Evolution, recombination and geographic spreading of global Coxsackievirus A6.

BACKGROUND: The increasing incidence of hand, foot, and mouth disease (HFMD) associated with Coxsackievirus A6 (CVA6) has become a very significant public health problem. The aim of this study is to investigate the recombination, geographic transmission, and evolutionary characteristics of the global CVA6. METHODS: From 2019 to 2022, 73 full-length CVA6 sequences were obtained from HFMD patients in China and analyzed in combination with 1032 published whole genome sequences. Based on this dataset, the phylogenetic features, recombinant diversity, Bayesian phylodynamic characteristics, and key amino acid variations in CVA6 were analyzed. RESULTS: The four genotypes of CVA6, A, D, E, and F, are divided into 24 recombinant forms (RFs, RF-A - RF-X) based on differences in the P3 coding region. The eastern China region plays a key role in the dissemination of CVA6 in China. VP1-137 and VP1-138 are located in the DE loop on the surface of the CVA6 VP1 protein, with the former being a highly variable site and the latter having more non-synonymous substitutions. CONCLUSIONS: Based on whole genome sequences, this study contributes to the CVA6 monitoring, early warning, and the pathogenic mechanism by studying recombination diversity, geographical transmission characteristics, and the variation of important amino acid sites.

Identification and genetic characterization of a recently identified enterovirus C116 in China.

Enterovirus C116 (EV-C116) is a new member of the enterovirus C group which is closely associated with several infectious diseases. Although sporadic studies have detected EV-C116 in clinical samples worldwide, there is currently limited information available. In this study, two EV-C-positive fecal specimens were detected in apparently healthy children, which harbored low abundance, through meta-transcriptome sequencing. Based on the prototypes of several EV-Cs, two lineages were observed. Lineage 1 included many types that could not cause EV-like cytopathic effect in cell culture. Three genogroups of EV-C116 were divided in the maximum likelihood tree, and the two strains in this study (XZ2 and XZ113) formed two different lineages, suggesting that EV-C116 still diffuses worldwide. Obvious inter-type recombination events were observed in the XZ2 strain, with CVA22 identified as a minor donor. However, another strain (XZ113) underwent different recombination situations, highlighting the importance of recombination in the formation of EV-Cs biodiversity. The EV-C116 strains could propagate in rhabdomyosarcoma cell cultures at low titer; however, EV-like cytopathic effects were not observed. HEp-2, L20B, VERO, and 293T cell lines did not provide an appropriate environment for EV-C116 growth. These results challenge the traditional recognition of the uncultured nature of EV-C116 strains and explain the difficulty of clinical detection.

Genetic characterization and molecular epidemiological analysis of enterovirus C99 in China.

Enterovirus C99 (EV-C99) is a newly identified EV serotype within the species Enterovirus C. Few studies on EV-C99 have been conducted globally. More information and research on EV-C99 are needed to assess its genetic characteristics, phylogenetic relationships, and associations with enteroviral diseases. Here, the phylogenetic characteristics of 11 Chinese EV-C99 strains have been reported. The full-length genomic sequences of these 11 strains show 79.4-80.5% nucleotide identity and 91.7-94.3% amino acid (aa) identity with the prototype EV-C99. A maximum likelihood phylogenetic tree constructed based on the entire VP1 coding region identified 13 genotypes (A-M), revealing a high degree of variation among the EV-C99 strains. Phylogeographic analysis showed that the Xinjiang Uygur Autonomous Region is an important source of EV-C99 epidemics in various regions of China. Recombination analysis revealed inter-serotype recombination events of 16 Chinese EV-C99 strains in 5' untranslated regions and 3D regions, resulting in the formation of a single recombination form. Additionally, the Chinese strain of genotype J showed rich aa diversity in the P1 region, indicating that the genotype J of EV-C99 is still going through variable dynamic changes. This study contributes to the global understanding of the EV-C99 genome sequence and holds substantial implications for the surveillance of EV-C99.

Genotype F of Echovirus 25 with multiple recombination pattern have been persistently and extensively circulating in Chinese mainland.

Echovirus 25 (E25), a member of the Enterovirus B (EV-B) species, can cause aseptic meningitis (AM), viral meningitis (VM), and acute flaccid paralysis (AFP). However, systematic studies on the molecular epidemiology of E25, especially those concerning its evolution and recombination, are lacking. In this study, 18 strains of E25, isolated from seven provinces of China between 2009 and 2018, were collected based on the Chinese hand, foot, and mouth disease (HFMD) surveillance network, and 95 sequences downloaded from GenBank were also screened. Based on the phylogenetic analysis of 113 full-length VP1 sequences worldwide, globally occurring E25 strains were classified into 9 genotypes (A-I), and genotype F was the dominant genotype in the Chinese mainland. The average nucleotide substitution rate of E25 was 6.08 × 10-3 substitutions/site/year, and six important transmission routes were identified worldwide. Seventeen recombination patterns were determined, of which genotype F can be divided into 9 recombination patterns. A positive selector site was found in the capsid protein region of genotype F. Recombination analysis and pressure selection analysis for genotype F showed multiple recombination patterns and evolution characteristics, which may be responsible for it being the dominant genotype in the Chinese mainland. This study provides a theoretical basis for the subsequent prevention and control of E25.

Characterizing enterovirus C96 genome and phylodynamics analysis.

Enterovirus C96 (EV-C96) is a recently discovered serotype belonging to enterovirus C species. It had been isolated from patients with acute flaccid paralysis, hand, foot, and mouth disease, diarrhea, healthy people, or environmental specimens. Despite increasing reports of the virus, the small number of full-length genomes available for EV-C96 has limited molecular epidemiological studies. In this study, newly collected rare EV-C96 strains in China from 1997 to 2020 were combined with sequences available in GenBank for comprehensive analyses. Sequence analysis revealed that the nucleotide sequence similarity of EV-C96 and the prototype strain (BAN00-10488) was 75%-81.8% and the amino acid sequence similarity was 85%-94.9%. EV-C96 had a high degree of genetic variation and could be divided into 15 genogroups. The mean evolutionary rate was 5.16 × 10-3 substitution/site/year, and the most recent common ancestor was dated to 1925. A recombination analysis revealed that EV-C96 may be a recombinant derived from other serotypes in the EV-C group in the nonstructural protein coding region. This comprehensive and integrated analysis of the whole genome sequence of EV-C96 provides valuable data for further studies on the molecular epidemiology of EV-C96 worldwide.

Molecular Epidemiology and Evolution of Coxsackievirus A14.

As the proportion of non-enterovirus 71 and non-coxsackievirus A16 which proportion of composition in the hand, foot, and mouth pathogenic spectrum gradually increases worldwide, the attention paid to other enteroviruses has increased. As a member of the species enterovirus A, coxsackievirus A14 (CVA14) has been epidemic around the world until now since it has been isolated. However, studies on CVA14 are poor and the effective population size, evolutionary dynamics, and recombination patterns of CVA14 are not well understood. In this study, 15 CVA14 strains were isolated from HFMD patients in mainland China from 2009 to 2019, and the complete sequences of CVA14 in GenBank as research objects were analyzed. CVA14 was divided into seven genotypes A-G based on an average nucleotide difference of the full-length VP1 coding region of more than 15%. Compared with the CVA14 prototype strain, the 15 CVA14 strains showed 84.0-84.7% nucleotide identity in the complete genome and 96.9-97.6% amino acid identity in the encoding region. Phylodynamic analysis based on 15 CVA14 strains and 22 full-length VP1 sequences in GenBank showed a mean substitution rate of 5.35 × 10-3 substitutions/site/year (95% HPD: 4.03-6.89 × 10-3) and the most recent common ancestor (tMRCA) of CVA14 dates back to 1942 (95% HPD: 1930-1950). The Bayesian skyline showed that the effective population size had experienced a decrease-increase-decrease fluctuation since 2004. The phylogeographic analysis indicated two and three possible migration paths in the world and mainland China, respectively. Four recombination patterns with others of species enterovirus A were observed in 15 CVA14 strains, among which coxsackievirus A2 (CVA2), coxsackievirus A4 (CVA4), coxsackievirus A6 (CVA6), coxsackievirus A8 (CVA8), and coxsackievirus A12 (CVA12) may act as recombinant donors in multiple regions. This study has filled the gap in the molecular epidemiological characteristics of CVA14, enriched the global CVA14 sequence database, and laid the epidemiological foundation for the future study of CVA14 worldwide.

Aromatized liposomes for sustained drug delivery.

Insufficient drug loading and leakage of payload remain major challenges in designing liposome-based drug delivery systems. These phenomena can limit duration of effect and cause toxicity. Targeting the rate-limiting step in drug release from liposomes, we modify (aromatized) them to have aromatic groups within their lipid bilayers. Aromatized liposomes are designed with synthetic phospholipids with aromatic groups covalently conjugated onto acyl chains. The optimized aromatized liposome increases drug loading and significantly decreases the burst release of a broad range of payloads (small molecules and macromolecules, different degrees of hydrophilicity) and extends their duration of release. Aromatized liposomes encapsulating the anesthetic tetrodotoxin (TTX) achieve markedly prolonged effect and decreased toxicity in an application where liposomes are used clinically: local anesthesia, even though TTX is a hydrophilic small molecule which is typically difficult to encapsulate. Aromatization of lipid bilayers can improve the performance of liposomal drug delivery systems.

Self-assembly of CXCR4 antagonist peptide-docetaxel conjugates for breast tumor multi-organ metastasis inhibition.

As a representative chemotherapeutic drug, docetaxel (DTX) has been used for breast cancer treatment for decades. However, the poor solubility of DTX limits its efficacy, and the DTX based therapy increases the metastasis risk due to the upregulation of C-X-C chemokine receptor type 4 (CXCR4) expression during the treatment. Herein, we conjugated CXCR4 antagonist peptide (CTCE) with DTX (termed CTCE-DTX) as an anti-metastasis agent to treat breast cancer. CTCE-DTX could self-assemble to nanoparticles, targeting CXCR4-upregulated metastatic tumor cells and enhancing the DTX efficacy. Thus, the CTCE-DTX NPs achieved promising efficacy on inhibiting both bone-specific metastasis and lung metastasis of triple-negative breast cancer. Our work provided a rational strategy on designing peptide-drug conjugates with synergistic anti-tumor efficacy.

Specific interaction based drug loading strategies.

Drug carriers have been commonly used for drug control release, enhancing drug efficacy and/or minimizing side-effects. However, it is still difficult to get a high loading efficiency when encapsulating super hydrophilic drugs with a narrow therapeutic index, such as many neurotoxins. Increasing the carrier proportion can improve drug loading to a certain degree, while the burst released drug when the formulation enters the body may cause overdose side-effects. Moreover, high-dose carriers themselves may increase the metabolic burden of the body. Hence, new drug carriers and/or loading strategies are urgently needed to promote the applications of these drugs. This minireview will introduce drug loading strategies based on specific interactions (between drugs and carriers) and will discuss the challenges and perspectives of these strategies. This work is expected to provide alternative inspiration for the delivery of hydrophilic drugs.

A Synthetic SARS-CoV-2-Derived T-Cell and B-Cell Peptide Cocktail Elicits Full Protection against Lethal Omicron BA.1 Infection in H11-K18-hACE2 Mice.

Emerging variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been developing the capacity for immune evasion and resistance to existing vaccines and drugs. To address this, development of vaccines against coronavirus disease 2019 (COVID-19) has focused on universality, strong T cell immunity, and rapid production. Synthetic peptide vaccines, which are inexpensive and quick to produce, show low toxicity, and can be selected from the conserved SARS-CoV-2 proteome, are promising candidates. In this study, we evaluated the effectiveness of a synthetic peptide cocktail containing three murine CD4+ T-cell epitopes from the SARS-CoV-2 nonspike proteome and one B-cell epitope from the Omicron BA.1 receptor-binding domain (RBD), along with aluminum phosphate (Al) adjuvant and 5' cytosine-phosphate-guanine 3' oligodeoxynucleotide (CpG-ODN) adjuvant in mice. The peptide cocktail induced good Th1-biased T-cell responses and effective neutralizing-antibody titers against the Omicron BA.1 variant. Additionally, H11-K18-hACE2 transgenic mice were fully protected against lethal challenge with the BA.1 strain, with a 100% survival rate and reduced pulmonary viral load and pathological lesions. Subcutaneous administration was found to be the superior route for synthetic peptide vaccine delivery. Our findings demonstrate the effectiveness of the peptide cocktail in mice, suggesting the feasibility of synthetic peptide vaccines for humans. IMPORTANCE Current vaccines based on production of neutralizing antibodies fail to prevent the infection and transmission of SARS-CoV-2 Omicron and its subvariants. Understanding the critical factors and avoiding the disadvantages of vaccine strategies are essential for developing a safe and effective COVID-19 vaccine, which would include a more effective and durable cellular response, minimal effects of viral mutations, rapid production against emerging variants, and good safety. Peptide-based vaccines are an excellent alternative because they are inexpensive, quick to produce, and very safe. In addition, human leukocyte antigen T-cell epitopes could be targeted at robust T-cell immunity and selected in the conserved region of the SARS-CoV-2 variants. Our study showed that a synthetic SARS-CoV-2-derived peptide cocktail induced full protection against lethal infection with Omicron BA.1 in H11-K18-hACE2 mice for the first time. This could have implications for the development of effective COVID-19 peptide vaccines for humans.

A Beta Strain-Based Spike Glycoprotein Vaccine Candidate Induces Broad Neutralization and Protection against SARS-CoV-2 Variants of Concern.

The coronavirus disease 2019 (COVID-19) pandemic is still ongoing. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOCs) are circulating worldwide, making it resistant to existing vaccines and antiviral drugs. Therefore, the evaluation of variant-based expanded spectrum vaccines to optimize the immune response and provide broad protectiveness is very important. In this study, we expressed spike trimer protein (S-TM) based on the Beta variant in a GMP-grade workshop using CHO cells. Mice were immunized twice with S-TM protein combined with aluminum hydroxide (Al) and CpG Oligonucleotides (CpG) adjuvant to evaluate its safety and efficacy. BALB/c immunized with S-TM + Al + CpG induced high neutralizing antibody titers against the Wuhan-Hu-1 strain (wild-type, WT), the Beta and Delta variants, and even the Omicron variant. In addition, compared with the S-TM + Al group, the S-TM + Al + CpG group effectively induced a stronger Th1-biased cell immune response in mice. Furthermore, after the second immunization, H11-K18 hACE2 mice were well protected from challenge with the SARS-CoV-2 Beta strain, with a 100% survival rate. The virus load and pathological lesions in the lungs were significantly reduced, and no virus was detected in mouse brain tissue. Our vaccine candidate is practical and effective for current SARS-CoV-2 VOCs, which will support its further clinical development for potential sequential immune and primary immunization. IMPORTANCE Continuous emergence of adaptive mutations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to challenge the use and development of existing vaccines and drugs. The value of variant-based vaccines that are capable of inducing a higher and broader protection immune response against SARS-CoV-2 variants is currently being evaluated. This article shows that a recombinant prefusion spike protein based on a Beta variant was highly immunogenic and could induced a stronger Th1-biased cell immune response in mice and was effectively protective against challenge with the SARS-CoV-2 Beta variant. Importantly, this Beta-based SARS-CoV-2 vaccine could also offer a robust humoral immune response with effectively broad neutralization ability against the wild type and different variants of concern (VOCs): the Beta, Delta, and Omicron BA.1 variants. To date, the vaccine described here has been produced in a pilot scale (200L), and the development, filling process, and toxicological safety evaluation have also been completed, which provides a timely response to the emerging SARS-CoV-2 variants and vaccine development.

Programmed initiation and enhancement of cGAS/STING pathway for tumour immunotherapy via tailor-designed ZnFe2O4-based nanosystem.

The cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS)/stimulator of interferon genes (STING) signalling pathway has been a promising target for anticancer immunity, but rationally activating and enhancing this pathway in tumour cells is critical. Herein, a glutathione sensitive ZnFe2O4-based nanosystem is developed to programmatically initiate and enhance the STING signalling pathway in tumour cells. The prepared ZnFe2O4 nanoparticles were coated with cancer cell membrane (CCM), which enabled the nanosystem target tumour cells. In tumour cells, ZnFe2O4 nanoparticles could be disintegrated by responding to high level glutathione, and the released Fe3+ generated reactive oxygen species to induce the DNA leakage into the cytoplasm to stimulate cGAS. Then Zn2+ promoted cGAS-DNA phase separation to intensify the cGAS enzymatic activity. In addition, the low dose encapsulation of paclitaxel (PTX) acting as an antimitotic agent (ZnFe2O4-PTX@CCM) ensured the sustained activation of cGAS/STING pathway. The in vitro and in vivo results confirmed that ZnFe2O4-PTX@CCM elevated the cGAS/STING activity, promoted dendritic cell maturation, increased cytotoxic T lymphocyte and natural killer cells infiltration, eventually inhibiting the tumour progress and postoperative recurrence. This study provided feasible references on constructing STING activation nanosystem for tumour immunotherapy.

Molecular Epidemiology Reveals the Co-Circulation of Two Genotypes of Coxsackievirus B5 in China.

Coxsackievirus B5 (CVB5) is an important enterovirus B species (EV-Bs) type. We used the full-length genomic sequences of 53 viral sequences from the national hand, foot, and mouth disease surveillance network in the Chinese mainland (2001-2021). Among them, 69 entire VP1 coding region nucleotide sequences were used for CVB5 genotyping and genetic evolution analysis. Phylogenetic analysis based on a data set of 448 complete VP1 sequences showed that CVB5 could be divided into four genotypes (A-D) worldwide. Sequences from this study belonged to genotypes B and D, which dominated transmission in the Chinese mainland. Two transmission lineages of CVB5 have been discovered in the Chinese mainland, lineage 2 was predominant. Markov chain Monte Carlo analysis indicated that the tMRCA of CVB5 in the Chinese mainland could be traced to 1955, while the global trend could be traced to 1862, 93 years earlier than China. The evolution rate of CVB5 was higher in the Chinese mainland than worldwide. The spatiotemporal dynamics analysis of CVB5 assessed that virus transportation events were relatively active in Central, Northeast, North and Northwest China. Recombination analysis revealed frequent intertypic recombination in the non-structural region of CVB5 genotypes B and D with the other EV-Bs, revealing eight recombination lineages. Our study showed the molecular evolution and phylogeography of CVB5 that could provide valuable information for disease prevention.

Molecular Characteristics and Genetic Evolution of Echovirus 33 in Mainland of China.

Echovirus, a member of the Enterovirus B (EV-B) family, has led to numerous outbreaks and pandemics, causing a broad spectrum of diseases. Based on the national hand, foot, and mouth disease (HFMD) surveillance system, seven strains of echovirus 33 (E33) were isolated from Mainland of China between 2010 and 2018. The whole genomes of these strains were isolated and sequenced, and phylogenetic trees were constructed based on the gene sequences in different regions of the EV-B prototype strains. It was found that E33 may be recombined in the P2 and P3 regions. Five genotypes (A-E) were defined based on the entire VP1 region of E33, of which the C gene subtype was the dominant gene subtype at present. Recombinant analysis showed that genotype C strains likely recombined with EV-B80, EV-B85, E13, and CVA9 in the P2 and P3 regions, while genotype E had the possibility of recombination with CVB3, E3, E6, and E4. Results of Bayesian analysis indicated that E33 may have appeared around 1955 (95% confidence interval: 1945-1959), with a high evolutionary rate of 1.11 × 10-2 substitution/site/year (95% highest posterior density (HPD): 8.17 × 10-3 to 1.4 × 10-2 substitution/site/year). According to spatial transmission route analysis, two significant transmission routes were identified: from Australia to India and from Oman to Thailand, which the E33 strain in Mainland of China likely introduced from Mexico and India. In conclusion, our study fills the gaps in the evolutionary analysis of E33 and can provide important data for enterovirus surveillance.

Sp1 Inhibits PGC-1α via HDAC2-Catalyzed Histone Deacetylation in Chronic Constriction Injury-Induced Neuropathic Pain.

BACKGROUND: Our previous study has illuminated that PGC-1α downregulation promoted chronification of pain after burn injury. RNA-seq analysis predicted association between Sp1 and chronic constriction injury (CCI)-provoked neuropathic pain. Further ChIP-Atlas data investigation suggested the binding to Sp1 to PGC-1α. Thereby, we performed this study to illustrate the functional relevance of the Sp1/PGC-1α axis in neuropathic pain. METHODS: Neuropathic pain was induced by CCI in vivo in rats, followed by assessment of neuropathic pain-like behaviors. The expression of Sp1 and correlated genes was determined in CCI rat spinal cord tissues. Furthermore, microglia were exposed to lipopolysaccharide (LPS) to mimic inflammation and then cocultured with neurons. Knockdown and ectopic expression methods were used in vivo and in vitro to define the role the Sp1/HDAC2/PGC-1α axis. RESULTS: Sp1 expression was upregulated in spinal cord tissues of CCI rats. Silencing Sp1 ameliorated CCI-induced neuropathic pain, as reflected by elevated paw withdrawal threshold and paw withdrawal latency, as well as alleviated microglia activation, neuronal dysfunction, inflammatory responses, mitochondrial dysfunction, and oxidative stress in spinal cord tissues. Sp1 knockdown also reversed LPS-induced microglial inflammation and neuronal dysfunction. Sp1 promoted histone deacetylation in the PGC-1α promoter and inhibited PGC-1α expression via recruiting HDAC2. PGC-1α overexpression diminished CCI-induced neuropathic pain and LPS-induced inflammation and mitochondrial dysfunction, based on which Sp1 aggravated microglial inflammation and neuronal dysfunction in neuropathic pain. CONCLUSION: This study elucidated the promoting effects of Sp1 on CCI-induced neuropathic pain via the HDAC2/PGC-1α axis.

Genomic Epidemiology and Phylodynamic Analysis of Enterovirus A71 Reveal Its Transmission Dynamics in Asia.

Enterovirus A71 (EV-A71) is one of the main pathogens causing hand, foot, and mouth disease (HFMD) outbreaks in Asian children under 5 years of age. In severe cases, it can cause neurological complications and be life-threatening. In this study, 200 newly sequenced EV-A71 whole-genome sequences were combined with 772 EV-A71 sequences from GenBank for large-scale analysis to investigate global EV-A71 epidemiology, phylogeny, and Bayesian phylodynamic characteristics. Based on the phylogenetic analysis of the EV-A71 3Dpol region, six new evolutionary lineages (lineages B, J, K, O, P, and Q) were found in this study, and the number of evolutionary lineages was expanded from 11 to 17. Temporal dynamics and recombination breakpoint analyses based on genotype C revealed that recombination of nonstructural protein-coding regions, including 3Dpol, is an important reason for the emergence of new lineages. The EV-A71 epidemic in the Asia-Pacific region is complex, and phylogeographic analysis found that Vietnam played a key role in the spread of subgenotypes B5 and C4. The origin of EV-A71 subgenotype C4 in China is East China, which is closely related to the prevalence of subgenotype C4 in the south and throughout China. Selection pressure analysis revealed that, in addition to VP1 amino acid residues VP1-98 and VP1-145, which are associated with EV-A71 pathogenicity, amino acid residues VP1-184 and VP1-249 were also positively selected, and their functions still need to be determined by biology and immunology. This study aimed to provide a solid theoretical basis for EV-A71-related disease surveillance and prevention, antiviral research, and vaccine development through a comprehensive analysis. IMPORTANCE EV-A71 is one of the most important pathogens causing HFMD outbreaks; however, large-scale studies of EV-A71 genomic epidemiology are currently lacking. In this study, 200 new EV-A71 whole-genome sequences were determined. Combining these with 772 EV-A71 whole-genome sequences in the GenBank database, the evolutionary and transmission characteristics of global and Asian EV-A71 were analyzed. Six new evolutionary lineages were identified in this study. We also found that recombination in nonstructural protein-coding regions, including 3Dpol, is an important cause for the emergence of new lineages. The results provided a solid theoretical basis for EV-A71-related disease surveillance and prevention, antiviral research, and vaccine development.

Cellulose-Based Cryogel Microspheres with Nanoporous and Controllable Wrinkled Morphologies for Rapid Hemostasis.

First-aid hemostatic agents for acute bleeding can save lives in emergency situations. However, rapid hemostasis remains challenging when uncontrolled hemorrhage occurs on lethal noncompressible and irregular wounds. Herein, cellulose-based cryogel microspheres with deliberately customized micromorphologies for ultrafast water transportation and diffusion, including the shark skin riblet-inspired wrinkled surface with low fluid drag and the hydrophilic nanoporous 3D networks, are developed to deal with the acute noncompressible bleeding within seconds. These cryogel microspheres can rapidly absorb a large amount of blood over 6 times their own weight in 10 s and form a robust barrier to seal a bleeding wound without applying pressure. Remarkably, massive bleeding from a cardiac penetrating hole is effectively stopped using the microspheres within 20 s and no blood leakage is observed after 30 min. Additionally, these microspheres could be readily removed without rebleeding and capillary thrombus, which is highly favorable to rapid hemostasis in emergency rescue.

Structural and functional analysis of a potent human neutralizing antibody against enterovirus A71.

Enterovirus A71 (EV-A71) causes major outbreaks of hand, foot, and mouth disease (HFMD) in many countries, most frequently affecting children, and a small proportion of cases may lead to death. Currently, no vaccine is available in most endemic regions, and no licenced treatments for EV-A71 infection are available. Here, we characterize a human monoclonal antibody (HuMAb), E1, by screening a Fab antibody phage library derived from patients who recovered from EV-A71 infection. E1 exhibits strong neutralizing activity against EV-A71 virus in cells. The cryo-electron microscopy (cryo-EM) structures of the EV-A71 virion in complex with E1 Fab fragments demonstrated that E1 recognized an epitope formed by residues in the BC and HI loops of VP1. In a mouse model, E1 effectively protected against lethal EV-A71 challenge in both prophylactic and therapeutic treatment. In particular, E1 significantly reduces virus titers and muscle damage. E1 might represent a potential adjunct to EV-A71 treatment.

Origin and evolution analysis and genetic characteristics of echovirus 9 in China.

BACKGROUND: Echovirus 9 (E9) is associated with a wide variety of diseases and medical conditions, and the clinical symptoms of sporadic cases caused by E9 often are severe. With a high global prevalence, E9 has caused multiple outbreaks worldwide. However, little is known about the genetic and geographic population dynamics of E9. METHOD: A total of 131 VP1 gene sequences, including15 generated in this study and 116 obtained from GenBank, were used to coestimate time-resolved phylogenies to infer viral evolution and transmission in worldwide. Overlapping fragments representing whole genomes were amplified by reverse transcription polymerase chain reaction (RT-PCR) using specific primers. Then, we reported the genetic characteristics of fifteen E9 strains in the Chinese Mainland. Similarity plots and bootscanning analysis were used to determine recombination patterns of E9. RESULTS: The estimated mean evolutionary rate of global E9 VP1 gene was 4.278 × 10-3 substitutions per site per year (95% confidence interval [CI], 3.822 × 10-3/site/year to 4.710 × 10-3/site/year), and the common ancestor of E9 likely emerged around 1868 (95% CI, 1840 to 1892). The full-length genomic sequences of the fifteen E9 strains showed 76.9-79.6% nucleotide identity and 95.3-95.9% amino acid identity with E9 Barty strain. 11 of 15 E9 whole genome sequence present four recombination patterns, and E9 recombinants have extensive genetic exchanges in the 2C and P3 regions with other Enterovirus B (EV-B) circulated in China. Four of six E9 strains were temperature sensitive, and two were temperature resistant, and a comparative genomics analysis suggested that 411, 865 and 867 amino acid substitution in the P1 region was related to temperature sensitivity. CONCLUSION: This study highlights a persistent transmission network of E9 in worldwide, provides valuable information regarding the molecular epidemiology of E9.

Identification of the first C1 subgenotype of enterovirus 71 in the Chinese mainland in a retrospective study.

The C4 sub-genotype of Enterovirus 71 (EV71) has been identified as the most dominant sub-genotype circulating in the Chinese mainland since 1998. The circulation situation of EV71 before 1998 is not well established due to insufficient experimental data. The C1 subgenotype of EV71 has not yet been reported in the Chinese mainland by now. Based on the AFP surveillance system of the mainland of China, this study conducted a retrospective study of AFP cases for 1985-1999: a strain of EV-A71 C1 subgenotype was found. To our knowledge, this strain (SD92-41) is the first C1 sub-genotype reported in the Chinese mainland. This study demonstrates that the C1 gene subtype also appeared in the Chinese mainland, but it is unknown whether it is an imported or a local epidemic strain. With sufficient information known from retrospective studies, the source of the SD92-41 strain will be identified and the prevalence of EV-A71 in the Chinese mainland before 1998 will be clearer.