Mesoscale DNA feature in antibody-coding sequence facilitates somatic hypermutation.

Somatic hypermutation (SHM), initiated by activation-induced cytidine deaminase (AID), generates mutations in the antibody-coding sequence to allow affinity maturation. Why these mutations intrinsically focus on the three nonconsecutive complementarity-determining regions (CDRs) remains enigmatic. Here, we found that predisposition mutagenesis depends on the single-strand (ss) DNA substrate flexibility determined by the mesoscale sequence surrounding AID deaminase motifs. Mesoscale DNA sequences containing flexible pyrimidine-pyrimidine bases bind effectively to the positively charged surface patches of AID, resulting in preferential deamination activities. The CDR hypermutability is mimicable in in vitro deaminase assays and is evolutionarily conserved among species using SHM as a major diversification strategy. We demonstrated that mesoscale sequence alterations tune the in vivo mutability and promote mutations in an otherwise cold region in mice. Our results show a non-coding role of antibody-coding sequence in directing hypermutation, paving the way for the synthetic design of humanized animal models for optimal antibody discovery and explaining the AID mutagenesis pattern in lymphoma.

Decomposing heritability and genetic covariance by direct and indirect effect paths.

Estimation of heritability and genetic covariance is crucial for quantifying and understanding complex trait genetic architecture and is employed in almost all recent genome-wide association studies (GWAS). However, many existing approaches for heritability estimation and almost all methods for estimating genetic correlation ignore the presence of indirect genetic effects, i.e., genotype-phenotype associations confounded by the parental genome and family environment, and may thus lead to incorrect interpretation especially for human sociobehavioral phenotypes. In this work, we introduce a statistical framework to decompose heritability and genetic covariance into multiple components representing direct and indirect effect paths. Applied to five traits in UK Biobank, we found substantial involvement of indirect genetic components in shared genetic architecture across traits. These results demonstrate the effectiveness of our approach and highlight the importance of accounting for indirect effects in variance component analysis of complex traits.

African swine fever virus infection regulates pyroptosis by cleaving gasdermin A via active caspase-3 and caspase-4.

African swine fever, caused by the African swine fever virus (ASFV), is a viral hemorrhagic disease that affects domestic pigs and wild boars. ASFV infection causes extensive tissue damage, and the associated mechanism is poorly understood. Pyroptosis is characterized by the activation of inflammatory caspases and pore formation in the cellular plasma membrane, resulting in the release of inflammatory cytokines and cell damage. How ASFV infection regulates pyroptosis remains unclear. Here, using siRNA assay and overexpression methods, we report that ASFV infection regulated pyroptosis by cleaving the pyroptosis execution protein gasdermin A (GSDMA). ASFV infection activated caspase-3 and caspase-4, which specifically cleaved GSDMA at D75-P76 and D241-V242 to produce GSDMA into five fragments, including GSDMA-N1-75, GSDMA-N1-241, and GSDMA-N76-241 fragments at the N-terminal end of GSDMA. Only GSDMA-N1-241, which was produced in the late stage of ASFV infection, triggered pyroptosis and inhibited ASFV replication. The fragments, GSDMA-N1-75 and GSDMA-N76-241, lose the ability to induce pyroptosis. Overall ASFV infection differentially regulates pyroptosis by GSDMA in the indicated phase, which may be conducive to its own replication. Our findings reveal a novel molecular mechanism for the regulation of pyroptosis.

Key subphenotypes of bipolar disorder are differentially associated with polygenic liabilities for bipolar disorder, schizophrenia, and major depressive disorder.

Bipolar disorder (BD) features heterogenous clinical presentation and course of illness. It remains unclear how subphenotypes associate with genetic loadings of BD and related psychiatric disorders. We investigated associations between the subphenotypes and polygenic risk scores (PRS) for BD, schizophrenia, and major depressive disorder (MDD) in two BD cohorts from Sweden (N = 5180) and the UK (N = 2577). Participants were assessed through interviews and medical records for inter-episode remission, psychotic features during mood episodes, global assessment of functioning (GAF, function and symptom burden dimensions), and comorbid anxiety disorders. Meta-analyses based on both cohorts showed that inter-episode remission and GAF-function were positively correlated with BD-PRS but negatively correlated with schizophrenia-PRS (SCZ-PRS) and MDD-PRS. Moreover, BD-PRS was negatively, and MDD-PRS positively, associated with the risk of comorbid anxiety disorders. Finally, SCZ-PRS was positively associated with psychotic symptoms during mood episodes. Assuming a higher PRS of certain psychiatric disorders in cases with a positive family history, we further tested the associations between subphenotypes in index BD people and occurrence of BD, schizophrenia, or MDD in their relatives using Swedish national registries. BD patients with a relative diagnosed with BD had: (1) higher GAF and lower risk of comorbid anxiety than those with a relative diagnosed with schizophrenia or MDD, (2) lower risk of psychotic symptoms than those with a relative diagnosed with schizophrenia. Our findings shed light on the genetic underpinnings of the heterogeneity in clinical manifestations and course of illness in BD, which ultimately provide insights for developing personalized approaches to the diagnosis and treatment.

Association of pre-existing depression and anxiety with Omicron variant infection.

Pre-existing psychiatric disorders were linked to an increased susceptibility to COVID-19 during the initial outbreak of the pandemic, while evidence during Omicron prevalence is lacking. Leveraging data from two prospective cohorts in China, we identified incident Omicron infections between January 2023 and April 2023. Participants with a self-reported history or self-rated symptoms of depression or anxiety before the Omicron pandemic were considered the exposed group, whereas the others were considered unexposed. We employed multivariate logistic regression models to examine the association of pre-existing depression or anxiety with the risk of any or severe Omicron infection indexed by medical interventions or severe symptoms. Further, we stratified the analyses by polygenic risk scores (PRSs) for COVID-19 and repeated the analyses using the UK Biobank data. We included 10,802 individuals from the Chinese cohorts (mean age = 51.1 years, 45.6% male), among whom 7841 (72.6%) were identified as cases of Omicron infection. No association was found between any pre-existing depression or anxiety and the overall risk of Omicron infection (odds ratio [OR] =1.04, 95% confidence interval [CI] 0.95-1.14). However, positive associations were noted for severe Omicron infection, either as infections requiring medical interventions (1.26, 1.02-1.54) or with severe symptoms (≥3: 1.73, 1.51-1.97). We obtained comparable estimates when stratified by COVID-19 PRS level. Additionally, using clustering method, we identified eight distinct symptom patterns and found associations between pre-existing depression or anxiety and the patterns characterized by multiple or complex severe symptoms including cough and taste and smell decline (ORs = 1.42-2.35). The results of the UK Biobank analyses corroborated findings of the Chinese cohorts. In conclusion, pre-existing depression and anxiety was not associated with the risk of Omicron infection overall but an elevated risk of severe Omicron infection, supporting the continued efforts on monitoring and possible early intervention in this high-risk population during Omicron prevalence.

African swine fever virus pS273R antagonizes stress granule formation by cleaving the nucleating protein G3BP1 to facilitate viral replication.

Cytoplasmic stress granules (SGs) are generally triggered by stress-induced translation arrest for storing mRNAs. Recently, it has been shown that SGs are regulated by different stimulators including viral infection, which is involved in the antiviral activity of host cells to limit viral propagation. To survive, several viruses have been reported to execute various strategies, such as modulating SG formation, to create optimal surroundings for viral replication. African swine fever virus (ASFV) is one of the most notorious pathogens in the global pig industry. However, the interplay between ASFV infection and SG formation remains largely unknown. In this study, we found that ASFV infection inhibited SG formation. Through SG inhibitory screening, we found that several ASFV-encoded proteins are involved in inhibition of SG formation. Among them, an ASFV S273R protein (pS273R), the only cysteine protease encoded by the ASFV genome, significantly affected SG formation. ASFV pS273R interacted with G3BP1 (Ras-GTPase-activating protein [SH3 domain] binding protein 1), a vital nucleating protein of SG formation. Furthermore, we found that ASFV pS273R cleaved G3BP1 at the G140-F141 to produce two fragments (G3BP1-N1-140 and G3BP1-C141-456). Interestingly, both the pS273R-cleaved fragments of G3BP1 lost the ability to induce SG formation and antiviral activity. Taken together, our finding reveals that the proteolytic cleavage of G3BP1 by ASFV pS273R is a novel mechanism by which ASFV counteracts host stress and innate antiviral responses.

Clinical outcome and peripheral immune profile of myasthenic crisis with omicron infections: A prospective cohort study.

The impact of Omicron infections on the clinical outcome and immune responses of myasthenia gravis (MG) remained largely unknown. From a prospective multicenter MG cohort (n = 189) with 197 myasthenic crisis (MC), we finally included 41 independent MG patients to classify into two groups: the Omicron Group (n = 13) and the Control Group (n = 28). In this matched cohort study, all-cause mortality was 7.69% (1/13) in Omicron Group and 14.29% (4/28) in Control Group. A higher proportion of elevated serum IL-6 was identified in the Omicron Group (88.89% vs 52.38%, P = 0.049). In addition, the proportions of CD3+CD8+T in lymphocytes and Tregs in CD3+CD4+ T cells were significantly elevated in the Omicron Group (both P = 0.0101). After treatment, the Omicron Group exhibited a marked improvement in MG-ADL score (P = 0.026) and MG-QoL-15 (P = 0.0357). MCs with Omicron infections were associated with elevated serum IL-6 and CD3+CD8+T response. These patients tended to present a better therapeutic response after fast-acting therapies and anti-IL-6 treatment.

Identification of quantitative trait loci associated with leaf rust resistance in rye by precision mapping.

BACKGROUND: Leaf rust (LR) is among the most destructive fungal diseases of rye (Secale cereale L.). Despite intensive research using various analytical and methodological approaches, such as quantitative trait locus (QTL) mapping, candidate gene expression analysis, and transcriptome sequencing, the genetic basis of the rye immune response to LR remains unclear. RESULTS: A genome-wide association study was employed to detect QTLs controlling the immune response to LR of rye. A mapping population, G38A, was constructed by crossing two inbred lines: 723 (susceptible to LR) and JKI-NIL-Pr3 (a donor of the LR resistance gene Pr3). For genotyping, SNP-DArT and silico-DArT markers were used. Resistance phenotyping was conducted by visual assessment of the infection severity in detached leaf segments inoculated with two isolates of Puccinia recondita f. sp. secalis, namely, 60/17/2.1 (isolate S) in the main experiment and 86/n/2.1_5x (isolate N) in the validation experiment, at 10 and 17 days post-infection (dpi), respectively. In total, 42,773 SNP-DArT and 105,866 silico-DArT markers were included in the main analysis including isolate S, of which 129 and 140 SNP-DArTs and 767 and 776 silico-DArTs were significantly associated (p ≤ 0.001; - log10(p) ≥ 3.0) with the immune response to LR at 10 and 17 dpi, respectively. Most significant markers were mapped to chromosome 1R. The number of common markers from both systems and at both time points occupying common chromosomal positions was 37, of which 21 were positioned in genes, comprising 18 markers located in exons and three in introns. This gene pool included genes encoding proteins with a known function in response to LR (e.g., a NBS-LRR disease resistance protein-like protein and carboxyl-terminal peptidase). CONCLUSION: This study has expanded and supplemented existing knowledge of the genetic basis of rye resistance to LR by (1) detecting two QTLs associated with the LR immune response of rye, of which one located on the long arm of chromosome 1R is newly detected, (2) assigning hundreds of markers significantly associated with the immune response to LR to genes in the 'Lo7' genome, and (3) predicting the potential translational effects of polymorphisms of SNP-DArT markers located within protein-coding genes.

Development and identification of a novel wheat-Thinopyrum ponticum disomic substitution line DS5Ag(5D) with new genes conferring resistance to powdery mildew and leaf rust.

BACKGROUND: Powdery mildew (caused by Blumeria graminis f. sp. tritici (Bgt)) and leaf rust (caused by Puccinia triticina (Pt)) are prevalent diseases in wheat (Triticum aestivum L.) production. Thinopyrum ponticum (2n = 10x = 70, EeEeEbEbExExStStStSt) contains genes that confer high levels of resistance to these diseases. RESULTS: An elite wheat-Th. ponticum disomic substitution line, DS5Ag(5D), was developed in the Bainong Aikang 58 (AK58) background. The line was assessed using genomic in situ hybridization (GISH), oligo-nucleotide probe multiplex (ONPM) fluorescence in situ hybridization (FISH), and molecular markers. Twenty eight chromosome-specific molecular markers were identified for the alien chromosome, and 22 of them were co-dominant. Additionally, SNP markers from the wheat 660 K SNP chip were utilized to confirm chromosome identification and they provide molecular tools for tagging the chromosome in concern. The substitution line demonstrated high levels of resistance to powdery mildew throughout its growth period and to leaf rust at the adult stage. Based on the resistance evaluation of five F5 populations between the substitution lines and wheat genotypes with different levels of sensitivity to the two diseases. Results showed that the resistance genes located on 5Ag confered stable resistance against both diseases across different backgrounds. Resistance spectrum analysis combined with diagnostic marker detection of known resistance genes of Th. ponticum revealed that 5Ag contained two novel genes, Pm5Ag and Lr5Ag, which conferred resistance to powdery mildew and leaf rust, respectively. CONCLUSIONS: In this study, a novel wheat-Th. ponticum disomic substitution line DS5Ag(5D) was successfully developed. The Th. ponticum chromosome 5Ag contain new resistance genes for powdery mildew and leaf rust. Chromosomic-specific molecular markers were generated and they can be used to track the 5Ag chromosome fragments. Consequently, this study provides new elite germplasm resources and molecular markers to facilitate the breeding of wheat varieties that is resistant to powdery mildew and leaf rust.

The association of psychological and trauma-related factors with biological and facial aging acceleration: evidence from the UK Biobank.

BACKGROUND: Psychological and trauma-related factors are associated with many diseases and mortality. However, a comprehensive assessment of the association between psycho-trauma exposures and aging acceleration is currently lacking. METHODS: Using data from 332,359 UK Biobank participants, we calculated biological aging acceleration, indexed by the presence of leukocyte telomere length (LTL) deviation (i.e., the difference between genetically determined and observed LTL > 0). The acceleration of facial aging (i.e., looking older than the chronological age) was assessed using a self-report question. Then, we estimated the associations of each psycho-trauma factor with biological and facial aging acceleration, using logistic regression models adjusted for multiple important covariates. Furthermore, restricted to 99,180 participants with complete psychological and trauma-related data, we identified clusters of individuals with distinct psycho-trauma patterns using the latent class analysis method and assessed their associations with aging acceleration using similar models. RESULTS: We observed most of the studied psycho-trauma factors were associated with biological and facial aging acceleration. Compared to the "Absence of trauma and psychopathology" cluster, the "adverse childhood experiences (ACEs) with psychopathology" cluster showed strong associations with those aging measurements (odds ratio [OR] = 1.13 [1.05 - 1.23] for biological and 1.52 [1.18 - 1.95] for facial aging acceleration), while no such association was observed for the "ACEs without psychopathology" cluster (1.04 [0.99 - 1.09] and 1.02 [0.84 - 1.24]. CONCLUSIONS: Our study demonstrated significant associations of psycho-trauma factors with both biological and facial aging acceleration. The differential aging consequences observed among ACEs exposed individuals with and without psychopathology prompt interventions aimed to improve individuals' psychological resilience to prevent aging acceleration.

Electrochemical Activation Inducing Rocksalt-to-Spinel Transformation for Prolonged Service Life of LiMn2O4 Cathodes.

LiMn2O4 spinel is emerging as a promising cathode material for lithium-ion batteries, largely due to its open framework that facilitates Li+ diffusion and excellent rate performance. However, the charge-discharge cycling of the LiMn2O4 cathode leads to severe structural degradation and rapid capacity decay. Here, an electrochemical activation strategy is introduced, employing a facile galvano-potentiostatic charging operation, to restore the lost capacity of LiMn2O4 cathode without damaging the battery configuration. With an electrochemical activation strategy, the cycle life of the LiMn2O4 cathode is extended from an initial 1500 to an impressive 14 000 cycles at a 5C rate with Li metal as the anode, while increasing the total discharge energy by ten times. Remarkably, the electrochemical activation enhances the diffusion kinetics of Li+, with the diffusion coefficient experiencing a 37.2% increase. Further investigation reveals that this improvement in capacity and diffusion kinetics results from a transformation of the redox-inert LiMnO2 rocksalt layer on the surface of degraded cathodes back into active spinel. This transformation is confirmed through electron microscopy and corroborated by density functional theory simulations. Moreover, the viability of this electrochemical activation strategy has been demonstrated in pouch cell configurations with Li metal as the anode, underscoring its potential for broader application.

Development of a new effective African swine fever virus vaccine candidate by deletion of the H240R and MGF505-7R genes results in protective immunity against the Eurasia strain.

IMPORTANCE: African swine fever (ASF) caused by ASF virus (ASFV) is a highly contagious and acute hemorrhagic viral disease in domestic pigs. Until now, no effective commercial vaccine and antiviral drugs are available for ASF control. Here, we generated a new live-attenuated vaccine candidate (ASFV-ΔH240R-Δ7R) by deleting H240R and MGF505-7R genes from the highly pathogenic ASFV HLJ/18 genome. Piglets immunized with ASFV-ΔH240R-Δ7R were safe without any ASF-related signs and produced specific antibodies against p30. Challenged with a virulent ASFV HLJ/18, the piglets immunized with high-dose group (105 HAD50) exhibited 100% protection without clinical symptoms, showing that low levels of virus replication with no observed pathogenicity by postmortem and histological analysis. Overall, our results provided a new strategy by designing live-attenuated vaccine candidate, resulting in protection against ASFV infection.

Combined genome and transcriptome provides insight into the genetic evolution of an edible halophyte Suaeda salsa adaptation to high salinity.

Suaeda salsa L. is a typical halophyte with high value as a vegetable. Here, we report a 447.98 Mb, chromosomal-level genome of S. salsa, assembled into nine pseudomolecules (contig N50 = 1.36 Mb) and annotated with 27,927 annotated protein-coding genes. Most of the assembled S. salsa genome, 58.03%, consists of transposable elements. Some gene families including HKT1, NHX, SOS and CASP related to salt resistance were significantly amplified. We also observed expansion of genes encoding protein that bind the trace elements Zn, Fe, Cu and Mn, and genes related to flavonoid and α-linolenic acid metabolism. Many expanded genes were significantly up-regulated under salinity, which might have contributed to the acquisition of salt tolerance in S. salsa. Transcriptomic data showed that high salinity markedly up-regulated salt-resistance related genes, compared to low salinity. Abundant metabolic pathways of secondary metabolites including flavonoid, unsaturated fatty acids and selenocompound were enriched, which indicates that the species is a nutrient-rich vegetable. Particularly worth mentioning is that there was no significant difference in the numbers of cis-elements in the promoters of salt-related and randomly selected genes in S. salsa when compared with Arabidopsis thaliana, which may affirm that plant salt tolerance is a quantitative rather than a qualitative trait in terms of promoter evolution. Our findings provide deep insight into the adaptation of halophytes to salinity from a genetic evolution perspective.

Three-state coherent control using narrowband and passband sequences.

In this work, we propose a comprehensive design for narrowband and passband composite pulse sequences by involving the dynamics of all states in the three-state system. The design is quite universal as all pulse parameters can be freely employed to modify the coefficients of error terms. Two modulation techniques, the strength and phase modulations, are used to achieve arbitrary population transfer with a desired excitation profile, while the system keeps minimal leakage to the third state. Furthermore, the current sequences are capable of tolerating inaccurate waveforms, detuning errors, and work well when rotating wave approximation is not strictly justified. Therefore, this work provides versatile adaptability for shaping various excitation profiles in both narrowband and passband sequences.

Research on the tilt-to-length coupling noise suppression method inside the gravitational wave detection telescope.

As an integral component of the laser interferometry measurement system, the tilt-to-length (TTL) coupling noise inside the telescope stands out as a critical noise factor that requires meticulous consideration. In the TianQin project, the non-geometric TTL-coupled noise inside the telescope should be less than 0.22 pm/Hz1/2. Additionally, the wavefront aberration RMS at the small pupil of the telescope needs to be better than 0.0065 λ. These requirements set for the telescope are exceptionally stringent. To address this challenge, this study aims to relax the wavefront aberration requirements by mitigating non-geometric TTL coupling noise, while ensuring the non-geometric TTL coupling noise remains below 0.22 pm/Hz1/2. By controlling the coupling aberration proportion, the wavefront aberration RMS at the small pupil of the telescope can be relaxed to 0.014 λ. Alternatively, optimizing the Gaussian beam waist radius can relax the wavefront aberration RMS to 0.016 λ. By simultaneously utilizing two optimization methods, the wavefront aberration at the small pupil of the telescope can be reduced to 0.033 λ, resulting in an impressive success rate of 91.15% in meeting the noise requirements.

Engineering dynamical photon blockade with Liouville exceptional points.

We investigate the dynamical blockade in a nonlinear cavity and demonstrate the connection between the correlation function g(2)(t) and system parameters in the entire nonlinear region. Utilizing the Liouville exceptional points (LEPs) and quantum dynamics, a near-perfect single-photon blockade (1PB) can be achieved. By fine-tuning system parameters to approach the second-order LEP (LEP2), we improved single-photon statistics in both weak and strong nonlinearity regimes, including a significant reduction of g(2)(t) and a pronounced increase in the single-photon occupation number. In the strong nonlinearity region, the maximum photon population may correspond to stronger antibunching effect. Simultaneously, the time window and period of blockade can be controlled by selecting detuning based on the LEP2. Furthermore, the 1PB exhibits robustness against parameter fluctuations, and this feature can be generalized to systems for implementing single-photon sources with nonharmonic energy levels.

Osmapentalenofurans Constructed by Reacting Os≡C1 of Osmapentalyne with Phenols.

Over the past decade, significant research efforts have focused on osmapentalyne, characterized by the more reactive Os≡C7 (Carbon atoms numbered in a clockwise direction on the osmapentalyne skeleton), across areas encompassing electrophilic, nucleophilic, and addition reactions. Nevertheless, the reactivity of osmapentalyne featuring Os≡C1 remains ripe for further exploration. In this investigation, we effectively synthesized a lineage of osmapentalenofurans through the nucleophilic reaction of osmapentalyne incorporating Os≡C1 with phenols. These resulting complexes demonstrate near-infrared luminescence traits in both solid and liquid states. Particularly noteworthy is the osmapentalenofuran derived from tetraphenylethane (TPE) unit, which showcases remarkable aggregation-induced emission ( AIE) property in the aggregated state. These osmapentalenofurans are also able to further extend their range of reactions, including reactions with base and isonitrile. This study not only broadens the scope of applications for metal aromatics but also furnishes valuable insights into the realm of specialized functional materials.

Permeation characteristics and cross-linking efficacy of iontophoresis-assisted riboflavin delivery for accelerated riboflavin-ultraviolet A scleral collagen cross-linking in porcine eyes.

The purpose of this study is to investigate whether the iontophoresis-assisted riboflavin delivery to posterior sclera with less delivery time, can achieve the same riboflavin permeation efficiency as the passive soaking way, and its effect on the mechanical properties of posterior sclera for accelerated scleral collagen cross-linking (A-SXL). In this study, 0.1% riboflavin solution was applied into the posterior sclera of porcine eyes either by the iontophoresis-assisted or passive soaking method, with delivery time of 5, 7.5, 10, 12.5, 15, 17.5, and 20 min, respectively. The fluorescence intensity and the distribution of riboflavin concentration in the 10 µm frozen sections of the sclera were evaluated by fluorescence inverted microscope. The posterior sclera with riboflavin treatment through either the iontophoresis-assisted or the passive soaking method for different durations ranging from 5 to 20 min was treated with ultraviolet A (UVA) irradiation at an intensity of 10 mW/cm2 for 9 min. The elastic modulus was determined at the physiological strain level using the uniaxial tensile test after ASXL. The results showed that the fluorescence intensity of riboflavin increased by prolonging the delivery time in both the iontophoresis and passive soaking groups, and the permeation depth of riboflavin remained constant over 15 min. The fluorescence intensity in the iontophoresis group was significantly higher than in the passive soaking group at 12.5 min and 15 min, respectively. The elastic modulus at 12.5 min in the iontophoresis group was significantly higher than in the passive soaking group at the same delivery time and showed no significant difference compared to the passive soaking group at 20 min. In conclusion, it indicated that iontophoresis-assisted delivery could not only shorten the surgery time but also achieve similar mechanical performance to the passive soaking method in ASXL.

Cleavage of Stau2 by 3C protease promotes EV-A71 replication.

BACKGROUND: Enterovirus A71 (EV-A71), as a neurotropic virus, mainly affects infants and young children under the age of 5. EV-A71 infection causes hand-foot-mouth disease and herpetic angina, and even life-threatening neurological complications. However, the molecular mechanism by which EV-A71 induces nervous system damage remains elusive. The viral protease 3C plays an important role during EV-A71 infection and is also a key intersection of virus-host interactions. Previously, we used yeast two-hybrid to screen out the host protein Double-stranded RNA-binding protein Staufen homolog 2 (Stau2), an important member involved in neuronal mRNA transport, potentially interacts with 3C. METHODS: We used coimmunoprecipitation (Co-IP) and immunofluorescence assay (IFA) to confirm that EV-A71 3C interacts with Stau2. By constructing the mutant of Stau2, we found the specific site where the 3C protease cleaves Stau2. Detection of VP1 protein using Western blotting characterized EV-A71 viral replication, and overexpression or knockdown of Stau2 exhibited effects on EV-A71 replication. The effect of different cleavage products on EV-A71 replication was demonstrated by constructing Stau2 truncates. RESULTS: In this study, we found that EV-A71 3C interacts with Stau2. Stau2 is cleaved by 3C at the Q507-G508 site. Overexpression of Stau2 promotes EV-A71 VP1 protein expression, whereas depletion of Stau2 by small interfering RNA inhibits EV-A71 replication. Stau2 is essential for EV-A71 replication, and the product of Stau2 cleavage by 3C, 508-570 aa, has activity that promotes EV-A71 replication. In addition, we found that mouse Stau2 is also cleaved by EV-A71 3C at the same site. CONCLUSIONS: Our research provides an example for EV-A71-host interaction, enriching key targets of host factors that contribute to viral replication.

MST1/2 exerts a pivotal role in inducing neuroinflammation and Coxsackievirus-A10 replication by interacting with innate immunity.

Coxsackievirus-A10 (CV-A10), responsible for the hand, foot and mouth disease (HFMD) pandemic, could cause serious central nervous system (CNS) complications. The underlying molecular basis of CV-A10 and host interactions inducing neuropathogenesis is still unclear. The Hippo signaling pathway, historically known for a dominator of organ development and homeostasis, has recently been implicated as an immune regulator. However, its role in host defense against CV-A10 has not been investigated. Herein, it was found that CV-A10 proliferated in HMC3 cells and promoted the release of inflammatory cytokines. Moreover, pattern recognition receptors (PRRs)-mediated pathways, including TLR3-TRIF-TRAF3-TBK1-NF-κB axis, RIG-I/MDA5-MAVS-TRAF3-TBK1-NF-κB axis and TLR7-MyD88-IRAK1/IRAK4-TRAF6-TAK1-NF-κB axis, were examined to be elevated under CV-A10 infection. Meanwhile, it was further uncovered that Hippo signaling pathway was inhibited in HMC3 cells with CV-A10 infection. Previous studies have been reported that there exist complex relations between innate immune and Hippo signaling pathway. Then, plasmids of knockdown and overexpression of MST1/2 were transfected into HMC3 cells. Our results showed that MST1/2 suppressed the levels of inflammatory cytokines via interacting with TBK1 and IRAK1, and also enhanced virus production via restricting IRF3 and IFN-ß expressions. Overall, these data obviously pointed out that CV-A10 accelerated the formation of neuroinflammation by the effect of the Hippo pathway on the PRRs-mediated pathway, which delineates a negative immunoregulatory role for MST1/2 in CV-A10 infection and the potential for this pathway to be pharmacologically targeted to treat CV-A10.