African swine fever virus(ASFV)is a large,double-stranded DNA virus classified within the family Asfarviridae,a clinically notable outlier in Baltimore Group Ⅰ.The virus harbors a linear double-stranded DNA genome of 170-194 kb,encoding over 150 open reading frames(ORFs),and features a highly complex multi-layered architecture,wreaking havoc on global swine populations and having caused massive culling and eco-nomic losses across Asia,Europe,and Africa(Costard et al.,2009;Penrith et al.,2013).The ability of ASFV to evade host immunity,persist in multiple wild Suidae reservoirs,including wild boars(Sus scrofa),warthogs(Phacochoerus spp.),and bush pigs(Potamochoerus spp.).

Invasive Aspergillus fumigatus infection poses a serious threat to immunocompromised individuals, characterized by high morbidity and mortality. Given the challenges of time-consuming diagnosis, limited therapeutic options, and the increasing emergence of drug resistance, there is an urgent need to develop novel and effective preventive strategies. Circular RNA (CircRNA) vaccines represent an emerging vaccine platform that exhibits high stability in vivo, enables sustained antigen expression, and can elicit robust and durable immune responses. Consequently, they hold considerable potential for the prevention of infectious diseases. In this study, we designed and constructed two circRNA vaccines, each encoding a fusion antigen derived from non-transmembrane regions of the iron ion permease FtrA located in the cell membrane of A. fumigatus. The circRNA vaccines were prepared using a group I intron-based cis-acting ribozyme system (CARS) and delivered via lipid nanoparticles (LNPs) in a murine model. The results revealed that the circRNAFtrA2 vaccine could effectively induce both cellular and humoral immune responses. Following challenge with A. fumigatus, vaccinated mice, particularly those receiving circRNAFtrA2, exhibited a significant reduction in fungal burden in the lungs compared with the unvaccinated controls. Furthermore, lung pathology was markedly alleviated, and survival rate was notably improved. Collectively, these findings highlight a promising and innovative vaccine for combating invasive A. fumigatus infection.

Vaccines have demonstrated greater efficiency in providing immunoprotection against bacterial species, making them potentially valuable in aquaculture. In this study, twenty-four outer membrane proteins (OMPs) of Pseudomonas fluorescens were cloned, purified, and 16 OMP mouse antisera were prepared, with titers all exceeding 1:3200. Subsequently, these 16 antisera were used to passively immunize crucian carp (Carassius auratus) followed by challenge with the pathogenic bacteria. The results showed that five OMP antisera (PF0542, SurA, PF1798, PF2253, and PF4616), as well as the whole OMP serum, provided immune protection rates exceeding 60% against P. fluorescens and Aeromonas hydrophila infection (p < 0.05). Moreover, these five OMP antisera reduced the mRNA expression of inflammatory cytokines and antioxidant factors (p < 0.05), and exerted protective effects on the structural integrity of the kidney, spleen, and intestinal tissues. In addition, active immunization of crucian carp with these five identified OMPs followed by pathogen challenge demonstrated that these proteins could activate non-specific immune responses in fish, confer immune protection against P. fluorescens and A. hydrophila infection, reduce the mRNA expression of inflammatory cytokines and antioxidant factors (p < 0.05), and protect the tissue structure of the kidney, spleen, and intestine. Collectively, these five OMPs (PF0542, SurA, PF1798, PF2253, and PF4616) can activate immune responses in crucian carp, confer protection against bacterial infection, and exhibit reductions in inflammatory/oxidative responses associated with protection following bacterial challenge, and as well as viscera structure-maintaining effects. Therefore, the five OMPs hold promise as vaccine candidates against bacterial infections (P. fluorescens and A. hydrophila) for both passive and active immunization in fish.

Respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infections among infants and older adults, posing a significant threat to global public health. The prophylactic use of neutralizing antibodies (nAbs) underscores the need to understand elite RSV antibody neutralization mechanisms, which is fundamental for developing next-generation therapies with enhanced potency and broader activity. In this study, we utilized H2L2 transgenic mice encoding human immunoglobulin variable regions for immunization and successfully screened multiple antibodies with significant neutralizing activity using the Beacon Optofluidic system. One of these antibodies, PR306007, exhibited significantly superior broad-spectrum neutralization against both RSV-A and B subgroups. Cryo-electron microscopy (Cryo-EM) structural analysis revealed that PR306007 binds to a unique epitope that overlaps with antigenic sites II and V of the F protein, with its primary binding regions located at the base of the α6 and α7 helices of site II, and residues S173 and N175 of site V. This binding mode offers valuable insights into enhanced neutralization activity and potentially reduces the risk of emerging immune evasive mutants. Furthermore, PR306007 showed potent in vivo antiviral activity against RSV infection and demonstrated good efficacy against both lower and upper respiratory tract infections, making it a promising prophylactic candidate for broad prevention. These findings provide new insights for the future development of RSV vaccines or nAbs.

Objective To observe the effect of moxibustion at u201CXinshuu201D (BL15) and u201CFeishuu201D (BL13) on transient receptor potential vanilloid type 1 (TRPV1), calcitonin gene-related peptide (CGRP), and serum interleukin-10 (IL-10) in the myocardial tissue of rats with chronic heart failure (CHF), so as to explore its underlying mechanisms in improvement of CHF. Methods Male SD rats were randomly divided into the normal, model, moxibustion, capsaicin, moxibustion + capsaicin, and moxibustion + solvent groups, with 10 rats in each group. The CHF model was established by permanent ligation of the anterior descending branch of the left coronary artery. Mild moxibustion was applied to bilateral BL13 and BL15 for 30 min once daily for 4 weeks. Rats in the capsaicin group were smeared with capsaicin in the acupoint area once a day for 4 weeks. For rats of the moxibustion + capsaicin and moxibustion +solvent groups, capsaicin and solvent were applied to the acupoint area before moxibustion for 4 weeks, respectively. The ejection fraction (EF) and left ventricular fractional shortening rate (FS) were examined by echocardiography. HE staining was used to observe the myecardial morphological structure. The mRNA and protein expression levels of TRPV1, CGRP and galectin-3 (Gal-3) in myocardial tissue were detected by real-time quantitative PCR and Western blot, respectively. The content of IL-10 in serum was detected by ELISA. Results After modeling, the pathological changes of myocardium (as cardiac muscle fiber disorder, inflammatory cell infiltration, etc.) were obvious, and the EF, FS, serum IL-10, protein and mRNA exspression of TRPV1 and CGRP were significantly decreased (PuFF1C0.01) in the model group compared with the normal group, while the protein and mRNA exspression of Gal-3 were significantly up-regulated (PuFF1C0.01). Following the interventions, the above-mentioned indexes were all reversed in moxibustion, capsaicin, and moxibustion + capsaicin groups (PuFF1C0.01), and the effect of moxibustion + capsaicin was the best (PuFF1C0.05,PuFF1C0.01). Conclusion Moxibustion can reduce myocardial injury and improve cardiac function in CHF rats, which may be related to its effects in up-regulating the expression of TRPV1 and CGRP, and down-regulating the expression of Gal-3 to alleviate myocardial fibrosis.

Emergence of variants of concern (VOC) with altered antigenic structures and waning humoral immunity to SARS-CoV-2 are harbingers of a long pandemic. Administration of a third dose of an inactivated virus vaccine can boost the immune response. Here, we have dissected the immunogenic profiles of antibodies from 3-dose vaccinees, 2-dose vaccinees and convalescents. Better neutralization breadth to VOCs, expeditious recall and long-lasting humoral response bolster 3-dose vaccinees in warding off COVID-19. Analysis of 171 complex structures of SARS-CoV-2 neutralizing antibodies identified structure-activity correlates, revealing ultrapotent, VOCs-refractory and broad-spectrum antigenic patches. Construction of immunogenic and mutational heat maps revealed a direct relationship between "hot" immunogenic sites and areas with high mutation frequencies. Ongoing antibody somatic mutation, memory B cell clonal turnover and antibody composition changes in B cell repertoire driven by prolonged and repeated antigen stimulation confer development of monoclonal antibodies with enhanced neutralizing potency and breadth. Our findings rationalize the use of 3-dose immunization regimens for inactivated vaccines.

Parechoviruses, including Parechovirus A that infects humans as well as Parechovirus B (formerly Ljungan virus) and Parechovirus C (formerly Sebokele virus) that infect rodents, belong to a group of picornaviruses whose 2A proteins, instead of being proteases, contain a conserved H-box and NC-motif and are homologous to a small cellular lipid-modifying enzyme (PLAAT3) that acts as a host factor, enabling the picornavirus life cycle. Despite the common evolutionary origin, 2AH/NC proteins and PLAAT3 have no conserved function, as the active site of the viral proteins cannot support catalysis. Here, we set out to find if all Parechovirus species share the structural rearrangement that destroys the active site configuration of the cellular enzyme. This has revealed a remarkable structural plasticity of these 2AH/NC proteins that arises not only from sequence differences between species, but also from differences in the length of the recombinantly expressed proteins, resulting in large structural rearrangements. These include rerouting of a large internal loop and repositioning of the C-terminal helix with respect to the central β-sheet, and these in turn influence the oligomeric state of the protein. We discuss how this structural plasticity could correlate with the function of these proteins in the viral life cycle and how this could recapitulate the possible evolution of this protein from host factor to viral 2AH/NC protein, with new independent functions in RNA replication. ### Competing Interest Statement The authors have declared no competing interest.

The migration of reducible metal oxides (for example, TiO 2 ) to the surface of metal nanoparticles can inhibit sintering but has a strong negative impact on the catalytic activity. Here we reveal the in situ creation of TiO x patches over an MnO support to generate effective transport channels for hydrogen spillover to form more active hydrogen species on the MnO surface which are responsible for reducing CO 2 to CO, a key reaction for CO 2 conversion to high-value chemicals. The Ru/(TiO x )MnO (Ru/Ti/Mn) catalyst shows a 3.3-fold increase in reverse water-gas shift performance compared with conventional Ru/MnO x catalysts. Through a combination of physicochemical methods, including in situ studies, catalytic and kinetic data, and theoretical modelling, we demonstrate that the oxide–oxide interfaces are spontaneously generated during reductive treatment in H 2 , contributing to the increased activity. The results open perspectives for the design of novel selective hydrogenation catalysts via the in situ creation of oxide–oxide interfaces acting as hydrogen-species transport channels.

Volume 96, no. 9, e00105-22, 2022, https://doi.org/10.1128/jvi.00105-22. Page 11, Acknowledgments: The second paragraph should be replaced with the following: “The research was funded by the Beijing Natural Science Foundation-Haidian Primitive Innovation Joint fund (L192008), Strategic Priority Research Program (XDB29010000, XDB37030000), Chinese Academy of Sciences (YSBR010), National Key Research and Development Program (2018YFA0900801), and National Natural Science Foundation of China (NSFC) (31900873, 12034006). Ling Zhu was supported by the Youth Innovation Promotion Association at the Chinese Academy of Sciences (2019098). Kang Wang is supported by the Special Research Assistant Project of the Chinese Academy of Sciences.”

Echovirus 3 (E3), a serotype of human enterovirus B (HEV-B), causes severe diseases in infants. Here, we determined the structures of E3 with a monoclonal antibody (MAb) 6D10 by cryo-EM to comprehensively understand the specificities and the immunological characteristic of this serotype. The solved cryo-EM structures of the F-, A-, and E-particles of E3 bound with 6D10 revealed the structural features of the virus–antibody interface. Importantly, the structures of E-particles bound with 6D10 revealed for the first time the nature of the C-terminus of VP1 for HEV-Bs at the structural level. The highly immunogenic nature of this region in the E-particles provides new strategies for vaccine development for HEV-Bs.

The glycan loop of Zika virus (ZIKV) envelope protein (E) contains the glycosylation site and has been well documented to be important for viral pathogenesis and transmission. In the present study, we report that deletions in the E glycan loop, which were recorded in African ZIKV strains previously, have re-emerged in their contemporary Asian lineages. Here, we generated recombinant ZIKV containing specific deletions in the E glycan loop by reverse genetics. Extensive in vitro and in vivo characterization of these deletion mutants demonstrated an attenuated phenotype in an adult A129 mouse model and reduced oral infections in mosquitoes. Surprisingly, these glycan loop deletion mutants exhibited an enhanced neurovirulence phenotype, and resulted in a more severe microcephalic brain in neonatal mouse models. Crystal structures of the ZIKV E protein and a deletion mutant at 2.5 and 2.6 angstrom, respectively, revealed that deletion of the glycan loop induces encephalitic flavivirus-like conformational alterations, including the appearance of perforations on the surface and a clear change in the topology of the loops. Overall, our results demonstrate that the E glycan loop deletions represent neonatal mouse neurovirulence markers of ZIKV.IMPORTANCE Zika virus (ZIKV) has been identified as a cause of microcephaly and acquired evolutionary mutations since its discovery. Previously deletions in the E glycan loop were recorded in African ZIKV strains, which have re-emerged in the contemporary Asian lineages recently. The glycan loop deletion mutants are not glycosylated, which are attenuated in adult A129 mouse model and reduced oral infections in mosquitoes. More importantly, the glycan loop deletion mutants induce an encephalitic flavivirus-like conformational alteration in the E homodimer, resulting in a significant enhancement of neonatal mouse neurovirulence. This study underscores the critical role of glycan loop deletion mutants in ZIKV pathogenesis, highlighting a need for global virological surveillance for such ZIKV variants. Zika virus (ZIKV) has been identified as a cause of microcephaly and acquired evolutionary mutations since its discovery. Previously deletions in the E glycan loop were recorded in African ZIKV strains, which have re-emerged in the contemporary Asian lineages recently.

As one of the main serotypes in Enterovirus B, CVB5 has been commonly reported in recent years. The atomic structures of CVB5 shown here revealed classical features found in EV-Bs and the structural rearrangement occurring during particle expansion and uncoating.

Receptor recognition and subsequent membrane fusion are essential for the establishment of successful infection by SARS-CoV-2. Halting these steps can cure COVID-19. Here we have identified and characterized a potent human monoclonal antibody, HB27, that blocks SARS-CoV-2 attachment to its cellular receptor at sub-nM concentrations. Remarkably, HB27 can also prevent SARS-CoV-2 membrane fusion. Consequently, a single dose of HB27 conferred effective protection against SARS-CoV-2 in two established mouse models. Rhesus macaques showed no obvious adverse events when administrated with 10 times the effective dose of HB27. Cryo-EM studies on complex of SARS-CoV-2 trimeric S with HB27 Fab reveal that three Fab fragments work synergistically to occlude SARS-CoV-2 from binding to the ACE2 receptor. Binding of the antibody also restrains any further conformational changes of the receptor binding domain, possibly interfering with progression from the prefusion to the postfusion stage. These results suggest that HB27 is a promising candidate for immuno-therapies against COVID-19.

A Correction to this paper has been published: https://doi.org/10.1038/s41422-021-00501-0

Viral assembly, a key step in any viral life cycle, is a dynamic process driven by genetically programmed sequential morphogenetic reactions involving protein-protein associations and interactions between the viral genome and capsid proteins. A variety of experimental, theoretical, and computational methods have been applied to study viral structures and their assembly. In this perspective, we review the three main strategies employed for viral capsid assembly: (1) self-assembly; (2) scaffolding protein-assisted assembly; and (3) viral genome-assisted assembly. The details of the processes underpinning the three modes of assembly garnered from some well-studied examples of viruses are summarized. A deep understanding of the assembly mechanism could facilitate identification of targets or opportunities for novel antiviral therapies and rationally guide the synthesis of nano-structures and bio-vectors for gene therapies.

SummaryThe onset of sepsis is an important feature of COVID19 and a main cause of death. It is unknown how SARS-CoV-2 infection results in viral sepsis in human. We recently found that SARS-CoV-2 provoked an anti-bacterial like response and activation of TLR4 pathway at the very early stage of infection in animal models. This abnormal immune response led to emergency granulopoiesis and sepsis. However, the original trigger of TLR4 signaling by SARS-CoV-2 is unknown. We here identified that the trimeric spike protein of SARS-CoV-2 could bind to TLR4 directly and robustly activate downstream signaling in monocytes and neutrophils. Moreover, specific TLR4 or NFKB inhibitor, or knockout of MyD88 could significantly block IL-1B induction by spike protein. We thus reveal that spike protein of SARS-CoV-2 functions as a potent stimulus causing TLR4 activation and sepsis related abnormal responses.