DC-SIGN of Largemouth Bass (Micropterus salmoides) Mediates Immune Functions against Aeromonas hydrophila through Collaboration with the TLR Signaling Pathway.

C-type lectins in organisms play an important role in the process of innate immunity. In this study, a C-type lectin belonging to the DC-SIGN class of Micropterus salmoides was identified. MsDC-SIGN is classified as a type II transmembrane protein. The extracellular segment of MsDC-SIGN possesses a coiled-coil region and a carbohydrate recognition domain (CRD). The key amino acid motifs of the extracellular CRD of MsDC-SIGN in Ca2+-binding site 2 were EPN (Glu-Pro-Asn) and WYD (Trp-Tyr-Asp). MsDC-SIGN-CRD can bind to four pathogen-associated molecular patterns (PAMPs), including lipopolysaccharide (LPS), glucan, peptidoglycan (PGN), and mannan. Moreover, it can also bind to Gram-positive, Gram-negative bacteria, and fungi. Its CRD can agglutinate microbes and displays D-mannose and D-galactose binding specificity. MsDC-SIGN was distributed in seven tissues of the largemouth bass, among which the highest expression was observed in the liver, followed by the spleen and intestine. Additionally, MsDC-SIGN was present on the membrane of M. salmoides leukocytes, thereby augmenting the phagocytic activity against bacteria. In a subsequent investigation, the expression patterns of the MsDC-SIGN gene and key genes associated with the TLR signaling pathway (TLR4, NF-κB, and IL10) exhibited an up-regulated expression response to the stimulation of Aeromonas hydrophila. Furthermore, through RNA interference of MsDC-SIGN, the expression level of the DC-SIGN signaling pathway-related gene (RAF1) and key genes associated with the TLR signaling pathway (TLR4, NF-κB, and IL10) was decreased. Therefore, MsDC-SIGN plays a pivotal role in the immune defense against A. hydrophila by modulating the TLR signaling pathway.

Analysis of Pickled Cucumber Products, Based on Microbial Diversity and Flavor Substance Detection.

Changes to the microbial community during pickled cucumber fermentation were studied using the 16S rDNA technique. The changes of volatile organic compounds (VOCs) during pickled cucumber fermentation were studied by gas chromatograph-ion mobility spectrometry. At the phylum level, Cyanophyta and Proteobacteria were the dominant flora in the natural fermentation group, and Firmicutes were the dominant flora in the added-bacteria fermentation group. At the generic level, the addition of Lactobacillus led to changes in the community of the bacteria in the added-bacterial fermentation group and decreased the species abundance of other bacteria. In total, 75 volatile organic compounds were identified from naturally fermented pickled cucumber, and 60 volatile organic compounds were identified from fermented pickled cucumber with bacterial addition. The main metabolites were esters, aldehydes, acids, alcohols, ketones, alkanes, nitriles, and alkenes. These metabolites will bring their unique aroma components to the pickled cucumber. Metabolomic analysis of the O2PLS model showed that Weissella and Lactobacillus were closely and positively correlated with nine alcohols, six esters, five aldehydes, four acids, three ketones, and one pyrazine. Pseudomonas and norank_f_Mitochondria show a close positive correlation with four kinds of alcohols, two kinds of esters, one kind of aldehyde, and one kind of nitrile.

Loop PDE of viral capsid protein is involved in immune escape of the emerging novel variant infectious bursal disease virus.

Infectious bursa disease (IBD) is an acute, highly contactable, lethal, immunosuppressive infectious disease caused by the Infectious bursa disease virus (IBDV). Currently, the emerged novel variant IBDV (nVarIBDV) and the sustainedly prevalent very virulent IBDV (vvIBDV) are the two most prevalent strains of IBDV in China. The antigenic properties of the two prevalent strains differed significantly, which led to the escape of nVarIBDV from the immune protection provided by the existing vvIBDV vaccine. However, the molecular basis of the nVarIBDV immune escape remains unclear. In this study, we demonstrated, for the first time, that residues 252, 254, and 256 in the PDE of VP2 are involved in the immune escape of the emerging nVarIBDV. Firstly, the IFA-mediated antigen-antibody affinity assay showed that PBC and PDE of VP2 could affect the affinity of vvIBDV antiserum to VP2, of which PDE was more significant. The key amino acids of PDE influencing the antigen-antibody affinity were also identified, with G254N being the most significant, followed by V252I and I256V. Then the mutated virus with point or combined mutations was rescued by reverse genetics. it was further demonstrated that mutations of V252I, G254N, and I256V in PDE could individually or collaboratively reduce antigen-antibody affinity and interfere with antiserum neutralization, with G254N being the most significant. This study revealed the reasons for the widespread prevalence of nVarIBDV in immunized chicken flocks and provided innovative ideas for designing novel vaccines that match the antigen of the epidemic strain.

CeO2 and Glucose Oxidase Co-Enriched Ti3C2Tx MXene for Hyperthermia-Augmented Nanocatalytic Cancer Therapy.

Foreseen as foundational in forthcoming oncology interventions are multimodal therapeutic systems. Nevertheless, the tumor microenvironment (TME), marked by heightened glucose levels, hypoxia, and scant concentrations of endogenous hydrogen peroxide could potentially impair their effectiveness. In this research, two-dimensional (2D) Ti3C2 MXene nanosheets are engineered with CeO2 nanozymes and glucose oxidase (GOD), optimizing them for TME, specifically targeting cancer therapy. Following our therapeutic design, CeO2 nanozymes, embodying both peroxidase-like and catalase-like characteristics, enable transformation of H2O2 into hydroxyl radicals for catalytic therapy while also producing oxygen to mitigate hypoxia. Concurrently, GOD metabolizes glucose, thereby augmenting H2O2 levels and disrupting the intracellular energy supply. When subjected to a near-infrared laser, 2D Ti3C2 MXene accomplishes photothermal therapy (PTT) and photodynamic therapy (PDT), additionally amplifying cascade catalytic treatment via thermal enhancement. Empirical evidence demonstrates robust tumor suppression both in vitro and in vivo by the CeO2/Ti3C2-PEG-GOD nanocomposite. Consequently, this integrated approach, which combines PTT/PDT and enzymatic catalysis, could offer a valuable blueprint for the development of advanced oncology therapies.

Infectious bursal disease virus VP5 triggers host shutoff in a transcription-dependent manner.

Viruses have evolved intricate mechanisms to evade host antiviral responses and exploit cellular resources by manipulating the expression profile of host genes. During infection, viruses encode proteins with shutoff activity to globally inhibit host protein synthesis, which is an effective strategy for immune evasion. In this study, compelling evidence shows that infectious bursal disease virus (IBDV) infection triggers the suppression of host protein synthesis. Furthermore, using both in vitro and in vivo viral infection models, we have identified that IBDV specifically impedes the transcription of host genes via the shutoff activity of viral VP5, simultaneously conferring advantages to IBDV infection in these circumstances. The proposed mechanism suggests that VP5 competitively binds to RanBP1, disrupting the RanGDP/GTP gradient. This disruption interferes with cellular nucleocytoplasmic transport, impairing the nuclear import of proteins bearing nuclear localization signals. The nuclear transport of pivotal transcriptional regulatory factors, such as p65 and IFN regulatory factor 7, is also compromised, leading to the inhibition of pro-inflammatory cytokines and interferon expression. This newly discovered strategy employed by IBDV enables them to manipulate host gene expression, providing novel insights into how viruses evade host immune responses and establish infections.IMPORTANCEViruses manipulate host processes at various levels to regulate or evade both innate and adaptive immune responses, promoting self-survival and efficient transmission. The "host shutoff," a global suppression of host gene expression mediated by various viruses, is considered a critical mechanism for evading immunity. In this study, we have validated the presence of host shutoff during infectious bursal disease virus (IBDV) infection and additionally uncovered that the viral protein VP5 plays a pivotal role in inhibiting the overall synthesis of host proteins, including cytokines, through a transcription-dependent pathway. VP5 competitively binds with RanBP1, leading to disruption of the Ran protein cycle and consequently interfering with nucleocytoplasmic transport, which ultimately results in the suppression of host gene transcription. These findings unveil a novel strategy employed by IBDV to evade host innate immunity and rapidly establish infection. This study also suggests a novel supplement to understanding the pathway through which viruses inhibit host protein synthesis.

Largemouth bass galectin, MsGal-9: Mediating various functions as a pattern recognition receptor and a potential damage-associated molecular pattern.

Galectins are lectins that bind to ß-galactose and are widely expressed in immune system tissues, playing pivotal roles in innate immunity through their conserved carbohydrate-recognition domains (CRDs). In this present investigation, a tandem-repeat galectin was discovered in the largemouth bass, Micropterus salmoides (designated as MsGal-9). The open reading frame of MsGal-9 encodes two CRDs, each containing two consensus motifs that are essential for ligand binding. MsGal-9 is expressed in various tissues of the largemouth bass, with particularly high expression levels in the liver and spleen. The full-length form of MsGal-9, as well as the N-terminal (MsGal-9-N) and C-terminal (MsGal-9-C) CRDs, were individually recombined. Their ability for nonself recognition was studied. The three recombinant proteins were able to bind to glucan (GLU), peptidoglycan (PGN), and lipopolysaccharide (LPS), with MsGal-9 displaying the highest binding activity. Furthermore, rMsGal-9-N exhibited higher binding activity towards GLU in comparison to rMsGal-9-C. Further investigations revealed that the full-length rMsGal-9 could significantly bind to Gram-positive bacteria, Gram-negative bacteria, and fungi, while rMsGal-9-C specifically bound to Escherichia coli. However, rMsGal-9-N did not exhibit significant binding activity towards any microbes. These findings indicate that MsGal-9 requires both CRDs to cooperate in order to fulfill its nonself recognition function. All three recombinant proteins demonstrated agglutination activity towards various microbes, with MsGal-9 and MsGal-9-N displaying a similar broad binding spectrum, while MsGal-9-C agglutinated three types of bacteria. Moreover, both MsGal-9 and MsGal-9-N were capable of coagulating largemouth bass red blood cells, whereas MsGal-9-C lacked this ability. However, MsGal-9-C played a significant role in enhancing the encapsulation of leukocytes in comparison to MsGal-9-N. All three proteins acted as potential damage-associated molecular patterns (DAMPs), inducing apoptosis in leukocytes.

Generating hematopoietic cells from human pluripotent stem cells: approaches, progress and challenges.

Human pluripotent stem cells (hPSCs) have been suggested as a potential source for the production of blood cells for clinical application. In two decades, almost all types of blood cells can be successfully generated from hPSCs through various differentiated strategies. Meanwhile, with a deeper understanding of hematopoiesis, higher efficiency of generating progenitors and precursors of blood cells from hPSCs is achieved. However, how to generate large-scale mature functional cells from hPSCs for clinical use is still difficult. In this review, we summarized recent approaches that generated both hematopoietic stem cells and mature lineage cells from hPSCs, and remarked their efficiency and mechanisms in producing mature functional cells. We also discussed the major challenges in hPSC-derived products of blood cells and provided some potential solutions. Our review summarized efficient, simple, and defined methodologies for developing good manufacturing practice standards for hPSC-derived blood cells, which will facilitate the translation of these products into the clinic.

Infection dynamic of Micropterus salmoides rhabdovirus and response analysis of largemouth bass after immersion infection.

Largemouth bass (Micropterus salmoides) is an important economic freshwater aquaculture fish originating from North America. However, the frequent outbreaks of Micropterus salmoides rhabdovirus (MSRV) have seriously limited the healthy development of Micropterus salmoides farming industry. In the present study, a strain of MSRV was isolated and identified from infected largemouth bass by PCR, transmission electron micrograph observation and genome sequences analysis, and tentatively named MSRV-HZ01 strain. Phylogenetic analyses showed that the MSRV-HZ01 presented the highest similarity to MSRV-2021, followed by MSRV-FJ985 and MSRV-YH01. The various tissues of juvenile largemouth bass exhibited significant pathological damage following MSRV-HZ01 immersion infection, and the mortality reached 90%. We also found that intestine was the key organ for MSRV to enter the fish body initially by dynamic analysis of viral infection, and the head kidney was the susceptible tissue of virus. Moreover, the MSRV was also transferred to the external mucosal tissue in later stage of viral infection to achieve horizontal transmission. In addition, the genes of IFN γ and IFN I-C were significantly up-regulated after MSRV infection to exert antiviral functions. The genes of cGAS and Sting might play an important role in the regulation of interferon expression. In conclusion, we investigated the virus infection dynamics and fish response following MSRV immersion infection, which would promote our understanding of the interaction between MSRV and largemouth bass under natural infection.

Comparative Pathogenicity of Three Strains of Infectious Bursal Disease Virus Closely Related to Poultry Industry.

Infectious bursal disease (IBD) is an acute, highly contagious, immunosuppressive, and fatal infectious disease of young chickens caused by infectious bursal disease virus (IBDV). Since 2017, a new trend has been discovered in the IBDV epidemic, with very virulent IBDV (vvIBDV) and novel variant IBDV (nVarIBDV) becoming the two current dominant strains in East Asia including China. In this study, we compared the biological characteristics of the vvIBDV (HLJ0504 strain), nVarIBDV (SHG19 strain), and attenuated IBDV (attIBDV, Gt strain) using specific-pathogen-free (SPF) chicken infection model. The results showed that vvIBDV distributed in multiple tissues, replicated the fastest in lymphoid organs such as bursa of Fabricius, induced significant viremia and virus excretion, and is the most pathogenic virus with a mortality of more than 80%. The nVarIBDV had a weaker replication capability and did not kill the chickens but caused severe damage to the central immune organ bursa of Fabricius and B lymphocytes and induced significant viremia and virus excretion. The attIBDV strain was found not to be pathogenic. Further studies preliminarily suggested that the expression level of inflammatory factors triggered by HLJ0504 was the highest, followed by the SHG19 group. This study is the first to systematically compare the pathogenic characteristics of three IBDVs closely related to poultry industry from the perspectives of clinical signs, micro-pathology, virus replication, and distribution. It is of great importance to obtain an extensive knowledge of epidemiology, pathogenicity, and comprehensive prevention, and control of various IBDV strains.

Peptidoglycan recognition protein MsPGRP in largemouth bass (Micropterus salmoides) mediates immune functions with broad nonself recognition ability.

Peptidoglycan (PGN) recognition proteins (PGRPs) are important immune factors in innate immunity that function in recognising pathogens and activating the immune system. These ubiquitous proteins are conserved in invertebrates and vertebrates. In this study, a PGRP gene (MsPGRP) from largemouth bass (Micropterus salmoides) was identified and characterised, and its transcription distribution was explored. Recombinant protein (rMsPGRP) exhibited dose-dependent binding to PGN and glucan (GLU), but weak binding to lipopolysaccharide (LPS). MsPGRP exhibited agglutinating activity against several Gram-negative bacteria, Gram-positive bacteria and fungi, and it promoted phagocytosis activity of leukocytes against Micrococcus luteus and Aeromonas hydrophila. The protein also possessed amidase activity in the presence of Zn2+, degraded PGN, and disrupted the M. luteus cell wall. The results suggest that MsPGRP plays an important role in pathogen recognition, and acts as a opsonin during immune system responses and elimination of invading pathogens.

An Evaluation of Laminarin Additive in the Diets of Juvenile Largemouth Bass (Micropterus salmoides): Growth, Antioxidant Capacity, Immune Response and Intestinal Microbiota.

A 28 day feeding trial was conducted to investigate the growth performance, immune response and intestinal microbiota of laminarin (LAM) supplemented diets in juvenile largemouth bass (Micropterus salmoides). Four hundred and eighty fish (initial average weight: 0.72 ± 0.04 g) were randomly divided into four groups (40 fish per tank with three replicates in each group) Four diets were prepared with LAM supplementation at the doses of 0 (control), 5 g Kg-1 (LL), 10 g Kg-1 (ML) and 15 g Kg-1 (HL), respectively. No significant difference in the specific growth rate (SGR) and hepatosomatic index (HSI) was observed in fish among the four groups, or in the lipid and ash content of fish flesh. In addition, fish in the LL group exhibited much higher antioxidant capacity (p < 0.05), while the diets with the inclusion of 5 and 10 g Kg-1 LAM remarkably decreased the antioxidant capacity of fish (p > 0.05). Dietary LAM at the dose of 5 g Kg-1 inhibited the transcription of interleukin-1ß (il-1ß) and tumor necrosis factor-α (tnf-α), while promoting the expression of transforming growth factor-ß (tgf-ß) in fish intestine. Moreover, the beneficial intestinal bacteria Bacteroide, Comamonas and Mycoplasma abundance significantly increased in fish from the LL group, while the content of opportunistic pathogens Plesiomonas, Aeromonas and Brevinema in fish of the HL group was substantially higher than the control group. Overall, the appropriate dose of supplemented LAM in the diet was 5 g Kg-1, while an excessive supplementation of LAM in the diet led to microbial community instability in largemouth bass.

Health literacy and fatigue, anxiety, depression, and somatic symptoms in patients with differentiated thyroid carcinoma from West China: A cross-sectional study.

Background and Aims: Differentiated thyroid carcinoma (DTC) patients are associated with excellent prognosis but impaired health-related quality of life (HRQOL) by initial and subsequent therapy. Health literacy plays a pivotal role in public health and medical settings, but data on its relationship with DTC patients' HRQOL are insufficient and equivocal. This study was designed to explore the relationship between health literacy and HRQOL in patients with DTC from West China areas. Methods: A cross-sectional study with a descriptive correlational design was conducted. 126 patients with DTC were recruited between 2020 and 2021. Levels of health literacy and HRQOL (including fatigue level, anxiety/depression status, and somatoform symptoms) were assessed by questionnaires. Pearson product-moment correlation and Stepwise multiple regression were used to examined the adjusted association of health literacy with HRQOL. Results: Health literacy and receiving DTC-related education together explained 16.2% of the variance in fatigue level. Patients who had higher health literacy, received more DTC-related education were currently employed and less fatigue. Health literacy, fatigue level and DTC-related education together explained 31.0% of the variance in anxiety and depression of DTC patients. Patients who had higher health literacy, received more DTC-related education and less fatigue level were less anxious and depressive. Age explained 8.3% of the variance in DTC patients' somatoform symptoms. Older patients complained more somatoform symptoms. Conclusion: Health literacy was positively associated with HRQOL in DTC patients regarding to fatigue level and anxiety/depression status across the entire sample. Interventions to improve HRQOL should take the patients' health literacy into account.

The role of TNF-α in the phagocytosis of largemouth bass (Micropterus salmoides) leukocytes.

Phagocytosis is an important innate immune process in which immune cells recognize, ingest and eliminate pathogens. Largemouth bass (Micropterus salmoides) has become an important economic farmed fish in many regions, while few studies has focused on phagocytosis of its leucocytes. In present study, largemouth bass peripheral blood leucocytes were separated using Percoll gradient to establish the phagocytic function. Flow cytometric analysis showed that largemouth bass leukocytes exhibited the phagocytic capacity to fluoresbrite microspheres and Aeromonas hydrophila, where higher phagocytic capacity to A. hydrophila were observed in granulocytes/monocytes than that of lymphocytes. The leukocytes engulfing fluoresbrite microspheres and A. hydrophila were also observed by fluorescence microscopy. Besides, manygenes associated with phagocytosis and TNF-α in leukocytes were up-regulated following A. hydrophila stimulation. Subsequently, the largemouth bass TNF-α was recombinantly expressed to investigate its role in regulating phagocytosis. The results showed that TNF-α in largemouth bass could significantly enhance the phagocytic ability of granulocytes/monocytes to A. hydrophila, but not lymphocytes. Moreover, we also found that TNF-α could not only significantly increase the ROS activity of granulocytes/monocytes, but also had the function of inducing its apoptosis. These results demonstrated that granulocytes/monocytes play more important role in phagocytosis, meanwhile, TNF-α has the function of enhancing the phagocytic ability of granulocytes/monocytes in largemouth bass.

Protective efficacy evaluation of immunogenic protein AHA_3793 of Aeromonas hydrophila as vaccine candidate for largemouth bass Micropterus salmoides.

Aeromonas hydrophila is a Gram-negative pathogen that can infect various fish, including largemouth bass (Micropterus salmoides), which have caused huge economic losses. In present study, largemouth bass anti-A. hydrophila antibodies were produced, then a highly immunogenic outer membrane proteins, AHA_3793, was identified by combined western blotting and mass spectrometry analysis. Moreover, AHA_3793 was expressed, and its immunogenicity was further verified by western blotting. Subsequently, the protective efficacy of AHA_3793 were evaluated in largemouth bass. The results showed that rAHA_3793 could produce a relative percentage survival (RPS) of 61.76% for largemouth bass against A. hydrophila challenge. ELISA analysis showed the specific serum antibodies of largemouth bass against rAHA_3793 and A. hydrophila in vaccinated group in weeks 4 and 5 after immunization were significantly higher than those in control group, which suggested that rAHA_3793 induced production of specific serum antibodies against rAHA_3793 and A. hydrophila. The qRT-PCR analysis showed that expressions of CD4-2 and MHC IIα were also significantly up-regulated after immunization. These results collectively demonstrated that rAHA_3793 could induce a strong humoral immune response of largemouth bass, and then produce high immune protection effects against A. hydrophila infection.

Intrinsic myocardial defects underlie an Rbfox-deficient zebrafish model of hypoplastic left heart syndrome.

Hypoplastic left heart syndrome (HLHS) is characterized by underdevelopment of left sided structures including the ventricle, valves, and aorta. Prevailing paradigm suggests that HLHS is a multigenic disease of co-occurring phenotypes. Here, we report that zebrafish lacking two orthologs of the RNA binding protein RBFOX2, a gene linked to HLHS in humans, display cardiovascular defects overlapping those in HLHS patients including ventricular, valve, and aortic deficiencies. In contrast to current models, we demonstrate that these structural deficits arise secondary to impaired pump function as these phenotypes are rescued when Rbfox is specifically expressed in the myocardium. Mechanistically, we find diminished expression and alternative splicing of sarcomere and mitochondrial components that compromise sarcomere assembly and mitochondrial respiration, respectively. Injection of human RBFOX2 mRNA restores cardiovascular development in rbfox mutant zebrafish, while HLHS-linked RBFOX2 variants fail to rescue. This work supports an emerging paradigm for HLHS pathogenesis that centers on myocardial intrinsic defects.

Effect of Autolyzed Yarrowia lipolytica on the Growth Performance, Antioxidant Capacity, Intestinal Histology, Microbiota, and Transcriptome Profile of Juvenile Largemouth Bass (Micropterus salmoides).

The improper components of formulated feed can cause the intestinal dysbiosis of juvenile largemouth bass and further affect fish health. A 28 day feeding trial was conducted to investigate the effect of partially replacing fish meal (FM) with autolyzed Yarrowia lipolytica (YL) on juvenile largemouth bass (Micropterus salmoides). We considered four diets-control, YL25, YL50, and YL75-in which 0%, 25%, 50%, and 75% of the FM content, respectively, was replaced with YL. According to results, the weight gain rate (WGR) and specific growth rate (SGR) of the fish with the YL25 and YL50 diets were significantly higher than the WGR and SGR with the control diet, while the YL75 diet significantly reduced fish growth and antioxidant enzymes activities, and shortened the villus height in the intestinal mucosa. The 16S rRNA analysis of the intestinal microbiota showed that the relative abundance of Mycoplasma was significantly increased with the YL25 and YL50 diets, while the Enterobacteriacea content was increased with the YL75 diet. Moreover, our transcriptome analysis revealed that certain differentially expressed genes (DEGs) that are associated with growth, metabolism, and immunity were modulated by YL inclusion treatment. Dietary YL25 and YL50 significantly reduced the mRNA level of ERBB receptor feedback inhibitor 1 (errfi1) and dual-specificity phosphatases (dusp), while the expression of the suppressor of cytokine signaling 1 (socs1), the transporter associated with antigen processing 2 subunit type a (tap2a), and the major histocompatibility complex class I-related gene (MHC-I-l) were sharply increased with YL75 treatment. We determined that the optimum dose of dietary YL required for maximum growth without any adverse influence on intestinal health was 189.82 g/kg (with 31.63% of the fishmeal replaced by YL), while an excessive substitution of YL for fishmeal led to suppressed growth and antioxidant capacity, as well as intestinal damage for juvenile largemouth bass.

Residues 318 and 323 in capsid protein are involved in immune circumvention of the atypical epizootic infection of infectious bursal disease virus.

Recently, atypical infectious bursal disease (IBD) caused by a novel variant infectious bursal disease virus (varIBDV) suddenly appeared in immunized chicken flocks in East Asia and led to serious economic losses. The epizootic varIBDV can partly circumvent the immune protection of the existing vaccines against the persistently circulating very virulent IBDV (vvIBDV), but its mechanism is still unknown. This study proved that the neutralizing titer of vvIBDV antiserum to the epizootic varIBDV reduced by 7.0 log2, and the neutralizing titer of the epizootic varIBDV antiserum to vvIBDV reduced by 3.2 log2. In addition, one monoclonal antibody (MAb) 2-5C-6F had good neutralizing activity against vvIBDV but could not well recognize the epizootic varIBDV. The epitope of the MAb 2-5C-6F was identified, and two mutations of G318D and D323Q of capsid protein VP2 occurred in the epizootic varIBDV compared to vvIBDV. Subsequently, the indirect immunofluorescence assay based on serial mutants of VP2 protein verified that residue mutations 318 and 323 influenced the recognition of the epizootic varIBDV and vvIBDV by the MAb 2-5C-6F, which was further confirmed by the serial rescued mutated virus. The following cross-neutralizing assay directed by MAb showed residue mutations 318 and 323 also affected the neutralization of the virus. Further data also showed that the mutations of residues 318 and 323 of VP2 significantly affected the neutralization of the IBDV by antiserum, which might be deeply involved in the immune circumvention of the epizootic varIBDV in the vaccinated flock. This study is significant for the comprehensive prevention and control of the emerging varIBDV.

A simple approach to C3-ethoxycarbonylmethylation of thiophenes/furans with diethyl bromomalonate.

A mild and efficient visible-light-induced radical method was developed to produce C3-malonated five-membered heterocycles using 2-substituted thiophenes/furans and diethyl bromomalonate as the starting materials. Various 2-substituted (benzo)thiophenes/furans were suitable for the C3-ethoxycarbonylmethylation. The free radical mechanism was proposed based on the results of control experiments, cyclic voltammetry experiments and luminescence quenching experiments. We suggested that the heteroleptic halogen-bridged iridium(III) dimers might play an important role in this system.

Dynamic Effects of Endo-Exogenous Stimulations on Enzyme-Activatable Polymeric Nanosystems with Photo-Sono-Chemo Synergy.

Activatable polymeric nanosystems have attracted great interest, and their interactions with endo-exogenous stimulations are highly vital for therapeutic efficacy, which urgently needs systematic study. Herein we focus on systematically investigating these interactions on an enzyme-nanosystem model, the tumor-overexpressed hyaluronidase (HAase) and the doxorubicin-loaded hyaluronic-acid-porphyrin nanoassemblies (DOX@HPNAs), to augment photo-sono-chemo therapies. The HAase degrades the HPNAs in acidic solution at a higher rate than that in neutral solution, which leads to structure disassembly at the nano level, chain cleavage at the molecular level, and strong radiative recovery at the energy level. Upon excitation with light and ultrasound, the enzymatically degraded sample produces ∼2.5 times more singlet oxygen than the HPNAs because of the absence of aggregation-induced quenching and 1O2 migration limitation. The nanosystem can be activated by trimodal stimulations (acidity, ultrasound, and HAase), exerting the controllable release behavior and high release content. Moreover, the nanosystem exhibits synergistic effects among efficient photodynamic therapy, high tissue-penetrating sonodynamic therapy, and lasting chemotherapy, which induces significant necrosis and apoptosis of cancer cells. With high compatibility, tumor-targeting ability, and fluorescent-imaging-guided capability, the nanosystem achieves the highest inhibition rate of malignant tumors than the single or dual-modal therapies. Thus, the enzyme-activatable nanosystem enables the therapeutic synergy and also provides insights to develop other polymeric nanosystems.