Turbinate Research Articles

Evaluation of the Effect of Nasal Septal Deviation and Concha Bullosa on Maxillary Sinus Volume by Cone Beam Computed Tomography

Purpose: The aim of this study was to examine, using cone beam computed tomography images, the direction and severity of nasal septal deviation as well as the relationship between the presence of concha bullosa with maxillary sinus volume.
 Materials & Methods: In this retrospective study, images of 50 individuals who had been referred for cone beam computed tomography imaging for a variety of reasons were used. Age, gender, the direction and severity of the nasal septal deviation, and the presence and types of concha bullosa, were all investigated. The maxillary sinus volume was calculated using the Simplant Pro 16 program (Materialise NV, Leuven, Belgium). SPSS v.22 software was used for all statistical analyses. The statistical significance level was accepted as p

Novel Spike-stabilized trimers with improved production protect K18-hACE2 mice and golden Syrian hamsters from the highly pathogenic SARS-CoV-2 Beta variant.

Most COVID-19 vaccines are based on the SARS-CoV-2 Spike glycoprotein (S) or their subunits. However, S shows some structural instability that limits its immunogenicity and production, hampering the development of recombinant S-based vaccines. The introduction of the K986P and V987P (S-2P) mutations increases the production and immunogenicity of the recombinant S trimer, suggesting that these two parameters are related. Nevertheless, S-2P still shows some molecular instability and it is produced with low yield. Here we described a novel set of mutations identified by molecular modeling and located in the S2 region of the S-2P that increase its production up to five-fold. Besides their immunogenicity, the efficacy of two representative S-2P-based mutants, S-29 and S-21, protecting from a heterologous SARS-CoV-2 Beta variant challenge was assayed in K18-hACE2 mice (an animal model of severe SARS-CoV-2 disease) and golden Syrian hamsters (GSH) (a moderate disease model). S-21 induced higher level of WH1 and Delta variants neutralizing antibodies than S-2P in K18-hACE2 mice three days after challenge. Viral load in nasal turbinate and oropharyngeal samples were reduced in S-21 and S-29 vaccinated mice. Despite that, only the S-29 protein protected 100% of K18-hACE2 mice from severe disease. When GSH were analyzed, all immunized animals were protected from disease development irrespectively of the immunogen they received. Therefore, the higher yield of S-29, as well as its improved immunogenicity and efficacy protecting from the highly pathogenic SARS-CoV-2 Beta variant, pinpoint the S-29 mutant as an alternative to the S-2P protein for future SARS-CoV-2 vaccine development.

Adaptation in brain structure and respiratory and olfactory structures across environmental gradients in African and North American muroid rodents.

Morphometric studies of 3D micro CT-scanned images can provide insights into the evolution of the brain and sensory structures but such data are still scarce for the most diverse mammalian order of rodents. From reviewed and new data, we tested for convergence to extreme aridity and high elevation in the sensory and brain morphology of rodents, from morphometric data from micro-CT X-ray scans of 174 crania of 16 species of three distantly related African murid (soft-furred mice, Praomyini, laminate-toothed rats, Otomyini, and gerbils, Gerbillinae) clades and one North American cricetid (deer mice and white-footed mice, Peromyscus) clade. Recent studies demonstrated convergent evolution acting on the oval window area of the cochlea (enlarged in extremely arid-adapted species of Otomyini and Gerbillinae) and on endocranial volume (reduced in high elevation taxa of Otomyini and Peromyscus). However, contrary to our predictions, we did not find evidence of convergence in brain structure to aridity, or in the olfactory/respiratory system (turbinate bones) to high elevation. Brain structure differed, particularly in the petrosal lobules of the cerebellum and the olfactory bulbs, between Otomyini and Gerbillinae, with extreme arid-adapted species in each clade being highly divergent (not convergent) from other species in the same clade. We observed greater "packing" of the maxillary turbinate bones, which have important respiratory functions, in Peromyscus mice from high and low elevations compared to the high-elevation African Praomyini, but more complex patterns within Peromyscus, probably related to trade-offs in respiratory physiology and heat exchange in the nasal epithelium associated with high-elevation adaptation.

ЧАСТЫЕ КЛИНИЧЕСКИЕ ПРИЗНАКИ ЗАБОЛЕВАНИЙ НОСА И ОКОЛОНОСОВЫХ ПАЗУХ У БОЛЬНЫХ ХРОНИЧЕСКОЙ ПОЧЕЧНОЙ НЕДОСТАТОЧНОСТЬЮ

Abstract. Introduction. Adequate advanced hemodialysis techniques reduce nosebleeds in patients with chronic renal failure. The most common otorhinolaryngological manifestations were nasal mucosa dryness, lower nasal concha pallor, and, to a lesser extent, crusts on both the nasal septum and the lower nasal concha. Aim of the study was to assess the frequency of various initial manifestations in hemodialysis patients with chronic renal failure. Materials and Methods. A crossover study was conducted in 2020-2022. It included 68 patients with chronic renal failure, receiving regular hemodialysis for 6 months and longer. Results and Discussion. Nasal mucosae were normal in 45.6% of patients, dry in 44.1%, and hyperemic in 10.3%. Inferior nasal conchae were pallor in 44.1% of patients, normal in 35.3%, and hypertrophic in 13.2%. Crusts were found in inferior nasal conchae in 7.4% of patients and in nasal septum in 14.7% of patients. Frequency of nosebleeds was lower in regularly hemodialyzed patients with chronic renal failure. Conclusions. Analysis of the studies conducted shows that the frequency of nosebleeds was reduced in regularly hemodialyzed patients with chronic renal failure. Ulceration and perforation of the nasal septum are the least frequent otorhinolaryngological signs. No cases of olfactory neuropathy were reported in our study.

Exploring the frontal recess: Specimens, endoscopy, and CT perspectives

Abstract The frontal sinus, situated between the external and internal plates of the frontal bone, posterior to the brow ridges, is the most superior and complex structure within the paranasal sinuses. The frontal sinus outflow tract encompasses two parts: the frontal ostium superiorly and the frontal recess inferiorly, collectively forming the frontal sinus drainage pathway. The frontal recess represents the most anterosuperior portion of the ethmoid. Pneumatization of this area can extend from the agger nasi cell anteriorly to the ethmoidal bulla posteriorly. This recess is bounded by the orbital plate of the ethmoid laterally and the middle nasal concha (‘middle turbinate’) medially. The detailed understanding of frontal sinus anatomy is indispensable for medical professionals, including surgeons, otolaryngologists, rhinologists, and radio-logists. The frontal recess is clinically important, especially in the diagnosis and management of various medical conditions, particularly sinusitis. Surgeons often need to navigate this intricate area. Radiological imaging, such as computed tomography (CT) scans, is frequently employed to evaluate the frontal sinus and its drainage pathway, enabling clinicians to identify abnormalities such as tumors, polyps, or foreign bodies. In this study, we investigated the anatomical intricacies of the frontal recess using specimens, CT scans, and endoscopic imagery sourced from didactic and clinical settings.

Trends in Nasal Septal and Inferior Turbinate Surgery in Korea From 2010 to 2022

Background and Objectives: Since the introduction of nasal valve surgery, trends in septoplasty and inferior turbinate surgery (ITS) have changed in Korea. However, a detailed analysis of these changes has yet to be conducted.Methods: Data on septoplasty and ITS performed from 2010 to 2022 were extracted from the Health Insurance Review and Assessment Service (HIRA) Bigdata Open portal and trends were analyzed. Analyses according to the type of medical institution, patient sex and age, and the specialty of the surgeon were also conducted.Results: The frequency of both septoplasty and ITS gradually decreased from 2012 to 2017, which marked the low point, and the frequency of these procedures gradually increased thereafter. In 2010, 41.5% of septoplasty procedures were performed in general hospitals, 7.3% in hospitals, and 47.3% in clinics. However, the proportion of these procedures performed in general hospitals subsequently decreased, while the corresponding proportion in hospitals and clinics increased. Both septoplasty and ITS were performed more than twice as often in men than in women. The number of patients under the age of 19 decreased, while the number of female patients aged 20–29 increased. The number of septoplasty procedures performed by plastic surgeons increased.Conclusion: Since the introduction of nasal valve surgery, the number of septoplasty procedures performed by plastic surgeons has increased.

Types of the nasal septum deviations and their influence on the state of mucociliary clearance of the nasal cavity in patients with postnasal obstruction syndrome

The flow of nasal secretions into the pharynx and larynx manifests itself differently throughout the day. At night, this mucus flows into the larynx, irritates reflexogenic zones and causes coughing, and during the day these complaints are less noticeable, due to involuntary swallowing of secretions. We hypothesized that different types of nasal septum deviations may affect mucociliary clearance and, as a result, lead to postnasal drip syndrome. However, we did not find any studies in the literature that examined the effect of types of nasal septum deviation (NSD) on mucociliary clearance (MCC). Therefore, in our study, we evaluated the effect of the types of nasal septum deviations on MCC. The aim of the study. To investigate the activity of mucociliary clearance of the mucous membrane of the nasal cavity in patients with different types of NSD. Materials and methods. 100 patients were investigated. All patients underwent an endoscopic examination of the nasal cavity, a ST scan of the nasal cavity, and a saccharin test. The results. The analysis made it possible to reveal that in most patients with type 2 deviation of the nasal septum with the presence of a unilateral caudal ridge, which cuts into the middle turbinate, there is PNDS. At the same time, while the average ST time of the concave side of the nasal mucosa in patients with type 1 was almost unchanged, it was significantly longer in patients with type 2 (P=0,02). Therefore, in this study, the ST indicator in min. was longer on the concave side of the nasal cavity than on the convex side. Conclusions. Our research has shown that nasal septum deviation reduces nasal mucociliary activity, and this effect can be easily assessed using the saccharin test. According to our observations and research results, it was the 2nd and 3rd types of deviation that significantly disturbed the architecture of the nasal cavity, due to the presence of contralateral vertical deviation of the nasal septum, contralateral hyperplasia of the nasal turbinates, and contralateral conchobulosis. And, as a result, led to a decrease in mucociliary clearance

SARS-CoV-2 Aerosol and Intranasal Exposure Models in Ferrets.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the worldwide COVID-19 pandemic. Animal models are extremely helpful for testing vaccines and therapeutics and for dissecting the viral and host factors that contribute to disease severity and transmissibility. Here, we report the assessment and comparison of intranasal and small particle (~3 µm) aerosol SARS-CoV-2 exposure in ferrets. The primary endpoints for analysis were clinical signs of disease, recovery of the virus in the upper respiratory tract, and the severity of damage within the respiratory tract. This work demonstrated that ferrets were productively infected with SARS-CoV-2 following either intranasal or small particle aerosol exposure. SARS-CoV-2 infection of ferrets resulted in an asymptomatic disease course following either intranasal or small particle aerosol exposure, with no clinical signs, significant weight loss, or fever. In both aerosol and intranasal ferret models, SARS-CoV-2 replication, viral genomes, and viral antigens were detected within the upper respiratory tract, with little to no viral material detected in the lungs. The ferrets exhibited a specific IgG immune response to the SARS-CoV-2 full spike protein. Mild pathological findings included inflammation, necrosis, and edema within nasal turbinates, which correlated to positive immunohistochemical staining for the SARS-CoV-2 virus. Environmental sampling was performed following intranasal exposure of ferrets, and SARS-CoV-2 genomic material was detected on the feeders and nesting areas from days 2-10 post-exposure. We conclude that both intranasal and small particle aerosol ferret models displayed measurable parameters that could be utilized for future studies, including transmission studies and testing SARS-CoV-2 vaccines and therapeutics.

A Rotation Alar Fold Flap for Cosmetic Nasal Plane Reconstruction: Description of the Technique and Outcome in Three Dogs.

Nasal planum reconstruction is a surgical challenge, and several surgical techniques have been described. The objective of this study was to describe the rotation alar fold flap technique and to report clinical outcomes in a short case series. The feasibility of the technique was first assessed in a canine cadaveric model. The rotation alar fold flap was obtained by a single sharp horizontal incision of the dorsolateral nasal cartilage, preserving the caudal mucosal attachment to the ventral nasal concha. The flap was then rotated ventro-medially for the reconstruction of the ventral aspect of the nasal planum unilaterally or bilaterally. The rotation alar fold flap technique was used following a subtotal or partial planectomy for excision of a squamous cell carcinoma or mast cell tumors in three dogs. No intraoperative complications were recorded. Superficial surgical site infection was reported in two cases and minor dehiscence was reported in one case. However, survival of the flap was not affected. The cosmetic and functional outcomes were considered very satisfactory in all cases. The rotation alar fold flap technique offers a safe, valuable, feasible, functional and aesthetically satisfactory alternative surgical option for selected cases of localized tumor involving the central and ventral planum.

Safety Evaluation of an Intranasally Applied Cocktail of Lactococcus lactis Strains in Pigs.

Three Lactococcus lactis strains from the nasal microbiota of healthy pigs were identified as candidates for reducing MRSA in pigs. The safety of nasal administration of a cocktail of these strains was examined in new-born piglets. Six days pre-farrowing, twelve sows were assigned to the placebo or cocktail group (n = 6/group). After farrowing, piglets were administered with either 0.5 mL of the placebo or the cocktail to each nostril. Health status and body weight were monitored at regular time points. Two piglets from three sows/treatment group were euthanised at 24 h, 96 h and 14 d after birth, and conchae, lung and tonsil samples were collected for histopathological and gene expression analysis. Health scores were improved in the cocktail group between d1-5. Body weight and daily gains did not differ between groups. Both groups displayed histological indications of euthanasia and inflammation in the lungs, signifying the findings were not treatment related. The expression of pBD2, TLR9 and IL-1β in the nasal conchae differed between groups, indicating the cocktail has the potential to modulate immune responses. In summary, the L. lactis cocktail was well tolerated by piglets and there was no negative impact on health scores, growth or lung histopathology indicating that it is safe for administration to new-born piglets.

Abstract 12525: Acute Pulmonary Edema, Mid-Ventricular Stress Cardiomyopathy and Cardiogenic Shock Following Intranasal Lidocaine/Epinephrine Administration During Septorhinoplasty

Case Presentation: A 19-year-old female presented for elective septorhinoplasty for nasal septal deviation and turbinate hypertrophy. After induction of anesthesia, and orotracheal intubation, pledgets soaked in 4% topical lidocaine with 1:1,000 epinephrine were placed in bilateral nares. Next, 1% lidocaine with 1:100,000 epinephrine was locally injected in the nasal mucosa to obtain hemostasis and analgesia. This resulted in transient hypertensive emergency, followed by undifferentiated shock requiring the initiation of norepinephrine. No signs of ischemia were seen on EKG. Chest X-ray revealed acute pulmonary edema. TTE showed reduced left ventricular systolic function, EF 30%, with mid-segment akinesis, consistent with mid-ventricular stress cardiomyopathy. Coronary angiography identified normal anatomy and patent arteries, supporting the diagnosis. Surveillance TTE after extubation and empiric treatment with metoprolol and losartan, showed improvement of EF to 45-50% and resolution of regional wall motion abnormalities. Discussion: Stress cardiomyopathy, also known as Takotsubo (TCM), is a rare form of cardiomyopathy accounting for 2-3% of ACS. The syndrome mainly affects the LV, causing a regional, transient, systolic dysfunction visualized on TTE or left ventriculography, that occurs in the absence of obstructive epicardial coronary lesions. Pathogenesis is poorly understood. Postulated mechanisms include catecholamine excess, coronary artery spasm and microvascular dysfunction. A systematic review found elevated norepinephrine levels in 74.3% of patients diagnosed with TCM, as was the case for our patient. Rapid systemic absorption of epinephrine can cause diffuse microvascular spasm and myocardial stunning. Catecholamine surge may also afflict direct myocardial toxicity, leading to disorganized cytoskeletal structures, excess extracellular matrix proteins and dysfunctional contractile properties of the myocardium.

An FcRn-targeted mucosal vaccine against SARS-CoV-2 infection and transmission

SARS-CoV-2 is primarily transmitted through droplets and airborne aerosols, and in order to prevent infection and reduce viral spread vaccines should elicit protective immunity in the airways. The neonatal Fc receptor (FcRn) transfers IgG across epithelial barriers and can enhance mucosal delivery of antigens. Here we explore FcRn-mediated respiratory delivery of SARS-CoV-2 spike (S). A monomeric IgG Fc was fused to a stabilized spike; the resulting S-Fc bound to S-specific antibodies and FcRn. Intranasal immunization of mice with S-Fc and CpG significantly induced antibody responses compared to the vaccination with S alone or PBS. Furthermore, we intranasally immunized mice or hamsters with S-Fc. A significant reduction of virus replication in nasal turbinate, lung, and brain was observed following nasal challenges with SARS-CoV-2 and its variants. Intranasal immunization also significantly reduced viral airborne transmission in hamsters. Nasal IgA, neutralizing antibodies, lung-resident memory T cells, and bone-marrow S-specific plasma cells mediated protection. Hence, FcRn delivers an S-Fc antigen effectively into the airway and induces protection against SARS-CoV-2 infection and transmission.

Chemoprophylactic Assessment of Combined Intranasal SARS-CoV-2 Polymerase and Exonuclease Inhibition in Syrian Golden Hamsters.

Pibrentasvir (PIB) has been demonstrated to block exonuclease activity of the SARS-CoV-2 polymerase, protecting favipiravir (FVP) and remdesivir (RDV) from post-incorporation excision and eliciting antiviral synergy in vitro. The present study investigated the chemoprophylactic efficacy of PIB, FVP, RDV, FVP with PIB, or RDV with PIB dosed intranasally twice a day, using a Syrian golden hamster contact transmission model. Compared to the saline control, viral RNA levels were significantly lower in throat swabs in FVP (day 7), RDV (day 3, 5, 7), and RDV+PIB (day 3, 5) treatment groups. Similarly, findings were evident for nasal turbinate after PIB and RDV treatment, and lungs after PIB, FVP, and FVP+PIB treatment at day 7. Lung viral RNA levels after RDV and RDV+PIB treatment were only detectable in two animals per group, but the overall difference was not statistically significant. In situ examination of the lungs confirmed SARS-CoV-2 infection in all animals, except for one in each of the RDV and RDV+PIB treatment groups, which tested negative in all virus detection approaches. Overall, prevention of transmission was observed in most animals treated with RDV, while other agents reduced the viral load following contact transmission. No benefit of combining FVP or RDV with PIB was observed.

Case Report: Case report: An unusual presentation of granulomatosis with polyangiitis

Aim: We are reporting a case of an unusual presentation of granulomatosis with polyangiitis (GPA) with liver involvement. Case presentation: A 45-year-old male patient presented with erythematous plaques on the face and bilateral nasal obstruction. On physical examination, the patient had a ring-shaped squamous plaque on the face. The laboratory findings revealed an accelerated erythrocyte sedimentation rate at 100 mm/h, an elevated C-reactive protein at 66 mg/L, hyper gamma globulinemia 16 g/L and an elevated alkaline phosphatase (twice the upper normal limit). The craniofacial and thoracoabdominal computed tomography (CT) -scans showed ethmoid and maxillary sinusitis, low facial bone density, multiple mediastinal and hilar lymphadenopathy, diffuse small pulmonary nodules, and hepatomegaly. A cutaneous lesion biopsy, the nasal mucosa, and the liver showed a chronic inflammatory granulomatosis process with necrosis. Serum anti-neutrophil cytoplasmic antibody (ANCA) against PR3 was positive. The clinical, biological, radiological, and histological findings substantiated the diagnosis of GPA. The patient received systemic steroids combined with cyclophosphamide pulses on days 1, 14 and 28 and then he was lost to follow-up. Two-years later, he presented with a cardiac failure and skin ulcer in the right lower limb. A nasal endoscopic exam showed nasal septum cartilage perforation with resorption of the middle and inferior nasal concha. Two weeks later, he developed a diffuse alveolar hemorrhage and was therefore transferred to the intensive care unit but died of respiratory failure 3 days later. Conclusion: Clinicians should be aware of GPA atypical clinical manifestations.

Combination of CRISPR-Cas9-RNP and Single-Cell RNAseq to Identify Cell State-Specific FOXJ1 Functions in the Human Airway Epithelium.

The study of the airway epithelium in vitro is routinely performed using air-liquid culture (ALI) models from nasal or bronchial basal cells. These 3D experimental models allow to follow the regeneration steps of fully differentiated mucociliary epithelium and to study gene function by performing gene invalidation. Recent progress made with CRISPR-based techniques has overcome the experimental difficulty of this approach, by a direct transfection of ribonucleoprotein complexes combining a mix of synthetic small guide RNAs (sgRNAs) and recombinant Cas9. The approach shows more than 95% efficiency and does not require any selection step. A limitation of this approach is that it generates cell populations that contain heterogeneous deletions, which makes the evaluation of invalidation efficiency difficult. We have successfully used Flongle sequencing (Nanopore) to quantify the number of distinct deletions. We describe the use of CRISPR-Cas9 RNP in combination with single-cell RNA sequencing to functionally characterize the impact of gene invalidation in ALI cultures. The complex ecosystem of the airway epithelium, composed of many cell types, makes single-cell approaches particularly relevant to study cell type, or cell state-specific events. This protocol describes the invalidation of FOXJ1 in ALI cultures through the following steps: (1) Establishment of basal cell cultures from nasal turbinates, (2) CRISPR-Cas9 RNP invalidation of FOXJ1, (3) Quantification of FOXJ1 invalidation efficiency by Nanopore sequencing, (4) Dissociation of ALI cultures and single-cell RNAseq, (5) Analysis of single-cell RNAseq data from FOXJ1-invalidated cells.We confirm here that FOXJ1 invalidation impairs the final differentiation step of multiciliated cells and provides a framework to explore other gene functions.

Cultured Mesenchymal Cells from Nasal Turbinate as a Cellular Model of the Neurodevelopmental Component of Schizophrenia Etiology.

The study of neurodevelopmental molecular mechanisms in schizophrenia requires the development of adequate biological models such as patient-derived cells and their derivatives. We previously utilized cell lines with neural progenitor properties (CNON) derived from the superior or middle turbinates of patients with schizophrenia and control groups to study schizophrenia-specific gene expression. In this study, we analyzed single-cell RNA seq data from two CNON cell lines (one derived from an individual with schizophrenia (SCZ) and the other from a control group) and two biopsy samples from the middle turbinate (MT) (also from an individual with SCZ and a control). We compared our data with previously published data regarding the olfactory neuroepithelium and demonstrated that CNON originated from a single cell type present both in middle turbinate and the olfactory neuroepithelium and expressed in multiple markers of mesenchymal cells. To define the relatedness of CNON to the developing human brain, we also compared CNON datasets with scRNA-seq data derived from an embryonic brain and found that the expression profile of the CNON closely matched the expression profile one of the cell types in the embryonic brain. Finally, we evaluated the differences between SCZ and control samples to assess the utility and potential benefits of using CNON single-cell RNA seq to study the etiology of schizophrenia.

Synthesis, evaluation, and mechanism of 1-(4-(arylethylenylcarbonyl)phenyl)-4-carboxy-2-pyrrolidinones as potent reversible SARS-CoV-2 entry inhibitors

A class of 1-(4-(arylethylenylcarbonyl)phenyl)-4-carboxy-2-pyrrolidinones were designed and synthesized via Michael addition, cyclization, aldol condensation, and deprotonation to inhibit the human transmembrane protease serine 2 (TMPRSS2) and Furin, which are involved in priming the SARS-CoV-2 Spike for virus entry. The most potent inhibitor 2f (81) was found to efficiently inhibit the replication of various SARS-CoV-2 delta and omicron variants in VeroE6 and Calu-3 cells, with EC50 range of 0.001–0.026 μM by pre-incubation with the virus to avoid the virus entry. The more potent antiviral activities than the proteases inhibitory activities led to discovery that the synthesized compounds also inhibited Spike's receptor binding domain (RBD):angiotensin converting enzyme 2 (ACE2) interaction as a main target, and their antiviral activities were enhanced by inhibiting TMPRSS2 and/or Furin. To further confirm the blocking effect of 2f (81) on virus entry, SARS-CoV-2 Spike pseudovirus was used in the entry assay and the results showed that the compound inhibited the pseudovirus entry in a ACE2-dependent pathway, via mainly inhibiting RBD:ACE2 interaction and TMPRSS2 activity in Calu-3 cells. Finally, in the in vivo animal model of SARS-CoV-2 infection, the oral administration of 25 mg/kg 2f (81) in hamsters resulted in reduced bodyweight loss and 5-fold lower viral RNA levels in nasal turbinate three days post-infection. Our findings demonstrated the potential of the lead compound for further preclinical investigation as a potential treatment for SARS-CoV-2.

SARS-CoV-2 Protein Nanoparticle Vaccines Formed In Situ From Lyophilized Lipids.

The receptor binding domain (RBD) of the SARS-CoV-2 Spike (S) glycoprotein is an appealing immunogen, but associated vaccine approaches must overcome the hapten-like nature of the compact protein and adapt to emerging variants with evolving RBD sequences. Here, a vaccine manufacturing methodology is proposed comprising a sterile-filtered freeze-dried lipid cake formulation that can be reconstituted with liquid proteins to instantaneously form liposome-displayed protein nanoparticles. Mannitol is used as a bulking agent and a small amount of Tween-80 surfactant is required to achieve reconstituted submicron particles that do not precipitate prior to usage. The lipid particles include an E. coli-derived monophosphoryl lipid A (EcML) for immunogenicity, and cobalt porphyrin-phospholipid (CoPoP) for antigen display. Reconstitution of the lipid cake with aqueous protein results in rapid conversion of the RBD into intact liposome-bound format prior to injection. Protein particles can readily be formed with sequent-divergent RBD proteins derived from the ancestral or Omicron strains. Immunization of miceelicits antibodies that neutralize respective viral strains. When K18-hACE2 transgenic mice are immunized and challenged with ancestral SARS-CoV-2 or the Omicron BA.5 variant, both liquid liposomes displaying the RBD and rapid reconstituted particles protect mice from infection, as measured by the viral load in the lungs and nasal turbinates.

Fc-mediated functions of nirsevimab complement direct respiratory syncytial virus neutralization but are not required for optimal prophylactic protection.

Nirsevimab is an extended half-life (M252Y/S254T/T256E [YTE]-modified) monoclonal antibody to the pre-fusion conformation of the respiratory syncytial virus (RSV) Fusion protein, with established efficacy in preventing RSV-associated lower respiratory tract infection in infants for the duration of a typical RSV season. Previous studies suggest that nirsevimab confers protection via direct virus neutralization. Here we use preclinical models to explore whether fragment crystallizable (Fc)-mediated effector functions contribute to nirsevimab-mediated protection. Nirsevimab, MEDI8897* (i.e., nirsevimab without the YTE modification), and MEDI8897*-TM (i.e., MEDI8897* without Fc effector functions) binding to Fc γ receptors (FcγRs) was evaluated using surface plasmon resonance. Antibody-dependent neutrophil phagocytosis (ADNP), antibody-dependent cellular phagocytosis (ADCP), antibody-dependent complement deposition (ADCD), and antibody-dependent cellular cytotoxicity (ADCC) were assessed through in vitro and ex vivo serological analyses. A cotton rat challenge study was performed with MEDI8897* and MEDI8897*-TM to explore whether Fc effector functions contribute to protection from RSV. Nirsevimab and MEDI8897* exhibited binding to a range of FcγRs, with expected reductions in FcγR binding affinities observed for MEDI8897*-TM. Nirsevimab exhibited in vitro ADNP, ADCP, ADCD, and ADCC activity above background levels, and similar ADNP, ADCP, and ADCD activity to palivizumab. Nirsevimab administration increased ex vivo ADNP, ADCP, and ADCD activity in participant serum from the MELODY study (NCT03979313). However, ADCC levels remained similar between nirsevimab and placebo. MEDI8897* and MEDI8897*-TM exhibited similar dose-dependent reduction in lung and nasal turbinate RSV titers in the cotton rat model. Nirsevimab possesses Fc effector activity comparable with the current standard of care, palivizumab. However, despite possessing the capacity for Fc effector activity, data from RSV challenge experiments illustrate that nirsevimab-mediated protection is primarily dependent on direct virus neutralization.

Immune-epithelial cell cross-talk enhances antiviral responsiveness to SARS-CoV-2 in children.

The risk of developing severe COVID-19 rises dramatically with age. Schoolchildren are significantly less likely than older people to die from SARS-CoV-2 infection, but the molecular mechanisms underlying this age-dependence are unknown. In primary infections, innate immunity is critical due to the lack of immune memory. Children, in particular, have a significantly stronger interferon response due to a primed state of their airway epithelium. In single-cell transcriptomes of nasal turbinates, we find increased frequencies of immune cells and stronger cytokine-mediated interactions with epithelial cells, resulting in increased epithelial expression of viral sensors (RIG-I, MDA5) via IRF1. In vitro, adolescent peripheral blood mononuclear cells produce more cytokines, priming A549 cells for stronger interferon responses to SARS-CoV-2. Taken together, our findings suggest that increased numbers of immune cells in the airways of children and enhanced cytokine-based interactions with epithelial cells tune the setpoint of the epithelial antiviral system. Our findings shed light on the molecular basis of children's remarkable resistance to COVID-19 and may suggest a novel concept for immunoprophylactic treatments.