Percorrer por autor "Taubert, Anja"
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- Besnoitia besnoiti bradyzoite stages induce suicidal- and rapid vital-NETosisPublication . Zhou, Ershun; Silva, Liliana M. R.; Conejeros, Iván; Velásquez, Zahady D.; Hirz, Manuela; Gärtner, Ulrich; Jacquiet, Philippe; Taubert, Anja; Hermosilla, CarlosBesnoitia besnoiti is an obligate intracellular apicomplexan protozoan parasite, which causes bovine besnoitiosis. Recently increased emergence within Europe was responsible for significant economic losses in the cattle industry due to the significant reduction of productivity. However, still limited knowledge exists on interactions between B. besnoiti and host innate immune system. Here, B. besnoiti bradyzoites were successfully isolated from tissue cysts located in skin biopsies of a naturally infected animal, and we aimed to investigate for the first time reactions of polymorphonuclear neutrophils (PMN) exposed to these vital bradyzoites. Freshly isolated bovine PMN were confronted to B. besnoiti bradyzoites. Scanning electron microscopy (s.e.m.)- and immunofluorescence microscopy-analyses demonstrated fine extracellular networks released by exposed bovine PMN resembling suicidal NETosis. Classical NETosis components were confirmed via co-localization of extracellular DNA decorated with histone 3 (H3) and neutrophil elastase (NE). Live cell imaging by 3D holotomographic microscopy (Nanolive®) unveiled rapid vital NETosis against this parasite. A significant increase of autophagosomes visualized by specific-LC3B antibodies and confocal microscopy was observed in B. besnoiti-stimulated bovine PMN when compared to non-stimulated group. As such, a significant positive correlation (r = 0.37; P = 0.042) was found between B. besnoiti-triggered suicidal NETosis and autophagy. These findings suggest that vital- as well as suicidal-NETosis might play a role in early innate host defence mechanisms against released B. besnoiti bradyzoites from tissue cysts, and possibly hampering further parasitic replication. Our data generate first hints on autophagy being associated with B. besnoiti bradyzoite-induced suicidal NETosis and highlighting for first time occurrence of parasite-mediated vital NETosis.
- Besnoitia besnoiti tachyzoite replication in bovine primary endothelial cells relies on host Niemann–Pick type C protein 1 for cholesterol acquisitionPublication . Larrazabal, Camilo; Hermosilla, Carlos; Taubert, Anja; Silva, Liliana M. R.Besnoitia besnoiti is a cyst-forming apicomplexan parasite and the causal agent of bovine besnoitiosis. During early phase of infection, tachyzoites replicate within host endothelial cells in a host cell cholesterol-dependent process. By applying U18666A treatments, we here evaluated the role of Niemann–Pick type C protein 1 (NPC1) in both, intracellular B. besnoiti replication and host cellular cholesterol distribution. Additionally, B. besnoiti-driven changes in NPC1 gene transcription were studied by qPCR. Overall, U18666A treatments significantly reduced B. besnoiti proliferation and induced cholesterol accumulation in host cytoplasmic dense vesicles. However, NPC1 gene transcription was not affected by B. besnoiti infection.
- Cellular immune responses of bovine polymorphonuclear neutrophils to Calicophoron daubneyiPublication . Silva, Liliana M. R.; López-Osorio, Sara; Peixoto, Raquel; Zhou, Ershun; Espinosa, Gabriel; Gärtner, Ulrich; Taubert, Anja; Conejeros, Iván; Hermosilla, CarlosCalicophoron daubneyi infections have increased in Europe, being more frequent than fasciolosis in some areas. Infection occurs once definitive hosts ingest encysted metacercariae present on vegetation. Following excystation, juvenile flukes penetrate the small intestinal mucosa and migrate into the rumen where adults mature. Throughout the somatic migration, juveniles come across different microenvironments and tissues and encounter host leukocytes. Besides phagocytosis, production of reactive oxygen species (ROS) and degranulation, polymorphonuclear neutrophils also cast neutrophil extracellular traps (NETs), which can entrap several parasite species, including the closely related liver fluke Fasciola hepatica. In this study, we analyzed whether in vitro exposure of bovine neutrophils to C. daubneyi antigen (CdAg) and eggs triggered neutrophils activation and NET formation. Results on scanning electron microscopy (SEM) and immunofluorescence analyses show weak formation of short spread NETs upon CdAg stimulation, corroborated by increased extracellular DNA measurements. Likewise, early NETosis was confirmed via nuclear area expansion assays. Bovine neutrophil stimulation with CdAg 100 µg/mL concentration led to a significant increase in oxygen consumption rates (p = 0.0152) and extracellular acidification rates (p = 0.0022), while lower concentrations of CdAg (10 µg/mL) failed to induce neutrophil activation, suggesting a dose dependent response. Both intra- and extracellular ROS production was not affected by any CdAg concentration here studied. Bovine neutrophil total adenosine triphosphate concentration significantly decreased after exposure to CdAg 100 µg/mL, in line to the observed with the positive control (phorbol myristate acetate/ionomycin). In summary, C. daubneyi activates bovine neutrophils with rather weak responses, which might suggest that the release of C. daubneyi-specific molecules (i.e. excretory-secretory antigens, proteases, or nucleases) could interfere with neutrophil-related effector mechanisms. Further ex vivo analyses will clarify if such mechanisms are also involved in pathogenesis of paramphistomosis by demonstrating neutrophil recruitment into affected intestinal mucosa.
- Fasciola hepatica soluble antigens (FhAg) induce ovine PMN innate immune reactions and NET formation in vitro and in vivoPublication . Muñoz-Caro, Tamara; Gómez-Ceruti, Marcela; Silva, Liliana M. R.; Gutiérrez-Expósito, Daniel; Wagner, Henrik; Taubert, Anja; Hermosilla, CarlosFasciola hepatica causes liver fluke disease, a worldwide neglected and re-emerging zoonotic disease, leading to hepatitis in humans and livestock. In the pathogenesis, flukes actively migrate through liver parenchyma provoking tissue damage. Here, parasites must confront leukocytes of the innate immune system in vivo. Polymorphonuclear neutrophils (PMN) are the most abundant granulocytes and first ones arriving at infection sites. PMN may display neutrophil extracellular traps (NETs), consisting of nuclear DNA, decorated with histones, enzymes, and antimicrobial peptides. We investigated for the first time whether F. hepatica soluble antigens (FhAg) can also trigger NETosis and innate immune reactions in exposed ovine PMN. Thus, isolated PMN were co-cultured with FhAg and NET formation was visualized by immunofluorescence and scanning electron microscopy analyses resulting in various phenotypes with spread NETs being the most detected in vitro. In line, NETs quantification via Picogreen®-fluorometric measurements revealed induction of anchored- and cell free NETs phenotypes. Live cell 3D-holotomographic microscopy revealed degranulation of stimulated PMN at 30 min exposure to FhAg. Functional PMN chemotaxis assays showed a significant increase of PMN migration (p = 0.010) and intracellular ROS production significantly increased throughout time (p = 0.028). Contrary, metabolic activities profiles of FhAg-exposed PMN did not significantly increase. Finally, in vivo histopathological analysis on F. hepatica-parasitized liver tissue sections of sheep showed multifocal infiltration of inflammatory cells within liver parenchyma, and further fluorescence microscopy analyses confirmed NETs formation in vivo. Overall, we hypothesized that NET-formation is a relevant host defence mechanism that might have a role in the pathogenesis of fasciolosis in vivo.
- Interaction of chicken heterophils and Eimeria tenella results in different phenotypes of heterophil extracellular traps (HETs)Publication . Rentería-Solís, Zaida; Silva, Liliana M. R.; Grochow, Thomas; Zhang, Runhui; Nguyen-Ho-Bao, Tran; Daugschies, Arwid; Taubert, Anja; Conejeros, Iván; Hermosilla, CarlosChicken coccidiosis causes annual losses exceeding GBP 10 billion globally. The most pathogenic species for domestic fowls including Eimeria tenella, E. acervulina, and E. maxima, can lead to gastrointestinal issues ranging from mild to fatal. In this study, stages of E. tenella and freshly isolated chicken heterophils were co-cultured for 180 min. These interactions were analyzed using live 3D holotomographic and confocal microscopy. We observed that E. tenella stages were entrapped by heterophils and heterophil extracellular traps (HETs). Notably, different HET phenotypes, specifically sprHETs and aggHETs, were induced regardless of the stage. Furthermore, the quantification of extracellular DNA release from co-cultures of heterophils and sporozoites (ratio 1:1) for 180 min demonstrated a significantly higher release (p = 0.04) compared to negative controls. In conclusion, research on the chicken innate immune system, particularly fowl-derived HETs, remains limited. More detailed investigations are needed, such as exploring the time-dependent triggering of HETs, to establish a standard incubation time for this pathogen defense mechanism. This will enhance our understanding of its role in parasite survival or death during HET confrontation.
- Isolation of a novel caprine Eimeria christenseni strain (GC) in Canary Islands and analysis of parasitological, clinical, and pathological findings on experimentally infected goat kidsPublication . Barba, Emilio; Molina, José Manuel; Rodriguez, Francisco; Ferrer, Otilia; Muñoz, Maria Carmen; Silva, Liliana M. R.; Río, María Crsitina Del; Molina, José Adrián; Taubert, Anja; Hermosilla, Carlos; Ruiz, AntonioEimeria christenseni is considered among the most pathogenic Eimeria species in goats. The aim of this study was to isolate an E. christenseni strain and to assess its infectivity, pathogenicity, and ability to develop a protective immune response. After previous collection of E. christenseni-positive faeces, purification of oocysts, and amplification in donor animals, an experimental infection was carried out. A total of 19 kids were divided into three groups: primary-infected and challenged, challenge control, and uninfected control. Infections were performed orally with 2 × 105 sporulated oocysts per animal. Oocyst shedding, clinical signs, and production parameters, in addition to haematological and histopathological features, were monitored. The results showed that the Gran Canaria (GC) E. christenseni strain had similar morphological and biological characteristics to those previously described, but no significant clinical signs were observed despite the high oocyst counts here recorded. The novel strain isolated would therefore be of low pathogenicity but still able to develop significant immunoprotective responses upon challenge infections. Its biological similarities to highly pathogenic species such as Eimeria ninakohlyakimovae and Eimeria arloingi might enable comparative studies aimed at developing alternative strategies for drug treatments, including Eimeria species (strain)-specific vaccination strategies for the efficient control of goat coccidiosis.
- Mass spectrometry imaging of in vitro Cryptosporidium parvum-infected cells and host tissuePublication . Anschütz, Nils H.; Gerbig, Stefanie; Ghezellou, Parviz; Silva, Liliana M. R.; Vélez, Juan Diego; Hermosilla, Carlos R.; Taubert, Anja; Spengler, BernhardCryptosporidium parvum is a zoonotic-relevant parasite belonging to the phylum Alveolata (subphylum Apicomplexa). One of the most zoonotic-relevant etiologies of cryptosporidiosis is the species C. parvum, infecting humans, cattle and wildlife. C. parvum-infected intestinal mucosa as well as host cells infected in vitro have not yet been the subject of extensive biochemical investigation. Efficient treatment options or vaccines against cryptosporidiosis are currently not available. Human cryptosporidiosis is currently known as a neglected poverty-related disease (PRD), being potentially fatal in young children or immunocompromised patients. In this study, we used a combination of atmospheric pressure scanning microprobe matrix-assisted laser desorption/ionization (AP-SMALDI) mass spectrometry imaging (MSI) and liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) to determine and locate molecular biomarkers in in vitro C. parvum-infected host cells as well as parasitized neonatal calf intestines. Sections of C. parvum-infected and non-infected host cell pellets and infected intestines were examined to determine potential biomarkers. Human ileocecal adenocarcinoma cells (HCT-8) were used as a suitable in vitro host cell system. More than a thousand different molecular signals were found in both positive- and negative-ion mode, which were significantly increased in C. parvum-infected material. A database search in combination with HPLC-MS/MS experiments was employed for the structural verification of markers. Our results demonstrate some overlap between the identified markers and data obtained from earlier studies on other apicomplexan parasites. Statistically relevant biomarkers were imaged in cell layers of C. parvum-infected and non-infected host cells with 5 µm pixel size and in bovine intestinal tissue with 10 µm pixel size. This allowed us to substantiate their relevance once again. Taken together, the present approach delivers novel metabolic insights on neglected cryptosporidiosis affecting mainly children in developing countries.
- Mass spectrometry imaging of lipid and metabolite distributions in cysts of Besnoitia besnoiti-Infected bovine skinPublication . Wiedemann, Katja R.; Gerbig, Stefanie; Ghezellou, Parviz; Pilgram, Alejandra; Hermosilla, Carlos; Taubert, Anja; Silva, Liliana M. R.; Spengler, BernhardBovine besnoitiosis is a disease caused by the obligate intracellular parasite Besnoitia besnoiti. During its chronic stage, the parasite forms large, thick-walled cysts of up to 600 μm in diameter in the skin and other tissues. To assess an overview of parasite-induced metabolic changes during chronic infection, B. besnoiti-infected skin samples were analyzed by high-resolution atmospheric-pressure scanning microprobe matrix-assisted laser desorption/ionization mass spectrometry imaging (AP-SMALDI MSI). Overall, infection-driven, significant changes of 467 lipids and metabolites were found in comparison to noninfected control samples. Most of them belong to the group of phosphatidic acids (PAs), phosphatidylserines (PSs), phosphatidylcholines (PCs)/phosphatidylethanolamines (PEs), triacylglycerides (TGs), phosphatidylinositols (PIs) and phosphatidylglycerols (PGs). When these quantitative data were combined with analyses on the lateral distribution of respective infection markers, MS images of significantly changed ion signals with specific lateral distributions were generated, matching with typical biological structures as observed in Hematoxylin and eosin (H&E)-stained tissue sections. Ultrahigh-resolution MALDI MSI with a pixel size of 2 μm and 3-dimensional reconstruction gave further insights into cyst construction.