibody, tocilizumab, or of its downstream effector STAT3 with the small molecule STAT3 inhibitor S3I-201, abrogated MSC-mediated tumor promotion and delayed tumor formation significantly. Our data demonstrate that MSCs promote pancreatic cancer growth, with IL-6 produced by MSCs playing a pivotal role. [ABSTRACT FROM AUTHOR]

• For the first time, we constructed a PD-L1 tropism-expanded oncolytic adenovirus ZD55-F-HI-sPD-1-EGFP. • ZD55-F-HI-sPD-1-EGFP retains similar viral replication and fiber trimer formation capabilities as control viruses. • ZD55-F-HI-sPD-1-EGFP increased viral infectivity and transgen transduction efficiency in PD-L1 positive cancer cells, and enhanced its anti-tumor effects. Recombinant adenovirus serotype 5 (Ad5)-mediated virotherapy is a maturing technique in cancer treatment. However, the utility of adenovirus (Ad) has been limited by low expression of coxsackievirus and adenovirus receptor (CAR) in cancer cells resulting in poor infectivity of Ads. To overcome the problem, we aimed to develop a novel tropism-modified oncolytic adenovirus, ZD55-F-HI-sPD-1-EGFP, which contains the epitope of PD-1 (70-77aa) at the HI-loop of Ad fiber. Trimerization of Fiber-sPD-1 was confirmed by immunoblot analysis. ZD55-F-HI-sPD-1-EGFP shows a remarkable improvement in viral infection rate and gene transduction efficiency in the PD-L1-positive cancer cells. Competition assays with a PD-L1 protein reveals that cell internalization of ZD55-F-HI-sPD-1-EGFP is mediated by both CAR and PD-L1 at a high dose. The progeny virus production capacity showed that sPD-1 incorporated fiber-modified oncolytic Ad replication was not affected. Furthermore, treating with ZD55-F-HI-sPD-1-EGFP significantly increased viral infection rate and enhanced anti-tumor effect in vivo. This study demonstrates that the strategy to expand tropism of oncolytic Ad may significantly improve therapeutic profile for cancer treatment. [ABSTRACT FROM AUTHOR]

Hepatitis E, caused by the hepatitis E virus (HEV), is a global public health issue. Low similarity between the gene sequences of mouse and human HEV led to the belief that the risk of human infection was low. Recent reports of chronic and acute hepatitis E caused by murine HEV infection in humans in Hong Kong have raised global concerns. Therefore, it is crucial to investigate the epidemiology and prevalence of HEV in China. We comprehensively analyzed different rodent HEV strains to understand rocahepevirus occurrence in Hubei Province, China. The HEV positivity rate for was 6.43% (73/1136). We identified seven near-full-length rocahepevirus strains and detected rat HEV antigens in tissues from different mouse species. HEV has extensive tissue tropism and a high viral load in the liver. We highlight the genetic diversity of HEVs in rodents and underscore the importance of paying attention to their variation and evolution. • The study found a 6.43% HEV positivity rate in wild rodents of Hubei Province, China. • Seven near-full-length Rocahepevirus strains were identified, showing genetic diversity. • Rat HEV antigens were detected in tissue samples from different mouse species, indicating a high viral load in the liver. [ABSTRACT FROM AUTHOR]

Infectious bronchitis virus (IBV) restricts cell tropism. Except for the Beaudette strain, other IBVs cannot infect mammalian cell lines. The limited cell tropism of other IBVs has hindered IBV vaccine development and research on the mechanisms of IBV infection. A novel Vero cell-adapted strain, HV80, has been previously reported. In this study, we constructed recombinants expressing the chimeric S glycoprotein, S1 or S2 subunit of strain H120 and demonstrated that mutations on S2 subunit are associated with the strain HV80 Vero cell adaptation. R687P or P687R substitution recombinants were constructed with the genome backbone of strains HV80 or H120. We found that the RRRR 690 /S motif at the S2′ cleavage site is crucial to the Vero cell adaptation of strain HV80. Another six amino acid substitutions in the S2 subunit of the recombinants showed that the Q855H mutation induced syncytium formation. A transient transfection assay demonstrated the S glycoprotein with the PRRR 690 /S motif at the S2′ cleavage site induced low-level cell–cell fusion, while H855Q substitution hindered cell–cell fusion and blocked cleavage event with S20 product. This study provides a basis for the construction of IBV recombinants capable of replicating in Vero cells, thus contributing to the advancement in the development of genetically engineered cell-based IBV vaccines. • S2 subunit mutations are associated with the strain HV80 Vero cell adaptation. • The RRRR 690 /S motif at the S2′ cleavage site triggers the infection. • The Q855H substitution enhances infection efficiency through cell-cell fusion. • The H855Q substitution also blocks the cleavage event with S20 product. [ABSTRACT FROM AUTHOR]

Trypanosoma cruzi is a parasite with a high capacity to adapt to the host. Animal models have already demonstrated that the tropism of this parasite occurs not only in cardiac/digestive tissues but also in adipose tissue (AT). That said, the consequences of T. cruzi infection for AT and the implications of treatment with Benzonidazole in this tissue are under discussion. Here, we tested the hypothesis that T. cruzi infection in adipose tissue upon treatment with Benzonidazole (Bz) and the interaction of mononuclear immune cells (PBMC) influences the relative expression of ACAT1, FASN, and PNPLA2 genes. Thus, stem cells derived from adipose tissue (ADSC) after adipogenic differentiation were indirectly cultivated with PBMC after infection with the T. cruzi Y strain and treatment with Bz. We use the TcSAT-IAM system and RT-qPCR to evaluate the parasite load and the relative quantification (ΔCt) of the ACAT1, FASN, and PNPLA2 genes. Our results demonstrate that treatment with Bz did not reduce adipocyte infection in the presence (p-value: 0.5796) or absence (p-value: 0.1854) of cultivation with PBMC. In addition, even though there is no statistical difference when compared to the control group (AT), T. cruzi induces the FASN expression (Rq: 14.00). However, treatment with Bz in AT suggests the increases of PNPLA2 expression levels (Rq: 12.58), even in the absence of T. cruzi infection. During indirect cultivation with PBMC, T. cruzi smooths the expression of PNPLA2 (Rq: 0.824) and instigates the expression of ACAT1 (Rq: 1.632) and FASN (Rq: 1.394). Furthermore, the treatment with Bz during infection induces PNPLA2 expression (Rq: 1.871), maintaining FASN expression levels (Rq: 1.334). Given this, our results indicate that treatment with Benzonidazole did not decrease T. cruzi infection in adipose tissue. However, treating the adipocyte cells with Bz during the interaction with PBMC cells influences the lipid pathways scenario, inducing lipolytic metabolism through the expression of PNPLA2. [Display omitted] • Treatment with Benznidazole did not decrease T. cruzi infection in adipose tissue. • Benznidazole induces PNPLA2 expression in adipocytes independent of Trypanosoma cruzi infection. • The PNPLA2 has smooth decrease expression in disorder by T. cruzi in indirect cultive with mononuclear cells. [ABSTRACT FROM AUTHOR]

Interest in gene therapy-based disease prevention and treatment has grown rapidly over the last decade. While lentivirus has been the viral vector of choice for gene therapy, recombinant adeno-associated viral (rAAV) vectors have seen recent widespread application due to the non-integrating ability. Baculoviruses are emerging as a highly adaptable vector with a broad tissue and host tropism. Regardless of vector, extensive quality control (QC) throughout the entire development and manufacturing process is essential. A robust QC process expedites safe, effective commercialization of final product. While Sanger sequencing can be ideal to verify and validate sequences pre-packaging, next generation sequencing (NGS) combined with post-viral production methodologies like CE analysis and transmission electron microscopy offer an effective high-throughput approach for monitoring quality, from initial construct assembly to analysis of the encapsulated product. Both short-read and long-read sequencing technologies offer distinct advantages including sequencing of the entire viral genome, with detection of potential mutations, truncations, and contaminants. Here we describe our novel proprietary vector-agnostic workflows, for use in lentiviral, AAV or baculovirus settings. Starting with high quality synthesis of either vector plasmid or region of interest, full-length plasmid sequence is confirmed. Depending on these results, correction or new synthesis of plasmid options are applied. Following packaging within the viral vector system of choice, QC results using both short- and long-read NGS platforms are supported with a regulatory-compliant Sanger assay. State of the art synthesis reduces potential upstream errors. Sanger ITR sequencing and sequence correction upstream alleviates potential downstream issues in viral packaging. High-quality viral packaging ensures robust viral titers for downstream use. The combined NGS approach post-packaging alleviates current constraints for high throughput AAV sequencing and thereby enhance the overall QC process. Our Good Laboratory Practices (GLP) Sanger sequencing method extends read lengths through the entire ITR regions, allowing for rapid sequence confirmation of the final AAV product. The combination of these approaches enables a comprehensive solution, ideal for sequence confirmation of both transfer plasmid and final packaged product for improved viral vector gene therapy manufacturing in advance of FDA or EMA filings. [ABSTRACT FROM AUTHOR]

Cancer presents an ongoing global public health challenge, leading to millions of annual deaths. Despite strides in oncology therapies, the quest for more effective treatments endures. Immunotherapy has emerged as a promising approach, enhancing the immune system's ability to recognize and eliminate malignant cells. Mesenchymal stromal cells (MSCs) display tumor tropism, rendering them ideal carriers for the targeted delivery of immunostimulatory molecules to the tumor microenvironment. This study explores the potential of genetically modified MSCs to overexpress flagellin, an immunostimulatory agent, with the aim of stimulating antitumor responses. An MSC line overexpressing flagellin (MSC-flag) was generated through lentiviral vector-mediated gene transfer. Gene overexpression was assessed via qRT-PCR, and protein production was quantified in the supernatant using Western Blotting. Phenotypic characterization encompassed differentiation assays (chondrogenic, osteogenic, and adipogenic) and flow cytometry immunophenotyping (Sca1, CD45, CD44, CD90, CD29, and CD11B). In vitro immunogenic properties were gauged through macrophage activation and the induction of in vivo antitumor responses was evaluated in a subcutaneous melanoma model using B16F12 cells in C57Bl/6 mice. Genetically modified MSCs exhibited gene expression and protein production post-puromycin selection, as demonstrated by qRT-PCR and Western Blotting. The MSC-flag maintained its mesenchymal phenotype and differentiation capabilities post-genetic modification (see Figure 1). In vitro assays showcased immunostimulatory potential, evidenced by heightened macrophage activation (see Figure 2). In vivo administration of MSC-Flag significantly impeded tumor growth compared to control MSCs (see Figure 2). In conclusion, MSC-Flag successfully retained its mesenchymal profile and exhibited immunogenic activities with therapeutic implications. These findings underscore the potential of utilizing these engineered MSCs in anticancer therapy [ABSTRACT FROM AUTHOR]

In recent years, multiple coronaviruses have emerged, with the latest one, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), causing a global pandemic. Besides respiratory symptoms, some patients experienced extrapulmonary effects, such as cardiac damage or renal injury, indicating the broad tropism of SARS-CoV-2. The ability of the virus to effectively invade the renal cellular environment can eventually cause tissue-specific damage and disease. Indeed, patients with severe coronavirus disease 2019 exhibited a variety of symptoms such as acute proximal tubular injury, ischemic collapse, and severe acute tubular necrosis resulting in irreversible kidney failure. This review summarizes the current knowledge on how it is believed that SARS-CoV-2 influences the renal environment and induces kidney disease, as well as current therapy approaches. ● Infectious SARS-CoV-2 is detectable in kidney tissue in vivo. ● Kidney damage occurs through direct and indirect mechanisms. ● Therapy approaches of renal injury function primarily as supportive measures. ● Research on SARS-CoV-2 lacks insights into the tissue tropism in moderate COVID-19. [ABSTRACT FROM AUTHOR]

Stem cell-based cancer treatment has garnered significant attention, yet its safety and efficacy remain incompletely understood. The nuclear factor-kappa B (NF-κB) pathway, a critical signaling mechanism involved in tumor growth, angiogenesis, and invasion, serves as an essential metric for evaluating the behavior of stem cells in tumor models. Herein, we report the development of a triple-channel imaging system capable of simultaneously monitoring the tropism of stem cells towards tumors, assessing tumor proliferation, and quantifying tumor NF-κB activity. In this system, we generated a CRISPR-Cas9 gene-edited human glioblastoma cell line, GE-U87-MG, which provided a reliable readout of the proliferation and NF-κB activity of tumors by EF1α-RFLuc- and NF-κB-GLuc-based bioluminescent imaging, respectively. Additionally, near infrared-II emitting Tat-PEG-AgAuSe quantum dots were developed for tracking of stem cell tropism towards tumor. In a representative case involving human mesenchymal stem cells (hMSCs), multichannel imaging revealed no discernible effect of hMSCs on the proliferation and NF-κB activity of GE-U87-MG tumors. Moreover, hMSCs engineered to overexpress the necrosis factor-related apoptosis-inducing ligand were able to inhibit NF-κB activity and growth of GE-U87-MG in vivo. Taken together, our imaging system represents a powerful and feasible approach to evaluating the safety and therapeutic efficacy of stem cells in tumor models. [Display omitted] [ABSTRACT FROM AUTHOR]

We performed a series of experiments to study the interaction between phototropism and gravitropism in Arabidopsis thaliana as part of the Seedling Growth Project on the International Space Station. Red-light-based and blue-light-based phototropism were examined in microgravity and at 1 g , a control that was produced by an on-board centrifuge. At the end of the experiments, seedlings were frozen and brought back to Earth for gene profiling studies via RNASeq methods. In this paper, we focus on five genes identified in these space studies by their differential expression in space: one involved in auxin transport and four others encoding genes for: a methyltransferase subunit, a transmembrane protein, a transcription factor for endodermis formation, and a cytoskeletal element (an intermediate filament protein). Time course studies using mutant strains of these five genes were performed for blue-light and red-light phototropism studies as well as for gravitropism assays on ground. Interestingly, all five of the genes had some effects on all the tropisms under the conditions studied. In addition, RT-PCR analyses examined expression of the five genes in wild-type seedlings during blue-light-based phototropism. Previous studies have supported a role of both microfilaments and microtubules in tropism pathways. However, the most interesting finding of the present space studies is that NFL , a gene encoding an intermediate filament protein, plays a role in phototropism and gravitropism, which opens the possibility that this cytoskeletal element modulates signal transduction in plants. • Seedlings grown on the ISS were frozen and returned for analysis via RNASeq. • Five genes with large differences in expression, pertaining to light and/or gravity perception, were selected. • Mutants of these five genes were studied with tropism assays on the ground. • One of these genes encoded an intermediate filament (n euro f ilament l ight protein). • NFL appears to play a role in phototropism and gravitropism pathways. [ABSTRACT FROM AUTHOR]

Imbalance between the activities of pro-inflammatory M1 and anti-inflammatory M2 macrophages in rheumatoid arthritis (RA) induces synovial inflammation and autoimmunity, leading to joint damage. Here we encapsulated a plasmid DNA encoding the anti-inflammatory cytokine interleukin-10 (IL-10 pDNA) and the chemotherapeutic drug betamethasone sodium phosphate (BSP) into biomimetic vector M2 exosomes (M2 Exo) derived from M2-type macrophages. We demonstrate that the loaded exosomes target and reduce inflammation for combined therapy against RA. The in vitro efficiency of the M2 Exo/pDNA/BSP co-delivery system was attributed to the synergistic effect of IL-10 pDNA and BSP, which also promoted M1-to-M2 macrophage polarization by reducing the secretion of pro-inflammatory cytokines (IL-1β, TNF-α) and increasing the expression of IL-10 cytokine. In a mouse model of RA, M2 Exo/pDNA/BSP showed good accumulation at inflamed joint sites, high anti-inflammatory activity, and potent therapeutic effect. The delivery system was non-toxic both in vitro and in vivo. Thus, this system may serve as a promising biocompatible drug carrier and anti-inflammatory agent for RA treatment based on M1-to-M2 macrophage re-polarization. we engaged molecularly engineered M2 macrophage-derived exosomes with inflammation tropism and anti-inflammatory capabilities for co-delivery of IL-10 pDNA and GCs to achieve RA treatment via M1-to-M2 macrophages re-polarization. [Display omitted] • M2-type macrophage derived exosomes serve as simple endogenous drug carrier with inflammation targeting and anti-inflammatory properties. • The biomimetic co-delivery system attenuated inflammation in joint lesions and promoted M1-to-M2 macrophage polarization through the synergistic effect. • The biomimetic co-delivery system reduced the dose of glucocorticoid and its adverse effects. [ABSTRACT FROM AUTHOR]

Disease management in shrimp aquaculture is heavily dependent on accurate and rapid pathogen detection and diagnosis. Understanding the presence and distribution of pathogens within various tissues of the shrimp host is critical to ensure detection efforts are targeted for optimal sensitivity and reliability. Modern advancements in molecular technologies, including nucleic acid extraction and RT-qPCR, have yielded significant improvements in pathogen detection capabilities. Despite these advancements and their widespread adoption within both research and industry applications, evidence to inform their optimised use, such as revisions to tissue-specific viral detection to support selection of appropriate target tissues, has not been established. To address these gaps, this study aimed to establish contemporary evidence of viral tissue tropism for three major shrimp pathogens. TaqMan qPCR analysis was used to determine tissue-specific loading of viral pathogens in naturally infected Penaeus monodon pleopod, gill, hepatopancreas, lymphoid organ, abdominal muscle tissue, hindgut and ventral nerve cord. The viral targets analysed included Penaeus stylirostris penstyldensovirus 1 (PstDV1), formerly named infectious hypodermal haematopoietic necrosis virus (IHHNV) and, two genotypes of the yellow head virus complex, including genotype 2 known as gill associated virus (YHV-2/ GAV), and genotype 7 (YHV-7). QPCR analyses demonstrated the highest level of genetic IHHNV detection from gill tissue, followed sequentially by hindgut, pleopod, hepatopancreas, lymphoid organ, ventral nerve cord and abdominal muscle. For the yellow head viruses (GAV and YHV-7), no significant differences in genetic viral detection were demonstrated, although a non-significant advantage was observed for lymphoid organ and hindgut tissue. Beyond establishing contemporary evidence of viral distribution to improve understanding of host-viral interactions, these findings offer supporting evidence for revisions to appropriate target tissue recommendations, within the World Organisation for Animal Health (WOAH, founded as OIE) Manual of Diagnostic Tests for Aquatic Animals, for optimised modern shrimp pathogen detection. • Farmed Penaeus monodon were naturally infected with IHHNV and GAV or YHV-7. • Viral tissue tropism was assessed by qPCR detection from seven tissue types. • Hepatopancreas yielded reliable, high-level detection of IHHNV. • Detection between pleopod and gill of GAV and YHV-7 was similar. • Pleopod is a suitable, non-destructive tissue for detection of IHHNV, GAV and YHV-7. [ABSTRACT FROM AUTHOR]

Eimeria maxima microneme protein 3 (EmMIC3) is pivotal in the initial recognition and attachment of E. maxima sporozoites to host cells. EmMIC3 comprises 5 tandem Type I microneme adhesive repeat (MAR) domains, among which MAR2 of EmMIC3 (EmMAR2) has been identified as the primary determinant of EmMIC3-mediated tissue tropism. Nonetheless, the mechanisms through which EmMAR2 guides the parasite to its invasion site through interactions with host receptors remained largely uncharted. In this study, we employed yeast two-hybrid (YTH) screening assays and shotgun LC-MS/MS analysis to identify EmMAR2 receptors in chicken intestine epithelial cells. ATPase H+ transporting V1 subunit G1 (ATP6V1G1), receptor accessory protein 5 (REEP5), transmembrane p24 trafficking protein (TMED2), and delta 4-desaturase sphingolipid 1 (DEGS1) were characterized as the 4 receptors of EmMAR2 by both assays. By blocking the interaction of EmMAR2 with each receptor using specific antibodies, we observed varying levels of inhibition on the invasion of E. maxima sporozoites, and the combined usage of all 4 antibodies resulted in the most pronounced inhibitory effect. Additionally, the spatio-temporal expression profiles of ATP6V1G1, REEP5, TMED2, and DEGS1 were assessed. The tissue-specific expression patterns of EmMAR2 receptors throughout E. maxima infection suggested that ATP6V1G1 and DEGS1 might play a role in early-stage invasion, whereas TMED2 could be involved in middle and late-stage invasion and REEP5 and DEGS1 may participate primarily in late-stage invasion. Consequently, E. maxima may employ a multitude of ligand-receptor interactions to drive invasion during different stages of infection. This study marks the first report of EmMAR2 receptors at the interface between E. maxima and the host, providing insights into the invasion mechanisms of E. maxima and the pathogenesis of coccidiosis. [ABSTRACT FROM AUTHOR]

Adeno-associated virus (AAV) is a member of the genus Dependoparvovirus , which infects a wide range of vertebrate species. Here, we observe that, unlike most primate AAV isolates, avian AAV is transcriptionally silenced in human cells. By swapping the VP1 N terminus from primate AAVs (e.g., AAV8) onto non-mammalian isolates (e.g., avian AAV), we identify a minimal component of the AAV capsid that controls viral transcription and unlocks robust transduction in both human cells and mouse tissue. This effect is accompanied by increased AAV genome chromatin accessibility and altered histone methylation. Proximity ligation analysis reveals that host factors are selectively recruited by the VP1 N terminus of AAV8 but not avian AAV. Notably, these include AAV essential factors implicated in the nuclear factor κB pathway, chromatin condensation, and histone methylation. We postulate that the AAV capsid has evolved mechanisms to recruit host factors to its genome, allowing transcriptional activation in a species-specific manner. [Display omitted] • Avian AAV cannot infect human cells due to transcriptional silencing • Swapping VP1 N-terminal domain from AAV8 onto avian AAV rescues infection • N-terminal swap increases transcription, chromatin accessibility, and histone methylation • VP1 N-terminal domain recruits essential host factors to the AAV genome Loeb et al. investigate the host range of avian AAV, which is limited in human cells due to transcriptional silencing. Swapping the avian AAV VP1 N terminus, however, with a primate AAV-derived domain unlocks transduction. The authors demonstrate that this domain recruits essential host factors and exerts control over viral transcription. [ABSTRACT FROM AUTHOR]

Swine enteric coronaviruses, such as porcine epidemic diarrhea virus (PEDV) or transmissible gastroenteritis virus (TGEV), have risen concern for the porcine industry and research community due to the increase in their virulence, their potential recombination capacity and the emergence of new variants. This in vivo study aims to compare the impact of three different strains of swine enteric coronaviruses [(two G1b (S-INDEL) PEDV strains and a recombinant TGEV-PEDV or Swine enteric coronavirus (SeCoV)] in the intestine of 3-weeks-old infected piglets, focusing on the pathology and main components of the intestinal barrier, including the number of goblet cells, and the expression of IgA as well as FoxP3, a regulatory T cell marker. Severity of lesions was evidenced in the three infected groups and was highly correlated with the viral load in feces and the frequency of viral antigen-positive cells. Furthermore, higher cellular death together with an increase in the expression of the FoxP3 marker was detected in the duodenum and jejunum of infected animals at 3 days post-infection. Our results highlight a recruitment of FoxP3+ cells in the small intestine of infected animals which may represent a response to the tissue damage caused by viral replication and cell death. Further studies should be addressed to determine the potential role of these cells during swine enteric coronavirus infections. • Swine enteric coronaviruses have risen concern for the porcine industry. • The immunopathogenesis of three strains of swine coronavirus was investigated. • Similar lesions, high tropism and cellular death were found in all infected groups. • FoxP3+ cells could be controlling the inflammation and the tissue damage caused by viral replication. [ABSTRACT FROM AUTHOR]

The Brighton Collaboration Viral Vector Vaccines Safety Working Group (V3SWG) was formed to evaluate the safety and characteristics of live, recombinant viral vector vaccines. The Modified Vaccinia Ankara (MVA) vector system is being explored as a platform for development of multiple vaccines. This paper reviews the molecular and biological features specifically of the MVA-BN vector system, followed by a template with details on the safety and characteristics of an MVA-BN based vaccine against Zaire ebolavirus and other filovirus strains. The MVA-BN-Filo vaccine is based on a live, highly attenuated poxviral vector incapable of replicating in human cells and encodes glycoproteins of Ebola virus Zaire, Sudan virus and Marburg virus and the nucleoprotein of the Thai Forest virus. This vaccine has been approved in the European Union in July 2020 as part of a heterologous Ebola vaccination regimen. The MVA-BN vector is attenuated following over 500 serial passages in eggs, showing restricted host tropism and incompetence to replicate in human cells. MVA has six major deletions and other mutations of genes outside these deletions, which all contribute to the replication deficiency in human and other mammalian cells. Attenuation of MVA-BN was demonstrated by safe administration in immunocompromised mice and non-human primates. In multiple clinical trials with the MVA-BN backbone, more than 7800 participants have been vaccinated, demonstrating a safety profile consistent with other licensed, modern vaccines. MVA-BN has been approved as smallpox vaccine in Europe and Canada in 2013, and as smallpox and monkeypox vaccine in the US in 2019. No signal for inflammatory cardiac disorders was identified throughout the MVA-BN development program. This is in sharp contrast to the older, replicating vaccinia smallpox vaccines, which have a known risk for myocarditis and/or pericarditis in up to 1 in 200 vaccinees. MVA-BN-Filo as part of a heterologous Ebola vaccination regimen (Ad26.ZEBOV/MVA-BN-Filo) has undergone clinical testing including Phase III in West Africa and is currently in use in large scale vaccination studies in Central African countries. This paper provides a comprehensive picture of the MVA-BN vector, which has reached regulatory approvals, both as MVA-BN backbone for smallpox/monkeypox, as well as for the MVA-BN-Filo construct as part of an Ebola vaccination regimen, and therefore aims to provide solutions to prevent disease from high-consequence human pathogens. [ABSTRACT FROM AUTHOR]

As adeno-associated virus (AAV)-based gene therapies are being increasingly approved for use in humans, it is important that we understand vector–host interactions in detail. With the advances in genome-wide genetic screening tools, a clear picture of AAV–host interactions is beginning to emerge. Understanding these interactions can provide insights into the viral life cycle. Accordingly, novel strategies to circumvent the current limitations of AAV-based vectors may be explored. Here, we summarize our current understanding of the various stages in the journey of the vector from the cell surface to the nucleus and contextualize the roles of recently identified host factors. Despite being the 'vector of choice' for in vivo gene transfer, the process of cellular transduction of adeno-associated virus (AAV)-based vectors is not fully understood. The AAV transduction process can be dissected and studied in a stepwise manner, each step requiring the vector to interact with cellular host factors. The interaction of AAV-based vectors with specific host factors is critical for efficient transduction. The expression profiles of these host factors in different cell types determine vector tropism. Modulation of specific steps in cellular transduction may offer a valuable strategy to enhance gene therapy. [ABSTRACT FROM AUTHOR]

Hepatitis E virus (HEV), the causative agent of hepatitis E, is an understudied but important pathogen. HEV typically causes self-limiting acute viral hepatitis, however chronic infection with neurological and other extrahepatic manifestations has increasingly become a significant clinical problem. The discovery of swine HEV from pigs and demonstration of its zoonotic potential led to the genetic identification of very diverse HEV strains from more than a dozen other animal species. HEV strains from pig, rabbit, deer, camel, and rat have been shown to cross species barriers and infect humans. Zoonotic HEV infections through consumption of raw or undercooked animal meat or direct contact with infected animals have been reported. The discovery of a large number of animal HEV variants does provide an opportunity to develop useful animal models for HEV. In this mini-review, we discuss recent advances in HEV host range, and cross-species and zoonotic transmission. [ABSTRACT FROM AUTHOR]

Skin is one of target organs affected by the novel coronavirus SARS-CoV-2, and in response to the current COVID-19 pandemic, a fast body of literature has emerged on related cutaneous manifestations. Current perspective is that the skin is not only a bystander of the general cytokines storm with thrombophilic multiorgan injury, but it is directly affected by the epithelial tropism of the virus, as confirmed by the detection of SARS‐CoV‐2 in endothelial cells and epithelial cells of epidermis and eccrine glands. In contrast with the abundance of epidemiologic and clinical reports, histopathologic characterization of skin manifestations is limited. Without an adequate clinicopathologic correlation, nosology of clinically similar conditions is confusing, and effective association with COVID-19 remains presumptive. Several patients with different types of skin lesions, including the most specific acral chilblains-like lesions, showed negative results at SARS-CoV-2 nasopharyngeal and serologic sampling. The aim of this review is to provide an overview of what has currently been reported worldwide, with a particular emphasis on microscopic patterns of the skin manifestations in patients exposed to or affected by COVID-19. Substantial breakthroughs may occur in the near future from more skin biopsies, improvement of immunohistochemistry studies, RNA detection of SARS-CoV-2 strain by real-time polymerase chain reaction-based assay, and electron microscopic studies. [ABSTRACT FROM AUTHOR]

Adeno-associated virus (AAV) is a promising vector for gene therapy, but its broad tropism can be detrimental if the transgene being delivered is harmful when expressed ubiquitously in the body, i.e. in non-target tissues. Delivering the transgene of interest to target cells at levels high enough to be therapeutically effective while maintaining safety by minimizing delivery to off-target cells is a prevalent challenge in the field of gene therapy. We have developed a protease activatable vector (provector) platform based on AAV9 that can be injected systemically to deliver therapeutic transgenes site-specifically to diseased cells by responding to extracellular proteases present at the disease site. The provector platform consists of a peptide insertion into the virus capsid which disrupts the virus' ability to bind to cell surface receptors. This peptide contains a blocking motif (aspartic acid residues) flanked on either side by cleavage sequences that are recognized by certain proteases. Exposure to proteases cleaves the peptides off the capsid, activating or "switching ON" the provector. In response to the activation, the provectors regain their ability to bind and transduce cells. Here, we have designed a provector that is activated by cysteine aspartic proteases (caspases), which have roles in inflammation and apoptosis and thus are elevated at sites of diseases such as heart failure, neurodegenerative diseases, and ischemic stroke. This provector demonstrates a 200-fold reduction in transduction ability in the OFF state compared to AAV9, reducing the virus' ability to transduce off-target healthy tissue. Following exposure to and proteolysis by caspase-3, the provector shows a 95-fold increase in transduction compared to the OFF state. The switchable transduction behavior was found to be a direct result of the peptide insertion ablating the ability of the virus to bind to cells. In vivo studies were conducted to characterize the biodistribution, blood circulation time, neutralizing antibody formation, and targeted delivery ability of the caspase-activatable provector in a model of heart failure. Unlabelled Image • AAV9 engineered to be activated by caspases, proteases upregulated at disease sites. • Caspase-activated provector switches on cell binding in response to caspases. • Provector has high ON/OFF activation ratio of gene delivery when tested in vitro. • Provector poorly delivers transgene cargo in healthy animal model. • Provector delivers transgene to MI-injured heart with lower off-target delivery. [ABSTRACT FROM AUTHOR]

Imaging-guiding and targeted drug delivery to tumors are essential for precision cancer therapy, which is a challenging goal to achieve extraordinary therapeutic efficacy. Functional live cells-based delivery systems are expected to play an important role in imaging-guiding and targeted drug delivery. Herein, we fabricated a delivery system mediated by IR-820 conjugated macrophages for tumor targeted combination therapy under fluorescence imaging guidance. The functional macrophages by nature could cross the barriers and recruit into tumors, and serve as host cells to targeted deliver drugs to tumors. The pH-sensitive doxorubicin nanoparticles were engulfed by the macrophages to enhance the drug loading and decrease the damage on host cells. IR-820 was anchored into macrophages cytoplasm to achieve the dual function of photothermal therapy and fluorescence imaging guidance. With Balb/C mice bearing murine breast tumor (4 T1) as models, the functional macrophages for their innate tumor tropism could targeted transport these therapeutic drugs into tumor site to exert efficient chemo-photothermal combination therapy. Moreover, fluorescence imaging-guided drug delivery was employed as the visible strategy to provide the optimized therapeutic window based on the fluorescence of IR-820. The multi-functional macrophages-mediated delivery system would provide a potential for precise and targeted delivery of combination therapy. Unlabelled Image • Fluorescent imaging guiding and targeted drug delivery for precision cancer therapy • Functional macrophages-based delivery system could recruit into tumors by nature • Fluorescence imaging-guided drug delivery open the optimized therapeutic window • Chemo-photothermal therapy achieve accurate tumor therapy with improved efficacy [ABSTRACT FROM AUTHOR]

Cells possess inherent advantages to facilitate targeted payload delivery. Current strategies to conjugate payload carriers to the surface of cells are either via covalent bonds that not only involve complicated synthetic process but also often impair cellular functions, or via biological ligand-receptor interactions that are only specific to particular types of cells. Herein, we report a facile, bioorthogonal supramolecular conjugation strategy to prepare targeted cell-hitchhiking delivery systems, mediated via artificial host–guest interactions between β-cyclodextrin and adamantane, respectively anchored (via insertion) on the surfaces of live cells and payload carriers. In a paw swelling inflammation mouse model, supramolecularly conjugated macrophage-carriers (either cell–cell or cell-nanoparticle systems) were efficiently delivered hand-in-hand to the swelling paw, driven by the inflammatory tropism of macrophage. Furthermore, in an acute lung inflammation model of mouse, supramolecular conjugation of peritoneal macrophage and quercetin-loaded liposomes significantly improved targeting efficiency of the liposomes, and effectively alleviated the lung inflammation through the anti-inflammatory and anti-oxidative effects of quercetin. The cell-friendly, facile, host–guest interactions mediated cellular conjugation may provide the very first general strategy for preparing various cell-hitchhiking delivery systems to meet the needs of diverse biomedical applications. [ABSTRACT FROM AUTHOR]

Characterizing neuronal cell types demands efficient strategies for specific labeling and manipulation of individual subtypes to dissect their connectivity and functions. Recombinant viral technology offers a powerful toolbox for targeted transgene expression in specific neuronal populations. In order to achieve cell type-specific targeting, exciting progress has been made to: alter viral tropisms, design rational delivery strategies, and drive selective expression patterns with engineered DNA sequences in viral genomes. For the latter case, emerging single-cell genomic analyses provide rich databases. In this review, we will summarize current status, and point out challenges, of using viral vectors for neuronal cell type-specific visualization and manipulations. With concerted efforts, progress will continue to be made toward developing viral vectors for the vast array of neuronal subtypes in the mammalian nervous system. [ABSTRACT FROM AUTHOR]

Two separate fatal outbreaks occurred in ornamental goldfish (Carassius auratus) farms, marked by clinical signs including depression, scale protrusion, massive mucus production, and mortality rates exceeding 50% were identified in Thailand. Detailed histological examination revealed extensive necrosis of hematopoietic tissues in kidneys and spleen, together with marked necrotizing branchitis and brachium hyperplasia. Furthermore, characteristic intranuclear inclusion bodies with margination of chromatin were observed in hematopoietic cells in the spleen and kidneys, and in gill epithelial cells. Conventional polymerase chain reaction (PCR) detected Cyprinid herpesvirus-2 (CyHV-2) DNA in the affected populations, with no presence of CyHV-1 or CyHV-3 DNA. Using quantitative PCR (qPCR), we found that viral DNA largely localized within the spleen and kidneys, followed by gills, heart, brain, and liver. In situ hybridization demonstrated CyHV-2 tropism, with localization identified in hematopoietic cells in the kidney and spleen, and in epithelial cells in the gill lamellae and skin. Apart from hematopoietic cells in kidneys and spleen, transmission electron microscopy confirmed herpesviral particles within the epithelial cells in the gills and skin of infected fish. Genomic analysis was conducted on partial genome sequences of CyHV-2 DNA polymerase and helicase genes, and the tandem repeats region were obtained and subsequently characterized using next generation sequencing-based approach. This data suggested that these two CyHV-2 Thai strains were nearly identical and closely related to other CyHV-2 strains found in Asia. Genomic analysis based on the helicase gene revealed that the CyHV-2 Thai strains were unique and distinct by creating monophyletic clade. Our findings report the first identification of CyHV-2 in Thailand for first time, and highlight its potential pathological implications. While these Thai sequences of CyHV-2 are indeed unique, further investigations are in progress to confirm the definitive role of this genetic variability in relation to its virulence. • Fatal outbreaks of ornamental goldfish (C. auratus) in association with CyHV-2 infection were firstly reported in Thailand • The presence of CyHV-2 was confirmed by real-time PCRs, in situ hybridization, and transmission electron microscopy. • CyHV-2 particles were identified in non-hematopoietic organs, suggesting broad-cellular tropism of the virus. • Phylogenetic analysis based on multiple regions of DNAPol and helicase genes indicated a unique topologic feature. [ABSTRACT FROM AUTHOR]

• The avian influenza A virus receptor (SA-α2,3-Gal) isexpressed in the porcine nasal mucosa. • The human influenza A virus receptors: Neu5Ac-α2,6 and Neu5Gc-α2,6 are equally expressed in the porcine trachea and alveoli. • The human- and swine-adapted H1N1pdm09 and H3N2 viruses had a preferred tropism for the porcine bronchial and bronchiolar epithelial cells and were less prominent in the nose, trachea and alveoli. Influenza A viruses (IAVs) originate from wild birds but have on several occasions jumped host barriers and are now also circulating in humans and mammals. The IAV host receptors (glycans with galactose linked to a sialic acid (SA) in an α2,3 or α2,6 linkage) are crucial host factors restricting inter-species transmission. In general, avian-origin IAVs show a preference for SA-α2,3 (avian receptor), whereas IAVs isolated from humans and pigs prefer SA-α2,6 (human receptor). N-acetylneuraminic acid (Neu5Ac) and N-glycolylneuraminic acid (Neu5Gc) are the two major SAs. Neu5Ac is expressed in all species, whereas Neu5Gc is only expressed in a limited number of domestic species such as pigs and horses, but not in humans. Despite that previous studies have shown that the IAV host receptor distribution appears to be similar in pigs and humans, none of these studies have investigated the expression of Neu5Gc-α2,6 in situ in porcine tissues. Thus, the aim of this study was to elucidate the distribution of IAV host receptors expressed in the porcine respiratory tract and relate the expression to the viral tropism of diverse host-adapted IAVs. The IAV receptor (SA-α2,3 and SA-α2,6) distribution and the presence of specifically Neu5Gc-α2,6 in the porcine nasal, tracheal, and lung tissues was investigated by lectin histochemistry. Furthermore, IAV immunohistochemistry was performed on tissues from pigs experimentally infected with IAVs, either adapted to pigs or humans, to investigate the significance of the IAV host receptors and the tropism of the diverse host-adapted IAVs. We document for the first time the expression of the avian receptor on the surface of the porcine nasal mucosa and an equal expression of Neu5Ac-α2,6 and Neu5Gc-α2,6 on the surface of the tracheal epithelium and alveoli. In all IAV-infected pigs, we found a low amount of IAV-positive cells in the trachea despite a high expression of the human receptor. Cumulatively, these findings suggest that optimal IAV replication involves a complex interplay between the viruses and their host receptors and that there might be other less clearly defined host factors that determine the site of replication. [Display omitted] [ABSTRACT FROM AUTHOR]

The family Papillomaviridae includes a plethora of viral species infecting virtually all vertebrates excluding amphibians, with astonishing impact on human and animal health. Although more than 250 species have been described in humans, the total number of papillomaviruses (PVs) discovered in animals does not reach up to this number. In animals, PV infections are mostly asymptomatic or can cause variable clinical conditions ranging from self-limiting papillomas and other cutaneous and mucosal benign lesions to cancer. Most of animal PV types have been discovered in cattle, dogs, horses, and cats with other farm host species remaining overlooked. In particular, the number of PV types so far identified in sheep is limited. This paper comprehensively reviews ovine PVs features, including viral taxonomy and evolution; genome organization; viral tropism and pathogenesis; macroscopical features and histopathological patterns, as well as available diagnostics tools. Data are critically presented and discussed in terms of impact on veterinary and public health. The development of future dedicated research is also discussed. • Ovine PVs are a diverse group of viruses in terms of clinical outcome, taxonomy, and evolution. • Ovine PVs are divided into 2 PV genera associated to different degree of malignancy. • The diversity of ovine PV is still uncovered, and more PVs are expected to exist. • OaPV3 can be an animal model of non melanoma skin cancer. [ABSTRACT FROM AUTHOR]

Group A Streptococcus (GAS) has a fantastically wide tissue tropism in humans, manifesting as different diseases depending on the strain's virulence factor repertoire and the tissue involved. Activation of immune cells and pro-inflammatory signaling has historically been considered an exclusively host-protective response that a pathogen would seek to avoid. However, recent advances in human and animal models suggest that in some tissues, GAS will activate and manipulate specific pro-inflammatory pathways to promote growth, nutrient acquisition, persistence, recurrent infection, competition with other microbial species, dissemination, and transmission. This review discusses molecular interactions between the host and pathogen to summarize how infection varies across tissue and stages of inflammation. A need for inflammation for GAS survival during common, mild infections may drive selection for mechanisms that cause pathological and excess inflammation severe diseases such as toxic shock syndrome, necrotizing fasciitis, and rheumatic heart disease. • Group A Streptococcus infects many body sites, causing clinically distinct diseases. • Immune responses can promote or inhibit pathogenesis, depending on tissue and timing. • Infection of a site depends on the specific virulence factor repertoire, which is variable. • Inflammation alters bacterial virulence factor expression and function in advanced disease. [ABSTRACT FROM AUTHOR]

• RHDV2_Bg12 originated in a hare through recombination at the RdP-VP60 junction. • Structural genes come from RHDV2, the non-structural ones from a new hare lagovirus. • Rabbits orally inoculated with RHDV2_Bg12 neither developed RHD nor seroconverted. • RHDV2_Bg12 has no longer been identified despite active surveillance on lagomorphs. The genus Lagovirus , belonging to the family Caliciviridae, emerged around the 1980s. It includes highly pathogenic species, rabbit hemorrhagic disease virus (RHDV/GI.1) and European brown hare syndrome virus (EBHSV/GII.1), which cause fatal hepatitis, and nonpathogenic viruses with enteric tropism, rabbit calicivirus (RCV/GI.3,4) and hare calicivirus (HaCV/GII.2). Lagoviruses have evolved along two independent genetic lineages: GI (RHDV and RCV) in rabbits and GII (EBHSV and HaCV) in hares. To be emphasized is that genomes of lagoviruses, like other caliciviruses, are highly conserved at RdRp-VP60 junctions, favoring intergenotypic recombination events at this point. The recombination between an RCV (genotype GI.3), donor of non-structural (NS) genes, and an unknown virus, donor of structural (S) genes, likely led to the emergence of a new lagovirus in the European rabbit, called RHDV type 2 (GI.2), identified in Europe in 2010. New RHDV2 intergenotypic recombinants isolated in rabbits in Europe and Australia originated from similar events between RHDV2 (GI.2) and RHDV (GI.1) or RCV (GI.3,4). RHDV2 (GI.2) rapidly spread worldwide, replacing RHDV and showing several lagomorph species as secondary hosts. The recombination events in RHDV2 viruses have led to a number of viruses with very different combinations of NS and S genes. Recombinant RHDV2 with NS genes from hare lineage (GII) was recently identified in the European hare. This study investigated the first RHDV2 (GI.2) identified in Italy in European hare (RHDV2_Bg12), demonstrating that it was a new virus that originated from the recombination between RHDV2, as an S-gene donor and a hare lagovirus, not yet identified but presumably nonpathogenic, as an NS gene donor. When rabbits were inoculated with RHDV2_Bg12, neither deaths nor seroconversions were recorded, demonstrating that RHDV2_Bg12 cannot infect the rabbit. Furthermore, despite intensive and continuous field surveillance, RHDV2_Bg12 has never again been identified in either hares or rabbits in Italy or elsewhere. This result showed that the host specificity of lagoviruses can depend not only on S genes, as expected until today, but potentially also on some species-specific NS gene sequences. Therefore, because RHDV2 (GI.2) infects several lagomorphs, which in turn probably harbor several specific nonpathogenic lagoviruses, the possibility of new speciation, especially in those other than rabbits, is real. RHDV2 Bg_12 demonstrated this, although the attempt apparently failed. [ABSTRACT FROM AUTHOR]

Pteropine orthoreovirus (PRV) causes respiratory tract infections in humans. Despite its emergence as a zoonotic and respiratory virus, little is known about its cell tropism, which hampers progress in fully understanding its pathogenesis in humans. Hek293 cells are most susceptible to PRV infection, while HeLa cells are the least. Human cytokeratin 1 (CK1) was identified as the protein that interacts with PRV. The immunofluorescence assay and qPCR results revealed prior treatment with anti-CK1 may provide Hek293 cells protection against PRV. The KRT1- knockout Hek293 cells were less susceptible to PRV infection. Further study into the pathogenesis of PRV in humans is needed. [ABSTRACT FROM AUTHOR]

Coxsackievirus B6 (CVB6), a member of the human enterovirus family, is associated with severe diseases such as myocarditis in children. However, to date, only a limited number of CVB6 strains have been identified, and their characterization in animal models has been lacking. To address this gap, in this study, a neonatal murine model of CVB6 infection was established to compare the replication and virulence of three infectious-clone-derived CVB6 strains in vivo. The results showed that following challenge with a lethal dose of CVB6 strains, the neonatal mice rapidly exhibited a series of clinical signs, such as weight loss, limb paralysis, and death. For the two high-virulence CVB6 strains, histological examination revealed myocyte necrosis in skeletal and cardiac muscle, and immunohistochemistry confirmed the expression of CVB6 viral protein in these tissues. Real-time PCR assay also revealed higher viral loads in the skeletal and cardiac muscle than in other tissues at different time points post infection. Furthermore, the protective effect of passive immunization with antisera and a neutralizing monoclonal antibody against CVB6 infection was evaluated in the neonatal mouse model. This study should provide insights into the pathogenesis of CVB6 and facilitate further research in the development of vaccines and antivirals against CVBs. • Infectious clones of coxsackievirus B6 (CVB6) strains were successfully constructed. • A lethal neonatal murine model of CVB6 infection with viral myocarditis was developed. • This is the first study to characterize the pathogenicity of CVB6 strains, showing their tropism for muscle tissues. • The infection mouse model was applied to evaluate an inactivated CVB6 vaccine. • The infection mouse model was applied to evaluate the therapeutic effect of an anti-CVB6 neutralizing antibody. [ABSTRACT FROM AUTHOR]

Tilapia lake virus (TiLV) has caused many deadly epidemics in wild and farmed tilapia, posing a great threat to the global tilapia-based industry. It is necessary and urgent to develop effective measures for TiLV control. Previously, we isolated a TiLV strain from naturally diseased tilapia, and its main target tissues are liver, spleen and brain. In the study, a TiLV-susceptive cell line is established based on the tissue tropism, and anti-TiLV activity of 11 Chinese herbal compounds (CHCs) is checked in vitro. A cell line from the brain of tilapia, designated as Nt-B, can be continuously subcultured for >100 passages and maintain a good proliferating state in L-15 media supplemented with 10% FBS at 28 °C. Following infection with TiLV, a series of cytopathic effects can be observed, including rounding, accumulation, vacuolation and detachment of cells. Enveloped viral particles can be observed in TiLV-infected cells, and TiLV-specific bands are identified by PCR analysis, confirming susceptibility of Nt-B cells to TiLV. For anti-TiLV activity evaluation, the selected CHCs show inhibition activity on TiLV-induced CPEs in different degrees except CHC-I. Two kinds of CHCs, CHC-II and CHC-X, have inhibition activity on TiLV-induced CPEs higher than 80%. Besides, the 90% inhibitory concentrations of CHC-II and CHC-X on TiLV are 51.12 ± 3.04 and 68.28 ± 6.37 mg/L, respectively. In summary, the newly established Nt-B cell line provides a useful tool for TiLV-related studies, moreover, CHC-II is a promising therapeutic agent against TiLV infection. Further studies will be required to reveal the active compounds and anti-TiLV mechanism of CHC-II. • A permanent growing cell line derived from brain of tilapia is established. • Nt-B cells are susceptible to TiLV. • Anti-TiLV activity of 11 Chinese herbal compounds (CHCs) is checked. • CHC-II can effectively inhibit TiLV infection. [ABSTRACT FROM AUTHOR]

Nipah virus (NiV) is a lethal bat-borne zoonotic virus that causes mild to acute respiratory distress and neurological manifestations in humans with a high mortality rate. NiV transmission to humans occurs via consumption of bat-contaminated fruit and date palm sap (DPS), or through direct contact with infected individuals and livestock. Since NiV outbreaks were first reported in pigs from Malaysia and Singapore, non-neutralizing antibodies against NiV attachment Glycoprotein (G) have also been detected in a few domestic mammals. NiV infection is initiated after NiV G binds to the host cell receptors Ephrin-B2 and Ephrin-B3. In this study, we assessed the degree of NiV host tropism in domestic and peridomestic mammals commonly found in Bangladesh that may be crucial in the transmission of NiV by serving as intermediate hosts. We carried out a protein-protein docking analysis of NiV G complexes (n = 52) with Ephrin-B2 and B3 of 13 domestic and peridomestic species using bioinformatics tools. Protein models were generated by homology modelling and the structures were validated for model quality. The different protein-protein complexes in this study were stable, and their binding affinity (ΔG) scores ranged between −8.0 to −19.1 kcal/mol. NiV Bangladesh (NiV-B) strain displayed stronger binding to Ephrin receptors, especially with Ephrin-B3 than the NiV Malaysia (NiV-M) strain, correlating with the observed higher pathogenicity of NiV-B strains. From the docking result, we found that Ephrin receptors of domestic rat (R. norvegicus) had a higher binding affinity for NiV G, suggesting greater susceptibility to NiV infections compared to other study species. Investigations for NiV exposure to domestic/peridomestic animals will help us knowing more the possible role of rats and other animals as intermediate hosts of NiV and would improve future NiV outbreak control and prevention in humans and domestic animals. [Display omitted] • Molecular evidence of stable protein-protein interaction between NiV G and Ephrin-B2/B3 of common Bangladeshi mammals. • NiV-B bindsmore strongly to Ephrin-B2/B3 in domestic and peridomestic mammals than NiV-M, confirming higher pathogenicity. • In silico analyses show rats are more susceptibility to NiV infections than known hosts and reservoirs of NiV. • Rattus norvegicus was identified as a species of concern, requiring special research attention to predict future outbreaks. [ABSTRACT FROM AUTHOR]