Biology subjects

Juste, J.

Publications and source records attributed to Juste, J..

6 recordsLinked to original sources

bioRxiv2025

Entry, replication and innate immunity evasion of BANAL-236, a SARS-CoV-2-related bat virus, in Rhinolophus and human cells

Asian Rhinolophus bats are considered the natural reservoirs of an ancestral SARS-CoV-2. However, the biology of SARS-CoV-2-related viruses in bat cells is not well understood. Here, we investigated the replication of BANAL-236, the only bat-derived SARS-CoV-2 relative isolated to date, in Rhinolophus cells. BANAL-236 did not replicate in wild-type Rhinolophus cell lines. Entry assays using pseudoviruses expressing the spike proteins (S) of SARS-CoV-2, BANAL-236, and BANAL-52 revealed that efficient S-mediated entry depends on the expression of human ACE2 (hACE2) and human TMPRSS2 (hTMPRSS2) in human and Rhinolophus cells. Expression of Rhinolophus entry factors, either alone or in combination, did not facilitate SARS-CoV-2 or BANAL-236 entry in human cells, suggesting that the S protein of BANAL-236 interacts more efficiently with hACE2 than with its Rhinolophus counterpart (rACE2). Through biochemical, virological, and electron microscopy analyses, we showed that BANAL-236 and SARS-CoV-2 completed their replication cycles in a Rhinolophus cell line engineered to express high levels of hACE2 and hTMPRSS2. Despite efficient viral replication in modified Rhinolophus and human cells, no induction of interferon (IFN)-stimulated genes was detected. Using a screening approach, we identified several BANAL-236 proteins that antagonize IFN production and signaling in human cells. Our findings thus show that BANAL-236 possesses critical features that enabled zoonotic spillover: hACE2 usage and potent evasion of human IFN responses. The Rhinolophus cellular model we established offers a platform for further investigating the interactions between bat coronaviruses and their reservoir hosts. Author summaryBats are known reservoirs for viruses that cause severe diseases in humans, such as coronaviruses and filoviruses. Bat species naturally or experimentally infected with these viruses rarely exhibit clinical symptoms, suggesting an evolved tolerance to viral infections. To elucidate the mechanisms underlying viral tolerance and to identify factors that could facilitate zoonotic spillover, it is essential to study the replication of bat-borne viruses in relevant bat cellular models. Here, we investigated the replication of BANAL-236, a SARS-CoV-2 related virus isolated from fecal samples of Rhinolophus bats in Northen Laos, in a novel cell line derived from Rhinolophus ferrumequinum lung fibroblasts. Our findings reveal that BANAL-236 can efficiently use human entry factors and potently evade the human innate immune response, two traits that may have contributed to its zoonotic transmission. Furthermore, the R. ferrumequinum cell lines we developed is a valuable model for investigating the molecular interactions between sarbecoviruses and their natural hosts.

microbiology↗

bioRxiv2025

Coronavirus protein interaction mapping in bat and human cells identifies molecular and genetic switches for immune evasion and replication

Coronaviruses, including SARS-CoV-2, can cause severe disease in humans, whereas reservoir hosts like Rhinolophus bats remain asymptomatic. To investigate how host-specific protein-protein interactions (PPIs) influence infection, we generated comparative PPI maps for SARS-CoV-2 and its bat-origin relative RaTG13 using affinity purification-mass spectrometry (AP-MS) in human and Rhinolophus ferrumequinum (RFe) bat cells. This approach identified both conserved and virus- and host-specific interactions that regulate infection dynamics. Notably, SARS-CoV-2 required a non-synonymous mutation in nucleocapsid to replicate in bat cells expressing human ACE2 and TMPRSS2. Analysis of the viral protein Orf9b revealed differential interactions with mitochondrial proteins Tom70 and MTARC2. A single residue difference in Orf9b between SARS-CoV-2 and RaTG13 functions as a molecular switch, weakening Tom70 binding and immune evasion in human cells while enhancing interaction with the bat-specific restriction factor MTARC2. These findings demonstrate how a single-residue substitution can reshape virus-host interactions and contribute to immune evasion and host adaptation.

systems biology↗

bioRxiv2023

Applying genomic approaches to identify historic population declines in European forest bats

O_LIAnthropogenically-driven environmental changes over the past two centuries have led to severe biodiversity loss, most prominently in the form of loss of populations and individuals. Better tools are needed to assess the magnitude of these wildlife population declines. Anecdotal evidence suggests European bat populations have suffered substantial declines in the past few centuries. However, there is little empirical evidence of these declines that can be used to put more recent population changes into historic context and set appropriate targets for species recovery. C_LIO_LIThis study is a collaboration between academics and conservation practitioners to develop molecular approaches capable of providing quantitative evidence of historic population changes and their drivers that can inform the assessment of conservation status and conservation management. We generated a genomic dataset for the Western barbastelle, Barbastella barbastellus, a globally Near Threatened and regionally Vulnerable bat species, including colonies from across the species British and Iberian ranges. We used a combination of landscape genetics and approximate Bayesian computation model-based inference of demographic history to identify both evidence of population size changes and possible drivers of these changes. C_LIO_LIWe found that levels of genetic diversity increased and inbreeding decreased with increasing broadleaf woodland cover around the colony location. Genetic connectivity was impeded by artificial lights and facilitated by the combination of rivers and broadleaf woodland cover. C_LIO_LIThe demographic history analysis showed that both the northern and southern British barbastelle populations have declined by 99% over the past 330-548 years. These declines may have been triggered by loss of large oak trees and native woodlands due to shipbuilding during the early colonial period. C_LIO_LISynthesis and applications. Genomic approaches can be applied to provide a better understanding of the conservation status of threatened species, within historic and contemporary context, and inform their conservation management. This study shows how we can bridge the implementation gap and promote the application of genomics in conservation management through co-designing studies with conservation practitioners and co-developing applied management targets and recommendations. C_LI

genomics↗

bioRxiv2022

Bat pluripotent stem cells reveal unique entanglement between host and viruses

Bats have evolved features unique amongst mammals, including flight, laryngeal echolocation, and certain species have been shown to have a unique immune response that may enable them to tolerate viruses such as SARS-CoVs, MERS-CoVs, Nipah, and Marburg viruses. Robust cellular models have yet to be developed for bats, hindering our ability to further understand their special biology and handling of viral pathogens. To establish bats as new model study species, we generated induced pluripotent stem cells (iPSCs) from a wild greater horseshoe bat (Rhinolophus ferrumequinum) using a modified Yamanaka protocol. Rhinolophids are amongst the longest living bat species and are asymptomatic carriers of coronaviruses, including one of the viruses most closely related to SARS-CoV-2. Bat induced pluripotent stem (BiPS) cells were stable in culture, readily differentiated into all three germ layers, and formed complex embryoid bodies, including organoids. The BiPS cells were found to have a core pluripotency gene expression program similar to that of other species, but it also resembled that of cells attacked by viruses. The BiPS cells produced a rich set of diverse endogenized viral sequences and in particular retroviruses. We further validated our protocol by developing iPS cells from an evolutionary distant bat species Myotis myotis (greater mouse-eared bat) non-lethally sampled in the wild, which exhibited similar attributes to the greater horseshoe bat iPS cells, suggesting that this unique pluripotent state evolved in the ancestral bat lineage. Although previous studies have suggested that bats have developed powerful strategies to tame their inflammatory response, our results argue that they have also evolved mechanisms to accommodate a substantial load of endogenous viral sequences and suggest that the natural history of bats and viruses is more profoundly intertwined than previously thought. Further study of bat iPS cells and their differentiated progeny should advance our understanding of the role bats play as virus hosts, provide a novel method of disease surveillance, and enable the functional studies required to ascertain the molecular basis of bats unique traits.

developmental biology↗

bioRxiv2019

Understanding social behaviour in mammals: Kin structure and roost fidelity in greater noctule bats

Roost fidelity is an important aspect of mammalian biology. Studying the mechanisms underlying philopatry can help us understand a species energetic requirements, ecological constraints and social organisation. Temperate bat species notably exhibit a comparatively high degree of female philopatry, resulting in maternity colonies segregated at the mitochondrial level. We focus on the greater noctule, Nyctalus lasiopterus, to study this behaviour in more depth. We make use of microsatellite data for 11 markers across 84 individuals residing in Maria Luisa Park in Seville, Spain. At the time of sampling, this urban park boasted the highest number of registered bats of this species, among which three social groups were observed to segregate spatially. We studied the distribution of pairs of individuals across filial relationship categories and relatedness estimates relative to the social group of each individual. This analysis was complemented by information on roost-use frequency among a subset of genotyped bats. We found no significant relationship between roost use and genetic distance, but there was evidence of higher group-sharing with increased levels of relatedness. Mother-daughter pairs shared the same group more often than expected, as did pairs of individuals of relatedness above 0.36. We discuss the implications of these results in terms of the behavioural ecology of temperate bats and for conservation efforts aimed at preserving them.

ecology↗

bioRxiv2019

Mating strategy is determinant of Adenovirus prevalence in European bats

Adenoviruses are double-strained DNA viruses found in a great number of vertebrates, including humans. In order to understand their transmission dynamics, it is crucial, even from a human health perspective, to investigate how host traits influence their prevalence. Bats are important reservoirs for Adenoviruses, and here we use the results of recent screenings in Western Europe to evaluate the association between characteristic traits of bat species and their probability of hosting Adenoviruses, taking into account their phylogenetic relationships. Across species, we found an important phylogenetic component in the presence of Adenoviruses and mating strategy as the most determinant factor conditioning the prevalence of Adenoviruses across bat species. Contrary to other more stable mating strategies (e.g. harems), swarming could hinder transmission of Adenoviruses since this strategy implies that contacts between individuals are too short. Alternatively, bat species with more promiscuous behavior may develop a stronger immune system. Outstandingly high prevalence of Adenoviruses was reported for the Iberian species Pipistrellus pygmaeus, P. kuhlii and Nyctalus lasiopterus and we found that in the latter, males were more likely to be infected by Adenoviruses than females, due to the immunosuppressing consequence of testosterone during the mating season. As a general trend across species, we found that the number of Adenoviruses positive individuals was different across localities and that the difference in prevalence between populations was correlated with their geographic distances (P. pygmaeus). These results increase our knowledge about the transmission mechanisms of Adenoviruses.\n\nAuthor SummaryAdenoviruses are DNA viruses with a wide range of vertebrate hosts, including humans, causing ocular, respiratory and gastrointestinal diseases. Here, we focus on the prevalence of Adenoviruses in bats, which are known to be natural reservoir of many viruses, using the results of recent screenings for prevalence of these viruses in 33 European bat species. Our aim is to find association between Adenoviruses prevalence and biological and behavioral host traits, considering the heterogeneity both between and within species in order to have a deeper understanding of mechanisms of viral transmission.\n\nOur results highlight the importance of mating strategy: bats species using swarming as mating strategy are less likely to be infected by Adenoviruses. Moreover, we found that locality of capture can explain a higher prevalence of Adenovirus within species. However, no general pattern has been found in the analysis at individual level, suggesting a strong species specificity and complex viral transmission dynamics.

ecology↗