CBR - Working Papers / Preprints
URI permanente para esta coleção:
Navegar
Entradas recentes
- A metabolite-based resistance mechanism against malariaPublication . Figueiredo, Ana M.; Rastogi, Sónia Trikha; Ramos, Susana; Nogueira, Fátima; Villiers, Katherine De; Sousa, António G. Gonçalves de; Votborg-Novel, Lasse; Wedel, Cäcilie von; Tober-Lau, Pinkus; Jentho, Elisa; Pagnotta, Sara; Mesquita, Miguel; Cardoso, Sílvia; Bortolussi, Giulia; Muro, Andrés F.; Tranfield, Erin M.; Thibaud, Jessica; Duarte, Denise; Sousa, Ana Laura; Pinto, Sandra N.; Kitoko, Jamil; Mombo-Ngoma, Ghyslain; Mischlinger, Johannes; Junttila, Sini; Alenquer, Marta; Amorim, Maria João; Vasavda, Chirag; Bosma, Piter J.; Violante, Sara; Drotleff, Bernhard; Paixão, Tiago; Portugal, Silvia; Kurth, Florian; Elo, Laura L.; Paul, Bindu D.; Martins, Rui; Soares, Miguel P.Whether jaundice, a common presentation of Plasmodium (P.) falciparum malaria (1-3) arising from the accumulation of circulating bilirubin, represents an adaptive or maladaptive response to Plasmodium spp. infection is not understood (1-3). We found that asymptomatic P. falciparum infection was associated with a >10-fold higher ratio of unconjugated bilirubin over parasite burden, compared to symptomatic malaria. Genetic suppression of bilirubin synthesis by biliverdin reductase A (BVRA) (4) increased parasite virulence and malaria mortality in mice. Accumulation of unconjugated bilirubin in plasma, via genetic inhibition of hepatic conjugation by UDP glucuronosyltransferase family 1 member A1 (UGT1A1) (5), was protective against malaria in mice. Unconjugated bilirubin inhibited P. falciparum proliferation in red blood cells (RBC) via a mechanism that suppressed mitochondrial pyrimidine synthesis. Moreover, unconjugated bilirubin inhibited hemozoin (Hz) crystallization and compromised the parasite’s food vacuole. In conclusion, jaundice represents a metabolic response to Plasmodium spp. infection that limits malaria severity.
- A critical role for the ER Membrane Complex (EMC) in lipid droplet homeostasisPublication . Carvalho, Érika de; Amin, Abdulbasit; Little, Richard; Silva, Keily Fonseca; Gaspar, Catarina; Badenes, Marina; Burbridge, Emma; Paixão, Tiago; Amorim, Maria João; Faísca, Pedro; Fischer, Roman; Vendrel, Iolanda; O’Brien, Darragh P.; Strisovsky, Kvido; Christianson, John C.; Domingos, Pedro M.; Adrain, ColinThe ER Membrane complex (EMC) facilitates insertion of multiple classes of integral membrane protein into the lipid bilayer of the endoplasmic reticulum (ER). Recent years have seen significant progress in understanding the structural aspects of EMC function, but the client protein/s enforcing its evolutionary conservation throughout eukaryotic kingdoms remain to be determined. Given reported role/s for the EMC in lipid homeostasis, we deleted the essential EMC3 subunit in the liver and adipose tissues of mice and examined the impact of EMC loss in a range of metabolic models. Intriguingly, absence of EMC3 in either the liver or adipose tissues results in defective storage of triglycerides and perturbations in lipid droplet (LD) homeostasis. EMC-deficient mouse adipose tissues were defective in their ability to mediate fat storage in response to a high fat diet and were unable to support non-shivering thermogenesis. Proteomic analyses of EMC3-deficient tissues found reduced levels of FITM2, a key regulator of LD biogenesis and ER homeostasis, identifying it as a novel EMC client. Strikingly, deletion of the EMC3 homolog dPob in the Drosophila fat body, which shares overlapping functions with mammalian liver/adipose tissues, revealed similar defects in LD homeostasis. Together, our results indicate that the EMC plays a key evolutionarily conserved role in biogenesis of machinery maintaining triglyceride storage in metazoans.
- Re-emergence of yellow fever virus in Brazil: evidence from forest and peri-urban settingsPublication . Andrade, Valnete das Graças Dantas; Adelino, Talita Emile Ribeiro; Fonseca, Vagner; Melo Farias Moreno, Keldenn; Tomé, Luiz Marcelo Ribeiro; Pereira, Luiz Augusto; LaRoque, Debora Glenda Lima de; Filippis, Ana Maria Bispo de; Garkauskas Ramos, Daniel; Ramalho, Dario Brock; de Lima Furtado, Kátia Cristina; Borges, Gleissy Adriane Lima; Martins, Livia Caricio; Frutuoso, Lívia C. V.; Oliveira Lamounier, Ludmila; Guimarães, Natália Rocha; Barros, Patrícia Miriam Sayuri Sato; Almeida, Priscila Souza de; Silva, Paulo Eduardo de Souza da; Pinheiro, Rodrigo Giesbrecht; Stabeli, Rodrigo Guerino; Chagas, Shirley Moreira da Silva; Pedroso, Sílvia Helena Sousa Pietra; Kashima, Simone; Penante, Solange Gonçalves; Oliveira, Marília Santini de; Silva, Vinicius Lemes da; Voorhis, Wesley C. Van; Holmes, Edward C.; Lourenço, José; Iani, Felipe Campos de Melo; Júnior, Alberto Simões Jorge; Giovanetti, Marta; Alcantara, Luiz Carlos JuniorYellow Fever virus (YFV) continues to challenge public health systems across the Americas, despite decades of successful control and the availability of a highly effective vaccine. Following major outbreaks between 2016 and 2022, YFV re-emerged in Brazil in 2023, with a confirmed infection in a non-human primate in São Paulo linked to viral strains circulating in the Midwest region. This reintroduction, combined with increased YFV activity reported across the Americas, signals an ongoing risk of viral persistence and geographic expansion. In this study, we investigate recent YFV dynamics in forest and peri-urban settings, integrating genomic evidence with ecological and spatial data to trace transmission pathways and assess the potential for urban re-emergence. Our findings highlight the need for sustained surveillance in both sylvatic and transitional zones, especially amid fluctuating vaccine coverage and environmental changes that may facilitate spillover events.
- Age-dependent disease tolerance to SARS-CoV-2 infectionPublication . Rastogi, Sónia Trikha; Mesquita, Miguel; Fonseca, Diogo Martins; Salazar, Sara; Cardoso, Sílvia; Faisca, Pedro; Drotleff, Bernhard; Alenquer, Marta; Lone, Jean-Christophe; Miguel, Verónica; Sancho, David; Herrero, Laura; Paixão, Tiago; Amorim, Maria João; Jentho, Elisa; Graça, Luís; Kitoko, Jamil Zola; Soares, Miguel P.Disease tolerance limits infectious disease severity through tissue damage control mechanisms that do not target pathogens directly. Here we demonstrate that age-dependent decline in adipose tissue lipolysis compromises disease tolerance to SARS-CoV-2 infection. Young adult mice exhibited robust adipocyte lipolysis and 80% survival, whereas old mice showed impaired adipocyte lipolysis and only 20% survival. Genetic repression of adipocyte lipolysis eliminated this age-dependent survival advantage without affecting viral titers, revealing that adipocyte lipolysis is essential for disease tolerance to SARS-CoV-2 in young adults. Impaired adipocyte lipolysis in aged mice was associated with a plasma lipidomic signature that predicts COVID-19 severity and mortality in three independent human cohorts. Mechanistically, adipocyte lipolysis provides free fatty acids (FFA) to support bone marrow emergency myelopoiesis, through CD36- and CPT1-dependent FFA cellular uptake and mitochondrial import, respectively. Bone marrow derived monocytes migrate to the lung via CCL2/CCR2-dependent mechanism where they enforce an immune-metabolic communication network with parenchymal cells to sustain lung structure and function. This circuit is not required to confer protection against influenza infection, revealing pathogen-specific disease tolerance mechanisms. These findings reveal adipose tissue catabolism as a central age-dependent factor responsible for exacerbated COVID-19 mortality in aged populations. One-Sentence SummarySARS-CoV-2 infection induces adipose tissue lipolysis to release fatty acids that drive myelopoiesis and monocyte production for lung protection and COVID-19 disease tolerance, but this protective circuit declines with age, increasing disease severity in the elderly.
- Effect of age and prior COVID-19 on BBIBP-CorV (Sinopharm) vaccination-induced antibody responses in a region with high seroprevalencePublication . Hasan, Zahra; Masood, Kiran Iqbal; Qaiser, Shama; Khan, Erum; Hussain, Areeba; Ghous, Zara; Khan, Unab; Hassan, Imran; Yameen, Maliha; Memon, Haris Ali; Ali, Shiza; Balouch, Sadaf; Nasir, Muhammad Imran; Qazi, Muhammad Farrukh; Veldhoen, Marc; Simas, J. Pedro; Bhutta, Zulfiqar A.; Mahmood, Syed Faisal; Hussain, Rabia; Ghias, KulsoomIntroduction: Sinopharm (BBIBP-CorV) inactivated virus vaccination for COVID-19 has been administered widely in Pakistan. We investigated the dynamics of BBIBP-CorV -induced antibody responses over a 24 week period in a region with a high seroprevalence. Methods: Study subjects (n = 312) were followed up over a 24-week period between May and August 2021. Sera were tested for IgG antibodies to spike and the receptor binding domain (RBD). Results: Study subjects were 62% female. Twenty-two percent had a prior history of COVID-19. At 4-, 8- 16- and 24- weeks post-vaccination, the rate of IgG antibodies positive to spike was 57%, 87%, 66% and 90% of individuals, compared with to RBD which was 48%, 62%, 68% and 85% of subjects, respectively,. IgG to spike and RBD showed a positive correlation at each interval (rho > 0.6, p < 0.0001). Seropositivity to both spike and RBD was reduced in those aged 50 years and over for up until 16 weeks post-vaccination (p < 0.05). Individuals with prior COVID-19 infection showed greater antibody responses for up to 16 weeks post-vaccination (p < 0.05). SARS-CoV-2 infections were observed with a mean interval of 16 weeks postvaccination. Antibody responses did not wane for up to 6 months post-vaccination. Conclusions: Sinopharm vaccination-induced antibody responses were negatively impacted by age and positively impacted by prior COVID-19 for 16 weeks after vaccination. Importantly, we did not find waning of IgG antibodies to RBD over the study period. Maintenance of antibodies may be the result of continued community exposure and boosting with COVID-19 vaccination.
- A rapid real-time polymerase chain reaction-based live virus microneutralization assay for detection of neutralizing antibodies against SARS-CoV-2 in blood/serumPublication . Abidi, Syed Hani; Imtiaz, Kehkeshan; Kanji, Akbar; Qaiser, Shama; Khan, Erum; Iqbal, Kiran; Veldhoen, Marc; Ghias, Kulsoom; Simas, J. Pedro; Hasan, ZahraBackground: Individuals recovering from COVID-19 are shown to have antibodies against the Spike and other structural proteins. Antibodies against Spike have been shown to display viral neutralization. However, not all antibodies against Spike have neutralizing ability and some may be cross-reactive. There is a need for easy-to-use SARS-CoV-2 neutralizing assays that allow the determination of virus neutralizing activity in sera of individuals. Here we describe a PCR-based micro-neutralization assay that can be used to evaluate the viral neutralization titers of serum from SARS-CoV-2 infected individuals. Methods: The SARS-CoV-2 strain used was isolated from a nasopharyngeal specimen of a COVID-19 case. The limiting dilution method was used to obtain a 50% tissue culture infective dose (TCID50) of Vero cells. For the micro‐neutralization assay, 19 serum samples, with positive IgG titers against Spike receptor binding domain (RBD) were tested. After 24 hours, infected cells were inspected for the presence of the cytopathic effect, then lysed and RNA RT-PCR of SARS-CoV-2. The Ct values were used to calculate percent neutralization/inhibition of SARS-CoV-2. Results: Out of 19 samples, 13 samples gave 100% neutralization at all dilutions, while 4 samples gave neutralization at lower dilution, while one sample did not give any neutralization. The correlation between RBD OD and neutralization potential was found to be statistically correlated. Conclusion: We describe a rapid RT-PCR based SARS-CoV-2 microneutralization assay for detection of neutralizing antibodies. This can effectively be used to test anti-viral activity of serum antibodies for investigation of both disease-driven and vaccine-induced responses.
- Modelling the transmission dynamics of H9N2 avian influenza viruses in a live bird marketPublication . Pinotti, Francesco; Kohnle, Lisa; Lourenço, José; Gupta, Sunetra; Hoque, Md Ahasanul; Mahmud, Rashed; Biswas, Paritosh; Pfeiffer, Dirk; Fournié, GuillaumeH9N2 avian influenza viruses (AIVs) are a major concern for the poultry sec24 tor and human health in countries where this subtype is endemic. By fitting a 25 model simulating H9N2 AIV transmission to data from a field experiment, we 26 characterise the epidemiology of the virus in a live bird market in Bangladesh. 27 Many supplied birds arrive already exposed to H9N2 AIVs, resulting in many 28 broiler chickens entering the market as infected, and many indigenous back29 yard chickens entering with pre-existing immunity. Most susceptible chickens 30 become infected within one day spent at the market, owing to high levels of 31 viral transmission within market and short latent periods, as brief as 5.3 hours. Although H9N2 AIV transmission can be substantially reduced under moderate 33 levels of cleaning and disinfection, effective risk mitigation also requires a range 34 of additional interventions targeting markets and other nodes along the poultry 35 production and distribution network.
- Influenza A virus hemagglutinin remodels membranes into a vRNP clustering platformPublication . Wachsmuth-Melm, Moritz; Peterl, Sarah; Makroczyová, Jana; Vale-Costa, Sílvia; Amorim, Maria João; Chlanda, PetrPandemics caused by influenza A virus are associated with co-infections of zoonotic and humanadapted viruses. To form an infectious entity, the virus must incorporate eight different ribonucleoproteins (vRNPs) into virions budding at the plasma membrane. The process of vRNP clustering is poorly understood and has not been investigated at a molecular resolution. Here we employ in situ cryo-correlative light and electron microscopy at late stages of viral infection to identify hemagglutinin and neuraminidase as drivers of membrane remodelling. We show that hemagglutinin, but not neuraminidase-remodelled compartments serve as vRNP clustering platforms. Our nearestneighbour analysis demonstrates that vRNPs cluster on hemagglutinin-remodelled membranes in a Rab11a-dependent manner. Additionally, we uncover that matrix protein 1 (M1) forms multi-layered cylindrical assemblies in the nucleus which restructure in the cytoplasm. Further, we show that M1 layer assembly precedes its attachment to the plasma membrane and M1 thereby coordinates the closure of the virion budding neck. In summary, we demonstrate that hemagglutinin is involved in intracellular vRNP clustering by inducing membrane remodelling to provide a large interaction surface. Thus hemagglutininmembrane remodelling may play a role during vRNP sorting and reassortment that lead to the adaptation of zoonotic influenza A viruses.
- Bioengineered 3D microvessels reveal novel determinants of Trypanosoma congolense sequestrationPublication . Porqueddu, Teresa; Niz, Mariana De; Casas-Sánchez, Aitor; Introini, Viola; Zorrinho-Almeida, Maria; Sender, Silvia Sanz; Carrasqueira, Diana; Figueiredo, Luisa; Bernabeu, Maria; Pereira, Sara SilvaIn the mammalian host, Trypanosoma congolense cytoadheres to the vascular endothelium in a process known as sequestration. Although sequestration influences clinical outcome, disease severity and organ pathology, its determinants and mediators remain unknown. Challenges such as the variability of animal models, the only-recently developed tools to genetically manipulate the parasite, and the lack of physiologically relevant in vitro models have hindered progress. Here, we engineered brain and cardiac 3D bovine endothelial microvessel models that mimic the bovine brain microvasculature and the bovine aorta, respectively. By perfusing these models with two T. congolense strains, we simulated physiologically relevant conditions and investigated the roles of flow for parasite sequestration and tropism for different endothelial beds. We discovered that sequestration is dependent on cyclic AMP signalling, closely linked to parasite proliferation, but not associated with parasite transmission to the tsetse fly vector. Finally, by comparing the expression profiles of sequestered and non-sequestered parasites collected from a rodent model, we showed gene expression changes in sequestered parasites, including of the surface variant antigens. This work presents a physiologically-relevant platform to study trypanosome interactions with the vasculature and provides a deeper understanding of the molecular and biophysical mechanisms underlying T. congolense sequestration.
- Land and climate suitability for West Nile virus in Atlantic archipelagos guided by historical data from EuropePublication . Geraldes, Martim Afonso; Giovanetti, Marta; Cunha, Mónica Vieira; Lourenço, JoséWest Nile (WNV) is a zoonotic mosquito-borne virus with an expanding geographical range and epidemic activity worldwide. Computational studies have contributed to the understanding of factors driving WNV occurrence, particularly in North America and Europe, providing invaluable insights towards surveillance and preparedness. Archipelagos have largely been overlooked, despite the risks WNV poses to unique local avian species and human populations. In this study, we apply a machine learning-based ecological niche approach, trained on WNV occurrence and (a)biotic factors from Portugal, Spain, and Italy, to estimate ecological suitability for WNV occurrence across several Atlantic archipelagos. The approach gives weight to the temporal dimension, moving beyond conventional spatial suitability estimations, and generating novel insights on seasonality both for Europe and the archipelagos. For Portugal, Spain and Italy, modelling results align with previous findings on spatial hotspots and (a)biotic drivers of WNV occurrence, while further unraveling properties of at-risk human populations within dynamically suitable land areas. For Atlantic archipelagos, results constitute a novel and detailed perspective on local ecological suitability for WNV occurrence, providing a data-driven framework that identifies spatial hotspots, defines seasonal patterns and quantifies the local population at risk. The synthetic data generated in this study supports the development of targeted preparedness, surveillance and mitigation plans tailored to the unique ecological and seasonal dynamics of each region under study.
- «
- 1 (current)
- 2
- 3
- »