Pulling Forces Differentially Affect Refolding Pathways Due to Entangled Misfolded States in SARS-CoV-1 and SARS-CoV-2 Receptor Binding Domain.

Single-molecule force spectroscopy (SMFS) experiments can monitor protein refolding by applying a small force of a few piconewtons (pN) and slowing down the folding process. Bell theory predicts that in the narrow force regime where refolding can occur, the folding time should increase exponentially with increased external force. In this work, using coarse-grained molecular dynamics simulations, we compared the refolding pathways of SARS-CoV-1 RBD and SARS-CoV-2 RBD (RBD refers to the receptor binding domain) starting from unfolded conformations with and without a force applied to the protein termini. For SARS-CoV-2 RBD, the number of trajectories that fold is significantly reduced with the application of a 5 pN force, indicating that, qualitatively consistent with Bell theory, refolding is slowed down when a pulling force is applied to the termini. In contrast, the refolding times of SARS-CoV-1 RBD do not change meaningfully when a force of 5 pN is applied. How this lack of a Bell response could arise at the molecular level is unknown. Analysis of the entanglement changes of the folded conformations revealed that in the case of SARS-CoV-1 RBD, an external force minimizes misfolding into kinetically trapped states, thereby promoting efficient folding and offsetting any potential slowdown due to the external force. These misfolded states contain non-native entanglements that do not exist in the native state of either SARS-CoV-1-RBD or SARS-CoV-2-RBD. These results indicate that non-Bell behavior can arise from this class of misfolding and, hence, may be a means of experimentally detecting these elusive, theoretically predicted states.

Fluoroamphiphiles for enhancing immune response of subunit vaccine against SARS-CoV-2.

In recent decades, protein-based therapy has garnered valid attention for treating infectious diseases, genetic disorders, cancer, and other clinical requirements. However, preserving protein-based drugs against degradation and denaturation during processing, storage, and delivery poses a formidable challenge. Herein, we designed a novel fluoroamphiphiles polymer to deliver protein. Two different formulations of nanoparticles, cross-linked (CNP) and micelle (MNP) polymer, were prepared rationally by disulfide cross-linked and thin-film hydration techniques, respectively. The size, zeta potential, and morphology of both formulations were characterized and the delivery efficacy of both in vitro and in vivo was also assessed. The in vitro findings demonstrated that both formulations effectively facilitated protein delivery into various cell lines. Moreover, in vivo experiments revealed that intramuscular administration of the two formulations loaded with a SARS-CoV-2 recombinant receptor-binding domain (RBD) vaccine induced robust antibody responses in mice without adding another adjuvant. These results highlight the potential use of our carrier system as a safe and effective platform for the in vivo delivery of subunit vaccines.

S-RBD-modified and miR-486-5p-engineered exosomes derived from mesenchymal stem cells suppress ferroptosis and alleviate radiation-induced lung injury and long-term pulmonary fibrosis.

BACKGROUND: Radiation-induced lung injury (RILI) is associated with alveolar epithelial cell death and secondary fibrosis in injured lung. Mesenchymal stem cell (MSC)-derived exosomes have regenerative effect against lung injury and the potential to intervene of RILI. However, their intervention efficacy is limited because they lack lung targeting characters and do not carry sufficient specific effectors. SARS-CoV-2 spike glycoprotein (SARS-CoV-2-S-RBD) binds angiotensin-converting enzyme 2 (ACE2) receptor and mediates interaction with host cells. MiR-486-5p is a multifunctional miRNA with angiogenic and antifibrotic potential and acts as an effector in MSC-derived exosomes. Ferroptosis is a form of cell death associated with radiation injury, its roles and mechanisms in RILI remain unclear. In this study, we developed an engineered MSC-derived exosomes with SARS-CoV-2-S-RBD- and miR-486-5p- modification and investigated their intervention effects on RIPF and action mechanisms via suppression of epithelial cell ferroptosis. RESULTS: Adenovirus-mediated gene modification led to miR-486-5p overexpression in human umbilical cord MSC exosomes (p < 0.05), thereby constructing miR-486-5p engineered MSC exosomes (miR-486-MSC-Exo). MiR-486-MSC-Exo promoted the proliferation and migration of irradiated mouse lung epithelial (MLE-12) cells in vitro and inhibited RILI in vivo (all p < 0.05). MiR-486-MSC-Exo suppressed ferroptosis in MLE-12 cells, and an in vitro assay revealed that the expression of fibrosis-related genes is up-regulated following ferroptosis (both p < 0.05). MiR-486-MSC-Exo reversed the up-regulated expression of fibrosis-related genes induced by TGF-ß1 in vitro and improved pathological fibrosis in RIPF mice in vivo (all p < 0.05). SARS-CoV-2-S-RBD-modified and miR-486-5p-engineered MSC exosomes (miR-486-RBD-MSC-Exo) were also constructed, and the distribution of DiR dye-labeled miR-486-RBD-MSC-Exo in hACE2CKI/CKI Sftpc-Cre+ mice demonstrated long-term retention in the lung (p < 0.05). MiR-486-RBD-MSC-Exo significantly improved the survival rate and pathological changes in hACE2CKI/CKI Sftpc-Cre+ RIPF mice (all p < 0.05). Furthermore, miR-486-MSC-Exo exerted anti-fibrotic effects via targeted SMAD2 inhibition and Akt phosphorylation activation (p < 0.05). CONCLUSIONS: Engineered MSC exosomes with SARS-CoV-2-S-RBD- and miR-486-5p-modification were developed. MiR-486-RBD-MSC-Exo suppressed ferroptosis and fibrosis of MLE-12 cells in vitro, and alleviated RILI and long-term RIPF in ACE2 humanized mice in vivo. MiR-486-MSC-Exo exerted anti-fibrotic effects via SMAD2 inhibition and Akt activation. This study provides a potential approach for RIPF intervention.

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.

Analysis of B-cell receptor repertoire to evaluate the immunogenicity of SARS-CoV-2 RBD mRNA vaccine: MAFB-7256a (DS-5670d).

A monovalent Omicron XBB.1.5 mRNA RBD analogue vaccine, MAFB-7256a (DS-5670d), was newly developed and approved in Japan in the Spring of 2024 for the prevention of COVID-19. However, clinical efficacy data for this vaccine are currently lacking. We previously established the Quantification of Antigen-specific Antibody Sequence (QASAS) method to assess the response to SARS-CoV-2 vaccination at the mRNA level using B-cell receptor (BCR) repertoire assays and the Coronavirus Antibody Database (CoV-AbDab). Here, we used this method to evaluate the immunogenicity of MAFB-7256a. We analyzed repeated blood samples using the QASAS method from three healthy volunteers before and after MAFB-7256a vaccination. BCR response increased rapidly one week post-vaccination and then decreased, as with conventional vaccine. Notably, the matched sequences after MAFB-7256a vaccination specifically bound to the receptor-binding domain (RBD), with no sequences binding to other epitopes. These results validate that MAFB-7256a is an effective vaccine that exclusively induces antibodies specific for the RBD, demonstrating its targeted immunogenic effect.

Neutralisation Resistance of SARS-CoV-2 Spike-Variants is Primarily Mediated by Synergistic Receptor Binding Domain Substitutions.

AbstractThe evolution of SARS-CoV-2 has led to the emergence of numerous variants of concern (VOCs), marked by changes in the viral spike glycoprotein, the primary target for neutralising antibody (nAb) responses. Emerging VOCs, particularly omicron sub-lineages, show resistance to nAbs induced by prior infection or vaccination. The precise spike protein changes contributing to this resistance remain unclear in infectious cell culture systems. In the present study, a large panel of infectious SARS-CoV-2 mutant viruses, each with spike protein changes found in VOCs, including omicron JN.1 and its derivatives KP.2 and KP.3, was generated using a reverse genetic system. The susceptibility of these viruses to antibody neutralisation was measured using plasma from convalescent and vaccinated individuals. Synergistic roles of combined substitutions in the spike receptor binding domain (RBD) were observed in neutralisation resistance. However, recombinant viruses with the entire spike protein from a specific VOC showed enhanced resistance, indicating that changes outside the RBD are also significant. In silico analyses of spike antibody epitopes suggested changes in neutralisation could be due to altered antibody binding affinities. Assessing ACE2 usage for entry through anti-ACE2 antibody blocking and ACE2 siRNA revealed that omicron BA.2.86 and JN.1 mutant viruses were less dependent on ACE2 for entry. However, surface plasmon resonance analysis showed increased affinity for ACE2 for both BA.2.86 and JN.1 compared to the ancestral spike. This detailed analysis of specific changes in the SARS-CoV-2 spike enhances understanding of coronavirus evolution, particularly regarding neutralising antibody evasion and ACE2 entry receptor dependence.

Prolonged Omicron-specific B cell maturation alleviates immune imprinting induced by SARS-CoV-2 inactivated vaccine.

SARS-CoV-2 ancestral strain-induced immune imprinting poses great challenges to updating vaccines for new variants. Studies showed that repeated Omicron exposures could override immune imprinting induced by inactivated vaccines but not mRNA vaccines, a disparity yet to be understood. Here, we analyzed the immune imprinting alleviation in inactivated vaccine (CoronaVac) cohorts after a long-term period following breakthrough infections (BTI). We observed in CoronaVac-vaccinated individuals who experienced BA.5/BF.7 BTI, the proportion of Omicron-specific memory B cells (MBCs) substantially increased after an extended period post-Omicron BTI, with their antibodies displaying enhanced somatic hypermutation and neutralizing potency. Consequently, the neutralizing antibody epitope distribution encoded by MBCs post-BA.5/BF.7 BTI after prolonged maturation closely mirrors that in BA.5/BF.7-infected unvaccinated individuals. Together, these results indicate the activation and expansion of Omicron-specific naïve B cells generated by first-time Omicron exposure helped to alleviate CoronaVac-induced immune imprinting, and the absence of this process should have caused the persistent immune imprinting seen in mRNA vaccine recipients.

A pontine-medullary loop crucial for REM sleep and its deficit in Parkinson's disease.

Identifying the properties of the rapid eye movement (REM) sleep circuitry and its relation to diseases has been challenging due to the neuronal heterogeneity of the brainstem. Here, we show in mice that neurons in the pontine sublaterodorsal tegmentum (SubLDT) that express corticotropin-releasing hormone-binding protein (Crhbp+ neurons) and project to the medulla promote REM sleep. Within the medullary area receiving projections from Crhbp+ neurons, neurons expressing nitric oxide synthase 1 (Nos1+ neurons) project to the SubLDT and promote REM sleep, suggesting a positively interacting loop between the pons and the medulla operating as a core REM sleep circuit. Nos1+ neurons also project to areas that control wide forebrain activity. Ablating Crhbp+ neurons reduces sleep and impairs REM sleep atonia. In Parkinson's disease patients with REM sleep behavior disorders, CRHBP-immunoreactive neurons are largely reduced and contain pathologic α-synuclein, providing insight into the mechanisms underlying the sleep deficits characterizing this disease.

Evaluation of the Effect of mRNA and Inactivated SARS-CoV-2 Vaccines on the Levels of Cytokines IL-2, IFN-γ, and Anti-RBD Spike SARS-CoV-2 Antibodies in People Living with HIV (PLHIV).

The safety of the mRNA and inactivated SARS-CoV-2 vaccine has been demonstrated for people living with HIV (PLHIV). However, vaccine studies in PLHIV are limited, and there is a gap in which vaccine type provides the best response in PLHIV. Thus, PLHIV may benefit from mRNA vaccine types compared to inactivated vaccines. This study aims to assess the immune responses to vaccination by measuring specific antibodies (IgG) targeting the receptor binding sites (RBDs) of the SARS-CoV-2 virus and the levels of IL-2 and IFN-γ in plasma. A total of 41 PLHIV who regularly take antiretroviral therapy (ART) over a period of six months, along with 31 individuals in a healthy control group (HC), were administered either two mRNA or inactivated vaccines. Data regarding demographics and clinical information were gathered from the medical records. An analysis was conducted on the neutralisation antibody IgG specific to RBD using the chemiluminescence microparticle assay (CMIA). The levels of IL-2 and IFN-γ were quantified using the Luminex assay method from plasma samples. Data were collected in the laboratory 28 days after each vaccination. After the first vaccination, the level of anti-SARS-CoV-2 RBD IgG was higher in PLHIV who received the mRNA vaccines than those who received inactivated vaccines (p = 0.006). The levels of mRNA in the PLHIV group showed a significant correlation with IL-2 and IFN-γ after the second vaccination (r = 0.51, p = 0.0035; r = 0.68, p = 0.002). The group of PLHIV who received the inactivated vaccine showed increased IL-2 and IFN-γ after the initial vaccination, compared to PLHIV who received the mRNA vaccine (p = 0.04; p = 0.08). Administering a two-dose vaccination is essential to increase the levels of neutralising antibodies significantly (p = 0.013) in PLHIV who have received inactivated vaccines; further study is needed to make this a recommendation. The responses observed after vaccination in PLHIV were not affected by their CD4 cell counts. PLHIV showed higher levels of SARS-CoV-2 IgG and increased IL-2 and IFN-γ levels. Our study encourages SARS-CoV-2 vaccination in PLHIV regardless of its CD4 cell counts. Furthermore, the mRNA vaccine may give robust high antibody responses in PLHIV.

Study of Potential Blocking Peptides Targeting the SARS-CoV-2 RBD/hACE2 Interaction.

BACKGROUND/OBJECTIVES: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19, was declared a public health emergency in early 2020. The infection initiates when the receptor-binding domain (RBD) of the viral spike protein binds to human angiotensin-converting enzyme 2 (ACE2). Despite the success of vaccination efforts, the emergence of new variants highlights the ongoing need for treatments targeting these evolving strains. In silico methods previously identified peptides BP2, BP9, and BP11 as being capable of disrupting the RBD-ACE2 interaction, though their efficacy has not been experimentally validated until now. METHODS: In this study, these peptides were recombinantly produced in the yeast Komagataella phaffii, and the activity was assessed in vitro using binding assays with multiple RBD variants and the inhibition of the RBD-ACE2 interaction. RESULTS: The production yield for BP2, BP9, and BP11 was 14.34, 4.01, and 1.35 mg per culture liter, respectively. Noteworthy, the three BPs interacted with the RBD of SARS-CoV-2 variants of concern, with BP2 showing higher recognition. Finally, the BPs showed an RBD/hACE2 interaction blocking capacity with IC50 values between 1.03 and 5.35 nM, with BP2 showing the lowest values among the evaluated peptides. CONCLUSIONS: These results demonstrate that BP2, specifically, is a promising candidate for the development of novel therapeutic interventions targeting SARS-CoV-2 and other coronaviruses that use hACE2 for cellular entry.

Structural inscrutabilities of Histone (H2BK123) monoubiquitination: A systematic review.

Histone H2B monoubiquitination in budding yeast is a highly conserved post-translational modification. It is involved in normal functions of the cells like DNA Repair, RNA Pol II activation, trans-histone H3K and H79K methylation, meiosis, vesicle budding, etc. Deregulation of H2BK123ub can lead to the activation of proto-oncogenes and is also linked to neurodegenerative and heart diseases. Recent discoveries have enhanced the mechanistic underpinnings of H2BK123ub. For the first time, the Rad6's acidic tail has been implicated in histone recognition and interaction with Bre1's RBD domain. The non-canonical backside of Rad6 showed inhibition in polyubiquitination activity. Bre1 domains RBD and RING play a role in site-specific ubiquitination. The role of single Alaline residue in Rad6 activity. Understanding the mechanism of ubiquitination before moving to therapeutic applications is important. Current advancements in this field indicate the creation of novel therapeutic approaches and a foundation for further study.

Emerging severe acute respiratory syndrome coronavirus 2 variants and their impact on immune evasion and vaccine-induced immunity.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants harboring mutations in the structural protein, especially in the receptor binding domain (RBD) of spike protein, have raised concern about potential immune escape. The spike protein of SARS-CoV-2 plays a vital role in infection and is an important target for neutralizing antibodies. The mutations that occur in the structural proteins, especially in the spike protein, lead to changes in the virus attributes of transmissibility, an increase in disease severity, a notable reduction in neutralizing antibodies generated and thus a decreased response to vaccines and therapy. The observed multiple mutations in the RBD of the spike protein showed immune escape because it increases the affinity of spike protein binding with the ACE-2 receptor of host cells and increases resistance to neutralizing antibodies. Cytotoxic T-cell responses are crucial in controlling SARS-CoV-2 infections from the infected tissues and clearing them from circulation. Cytotoxic T cells efficiently recognized the infected cells and killed them by releasing soluble mediator's perforin and granzymes. However, the overwhelming response of T cells and, subsequently, the overproduction of inflammatory mediators during severe infections with SARS-CoV-2 may lead to poor outcomes. This review article summarizes the impact of mutations in the spike protein of SARS-CoV-2, especially mutations of RBD, on immunogenicity, immune escape and vaccine-induced immunity, which could contribute to future studies focusing on vaccine design and immunotherapy.

Investigations on the Potential Role of Free-Ranging Wildlife as a Reservoir of SARS-CoV-2 in Switzerland.

Amid the SARS-CoV-2 pandemic, concerns surfaced regarding the spread of the virus to wildlife. Switzerland lacked data concerning the exposure of free-ranging animals to SARS-CoV-2 during this period. This study aimed to investigate the potential exposure of Swiss free-ranging wildlife to SARS-CoV-2. From 2020 to 2023, opportunistically collected samples from 712 shot or found dead wild mustelids (64 European stone and pine martens, 13 European badgers, 10 European polecats), canids (449 red foxes, 41 gray wolves, one golden jackal) and felids (56 Eurasian lynx, 18 European wildcats), as well as from 45 captured animals (39 Eurasian lynx, 6 European wildcats) were tested. A multi-step serological approach detecting antibodies to the spike protein receptor binding domain (RBD) and N-terminal S1 subunit followed by surrogate virus neutralization (sVNT) and pseudotype-based virus neutralization assays against different SARS-CoV-2 variants was performed. Additionally, viral RNA loads were quantified in lung tissues and in oronasal, oropharyngeal, and rectal swabs by reverse transcription polymerase chain reactions (RT-qPCRs). Serologically, SARS-CoV-2 exposure was confirmed in 14 free-ranging Swiss red foxes (prevalence 3.1%, 95% CI: 1.9-5.2%), two Eurasian lynx (2.2%, 95% CI: 0.6-7.7%), and one European wildcat (4.2%, 95% CI: 0.2-20.2%). Two positive foxes exhibited neutralization activity against the BA.2 and BA.1 Omicron variants. No active infection (viral RNA) was detected in any animal tested. This is the first report of SARS-CoV-2 antibodies in free-ranging red foxes, Eurasian lynx, and European wildcats worldwide. It confirms the spread of SARS-CoV-2 to free-ranging wildlife in Switzerland but does not provide evidence of reservoir formation. Our results underscore the susceptibility of wildlife populations to SARS-CoV-2 and the importance of understanding diseases in a One Health Concept.

The Protection Level of S-RBD SARS-CoV-2 Immunoglobulin G Antibodies Using the Chemiluminescent Immunoassay Compared to the Surrogate Virus Neutralization Test Method.

COVID-19 infection in high-risk populations is fatal and has a poor prognosis, necessitating a test to determine the protectiveness of immune response. Antibody testing is necessary to determine the body's immune response to COVID-19 infection and also vaccination strategies. Among the various methods available, the chemiluminescent immunoassay (CLIA) test is more widely used and accessible to determine antibody levels. This study aimed to determine the protection level of S-RBD SARS-CoV-2 IgG using CLIA compared to the Surrogate Virus Neutralization Test (SVNT). The population of this study comprised all healthcare professionals who experienced S-RBD SARS-CoV-2 IgG antibody level examinations. S-RBD SARS-CoV-2 IgG antibody levels were examined using CLIA and SVNT. The cut-off was determined using a receiver operating characteristic (ROC) curve, and area under the curve (AUC) measurements were evaluated. The result showed a strong positive correlation between S-RBD SARS-CoV-2 IgG CLIA and SVNT, with a value of r = 0.933 and p < 0.001. The value ≥ 37.29 BAU/mL was determined as the cut-off based on SVNT 30% inhibition level with sensitivity, specificity, and positive and negative predictive values of 96.5%, 90.9%, 96.5%, and 90.9%, respectively. A titer of antibodies greater than or equal to 37.29 BAU/mL with CLIA showed the presence of protective antibodies compared to SVNT.

Novel Competitive ELISA Utilizing Trimeric Spike Protein of SARS-CoV-2, Could Identify More Than RBD-RBM Specific Neutralizing Antibodies in Hybrid Sera.

Since the initiation of the COVID-19 pandemic, there has been a need for the development of diagnostic methods to determine the factors implicated in mounting an immune response against the virus. The most promising indicator has been suggested to be neutralizing antibodies (nAbs), which mainly block the interaction between the Spike protein (S) of SARS-CoV-2 and the host entry receptor ACE2. In this study, we aimed to develop and optimize conditions of a competitive ELISA to measure serum neutralizing titer, using a recombinant trimeric Spike protein modified to have six additional proline residues (S(6P)-HexaPro) and h-ACE2. The results of our surrogate Virus Neutralizing Assay (sVNA) were compared against the commercial sVNT (cPass, Nanjing GenScript Biotech Co., Nanjing City, China), using serially diluted sera from vaccinees, and a high correlation of ID50-90 titer values was observed between the two assays. Interestingly, when we tested and compared the neutralizing activity of sera from eleven fully vaccinated individuals who subsequently contracted COVID-19 (hybrid sera), we recorded a moderate correlation between the two assays, while higher sera neutralizing titers were measured with sVNA. Our data indicated that the sVNA, as a more biologically relevant model assay that paired the trimeric S(6P) with ACE2, instead of the isolated RBD-ACE2 pairing cPass test, could identify nAbs other than the RBD-RBM specific ones.

Major Alteration Of Motor Control During Rem Sleep In Mice Models Of Sleep Disorders.

Alteration of motor control during REM sleep has been extensively described in sleep disorders, in particular in isolated REM sleep behavior disorder (iRBD) and narcolepsy type 1 (NT1). NT1 is caused by the loss of orexin/hypocretin (ORX) neurons. Unlike in iRBD, the RBD comorbid symptoms of NT1 is not associated with alpha-synucleinopathies. To determine whether the chronic absence of ORX neuropeptides is sufficient to induce RBD symptoms, we analyzed during REM sleep the EMG signal of the prepro-hypocretin knockout mice (ORX-/-), a recognized mouse model of NT1. Then, we evaluated the severity of motor alterations by comparing EMG data of ORX-/- mice to those of mice with a targeted suppression of the sublaterodorsal glutamatergic neurotransmission, a recognized rodent model of iRBD. We found a significant alteration of tonic and phasic components of EMG during REM sleep in ORX-/- mice, with more phasic events and more REM sleep episodes without atonia compared to the control wild-type mice. However, these phasic events were fewer, shorter and less complex in ORX-/- mice compared to the RBD-like ORX-/- mice. We thus show that ORX-deficiency, as seen in NT1, is sufficient to impair muscle atonia during REM sleep with a moderate severity of alteration as compared to isolated RBD mice. As described in NT1 patients, we report a major inter-individual variability in the severity and the frequency of RBD symptoms in ORX-deficient mice.

Sleep disorders and Parkinson's disease: is there a right direction?

In the last years, the hypothesis of a close relationship between sleep disorders (SDs) and Parkinson's disease (PD) has significantly strengthened. Whether this association is causal has been also highlighted by recent evidence demonstrating a neurobiological link between SDs and PD. Thus, the question is not whether these two chronic conditions are mutually connected, but rather how and when this relationship is expressed. Supporting this, not all SDs manifest with the same temporal sequence in PD patients. Indeed, SDs can precede or occur concomitantly with the onset of the clinical manifestation of PD. This review discusses the existing literature, putting under a magnifying glass the timing of occurrence of SDs in PD-neurodegeneration. Based on this, here, we propose two possible directions for studying the SDs-PD relationship: the first direction, from SDs to PD, considers SDs as potential biomarker/precursor of future PD-neurodegeneration; the second direction, from PD to SDs, considers SDs as concomitant symptoms in manifest PD, mainly related to primary PD-neuropathology and/or parkinsonian drugs. Furthermore, for each direction, we questioned SDs-PD relationship in terms of risk factors, neuronal circuits/mechanisms, and impact on the clinical phenotype and disease progression. Future research is needed to investigate whether targeting sleep may be the winning strategy to treat PD, in the context of a personalized precision medicine.

Mosaic sarbecovirus nanoparticles elicit cross-reactive responses in pre-vaccinated animals.

Immunization with mosaic-8b (nanoparticles presenting 8 SARS-like betacoronavirus [sarbecovirus] receptor-binding domains [RBDs]) elicits more broadly cross-reactive antibodies than homotypic SARS-CoV-2 RBD-only nanoparticles and protects against sarbecoviruses. To investigate original antigenic sin (OAS) effects on mosaic-8b efficacy, we evaluated the effects of prior COVID-19 vaccinations in non-human primates and mice on anti-sarbecovirus responses elicited by mosaic-8b, admix-8b (8 homotypics), or homotypic SARS-CoV-2 immunizations, finding the greatest cross-reactivity for mosaic-8b. As demonstrated by molecular fate mapping, in which antibodies from specific cohorts of B cells are differentially detected, B cells primed by WA1 spike mRNA-LNP dominated antibody responses after RBD-nanoparticle boosting. While mosaic-8b- and homotypic-nanoparticles boosted cross-reactive antibodies, de novo antibodies were predominantly induced by mosaic-8b, and these were specific for variant RBDs with increased identity to RBDs on mosaic-8b. These results inform OAS mechanisms and support using mosaic-8b to protect COVID-19-vaccinated/infected humans against as-yet-unknown SARS-CoV-2 variants and animal sarbecoviruses with human spillover potential.

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

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.

Impact of Institutionalisation of Births on Health Policies and Birth Registration in India.

Background: The Registration of Births and Deaths Act (RBD) of 1969 in India mandates continuous recording of vital events; however, after more than 50 years of its enactment, universality remains elusive. Birth registration, a fundamental right, is essential for demographic analysis and effective policy planning. Birth registration is closely linked to child development, access to healthcare, and other societal factors. Analysing its trends helps in designing targeted interventions and monitoring progress toward the Sustainable Development Goals (SDGs). Objectives: This paper aims to analyse the changes in birth registration across Indian states. This paper also examines the impact of institutionalization of births on registration and underscores its significance in policymaking. Methods: The study utilises data from the latest two rounds of National Family Health Survey (NFHS-4 & NFHS-5) to analyse birth registration trends in India. Multivariable logistic regression analysis was employed to examine the impact of place of delivery on birth registration. Findings: The comparison of NFHS-4 and NFHS-5 data demonstrates varying birth registration rates across Indian states, with notable progress in some regions and persistent challenges in others. Multivariable logistic regression analysis highlights the significant influence of place of delivery on registration likelihood. The interaction between wealth and place of delivery suggests a mitigating effect, indicating that increasing institutional births has a positive impact on birth registration, with this effect being more pronounced at different levels of household wealth. It highlights that wealthier households were more likely to register births due to the higher rate of institutional deliveries. Conclusion: India's journey towards universal birth registration under the SDGs presents progress and challenges. NFHS data shows improvements in birth registration, but disparities still persist. Socio-economic status, place of delivery, and maternal education have strong influences on birth registration. Institutional deliveries significantly increase registration likelihood, facilitated by programs like Janani Suraksha Yojana. Integrating birth registration with health services enhances health data accuracy and service delivery. By prioritising targeted interventions, addressing social barriers, and leveraging existing programs, India can ensure that every child's birth is registered, advancing towards a healthier, more equitable future.