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Vaccines Jun 2024Sublingual vaccines offer the benefits of inducing mucosal immunity to protect against respiratory viruses, including Severe Acute Respiratory Syndrome Coronavirus 2...
Sublingual vaccines offer the benefits of inducing mucosal immunity to protect against respiratory viruses, including Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and influenza, while also enabling needle-free self-administration. In a previous study, a sublingual SARS-CoV-2 vaccination was created by combining a recombinafigureCoV-2 spike protein receptor-binding domain antigen with a double strand RNA Poly(I:C) adjuvant. This vaccine was tested on nonhuman primates, Cynomolgus macaques. This study examined the immune and inflammatory responses elicited by the sublingual influenza vaccine containing hemagglutinin (HA) antigen and Poly(I:C) adjuvants, and assessed the safety of this vaccine in nonhuman primates. The Poly(I:C)-adjuvanted sublingual vaccine induced both mucosal and systemic immunities. Specifically, the sublingual vaccine produced HA-specific secretory IgA antibodies in saliva and nasal washings, and HA-specific IgA and IgG were detected in the blood. This vaccine appeared to be safe, as judged from the results of blood tests and plasma C-reactive protein levels. Notably, sublingual vaccination neither increased the production of inflammation-associated cytokines-IFN-alpha, IFN-gamma, and IL-17-in the blood, nor upregulated the gene expression of proinflammatory cytokines-IL12A, IL12B, IFNA1, IFNB1, CD69, and granzyme B-in white blood cells. Moreover, DNA microarray analyses revealed that sublingual vaccination evoked both enhancing and suppressing expression changes in genes associated with immune-related responses in cynomolgus monkeys. Therefore, the sublingual vaccine with the Poly(I:C) adjuvant is safe, and creates a balanced state of enhancing and suppressing the immune-related response.
PubMed: 38932372
DOI: 10.3390/vaccines12060643 -
Vaccines Jun 2024There is minimal knowledge regarding the durability of neutralization capacity and level of binding antibody generated against the highly transmissible circulating...
There is minimal knowledge regarding the durability of neutralization capacity and level of binding antibody generated against the highly transmissible circulating Omicron subvariants following SARS-CoV-2 infection in children with acute COVID-19 and those diagnosed with multisystem inflammatory syndrome in children (MIS-C) in the absence of vaccination. In this study, SARS-CoV-2 neutralization titers against the ancestral strain (WA1) and Omicron sublineages were evaluated in unvaccinated children admitted for COVID-19 ( = 32) and MIS-C ( = 32) at the time of hospitalization (baseline) and at six to eight weeks post-discharge (follow-up) between 1 April 2020, and 1 September 2022. In addition, antibody binding to the spike receptor binding domain (RBD) from WA1, BA.1, BA.2.75, and BA.4/BA.5 was determined using surface plasmon resonance (SPR). At baseline, the children with MIS-C demonstrated two-fold to three-fold higher binding and neutralizing antibodies against ancestral WA1 compared to those with COVID-19. Importantly, in children with COVID-19, the virus neutralization titers against the Omicron subvariants at six to eight weeks post-discharge reached the same level as those with MIS-C had at baseline but were higher than titers at 6-8 weeks post-discharge for MIS-C cases. Cross-neutralization capacity against recently emerged Omicron BQ.1, BQ.1.1, and XBB.1 variants was very low in children with either COVID-19 or MIS-C at all time points. These findings about post-infection immunity in children with either COVID-19 or MIS-C suggest the need for vaccinations in children with prior COVID-19 or MIS-C to provide effective protection from emerging and circulating SARS-CoV-2 variants.
PubMed: 38932367
DOI: 10.3390/vaccines12060638 -
Vaccines Jun 2024The 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...
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.
PubMed: 38932334
DOI: 10.3390/vaccines12060605 -
Viruses Jun 2024Metabolic-associated fatty liver disease (MAFLD) is a risk factor for severe COVID-19. This study explores the potential influence of gut hormone receptor and immune...
UNLABELLED
Metabolic-associated fatty liver disease (MAFLD) is a risk factor for severe COVID-19. This study explores the potential influence of gut hormone receptor and immune response gene expression on COVID-19 outcomes in MAFLD patients.
METHODS
We investigated gene expression levels of , , , and in patients with MAFLD and COVID-19 compared to controls. We examined associations between gene expression and clinical outcomes.
RESULTS
COVID-19 patients displayed altered expression, potentially impacting immune response and recovery. Downregulated in patients with MAFLD correlated with increased coagulation parameters. Elevated expression in patients with MAFLD was linked to specific immune cell populations and hospital stay duration. A significantly lower expression was observed in both MAFLD and severe COVID-19.
CONCLUSION
Our findings suggest potential modulatory roles for , , and in COVID-19 and MAFLD.
Topics: Humans; COVID-19; Receptors, G-Protein-Coupled; Male; Female; Receptors, Aryl Hydrocarbon; SARS-CoV-2; Middle Aged; Aged; Receptors, Cytoplasmic and Nuclear; Gene Expression; Fatty Liver; Adult; RNA-Binding Proteins; Basic Helix-Loop-Helix Transcription Factors
PubMed: 38932276
DOI: 10.3390/v16060985 -
Viruses Jun 2024Innate immunity, the first line of host defense against viral infections, recognizes viral components through different pattern-recognition receptors. Nucleic acids... (Review)
Review
Innate immunity, the first line of host defense against viral infections, recognizes viral components through different pattern-recognition receptors. Nucleic acids derived from viruses are mainly recognized by Toll-like receptors, nucleotide-binding domain leucine-rich repeat-containing receptors, absent in melanoma 2-like receptors, and cytosolic DNA sensors (e.g., Z-DNA-binding protein 1 and cyclic GMP-AMP synthase). Different types of nucleic acid sensors can recognize specific viruses due to their unique structures. PANoptosis is a unique form of inflammatory cell death pathway that is triggered by innate immune sensors and driven by caspases and receptor-interacting serine/threonine kinases through PANoptosome complexes. Nucleic acid sensors (e.g., Z-DNA-binding protein 1 and absent in melanoma 2) not only detect viruses, but also mediate PANoptosis through providing scaffold for the assembly of PANoptosomes. This review summarizes the structures of different nucleic acid sensors, discusses their roles in viral infections by driving PANoptosis, and highlights the crosstalk between different nucleic acid sensors. It also underscores the promising prospect of manipulating nucleic acid sensors as a therapeutic approach for viral infections.
Topics: Humans; Virus Diseases; Immunity, Innate; Nucleic Acids; Animals; DNA-Binding Proteins; Viruses; Receptors, Pattern Recognition; RNA-Binding Proteins
PubMed: 38932258
DOI: 10.3390/v16060966 -
Viruses Jun 2024Multisystem Inflammatory Syndrome in Children (MIS-C) is a potentially life-threatening complication of COVID-19. The pathophysiological mechanisms leading to severe...
Multisystem Inflammatory Syndrome in Children (MIS-C) is a potentially life-threatening complication of COVID-19. The pathophysiological mechanisms leading to severe disease are poorly understood. This study leveraged clinical samples from a well-characterized cohort of children hospitalized with COVID-19 or MIS-C to compare immune-mediated biomarkers. Our objective was to identify selected immune molecules that could explain, in part, why certain SARS-CoV-2-infected children developed MIS-C. We hypothesized that type-2 helper T cell-mediated inflammation can elicit autoantibodies, which may account for some of the differences observed between the moderate-severe COVID-19 (COVID) and MIS-C cohort. We enumerated blood leukocytes and measured levels of selected serum cytokines, chemokines, antibodies to COVID-19 antigens, and autoantibodies in children presenting to an academic medical center in Connecticut, United States. The neutrophil/lymphocyte and eosinophil/lymphocyte ratios were significantly higher in those in the MIS-C versus COVID cohort. IgM and IgA, but not IgG antibodies to SARS-CoV-2 receptor binding domain were significantly higher in the MIS-C cohort than the COVID cohort. The serum levels of certain type-2 cytokines (interleukin (IL)-4, IL-5, IL-6, IL-8, IL-10, IL-13, and IL-33) were significantly higher in children with MIS-C compared to the COVID and SARS-CoV-2-negative cohorts. IgG autoantibodies to brain antigens and pentraxin were higher in children with MIS-C compared to SARS-CoV-19-negative controls, and children with MIS-C had higher levels of IgG anti-contactin-associated protein-like 2 (caspr2) compared to the COVID and SARS-CoV-19-negative controls. We speculate that autoimmune responses in certain COVID-19 patients may induce pathophysiological changes that lead to MIS-C. The triggers of autoimmunity and factors accounting for type-2 inflammation require further investigation.
Topics: Humans; COVID-19; Systemic Inflammatory Response Syndrome; Child; Female; Male; Prospective Studies; SARS-CoV-2; Child, Preschool; Autoantibodies; Cytokines; Adolescent; Infant; Biomarkers; Antibodies, Viral; Inflammation
PubMed: 38932242
DOI: 10.3390/v16060950 -
Viruses Jun 2024Disease resistance gene (R gene)-encoded nucleotide-binding leucine-rich repeat proteins (NLRs) are critical players in plant host defence mechanisms because of their...
Disease resistance gene (R gene)-encoded nucleotide-binding leucine-rich repeat proteins (NLRs) are critical players in plant host defence mechanisms because of their role as receptors that recognise pathogen effectors and trigger plant effector-triggered immunity (ETI). This study aimed to determine the putative role of a cassava coiled-coil (CC)-NLR (CNL) gene () (single allele) located on chromosome 12 in the tolerance or susceptibility to South African cassava mosaic virus (SACMV), one of the causal agents of cassava mosaic disease (CMD). A transient protoplast system was used to knock down the expression of by clustered regularly interspaced short palindromic repeats-CRISPR-associated protein 9 (CRISPR-Cas9). The -targeting CRISPR vectors and/or SACMV DNA A and DNA B infectious clones were used to transfect protoplasts isolated from leaf mesophyll cells from the SACMV-tolerant cassava () cultivar TME3. The CRISPR/Cas9 silencing vector significantly reduced expression in protoplasts whether with or without SACMV co-infection. Notably, SACMV DNA A replication was higher in protoplasts with lower expression levels than in non-silenced protoplasts. Mutagenesis studies revealed that protoplast co-transfection with CRISPR- silencing vector + SACMV and transfection with only SACMV induced nucleotide substitution mutations that led to altered amino acids in the highly conserved MHD motif of the -translated polypeptide. This may abolish or alter the regulatory role of the MHD motif in controlling R protein activity and could contribute to the increase in SACMV-DNA A accumulation observed in -silenced protoplasts. The results herein demonstrate for the first time a role for a CNL gene in tolerance to a geminivirus in TME3.
Topics: Manihot; Plant Diseases; Begomovirus; Virus Replication; Plant Proteins; Geminiviridae; CRISPR-Cas Systems; Disease Resistance; Protoplasts; Leucine-Rich Repeat Proteins
PubMed: 38932233
DOI: 10.3390/v16060941 -
Viruses Jun 2024The Omicron variant and its sub-lineages are the only current circulating SARS-CoV-2 viruses worldwide. In this study, the conformational stability of the isolated...
The Omicron variant and its sub-lineages are the only current circulating SARS-CoV-2 viruses worldwide. In this study, the conformational stability of the isolated Receptor Binding Domain (RBD) of Omicron's spike protein is examined in detail. The parent Omicron lineage has over ten mutations in the ACE2 binding region of the RBD that are specifically associated with its β hairpin loop domain. It is demonstrated through biophysical molecular computations that the mutations in the β hairpin loop domain significantly increase the intra-protein interaction energies of intra-loop and loop-RBD interactions. The interaction energy increases include the formation of new hydrogen bonds in the β hairpin loop domain that help stabilize this critical ACE2 binding region. Our results also agree with recent experiments on the stability of Omicron's core β barrel domain, outside of its loop domain, and help demonstrate the overall conformational stability of the Omicron RBD. It is further shown here through dynamic simulations that the unbound state of the Omicron RBD remains closely aligned with the bound state configuration, which was not observed for the wild-type RBD. Overall, these studies demonstrate the significantly increased conformational stability of Omicron over its wild-type configuration and raise a number of questions on whether conformational stability could be a positive selection feature of SARS-CoV-2 viral mutational changes.
Topics: Spike Glycoprotein, Coronavirus; SARS-CoV-2; Mutation; Protein Binding; Humans; Molecular Dynamics Simulation; Angiotensin-Converting Enzyme 2; Protein Conformation; Protein Domains; Protein Stability; COVID-19; Binding Sites
PubMed: 38932204
DOI: 10.3390/v16060912 -
Viruses May 2024As solid organ transplant (SOT) recipients remain at risk of severe outcomes after SARS-CoV-2 infections, vaccination continues to be an important preventive measure. In...
As solid organ transplant (SOT) recipients remain at risk of severe outcomes after SARS-CoV-2 infections, vaccination continues to be an important preventive measure. In SOT recipients previously vaccinated with at least three doses of BNT162b2, we investigated humoral responses to BNT162b2 booster doses. Anti-SARS-CoV-2 receptor binding domain (RBD) immunoglobulin G (IgG) was measured using an in-house ELISA. Linear mixed models were fitted to investigate the change in the geometric mean concentration (GMC) of anti-SARS-CoV-2 RBD IgG after vaccination in participants with intervals of more or less than six months between the last two doses of vaccine. We included 107 SOT recipients vaccinated with a BNT162b2 vaccine. In participants with an interval of more than six months between the last two vaccine doses, we found a 1.34-fold change in GMC per month (95% CI 1.25-1.44), while we found a 1.09-fold change in GMC per month (95% CI 0.89-1.34) in participants with an interval of less than six months between the last two vaccine doses, resulting in a rate ratio of 0.82 (95% CI 0.66 to 1.01, = 0.063). In conclusion, the administration of identical COVID-19 mRNA vaccine boosters within six months to SOT recipients may result in limited humoral immunogenicity of the last dose.
Topics: Humans; BNT162 Vaccine; COVID-19; Male; Female; Antibodies, Viral; Middle Aged; Immunity, Humoral; Transplant Recipients; SARS-CoV-2; Immunization, Secondary; Immunoglobulin G; Aged; Organ Transplantation; Adult; COVID-19 Vaccines; Vaccination; Spike Glycoprotein, Coronavirus
PubMed: 38932153
DOI: 10.3390/v16060860 -
Viruses May 2024Respiratory syncytial virus (RSV) is a major cause of severe respiratory tract disease worldwide, and a pediatric vaccine is not available. We generated a filamentous...
Intranasal Vaccination with a Respiratory-Syncytial-Virus-Based Virus-like Particle Displaying the G Protein Conserved Region Induces Severe Weight Loss and Pathology upon Challenge with Wildtype Respiratory Syncytial Virus.
Respiratory syncytial virus (RSV) is a major cause of severe respiratory tract disease worldwide, and a pediatric vaccine is not available. We generated a filamentous RSV-based virus-like particle (VLP) that presents the central conserved region of the attachment protein G. This was achieved by co-expressing the matrix protein, phosphoprotein, nucleoprotein, and a hybrid fusion protein in which the F ectodomain was replaced with the G central region (GCR). The latter is relatively conserved and contains a receptor binding site and hence is a logical vaccine target. The immunogenicity and efficacy of the resulting VLP, termed VLP-GCR, were examined in mice using intranasal application without adjuvant. VLP-GCR induced substantial anti-N antibody levels but very low anti-G antibody levels, even after three vaccinations. In contrast, a VLP presenting prefusion-stabilized fusion (preF) protein instead of GCR induced both high anti-F and anti-nucleoprotein antibody levels, suggesting that our GCR antigen was poorly immunogenic. Challenge of VLP-GCR-vaccinated mice caused increased weight loss and lung pathology, and both VLPs induced mucus in the lungs. Thus, neither VLP is suitable as a vaccine for RSV-naive individuals. However, VLP-preF enhanced the proportion of preF antibodies and could serve as a multi-antigen mucosal booster vaccine in the RSV-experienced population.
Topics: Animals; Female; Humans; Mice; Administration, Intranasal; Antibodies, Viral; Lung; Mice, Inbred BALB C; Respiratory Syncytial Virus Infections; Respiratory Syncytial Virus Vaccines; Respiratory Syncytial Virus, Human; Vaccination; Vaccines, Virus-Like Particle; Viral Envelope Proteins; Viral Fusion Proteins; Weight Loss
PubMed: 38932136
DOI: 10.3390/v16060843