Biology subjects

Neto, M. M.

Publications and source records attributed to Neto, M. M..

3 recordsLinked to original sources

bioRxiv2025

Development and optimisation of Influenza C and Influenza D pseudotyped viruses

To facilitate the study of influenza C (ICV) and influenza D (IDV) viruses, we generated lentiviral pseudotyped viruses (PVs) expressing the hemagglutinin-esterase fusion (HEF) glycoprotein from ICV (C/Minnesota/33/2015) and IDV (D/Swine/Italy/199724-3/2015, D/Bovine/France/5920/2014, and D/Bovine/Ibaraki/7768/2016). The production of these PVs was optimised using different amount of human airway trypsin-like (HAT) protease to enhance HEF maturation, and the transduction efficiency was evaluated in multiple cell lines. Using these PVs, we established a pseudovirus-based microneutralisation (pMN) assay to measure neutralising antibody responses and adapted an esterase activity assay to evaluate PV. Specific antisera neutralised PVs but failed to inhibit esterase activity. These findings confirm that ICV and IDV PVs provide a scalable, sensitive, and safe tool for antiviral screening, and sero-epidemiological research.

immunology↗

bioRxiv2024

Mitochondrial dysfunction heightens the integrated stress response to drive ALS pathogenesis

Vesicle-associated membrane protein-associated protein-B (VAPB) is an ER membrane bound protein. VAPB P56S causes a dominant, familial form of amyotrophic lateral sclerosis (ALS), however, the mechanism through which this mutation causes motor neuron (MN) disease remains unknown. Using inducible wild type (WT) and VAPB P56S expressing iPSC-derived MNs we show that VAPB P56S, but not WT, protein decreased neuronal firing and mitochondrial-ER contact (MERC) with an associated age-dependent decrease in mitochondrial membrane potential (MMP); all typical characteristics of MN-disease. We further show that VAPB P56S expressing iPSC-derived MNs have enhanced age-dependent sensitivity to ER stress. We identified elevated expression of the master regulator of the Integrated Stress Response (ISR) marker ATF4 and decreased protein synthesis in the VAPB P56S iPSC-derived MNs. Chemical inhibition of ISR with the compound, ISRIB, rescued all MN disease phenotype in VAPB P56S MNs. Thus, our results not only support ISR inhibition as a potential therapeutic target for ALS patients, but also provides evidence to pathogenesis.

neuroscience↗

bioRxiv2024

B cell maturation restored ancestral germlines to control Omicron BA.2.86

The unceasing interplay between SARS-CoV-2 and the human immune system has led to a continuous maturation of the virus and B cell response providing an opportunity to track their evolution in real time. We longitudinally analyzed the functional activity of almost 1,000 neutralizing human monoclonal antibodies (nAbs) isolated from vaccinated people, and from individuals with hybrid and super hybrid immunity (SH), developed after three mRNA vaccine doses and two breakthrough infections. The most potent neutralization and Fc functions against highly mutated variants, including BA.2.86, were found in the SH cohort. Despite different priming, epitope mapping revealed a convergent maturation of the functional antibody response. Neutralization was mainly driven by Class 1/2 nAbs while Fc functions were induced by Class 3/4 antibodies. Remarkably, broad neutralization was mediated by restored IGHV3-53/3-66 B cell germlines which, after heterogenous exposure to SARS-CoV-2 S proteins, increased their level of somatic hypermutations. Our study shows the resilience of the human immune system which restored previously expanded germlines and activated naive B cells to broaden the antibody repertoire of antibodies to control future SARS-CoV-2 variants.

immunology↗