Strong Neutralizing Research Articles

Multi-Component Protein Vaccine Induces a Strong and Long-Term Immune Response Against Monkeypox Virus.

Since 2022, outbreaks of monkeypox have raised widespread concern and have been declared a public health emergency of international concern by the World Health Organization. There is an urgent need to develop a safe and effective vaccine against the monkeypox virus (MPXV). Recombinant protein vaccines play a significant role in the prevention of infectious diseases due to their high safety and efficacy. We used the A29, E8, M1, A35, and B6 proteins of MPXV as candidate antigens to generate a panel of multi-component MPXV vaccine candidates, which were administered subcutaneously to immunize mice. The results showed that the vaccine candidates Mix-AEM, Mix-AEMA, Mix-AEMB, and Mix-AEMAB effectively elicited strong neutralizing antibody responses and demonstrated significant protection against vaccinia virus (VACV) infection in a murine model. The vaccine candidate Mix-AEM induced significantly higher levels of neutralizing antibodies, cellular immunity capacity, and virus clearance compared to the vaccine candidate Mix-AE (lacking M1). Single-component immunization showed that M1 induced higher levels of neutralizing antibodies than A29 and E8. These results indicated that M1 is a critical and essential antigen in the MPXV vaccine. The number of cells secreting IFN-γ was significantly increased in the Mix-AEMA and Mix-AEMAB groups compared to the A35-deficient vaccine candidates, demonstrating the important role of A35 in inducing IFN-γ secreting. In addition, the neutralizing antibodies induced by these multi-component vaccine candidates were maintained at high levels six months after the third immunization. In summary, this study lays the groundwork for combining antigens to develop multi-component subunit vaccines.

High-throughput specificity profiling of antibody libraries using ribosome display and microfluidics.

In this work, we developed PolyMap (polyclonal mapping), a high-throughput method for mapping protein-protein interactions. We demonstrated the mapping of thousands of antigen-antibody interactions between diverse antibody libraries isolated from convalescent and vaccinated COVID-19 donors and a set of clinically relevant SARS-CoV-2 spike variants. We identified over 150 antibodies with a variety of distinctive binding patterns toward the antigen variants and found a broader binding profile, including targeting of the Omicron variant, in the antibody repertoires of more recent donors. We then used these data to select mixtures of a small number of clones with complementary reactivity that together provide strong potency and broad neutralization. PolyMap is a generalizable platform that can be used for one-pot epitope mapping, immune repertoire profiling, and therapeutic design and, in the future, could be expanded to other families of interacting proteins.

Lung-Selective Delivery of mRNA-Encoding Anti-MERS-CoV Nanobody Exhibits Neutralizing Activity Both In Vitro and In Vivo.

Background/Objectives: The Middle East Respiratory Syndrome Coronavirus (MERS-CoV) is a highly pathogenic virus causing severe respiratory illness, with limited treatment options that are mostly supportive. The success of mRNA technology in COVID-19 vaccines has opened avenues for antibody development against MERS-CoV. mRNA-based antibodies, expressed in vivo, offer rapid adaptability to viral mutations while minimizing long-term side effects. This study aimed to develop a lung-targeted lipid nanoparticle (LNP) system for mRNA-encoding neutralizing nanobodies against MERS-CoV, proposing a novel therapeutic strategy. Methods: An mRNA-encoding nanobody NbMS10 (mRNA-NbMS10) was engineered for enhanced stability and reduced immunogenicity. This mRNA was encapsulated in lung-selective LNPs using microfluidics to form the LNP-mRNA-NbMS10 system. Efficacy was assessed through in vitro assays and in vivo mouse studies, focusing on antigen-binding, neutralization, and sustained nanobody expression in lung tissues. Results: The LNP-mRNA-NbMS10 system expressed the nanobody in vitro, showing strong antigen-binding and significant MERS-CoV pseudovirus neutralization. In vivo studies confirmed selective lung mRNA delivery, with high nanobody expression sustained for up to 24 h, confirming lung specificity and prolonged antiviral activity. Conclusions: Extensive in vitro and in vivo evaluations demonstrate the LNP-mRNA-NbMS10 system's potential as a scalable, cost-effective, and adaptable alternative to current MERS-CoV therapies. This innovative platform offers a promising solution for preventing and treating respiratory infections, and countering emerging viral threats.

Impact of Acid Rain on Release Characteristics of Heavy Metals in Low-Sulfur Tailings with Strong Acid Neutralization Capacity: A Case Study from Northern Guangxi, China

Tailing ponds are major sources of heavy metal pollution. Previous studies primarily focused on tailings with high sulfur content, with limited attention to low-sulfur tailings. This study explored the release behavior of Pb, Zn, and Cd from low-sulfur tailings under simulated acid rain conditions, considering factors such as pH, particle size, and weathering degree. Samples were collected from a lead–zinc tailing pond in the karst regions of northern Guangxi, China. Batch leaching experiments indicated that even with high acid neutralization capacity (ANC = 166.57–167.45 kg H2SO4/t), substantial heavy metal leaching occurred under acidic conditions (pH 2–3), with Pb, Zn, and Cd concentrations increasing 4–6 times compared to neutral conditions. Leachate concentrations were slightly higher in coarser particles than in finer ones, while weathering further enhanced metal release, particularly for Cd. These findings suggest that acid neutralization alone may not be sufficient to prevent heavy metal leaching in low-sulfur tailings exposed to acid rain. However, due to the laboratory scale of this study, further validation through field-scale or mesocosm experiments is necessary to confirm the observed trends and assess their implications for environmental risk management in karst regions.

Insights into the wetting mechanisms in low-permeability sandstone reservoirs and its evolution processes: The shahejie formation in the Dongying Depression, Bohai Bay basin

During the accumulation and development processes of low-permeability oil, wettability plays a crucial role in the percolation capacity of fluids. In particular, the evolution of low-permeability sandstones involves complex changes in formation fluid properties and mineral types, leading to a deficient understanding of wetting mechanisms in low-permeability sandstones. This gap significantly impedes research on the accumulation mechanisms of low-permeability oil. Focusing on the low-permeability sandstones in Shahejie formation of Dongying Depression, Bohai Bay Basin, tests like Casting thin section, scanning electron microscope, contact angle measurement, molecular dynamics simulation and the Amott method based on nuclear magnetic resonance technology were performed to comprehensively investigate sandstone wettability and its evolutionary process. The results indicate that the adsorption capacity of hydroxyl groups or monovalent cations (K+and Na+) for water molecules causes residual intergranular pores, feldspar dissolution pores, quartz dissolution pores, clay mineral intercrystalline pores and micro-cracks to exhibit hydrophilicity; while the adsorption capacity of divalent cations (Ca2+and Mg2+) for oil molecules causes the surface of dissolution pores of carbonate minerals to exhibit neutrality or lipophilicity. Additionally, changes in formation conditions (temperature, pressure, ion types, and ion concentration) significantly control the wettability of pore surfaces, further determining the overall wettability of low-permeability sandstone reservoirs. Throughout the evolutionary process of low-permeability sandstones, the Amott-Harvey index of low permeability sandstone is greater than zero, and the wettability exhibited hydrophilic or neutral. From A-stage eodiagenesis to B-stage mesodiagenesis, the Amott-Harvey index is 0.82, 0.12, 0.37, 0.03, and 0.49, and the wettability of reservoirs transitions through phases of strong hydrophilicity, weak hydrophilicity, hydrophilicity, neutrality, and hydrophilicity, respectively. Finally, an evolutionary model of the wettability of low-permeability sandstone reservoirs was established, which is of great significance for predicting the quality of low-permeability sandstone reservoirs.

Generation and epitope mapping of novel neutralizing monoclonal antibodies against glycoprotein E2 of CSFV

Classical swine fever virus (CSFV) is a highly contagious and economically important pathogen threatening pig industry worldwide, the envelope glycoprotein E2 of CSFV is the dominant antigen inducing strong antiviral neutralizing immunity. In this study, 7 monoclonal antibodies (mAbs) with neutralizing potency were generated using E2 protein of CSFV Shimen strain (SM) expressed by eukaryotic cells. Their reactivity with 116 CSFV strains in cell cultures and E2 proteins of 10 subgenotypes in western blots showed different CSFV spectrums they recognized. Of them, three (HCL-001, HCL-005 and HCL-010) reacted with all CSFV subgenotypes, while HCL-014 and HCL-002 reacted with most CSFV strains, except for some variants in genotype 2.3. In contrast, mAb HCL-009 reacted only with a few subgenotype 1.1 strains including SM, field strains and some vaccine strains. Interestingly, mAb HCL-018 reacted only with SM and field subgenotype 1.1 strains, not with any vaccine strains. Further epitope mapping using chimeric and site-directed mutated E2 proteins showed that HCL-001, HCL-005 and HCL-010 recognized a conservative epitope motif 143SPT145,L147, and HCL-002 recognized a conformational epitope with key aa motifs of 95GDD97,157RX(D/E)K(R)XFXXR164. HCL-014 recognized a new conservative epitope with key aa motifs of 41D,58XNVVXRR64. HCL-009 and HCL-018 recognized the epitope with key aa motifs of 36D,40ND41,45KXI47 and 69LHXGXLLT76, respectively. Taken together, present study has provided not only new insights into the antigenic structure of E2 protein, but also key reagents for antigenic characterization of CSFV strains and development of antibody assay for evaluation of the vaccination efficacy.

Identification of a potent SARS-CoV-2 neutralizing nanobody targeting the receptor-binding domain of the spike protein

SARS-CoV-2 and its variants continue to pose a significant threat to public health. Nanobodies (Nbs) that inhibit the interaction between the receptor-binding domain (RBD) of the spike protein and the host cell receptor angiotensin-converting enzyme 2 (ACE2) are promising drug candidates. In this study, we report the discovery and structural characterization of a potent Nb that targets the RBD. By screening a phage display alpaca naive Nbs library using the RBD as bait, we identified sixteen candidate Nbs. Of these, nine exhibited nanomolar to micromolar binding affinity and strong neutralizing activity against pseudotyped SARS-CoV-2 viruses, with NbS4 showing the highest neutralization potency. The crystal structure of the SARS-CoV-2 RBD in complex with NbS4 revealed that this Nb binds to a site partially overlapping the ACE2 binding region. Importantly, the key binding residues of NbS4 in the RBD are conserved across most known variants, making it a promising candidate for COVID-19 treatment.

Impaired mucosal IgA response in patients with severe COVID-19

ABSTRACT Several studies have investigated the antibody response to SARS-CoV-2, focusing particularly on the systemic humoral immune response and the production of immunoglobulin G (IgG) antibodies. IgA antibodies play a crucial role in protecting against respiratory viral infections but have also been associated with the pathophysiology of COVID-19. We performed a prospective study of 169 COVID-19 patients – 50 with critical/severe (ICU), 47 with moderate (Non-ICU), and 72 with asymptomatic COVID-19 – to explore the humoral immune response to SARS-CoV-2 infection. We found that the early systemic IgA response strongly induced in patients with severe disease did not block IgG neutralization functions and activated FcRs more effectively than IgG. However, even if SIgA levels were high, mucosal IgA antibodies could not control the infection effectively in patients with severe disease. Our findings highlight the complexity of the immune response to SARS-CoV-2 exhibiting high systemic levels of IgA with strong neutralizing capacity in severe cases, together with higher levels of IgA-FcR activation than in asymptomatic patients. They also suggest the need for further research to fully understand the role of IgA and its structural alterations in mucosal tissues in cases of severe disease and the impact of these antibodies on disease progression.

CoronaVac-vaccinated kidney transplant recipients with hybrid immunity have strong neutralizing responses against Omicron and Mu variants of SARS-CoV-2.

Neutralizing antibody (nAb) responses against SARS-CoV-2 variants after inactivated virus vaccine (CoronaVac) in kidney transplant recipients (KTRs) with or without SARS-CoV-2 infection history remains unclear. We aimed to evaluate the neutralizing antibody responses against emerging SARS-CoV-2 variants after two doses of CoronaVac in these patients. 22.2% of participants had hybrid immunity. Anti-spike IgG antibodies were evidenced in 44% of the patients. nAbs against B.1.111, Mu, and Omicron were detected in 28.5%, 17.9%, and 21.4% of naïve KTRs, respectively. Furthermore, nearly 100% of KTRs with hybrid immunity had nAbs against the variants evaluated. Thus, a significant proportion of infection-naïve KTRs had no detectable nAb titers against Mu and Omicron variants after two doses of the CoronaVac vaccine. However, the nAb titers were significantly higher in patients with hybrid immunity, and it was no association between the immunosuppressive regimen and the seropositivity rate of anti-SARS-CoV-2 neutralizing antibodies. Therefore, hybrid KTRs are protected against COVID-19 by emerging variants able to escape from vaccine-elicited nAbs such as Mu and Omicron.

The Anti-SARS-CoV-2 S-Protein IgG, Which Is Detected Using the Chemiluminescence Microparticle Immunoassay (CMIA) in Individuals Having Either a History of COVID-19 Vaccination and/or SARS-CoV-2 Infection, Showed a High-Titer Neutralizing Effect.

Neutralizing antibodies plays a primary role in protective immunity by preventing severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) from entering the cells. Therefore, characterization of antiviral immunity is important for protection against SARS-CoV-2. In this study, the neutralizing effect of the anti-SARS-CoV-2 S1 protein IgG, which was detected using the chemiluminescence microparticle immunoassay (CMIA)-based SARS-CoV-2 IgG II Quant (Abbott, Waukegan, IL, USA) test in SARS-CoV-2 infected and/or vaccinated individuals, was investigated with a surrogate virus neutralization test (sVNT). In total, 120 Seropositive individuals were included in this study. They were divided into two groups: Vaccinated (n = 60) and Vaccinated + Previously Infected (n = 60). A commercial sVNT, the ACE2-RBD Neutralization Test (Dia.Pro, Milan, Italy), was used to assess the neutralizing effect. The assay is performed in two steps: screening and titration. The screening showed positive results in all seropositive samples. Low titration in 1.7%, medium titration in 5%, and high titration in 93.3% of the Vaccinated group, and medium titration in 1.7% and high titration in 98.3% of the other group, as obtained from the ACE2-RBD titration test. A strong positive and significant correlation was found between the SARS-CoV-2 IgG II Quant test and the ACE2-RBD titration test at the 1/32 titration level for both groups (p < 0.001 for both). This study shows that the SARS-CoV-2 IgG detected using the CMIA method after SARS-CoV-2 infection and/or vaccination has a high neutralizing titration by using the sVNT. In line with these data, knowledge that seropositivity determined by CMIA also indicates a strong neutralizing effect contributes to countrywide planning for protecting the population.

Heterologous mRNA/MVA delivering trimeric-RBD as effective vaccination regimen against SARS-CoV-2: COVARNA Consortium

ABSTRACT Despite the high efficiency of current SARS-CoV-2 mRNA vaccines in reducing COVID-19 morbidity and mortality, waning immunity and the emergence of resistant variants underscore the need for novel vaccination strategies. This study explores a heterologous mRNA/Modified Vaccinia virus Ankara (MVA) prime/boost regimen employing a trimeric form of the receptor binding domain (RBD) of the SARS-CoV-2 spike (S) protein compared to a homologous MVA/MVA regimen. In C57BL/6 mice, the RBD was delivered during priming via an mRNA vector encapsulated in nanoemulsions (NE) or lipid nanoparticles (LNP), followed by a booster with a replication-deficient MVA-based recombinant virus (MVA-RBD). This heterologous mRNA/MVA regimen elicited strong anti-RBD binding and neutralizing antibodies (BAbs and NAbs) against both the ancestral SARS-CoV-2 strain and different variants of concern (VoCs). Additionally, this protocol induced robust and polyfunctional RBD-specific CD4 and CD8 T cell responses, particularly in animals primed with mLNP-RBD. In K18-hACE2 transgenic mice, the LNP-RBD/MVA combination provided complete protection from morbidity and mortality following a live SARS-CoV-2 challenge compared with the partial protection observed with mNE-RBD/MVA or MVA/MVA regimens. Although the mNE-RBD/MVA regimen only protects half of the animals, it was able to induce antibodies with Fc-mediated effector functions besides NAbs. Moreover, viral replication and viral load in the respiratory tract were markedly reduced and decreased pro-inflammatory cytokine levels were observed. These results support the efficacy of heterologous mRNA/MVA vaccine combinations over homologous MVA/MVA regimen, using alternative nanocarriers that circumvent intellectual property restrictions of current mRNA vaccine formulations.

Protection of K18-hACE2 Mice against SARS-CoV-2 Challenge by a Capsid Virus-like Particle-Based Vaccine.

The SARS-CoV-2 pandemic and the emergence of novel virus variants have had a dramatic impact on public health and the world economy, underscoring the need for detailed studies that explore the high efficacy of additional vaccines in animal models. In this study, we confirm the pathogenicity of the SARS-CoV-2/Leiden_008 isolate (GenBank accession number MT705206.1) in K18-hACE2 transgenic mice. Using this isolate, we show that a vaccine consisting of capsid virus-like particles (cVLPs) displaying the receptor-binding domain (RBD) of SARS-CoV-2 (Wuhan strain) induces strong neutralizing antibody responses and sterilizing immunity in K18-hACE2 mice. Furthermore, we demonstrate that vaccination with the RBD-cVLP vaccine protects mice from both a lethal infection and symptomatic disease. Our data also indicate that immunization significantly reduces inflammation and lung pathology associated with severe disease in mice. Additionally, we show that the survival of naïve animals significantly increases when sera from animals vaccinated with RBD-cVLP are passively transferred, prior to a lethal virus dose. Finally, the RBD-cVLP vaccine has a similar antigen composition to the clinical ABNCOV2 vaccine, which has shown non-inferiority to the Comirnaty mRNA vaccine in phase I-III trials. Therefore, our study provides evidence that this vaccine design is highly immunogenic and confers full protection against severe disease in mice.

The Protective Efficacy of a SARS-CoV-2 Vaccine Candidate B.1.351V against Several Variant Challenges in K18-hACE2 Mice.

The emergence of SARS-CoV-2 variants of concern (VOCs) with increased transmissibility and partial resistance to neutralization by antibodies has been observed globally. There is an urgent need for an effective vaccine to combat these variants. Our study demonstrated that the B.1.351 variant inactivated vaccine candidate (B.1.351V) generated strong binding and neutralizing antibody responses in BALB/c mice against the B.1.351 virus and other SARS-CoV-2 variants after two doses within 28 days. Immunized K18-hACE2 mice also exhibited elevated levels of live virus-neutralizing antibodies against various SARS-CoV-2 viruses. Following infection with these viruses, K18-hACE2 mice displayed a stable body weight, a high survival rate, minimal virus copies in lung tissue, and no lung damage compared to the control group. These findings indicate that B.1.351V offered protection against infection with multiple SARS-CoV-2 variants in mice, providing insights for the development of a vaccine targeting SARS-CoV-2 VOCs for human use.

Comparative pathogenesis of three Mayaro virus genotypes in the cynomolgus macaque.

Mayaro virus (MAYV), a mosquito-borne alphavirus, is considered an emerging threat to public health with epidemic potential. Phylogenetic studies show the existence of three MAYV genotypes. In this study, we provide a preliminary analysis of the pathogenesis of all three MAYV genotypes in cynomolgus macaques (Macaca facicularis, Mauritian origin). Significant MAYV-specific RNAemia and viremia were detected during acute infection in animals challenged intravenously with the three MAYV genotypes, and strong neutralizing antibody responses were observed. MAYV RNA was detected at high levels in lymphoid tissues, joint muscle and synovia over 1 month after infection, suggesting that this model could serve as a promising tool in studying MAYV-induced chronic arthralgia, which can persist for years. Significant leucopenia was observed across all MAYV genotypes, peaking with RNAemia. Notable differences in the severity of acute RNAemia and composition of cytokine responses were observed among the three MAYV genotypes. Our model showed no outward signs of clinical disease, but several major endpoints for future MAYV pathology and intervention studies are described. Disruptions to normal blood cell counts and cytokine responses were markedly distinct from those observed in macaque models of CHIKV infection, underlining the importance of developing non-human primate models specific to MAYV infection.

Evaluation of safety and immunogenicity of a genetically modified rabies virus for use as an oral vaccine in several non-target species1

Oral immunization is an alternative or supplementary approach that can significantly improve dog vaccination coverage, especially for free-roaming dogs. Safe and effective oral rabies vaccines for dogs are still being sought. In our previous studies, we generated a genetically modified rabies virus (RABV) ERA strain, rERAG333E, containing a mutation from arginine (Arg, R) to glutamic acid (Glu, E) at residue 333 of the G protein (G333E). Our previous results demonstrated that rERAG333E was safe for adult mice and dogs, and oral vaccination with rERAG333E induced a strong and long-lasting protective immune response in dogs. Here, we further investigated the safety and immunogenicity of rERAG333E in non-target species, including suckling mice, rhesus monkeys, foxes, raccoon dogs, piglets, goats, and sheep. Suckling mice studies demonstrated that the G333E mutation significantly reduced the virulence of the ERA strain. All of the suckling mice aged 10 days and above survived and showed no apparent signs of disease after intracerebral inoculation with rERAG333E. Animal studies demonstrated that rERAG333E was safe in rhesus monkeys, foxes, raccoon dogs, piglets, goats, and sheep. None of those animals inoculated orally with 10 times the intended field dose of rERAG333E showed abnormal clinical signs before and after the booster immunization with Rabvac 3, an inactivated rabies vaccine. Meanwhile, oral inoculation with rERAG333E induced strong neutralizing antibody (NA) responses to RABV in rhesus monkeys, foxes, raccoon dogs, and piglets. These results demonstrated that rERAG333E has the potential to serve as a safe oral rabies vaccine for dogs.

Repeated Omicron infection dampens immune imprinting from previous vaccination and induces broad neutralizing antibodies against Omicron sub-variants

ObjectiveSimilar with influenza virus, antigenic drift is highly relevant to SARS-CoV-2 evolution, and immune imprinting has been found to limit the performance of updated vaccines based on the emerging variants of SARS-CoV-2. We aimed to investigate whether repeated exposure to Omicron variant could reduce the immune imprinting from previous vaccination. MethodsA total of 194 participants with different status of vaccination (unvaccinated, regular vaccination and booster vaccination) confirmed for first infection and re-infection with BA.5, BF.7 and XBB variants were enrolled, and the neutralizing profiles against wild type (WT) SARS-CoV-2 and Omicron sub-variants were analyzed. ResultsNeutralizing potency against the corresponding infected variant is significantly hampered along with the doses of vaccination during first infection. However, for the participants with first infection of BA.5/BF.7 variants and re-infection of XBB variant, immune imprinting was obviously alleviated, indicated as significantly increased ratio of the corresponding infected variant/WT ID50 titers and higher percentage of samples with high neutralizing activities (ID50>500) against BA.5, BF.7 and XBB variants. Moreover, repeated Omicron infection could induce strong neutralizing potency with broad neutralizing profiles against a series of other Omicron sub-variants, both in the vaccine naive and vaccine experienced individuals. ConclusionsOur results demonstrate that repeated Omicron infection dampens immune imprinting from vaccination with WT SARS-CoV-2 and induces broad neutralizing profiles against Omicron sub-variants.

A Unique mRNA Vaccine Elicits Protective Efficacy against the SARS-CoV-2 Omicron Variant and SARS-CoV.

The highly pathogenic coronaviruses SARS-CoV-2 and SARS-CoV have led to the COVID-19 pandemic and SARS outbreak, respectively. The receptor-binding domain (RBD) of the spike (S) protein of SARS-CoV-2, particularly the Omicron variant, has frequent mutations, resulting in the reduced efficiency of current COVID-19 vaccines against new variants. Here, we designed two lipid nanoparticle-encapsulated mRNA vaccines by deleting the mutant RBD of the SARS-CoV-2 Omicron variant (SARS2-S (RBD-del)) or by replacing this mutant RBD with the conserved and potent RBD of SARS-CoV (SARS2-S (SARS-RBD)). Both mRNA vaccines were stable at various temperatures for different time periods. Unlike SARS2-S (RBD-del) mRNA, SARS2-S (SARS-RBD) mRNA elicited effective T-cell responses and potent antibodies specific to both SARS-CoV-2 S and SARS-CoV RBD proteins. It induced strong neutralizing antibodies against pseudotyped SARS-CoV-2 and SARS-CoV infections and protected immunized mice from the challenge of the SARS-CoV-2 Omicron variant and SARS-CoV by significantly reducing the viral titers in the lungs after Omicron challenge and by completely preventing SARS-CoV-induced weight loss and death. SARS2-S (SARS-RBD)-immunized serum antibodies protected naïve mice from the SARS-CoV challenge, with its protective efficacy positively correlating with the neutralizing antibody titers. These findings indicate that this mRNA vaccine has the potential for development as an effective vaccine against current and future SARS-CoV-2 variants and SARS-CoV.

Potential of artificial soil preparation for vegetation restoration using red mud and phosphogypsum

Red mud and phosphogypsum have long been a focus and challenge in global industrial waste management, and their low-cost and large-scale utilization technology has always been an urgent need. This study is based on the strong acid-base neutralization reaction between red mud and phosphogypsum, which contain an elemental composition similar to that of natural soil, red mud itself has characteristic of clay minerals, and other auxiliary materials (i.e. rice husk powder, bentonite, fly ash, polyacrylamide flocculant and microbial suspension) were added, so as to explore the potential of synergistically prepared artificial soil for vegetation restoration. The results showed that the artificial soils exhibited physicochemical characteristics (e.g., pH, moisture content, cation exchange capacity) similar to those of natural soil, along with abundant organic matter, nitrogen, phosphorus, and potassium contents, meeting the growth requirements of plants. The artificial soils were able to support favorable growth of suitable plants (e.g., sunflower, wheat, rye grass), accumulating high levels of diverse enzymatic activities, comparable to those in natural soils (e.g., catalase, urease, phosphatase), or even surpassing natural soils (e.g., sucrase), and rich microorganism communities, such as Cyanobacteria, Proteobacteria, Actinobacteria in the bacteria domain, and Ascomycota in the fungi domain, were initially developed. It's suggested that preparing 1 ton of artificial soil entails synergistic consumption of 613.7 kg of red mud and 244.6 kg of phosphogypsum, accounting for mass proportions of 61.4 % and 24.5 %, respectively. In future, more evaluations on the leaching loss of nutrients and alkalinity and the environmental risks of heavy metals should be conducted to more references for the artificial soil application. In summary, the preparation of artificial soil is a very simple, efficient, scalable and low-cost collaborative resource utilization scheme of red mud and phosphogypsum, which has great potential for vegetation restoration in some places such as tailings field and soil-deficient depression.

Vaccine targeting to mucosal lymphoid tissues promotes humoral immunity in the gastrointestinal tract.

Viruses, bacteria, and parasites frequently cause infections in the gastrointestinal tract, but traditional vaccination strategies typically elicit little or no mucosal antibody responses. Here, we report a strategy to effectively concentrate immunogens and adjuvants in gut-draining lymph nodes (LNs) to induce gut-associated mucosal immunity. We prepared nanoemulsions (NEs) based on biodegradable oils commonly used as vaccine adjuvants, which encapsulated a potent Toll-like receptor agonist and displayed antigen conjugated to their surface. Following intraperitoneal administration, these NEs accumulated in gut-draining mesenteric LNs, priming strong germinal center responses and promoting B cell class switching to immunoglobulin A (IgA). Optimized NEs elicited 10- to 1000-fold higher antigen-specific IgG and IgA titers in the serum and feces, respectively, compared to free antigen mixed with NE, and strong neutralizing antibody titers against severe acute respiratory syndrome coronavirus 2. Thus, robust gut humoral immunity can be elicited by exploiting the unique lymphatic collection pathways of the gut with a lymph-targeting vaccine formulation.

Universal paramyxovirus vaccine design by stabilizing regions involved in structural transformation of the fusion protein

The Paramyxoviridae family encompasses medically significant RNA viruses, including human respiroviruses 1 and 3 (RV1, RV3), and zoonotic pathogens like Nipah virus (NiV). RV3, previously known as parainfluenza type 3, for which no vaccines or antivirals have been approved, causes respiratory tract infections in vulnerable populations. The RV3 fusion (F) protein is inherently metastable and will likely require prefusion (preF) stabilization for vaccine effectiveness. Here we used structure-based design to stabilize regions involved in structural transformation to generate a preF protein vaccine antigen with high expression and stability, and which, by stabilizing the coiled-coil stem region, does not require a heterologous trimerization domain. The preF candidate induces strong neutralizing antibody responses in both female naïve and pre-exposed mice and provides protection in a cotton rat challenge model (female). Despite the evolutionary distance of paramyxovirus F proteins, their structural transformation and local regions of instability are conserved, which allows successful transfer of stabilizing substitutions to the distant preF proteins of RV1 and NiV. This work presents a successful vaccine antigen design for RV3 and provides a toolbox for future paramyxovirus vaccine design and pandemic preparedness.