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22
result(s) for
"Escalera, Alba"
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Immunological imprinting of the antibody response in COVID-19 patients
by
Abelenda-Alonso, Gabriela
,
García-Sastre, Adolfo
,
Rombauts, Alexander
in
13/1
,
631/250/2152/1566/1571
,
631/250/2152/2153
2021
In addition to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), humans are also susceptible to six other coronaviruses, for which consecutive exposures to antigenically related and divergent seasonal coronaviruses are frequent. Despite the prevalence of COVID-19 pandemic and ongoing research, the nature of the antibody response against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is unclear. Here we longitudinally profile the early humoral immune response against SARS-CoV-2 in hospitalized coronavirus disease 2019 (COVID-19) patients and quantify levels of pre-existing immunity to OC43, HKU1 and 229E seasonal coronaviruses, and find a strong back-boosting effect to conserved but not variable regions of OC43 and HKU1 betacoronaviruses spike protein. However, such antibody memory boost to human coronaviruses negatively correlates with the induction of IgG and IgM against SARS-CoV-2 spike and nucleocapsid protein. Our findings thus provide evidence of immunological imprinting by previous seasonal coronavirus infections that can potentially modulate the antibody profile to SARS-CoV-2 infection.
In addition to SARS-CoV-2, other coronaviruses also infect human, but whether consecutive infections cross-modulate the induced immune response is still unclear. Here the authors show that SARS-CoV-2 infection boosts pre-existing responses to other coronaviruses, yet such back-boosting hampers the induction of specific antibodies against SARS-CoV-2.
Journal Article
The impact of S2 mutations on Omicron SARS-CoV-2 cell surface expression and fusogenicity
by
Karakus, Umut
,
García-Sastre, Adolfo
,
Escalera, Alba
in
cell–cell fusion
,
COVID-19
,
COVID-19 Vaccines
2024
SARS-CoV-2 Omicron subvariants are still emerging and spreading worldwide. These variants contain a high number of polymorphisms in the spike (S) glycoprotein that could potentially impact their pathogenicity and transmission. We have previously shown that the S:655Y and P681H mutations enhance S protein cleavage and syncytia formation. Interestingly, these polymorphisms are present in Omicron S protein. Here, we characterized the cleavage efficiency and fusogenicity of the S protein of different Omicron sublineages. Our results showed that Omicron BA.1 subvariant is efficiently cleaved but it is poorly fusogenic compared to previous SARS-CoV-2 strains. To understand the basis of this phenotype, we generated chimeric S protein using combinations of the S1 and S2 domains from WA1, Delta and Omicron BA.1 variants. We found that the S2 domain of Omicron BA.1 hindered efficient cell-cell fusion. Interestingly, this domain only contains six unique polymorphisms never detected before in ancestral SARS-CoV-2 variants. WA1
S proteins containing the six individuals S2 Omicron mutations were assessed for their fusogenicity and S surface expression after transfection in cells. Results showed that the S:N856K and N969K substitutions decreased syncytia formation and impacted S protein cell surface levels. However, we observed that \"first-generation\" Omicron sublineages that emerged subsequently, had convergently evolved to an enhanced fusogenic activity and S expression on the surface of infected cells while \"second-generation\" Omicron variants have highly diverged and showed lineage-specific fusogenic properties. Importantly, our findings could have potential implications in the improvement and redesign of COVID-19 vaccines.
Journal Article
Concomitant administration of seasonal influenza and COVID-19 mRNA vaccines
by
Sánchez-Cordero, María José
,
García-Sastre, Adolfo
,
Escalera, Alba
in
Antibodies
,
COVID-19
,
COVID-19 vaccines
2024
Current clinical guidelines support the concomitant administration of seasonal influenza vaccines and COVID-19 mRNA boosters vaccine. Whether dual vaccination may impact vaccine immunogenicity due to an interference between influenza or SARS-CoV-2 antigens is unknown. We aimed to understand the impact of mRNA COVID-19 vaccines administered concomitantly on the immune response to influenza vaccines. For this, 128 volunteers were vaccinated during the 22-23 influenza season. Three groups of vaccination were assembled: FLU vaccine only (46, 35%)
volunteers that received the mRNA bivalent COVID-19 vaccines concomitantly to seasonal influenza vaccines, FluCOVID vaccine in the same arm (42, 33%) or different arm (40, 31%), respectively. Sera and whole blood were obtained the day of vaccination, +7, and +28 days after for antibody and T cells response quantification. As expected, side effects were increased in individuals who received the FluCOVID vaccine as compared to FLU vaccine only based on the known reactogenicity of mRNA vaccines. In general, antibody levels were high at 4 weeks post-vaccination and differences were found only for the H3N2 virus when administered in different arms compared to the other groups at day 28 post-vaccination. Additionally, our data showed that subjects that received the FluCOVID vaccine in different arm tended to have better antibody induction than those receiving FLU vaccines for H3N2 virus in the absence of pre-existing immunity. Furthermore, no notable differences in the influenza-specific cellular immune response were found for any of the vaccination groups. Our data supports the concomitant administration of seasonal influenza and mRNA COVID-19 vaccines.
Journal Article
Different Contribution of Missense and Loss‐of‐Function Variants to the Genetic Structure of Familial and Sporadic Meniere Disease
by
Escalera‐Balsera, Alba
,
Gallego‐Martinez, Alvaro
,
Robles‐Bolivar, Paula
in
exome sequencing
,
genetic diagnosis
,
genomics
2025
ABSTRACT
Meniere disease (MD) is a chronic inner ear disorder with significant heritability. This study compares the burden of rare high‐ and moderate‐impact coding variants in an MD cohort to determine whether genetic burden in sporadic MD (SMD) overlaps familial MD (FMD), potentially revealing hidden inheritance in SMD. Exome sequencing identified rare variants in unrelated FMD (N = 93) and SMD (N = 287) patients. Gene Burden Analysis (GBA) was performed, and candidate genes were prioritized using the number of variant carriers, inner‐ear expression, and hearing/balance‐related phenotypic annotations. FMD patients showed higher accumulation of missense and loss‐of‐function variants than SMD, especially in genes linked to auditory and vestibular function. GBA identified 269 enriched genes in SMD, with 31 annotated for inner ear phenotypes, while FMD had 432 with 51 pinpointed. Sporadic and FMD overlapped in 28.1% of enriched genes, with ADGRV1, MEGF8, and MYO7A most commonly shared. Auditory brainstem responses from knockout mouse models supported hearing loss of three novel MD candidate genes (NIN, CCDC88C, and ANKRD24), consistent with patient hearing profiles. In conclusion, SMD and FMD have a divergent genetic architecture. The enrichment of missense variants in stria vascularis and hair cell stereocilia genes supports distinct pathogenic mechanisms and a multiallelic‐recessive inheritance pattern in MD.
This study examines the genetic basis of sporadic (SMD) and familial Meniere disease (FMD) by comparing rare protein‐coding variants using exome sequencing and gene burden analysis. FMD patients had a higher accumulation of missense and LoF variants, especially in genes linked to auditory and vestibular function. Although SMD and FMD share enriched genes, both have genetic architectures suggesting different pathogenic mechanisms and a possible multiallelic‐recessive inheritance pattern.
Journal Article
Obesity and Metabolic Dysregulation in Children Provide Protective Influenza Vaccine Responses
by
Fishbein, Joanna S.
,
García-Sastre, Adolfo
,
Escalera, Alba
in
Adolescent
,
Antibodies
,
Blood pressure
2022
The most effective intervention for influenza prevention is vaccination. However, there are conflicting data on influenza vaccine antibody responses in obese children. Cardio-metabolic parameters such as waist circumference, cholesterol, insulin sensitivity, and blood pressure are used to subdivide individuals with overweight or obese BMI into ‘healthy’ (MHOO) or ‘unhealthy’ (MUOO) metabolic phenotypes. The ever-evolving metabolic phenotypes in children may be elucidated by using vaccine stimulation to characterize cytokine responses. We conducted a prospective cohort study evaluating influenza vaccine responses in children. Participants were identified as either normal-weight children (NWC) or overweight/obese using BMI. Children with obesity were then characterized using metabolic health metrics. These metrics consisted of changes in serum cytokine and chemokine concentrations measured via multiplex assay at baseline and repeated at one month following vaccination. Changes in NWC, MHOO and MUOO were compared using Chi-square/Fisher’s exact test for antibody responses and Kruskal–Wallis test for cytokines. Differences in influenza antibody responses in normal, MHOO and MUOO children were statistically indistinguishable. IL-13 was decreased in MUOO children compared to NWC and MHOO children (p = 0.04). IL-10 approached a statistically significant decrease in MUOO compared to MHOO and NWC (p = 0.07). Influenza vaccination does not provoke different responses in NCW, MHOO, or MUOO children, suggesting that obesity, whether metabolically healthy or unhealthy, does not alter the efficacy of vaccination. IL-13 levels in MUO children were significantly different from levels in normal and MHOO children, indicating that the metabolically unhealthy phenotypes may be associated with an altered inflammatory response. A larger sample size with greater numbers of metabolically unhealthy children may lend more insight into the relationship of chronic inflammation secondary to obesity with vaccine immunity.
Journal Article
Defective α‐tectorin may involve tectorial membrane in familial Meniere disease
by
Roman‐Naranjo, Pablo
,
Gonzalez‐Aguado, Rocio
,
Aran, Ismael
in
Conflicts of interest
,
Extracellular matrix
,
Gene expression
2022
SEE PDF] The TECTA gene encodes α-tectorin, a large protein that contains 10 functional domains divided into three major regions: (1) an entactin-like (NIDO) region; (2) a larger middle region, the zonadhesin region containing a von Willebrand factor type C (VWFC) domain, four VWFD domains, and three trypsin inhibitor-like cysteine-rich (TIL) domains; and (3) the zona pellucida region.5 This protein is one of the main non-collagenous proteins of the TM, an extracellular matrix that lies over the stereocilia of the sensory hair cells and mediates the deflection of the stereocilia and the gating of mechanotransduction channels. According to the protein model, the change of cysteine to serine at residue 1402 can lead to the breaking of the Cys1359-Cys1402 disulphide bond with a destabilizing effect on α-tectorin (Figure 3). [...]the short deletion p.Gly2118ProfsTer22 observed in F6 causes a premature stop codon at position 2139, generating a slightly shorter protein with a modified C-terminal region and, in turn, an alteration of the glycosylphosphatidylinositol (GPI) anchorage signal located in this region. [...]the results of this study seem to be in line with the results obtained in recent genetic studies about familial MD, where rare variants in MYO7A and OTOG gene were suggested to modify the stability or the interactions of different proteins in the apical surface of the sensory epithelia such as hair cells (stereocilia) or TM.
Journal Article
A rare haplotype of the GJD3 gene segregating in familial Meniere’s disease interferes with connexin assembly
by
Escalera-Balsera, Alba
,
Contreras, Julio
,
Varela-Nieto, Isabel
in
Animals
,
Anopheles
,
Bioinformatics
2025
Background
Familial Meniere’s disease (FMD) is a rare polygenic disorder of the inner ear. Mutations in the connexin gene family, which encodes gap junction proteins, can also cause hearing loss, but their role in FMD is largely unknown.
Methods
We retrieved exome sequencing data from 94 individuals in 70 Meniere's disease (MD) families. Through gene burden analysis, we calculated the enrichment of rare variants (allele frequency < 0.05) in connexins genes in FMD individuals compared with the reference population. The connexin monomer and the homomeric connexon structural models were predicted using AlphaFold2 and HDOCK. RT-qPCR and immunofluorescence were done in mice cochleae to identify expression of the mouse ortholog candidate gene
Gjd3
.
Results
We found an enrichment of rare missense variants in the
GJD3
gene when comparing allelic frequencies in FMD (
N
= 94) with the Spanish reference population (OR = 3.9[1.92–7.91], FDR = 2.36E-03). In the
GJD3
sequence, we identified a rare haplotype (TGAGT) composed of two missense, two synonymous, and one downstream variant. This haplotype was found in five individuals with FMD, segregating in three unrelated families with a total of ten individuals; and in another eight MD individuals.
GJD3
encodes the gap junction protein delta 3, also known as human connexin 31.9 (Cx31.9). The protein model predicted that the NP_689343.3:p.(His175Tyr) missense variant could modify the interaction between connexins and the connexon assembly, affecting the homotypic GJD3 gap junction between cells. Our studies in mice revealed that
Gjd3
—encoding Gjd3 or mouse connexin 30.2 (Cx30.2)—was expressed in the organ of Corti and vestibular organs, particularly in the tectorial membrane, the base of inner and outer hair cells and the nerve fibers.
Conclusions
The present results describe a novel association between
GJD3
and FMD, providing evidence that FMD is related to changes in the inner ear channels, and supporting a new role of tectorial membrane proteins in MD.
Journal Article
Integration of Membrane Contactors and Bioelectrochemical Systems for CO2 Conversion to CH4
by
Della Pirriera, Monica
,
Bosch-Jimenez, Pau
,
Borràs, Eduard
in
Alternative energy sources
,
Biogas
,
Carbon dioxide
2019
Anaerobic digestion of sewage sludge produces large amounts of CO2 which contribute to global CO2 emissions. Capture and conversion of CO2 into valuable products is a novel way to reduce CO2 emissions and valorize it. Membrane contactors can be used for CO2 capture in liquid media, while bioelectrochemical systems (BES) can valorize dissolved CO2 converting it to CH4, through electromethanogenesis (EMG). At the same time, EMG process, which requires electricity to drive the conversion, can be utilized to store electrical energy (eventually coming from renewables surplus) as methane. The study aims integrating the two technologies at a laboratory scale, using for the first time real wastewater as CO2 capture medium. Five replicate EMG-BES cells were built and operated individually at 0.7 V. They were fed with both synthetic and real wastewater, saturated with CO2 by membrane contactors. In a subsequent experimental step, four EMG-BES cells were electrical stacked in series while one was kept as reference. CH4 production reached 4.6 L CH4 m−2 d−1, in line with available literature data, at a specific energy consumption of 16–18 kWh m−3 CH4 (65% energy efficiency). Organic matter was removed from wastewater at approximately 80% efficiency. CO2 conversion efficiency was limited (0.3–3.7%), depending on the amount of CO2 injected in wastewater. Even though achieved performances are not yet competitive with other mature methanation technologies, key knowledge was gained on the integrated operation of membrane contactors and EMG-BES cells, setting the base for upscaling and future implementation of the technology.
Journal Article
The statistical analysis plan for the unification of treatments and interventions for tinnitus patients randomized clinical trial (UNITI-RCT)
by
Vassou, Evgenia
,
Pryss, Rüdiger
,
Spiliopoulou, Myra
in
Anesthetics, Local
,
Behavior modification
,
Behavioral health care
2023
Background
Tinnitus is a leading cause of disease burden globally. Several therapeutic strategies are recommended in guidelines for the reduction of tinnitus distress; however, little is known about the potentially increased effectiveness of a combination of treatments and personalized treatments for each tinnitus patient.
Methods
Within the Unification of Treatments and Interventions for Tinnitus Patients project, a multicenter, randomized clinical trial is conducted with the aim to compare the effectiveness of single treatments and combined treatments on tinnitus distress (UNITI-RCT). Five different tinnitus centers across Europe aim to treat chronic tinnitus patients with either cognitive behavioral therapy, sound therapy, structured counseling, or hearing aids alone, or with a combination of two of these treatments, resulting in four treatment arms with single treatment and six treatment arms with combinational treatment. This statistical analysis plan describes the statistical methods to be deployed in the UNITI-RCT.
Discussion
The UNITI-RCT trial will provide important evidence about whether a combination of treatments is superior to a single treatment alone in the management of chronic tinnitus patients. This pre-specified statistical analysis plan details the methodology for the analysis of the UNITI trial results.
Trial registration
ClinicalTrials.gov
NCT04663828
. The trial is ongoing. Date of registration: December 11, 2020. All patients that finished their treatment before 19 December 2022 are included in the main RCT analysis.
Journal Article
DNA Methylation Signature in Mononuclear Cells and Proinflammatory Cytokines May Define Molecular Subtypes in Sporadic Meniere Disease
by
Espinosa-Sanchez, Juan Manuel
,
Soto-Varela, Andres
,
Aran, Ismael
in
Bias
,
Bisulfite
,
CpG islands
2021
Meniere Disease (MD) is a multifactorial disorder of the inner ear characterized by vertigo attacks associated with sensorineural hearing loss and tinnitus with a significant heritability. Although MD has been associated with several genes, no epigenetic studies have been performed on MD. Here we performed whole-genome bisulfite sequencing in 14 MD patients and six healthy controls, with the aim of identifying an MD methylation signature and potential disease mechanisms. We observed a high number of differentially methylated CpGs (DMC) when comparing MD patients to controls (n= 9545), several of them in hearing loss genes, such as PCDH15, ADGRV1 and CDH23. Bioinformatic analyses of DMCs and cis-regulatory regions predicted phenotypes related to abnormal excitatory postsynaptic currents, abnormal NMDA-mediated receptor currents and abnormal glutamate-mediated receptor currents when comparing MD to controls. Moreover, we identified various DMCs in genes previously associated with cochleovestibular phenotypes in mice. We have also found 12 undermethylated regions (UMR) that were exclusive to MD, including two UMR in an inter CpG island in the PHB gene. We suggest that the DNA methylation signature allows distinguishing between MD patients and controls. The enrichment analysis confirms previous findings of a chronic inflammatory process underlying MD.
Journal Article