Biology subjects

Medaglini, D.

Publications and source records attributed to Medaglini, D..

3 recordsLinked to original sources

bioRxiv2025

Establishment and application of a vesicle extraction method for clinical strains of Pseudomonas aeruginosa

Pseudomonas aeruginosa is a versatile pathogen capable of causing illnesses that range from mild infections to life-threatening conditions. Its virulence is driven by a wide array of factors, among which extracellular vesicles (EVs) have gained recognition as important contributors to its pathogenicity. Despite this, the full scope of their roles remains unclear. A major barrier to EV characterization is the difficulty of vesicle isolation--procedures are often lengthy, yield is low, and specialized equipment is required. In this study, we assessed the effectiveness of a rapid vesicle extraction method from clinical strains of P. aeruginosa. To that end, we first selected and characterized six phenotypically diverse clinical strains of P. aeruginosa (two reference strains and 4 clinical isolates, including one strain from a cystic fibrosis patient) and used them to evaluate the vesicle extraction method. The results obtained through SDS-PAGE analysis, western blot, protein quantification, and TEM indicated the presence of vesicles in all samples; however, it was also possible to observe a large number of contaminants in some of them (mainly LS07 and Z37). Subsequent treatment with enzymes (DNase and/or alginate lyase) allowed for the elimination of the contaminants as observed by electron microscopy. Our results suggest that the method is suited for the vesicle extraction of clinical isolates of P. aeruginosa. The phenotypic complexity of these strains presents challenges that current rapid purification methods are ill-equipped to handle, highlighting the need for improved or alternative approaches.

microbiology↗

bioRxiv2025

Long Non-Coding RNAs in Response to Ebola Virus Vaccine-Induced Immunity

Long noncoding RNAs (lncRNAs) have emerged as critical regulators of gene expression, yet their role in shaping human responses to vaccination remains largely uncharacterized. Here, we analyzed RNA-sequencing data from three independent human cohorts vaccinated with the rVSV{Delta}G-ZEBOV-GP Ebola vaccine to profile lncRNA expression dynamics. Using differential expression analysis and correlation meta-analysis across cohorts, we identified an expression signature with several lncRNAs, including LEF1-AS1 and DOCK8-AS1, that exhibit conserved transcriptional activation following vaccination. Correlation of lncRNA expression with gene targets and IgG titers revealed putative roles for lncRNAs in regulating and/or participate in both innate immune responses and adaptive antibody production. Functional enrichment of lncRNA co-expressed protein-coding genes highlighted involvement in T-cell differentiation, interferon signaling, and leukocyte activation. Integrating global run-on sequencing data and comparative transcriptomic analysis across other vaccine studies suggests that LEF1-AS1 modulation is distinctively associated with Ebola vaccination. Our findings demonstrate that lncRNAs are potential integral components of the human vaccine response and provide a foundation for future mechanistic studies targeting noncoding RNA regulation of immunity SignificanceEbola virus remains a significant global health threat due to its high mortality rate and potential for widespread outbreaks, underscoring the urgent need for effective and durable vaccines to control future epidemics. Understanding the transcriptional mechanisms underlying immune responses to vaccination is important to improving vaccine design and efficacy. While protein-coding genes have been extensively studied, the role of long noncoding RNAs (lncRNAs) in vaccine-induced immunity remains poorly understood. Here, we characterize the dynamics of lncRNA expression following administration of the rVSV{Delta}G-ZEBOV-GP Ebola vaccine across multiple human cohorts and identify conserved lncRNA signatures associated with both innate and adaptive immunity. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=154 SRC="FIGDIR/small/671152v1_ufig1.gif" ALT="Figure 1"> View larger version (27K): org.highwire.dtl.DTLVardef@25581aorg.highwire.dtl.DTLVardef@1bb31cforg.highwire.dtl.DTLVardef@c3299eorg.highwire.dtl.DTLVardef@e176b9_HPS_FORMAT_FIGEXP M_FIG C_FIG

systems biology↗

bioRxiv2022

Human neutralizing antibodies to cold linear epitopes and to subdomain 1 of SARS-CoV-2

Emergence of SARS-CoV-2 variants diminishes the efficacy of vaccines and antiviral monoclonal antibodies. Continued development of immunotherapies and vaccine immunogens resilient to viral evolution is therefore necessary. Using coldspot-guided antibody discovery, a screening approach that focuses on portions of the virus spike that are both functionally relevant and averse to change, we identified human neutralizing antibodies to highly conserved viral epitopes. Antibody fp.006 binds the fusion peptide and cross-reacts against coronaviruses of the four genera, including the nine human coronaviruses, through recognition of a conserved motif that includes the S2 site of proteolytic cleavage. Antibody hr2.016 targets the stem helix and neutralizes SARS-CoV-2 variants. Antibody sd1.040 binds to subdomain 1, synergizes with antibody rbd.042 for neutralization and, like fp.006 and hr2.016, protects mice when present as bispecific antibody. Thus, coldspot-guided antibody discovery reveals donor-derived neutralizing antibodies that are cross-reactive with Orthocoronavirinae, including SARS-CoV-2 variants. One sentence summaryBroadly cross-reactive antibodies that protect from SARS-CoV-2 variants are revealed by virus coldspot-driven discovery.

immunology↗