Biology subjects

Essaidi-Laziosi, M.

Publications and source records attributed to Essaidi-Laziosi, M..

4 recordsLinked to original sources

bioRxiv2025

Age- and Virus-Specific Signatures of In Vitro Reconstituted Human Airway Epithelia in the Presence and Absence of Respiratory Viral Infections

While Influenza Virus and Respiratory Syncytial Virus (RSV) are considered as a significant health burden in children, Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) causes milder diseases in this age group compared to adults. To investigate the involvement of the upper respiratory tract human airway epithelium (HAE) in this pattern, we established an in-house model of reconstituted HAE cultured in air-liquid interface from nasal swabs of children and adults and characterised it before and after ex vivo respiratory viral infections using focused and unbiased approaches. Fully differentiated paediatric HAE exhibited an increasing induction level of genes related to mucociliary clearance, while higher expression of innate immune pathways was found in the ones from adults. While similar viral replication kinetics in both age groups were shown for SARS-CoV-2, Influenza A Virus (IAV), RSV and Rhinovirus (RV) infection, transcriptomic analysis showed stronger and earlier induction of IFN-related pathways in SARS-CoV-2-infected HAE from children compared to IAV, RSV and RV. IAV and RSV had the weakest innate immune response increase in HAE from children versus adults. RV infection showed an intermediate pattern, resembling SARS-CoV-2 more than RSV or IAV. Our work demonstrates a distinct sensing of SARS-CoV-2 compared to other respiratory viruses ex vivo, which may contribute to the milder course of disease in SARS-CoV-2 infected children and argues for a role of early virus-HAE interaction in shaping viral pathogenesis. Furthermore, we show that innate immune responses towards respiratory viruses are virus-specific and differ between age groups. Hence, findings on SARS-CoV-2 cannot be extrapolated to other respiratory viruses.

microbiology↗

bioRxiv2024

Immune escape of Omicron lineages BA.1, BA.2, BA.5.1, BQ.1, XBB.1.5, EG.5.1 and JN.1.1 after vaccination, infection and hybrid immunity

In the 5th year after the emergence of SARS-CoV-2, Omicron lineages continue to evolve and cause infections. Here, we used eight authentic SARS-CoV-2 isolates to assess their capacity to escape immunity of different exposure histories and their replicative capacity in polarized human airway epithelial cells (HAE) derived from the nasal and bronchial epithelium. Using live-virus neutralization assays of 108 human sera or plasma of different immunological backgrounds, progressive immune escape was observed from B.1 (ancestral virus) to EG.5.1, but no significant difference between EG.5.1 and JN.1.1. Vaccinated individuals without natural infection and individuals with a single infection, but no vaccination showed markedly reduced or completely lost neutralization against the latest variants, while in those with hybrid immunity almost all sera showed some neutralization capacity. Furthermore, although absolute titers differed between groups, the pattern of immune escape between the variants remains comparable with strongest loss of neutralization observed for the latest variants. In vitro studies with HAE at 33{degrees}C and 37{degrees}C showed some, but minor differences in virus replication and innate immune responses upon infection. Notably, infection with XBB.1.5, EG.5.1 and JN.1.1 showed slightly increased viral growth in nasal HAE at 33{degrees}C. Altogether, these data underscore increasing immune escape across heterogeneous immunological backgrounds with gradually increasing antibody escape of evolving Omicron lineages until variant EG.5.1, but not any further for the latest dominant lineage JN.1.1. They also suggest that viral dynamics within Omicron lineages are driven by a combination of immune evasion and increase in viral replication.

microbiology↗

bioRxiv2022

Distinct phenotype of SARS-CoV-2 Omicron BA.1 in human primary cells but no increased host range in cell lines of putative mammalian reservoir species

SARS-CoV-2s genetic plasticity has led to several variants of concern (VOCs). Here we studied replicative capacity for seven SARS-CoV-2 isolates (B.1, Alpha, Beta, Gamma, Delta, Zeta, and Omicron BA.1) in primary reconstituted airway epithelia (HAE) and lung-derived cell lines. Furthermore, to investigate the host range of Delta and Omicron compared to ancestral SARS-CoV-2, we assessed replication in 17 cell lines from 11 non-primate mammalian species, including bats, rodents, insectivores and carnivores. Only Omicrons phenotype differed in vitro, with rapid but short replication and efficient production of infectious virus in nasal HAEs, in contrast to other VOCs, but not in lung cell lines. No increased infection efficiency for other species was observed, but Delta and Omicron infection efficiency was increased in A549 cells. Notably replication in A549 and Calu3 cells was lower than in nasal HAE. Our results suggest better adaptation of VOCs towards humans, without an extended host range.

microbiology↗

bioRxiv2021

Enhanced fitness of SARS-CoV-2 variant of concern B.1.1.7, but not B.1.351, in animal models

Emerging variants of concern (VOCs) drive the SARS-CoV-2 pandemic. We assessed VOC B.1.1.7, now prevalent in several countries, and VOC B.1.351, representing the greatest threat to populations with immunity to the early SARS-CoV-2 progenitors. B.1.1.7 showed a clear fitness advantage over the progenitor variant (wt-S614G) in ferrets and two mouse models, where the substitutions in the spike glycoprotein were major drivers for fitness advantage. In the "superspreader" hamster model, B.1.1.7 and wt-S614G had comparable fitness, whereas B.1.351 was outcompeted. The VOCs had similar replication kinetics as compared to wt-S614G in human airway epithelial cultures. Our study highlights the importance of using multiple models for complete fitness characterization of VOCs and demonstrates adaptation of B.1.1.7 towards increased upper respiratory tract replication and enhanced transmission in vivo. Summary sentenceB.1.1.7 VOC outcompetes progenitor SARS-CoV-2 in upper respiratory tract replication competition in vivo.

microbiology↗