Papers by Anna Rita Taddei
International Journal of Molecular Sciences, Mar 25, 2021
In jawed vertebrates, adaptive immune responses are enabled by T cells. Two lineages were charact... more In jawed vertebrates, adaptive immune responses are enabled by T cells. Two lineages were characterized based on their T cell receptor (TcR) heterodimers, namely αβ or γδ peptide chains, which display an Ig domain-type sequence that is somatically rearranged. γδ T cells have been less extensively characterized than αβ and teleost fish, in particular, suffer from a severe scarcity of data. In this paper, we worked on the well-known model, the European sea bass Dicentrarchus labrax, to broaden the understanding of teleost γδ-T cells. The T cell receptor chain (TR) γ transcript was expressed at a later developmental stage than TRβ, suggesting a layered appearance of fish immune cells, and the thymus displayed statistically-significant higher mRNA levels than any other organ or lymphoid tissue investigated. The polyclonal antibody developed against the TRγ allowed the localization of TRγ-expressing cells in lymphoid organs along the ontogeny. Cell positivity was investigated through flow cytometry and the highest percentage was found in peripheral blood leukocytes, followed by thymus, gut, gills, spleen and head kidney. Numerous TRγ-expressing cells were localized in the gut mucosa, and the immunogold labelling revealed ultrastructural features that are typical of T cells. At last, microalgae-based diet formulations significantly modulated the abundance of TRγ + cells in the posterior intestine, hinting at a putative involvement in nutritional immunity. From a comparative immunological perspective, our results contribute to the comprehension of the diversity and functionalities of γδ T cells during the development of a commercially relevant marine teleost model.
PLOS Pathogens, May 22, 2023
Neisseria gonorrhoeae is an exclusively human pathogen able to evade the host immune system throu... more Neisseria gonorrhoeae is an exclusively human pathogen able to evade the host immune system through multiple mechanisms. Gonococci accumulate a large portion of phosphate moieties as polyphosphate (polyP) on the exterior of the cell. Although its polyanionic nature has suggested that it may form a protective shield on the cell surface, its role remains controversial. Taking advantage of a recombinant His-tagged polyP-binding protein, the presence of a polyP pseudo-capsule in gonococcus was demonstrated. Interestingly, the polyP pseudo-capsule was found to be present in specific strains only. To investigate its putative role in host immune evasion mechanisms, such as resistance to serum bactericidal activity, antimicrobial peptides and phagocytosis, the enzymes involved in polyP metabolism were genetically deleted, generating mutants with altered polyP external content. The mutants with lower polyP content on their surface compared to the wild-type strains, became sensitive to complement-mediated killing in presence of normal human serum. Conversely, naturally serum sensitive strains that did not display a significant polyP pseudo-capsule became resistant to complement in the presence of exogenous polyP. The presence of polyP pseudo-capsule was also critical in the protection from antibacterial activity of cationic antimicrobial peptide, such as cathelicidin LL-37. Results showed that the minimum bactericidal concentration was lower in strains lacking polyP than in those harboring the pseudo-capsule. Data referring to phagocytic killing resistance, assessed by using neutrophil-like cells, showed a significant decrease in viability of mutants lacking polyP on their cell surface in comparison to the wild-type strain. The addition of exogenous polyP overturned the killing phenotype of sensitive strains suggesting that gonococcus could exploit environmental polyP to survive to complement-mediated, cathelicidin and intracellular killing. Taken together, data presented here indicate an essential role of the polyP pseudo-capsule in the gonococcal pathogenesis, opening new perspective on gonococcal biology and more effective treatments.
Developmental and Comparative Immunology, Jul 1, 2019
The increasing resistance to conventional antibiotics is an urgent problem that can be addressed ... more The increasing resistance to conventional antibiotics is an urgent problem that can be addressed by the discovery of new antimicrobial drugs such as antimicrobial peptides (AMPs). AMPs are components of innate immune system of eukaryotes and are not prone to the conventional mechanisms that are responsible of drug resistance. Fish are an important source of AMPs and, recently, we have isolated and characterized a new 22 amino acid residues peptide, the chionodracine (Cnd), from the Antarctic icefish Chionodraco hamatus. In this paper we focused on a new Cndderived mutant peptide, namely Cnd-m3a, designed to improve the selectivity against prokaryotic cells and the antimicrobial activity against human pathogens of the initial Cnd template. Cnd-m3a was used for immunization of rabbits, which gave rise to a polyclonal antibody able to detect the peptide. The interaction kinetic of Cnd-m3a with the Antarctic bacterium Psychrobacter sp. (TAD1) was imaged using a transmission electron microscopy (TEM) immunogold method. Initially the peptide was associated with the plasma membrane, but after 180 min of incubation, it was found in the cytoplasm interacting with a DNA target inside the bacterial cells. Using fluorescent probes we showed that the newly designed mutant can create pores in the outer membrane of the bacteria E. coli and Psychrobacter sp. (TAD1), confirming the results of TEM analysis. Moreover, in vitro assays demonstrated that Cnd-m3a is able to bind lipid vesicles of different compositions with a preference toward negatively charged ones, which mimics the prokaryotic cell. The Cnd-m3a peptide showed quite low hemolytic activity and weak cytotoxic effect against human primary and tumor cell lines, but high antimicrobial activity against selected Gram -human pathogens. These results highlighted the high potential of the Cnd-m3a peptide as a starting point for developing a new human therapeutic agent.
International Journal of Insect Morphology & Embryology, Apr 1, 1997
Sexual plant reproduction, Sep 1, 2003
We recently reported the involvement of the ubiquitin pathway in microgametophyte development, an... more We recently reported the involvement of the ubiquitin pathway in microgametophyte development, and a direct role for the 26S proteasome in regulating pollen tube emergence in kiwifruit. Here we show that the ubiquitin/proteasome proteolytic pathway is involved not only in early kiwifruit pollen tube organisation, but also in maintaining polarised growth of tubes. By immunofluorescence analysis we show that ubiquitin
Tissue & Cell, Jun 1, 2000
Horticulturae
Nanotechnology could play a huge role in ensuring safer and greener agriculture in the years ahea... more Nanotechnology could play a huge role in ensuring safer and greener agriculture in the years ahead by providing sustainable tools to control plant diseases. In this study, the possibility of using cellulose nanocrystals (CNCs) obtained from tomato waste to control the bacterial speck disease’s causal agent was evaluated for the effects on plant development. Biocompatibility was assessed by studying seeds’ germination, leaf area, biomass and nitrogen balance index of tomato seedlings treated with CNC. Since epiphytic survival represents a relevant phase in early and later infections provoked by Pseudomonas syringae pv. tomato (Pst), the CNC’s ability to lower the level of bacterial cells in the plant canopy was evaluated in treated seedlings at 1, 7 and 14 days after being artificially inoculated. Leaflets were collected and washed to quantify the epiphytic bacterial population and observed through electron microscopy. Obtained results indicate that CNCs are non-toxic, compatible nan...
PeerJ
Three sexually mature goshawks reared in captivity and imprinted on humans to express reproductiv... more Three sexually mature goshawks reared in captivity and imprinted on humans to express reproductive behavior according to the cooperative method were studied for three consecutive breeding seasons to assess the quality of their sperm. The following parameters were analyzed: ejaculate volume and sperm concentration, motility, viability, and morphology. Ejaculate volume, sperm concentration and motility fluctuated along the reproductive season, revealing the greatest quality of the reproductive material at full springtime (i.e., April). Motility of the sperm collected in March strongly reduced with age, contrary to samples collected in April or May. Sperm viability was not influenced by either age or month of collection within each season. Ultrastructural investigations provided information on normal sperm morphology for the first time in this species. The morphological categories of sperm defects in fresh semen, present at low percentages, are also described. Functional analyses (peri...
Pharmaceuticals
In this study, essential oils (EOs) and hydrolates (Hys) from Italian hemp (Cannabis sativa L. Ko... more In this study, essential oils (EOs) and hydrolates (Hys) from Italian hemp (Cannabis sativa L. Kompolti cv.) and hop (Humulus Lupulus L., Chinook cv.) supply chains were chemically characterized and tested to investigate their apoptotic potential for the first time. Headspace–Gas Chromatography–Mass Spectrometry (HS-GC-MS) techniques were performed to describe their volatile chemical profile, highlighting a composition rich in terpene derivatives such as monoterpenes and sesquiterpenes among which β-myrcene, limonene, β-caryophyllene and α-humulene were the main constituents of EOs; in contrast, linalool, cis-p-menth-2,8-dien-1-ol, terpinen-4-ol, α-terpineol, caryophyllene oxide, and τ-cadinol were found in the Hys. The cytotoxicity activity on human leukemia cells (HL60), human neuroblastoma cells (SH-SY5Y), human metastatic adenocarcinoma breast cells (MCF7), human adenocarcinoma breast cells (MDA), and normal breast epithelial cell (MCF10A) for the EOs and Hys was studied by MTT ...
Heritage
The object of this paper is the diagnostic campaign performed on the polychrome wooden statue, re... more The object of this paper is the diagnostic campaign performed on the polychrome wooden statue, revered as St. John, stored in the church dedicated to the “Beata Vergine d’Itria” (Blessed Virgin of Itria), (Noragugume town, Sardinia, Italy). The restoration of the statue gave the occasion to investigate micro-samples from the wooden support and from the polychromy in order to gather information that could be useful for the intervention. In fact, there was limited information on this fine carved statue and its iconographic pattern appeared to be not strictly canonical. Moreover, these kinds of artworks, having religious significant for the faithful, have been generally modified over time to satisfy possible changes in artistic or religious needs or ecclesiastical reforms. The aims of this study are: (i) support the restorers in defining the conservation status of the statue, and (ii) perform a series of analyses to identify the wood and the materials of the painting layers. Specifical...
Scientific Reports
Nanomaterials in agriculture represent one of the most innovative method for protecting crops, du... more Nanomaterials in agriculture represent one of the most innovative method for protecting crops, due to possibility of being applied as nanopesticides or nanocarriers for active ingredients. Furthermore, nanotechnology could be combined with the concept of circular economy through the opportunity of obtaining highly technological nanometric materials starting from agro-industrial wastes. The present research evaluated the possibility of synthesizing cellulose nanocrystals (CNCs) from olive pruning wastes through chemical bleaching, reusing them as sustainable tool to control the causal agent of the olive knot disease (Pseudomonas savastanoi pv. savastanoi). CNCs showed an interesting in vitro effect in inhibiting bacterial growth and bacterial biofilm formation, as well as the ability of reducing bacterial epiphytic survival in a comparable way to copper sulphate on leaf surfaces, when used at 1% w/v. CNCs were at the same time investigated for their interaction with olive tree seedli...
Viral particles of the endogenous retrovirus ZAM from Drosophila melanogaster use a pre-existing ... more Viral particles of the endogenous retrovirus ZAM from Drosophila melanogaster use a pre-existing endosome/exosome pathway for transfer to the oocyte
Journal of the Science of Food and Agriculture, 2021
BACKGROUNDEveryday pasta cooking has a large environmental impact. The aims of this work were to ... more BACKGROUNDEveryday pasta cooking has a large environmental impact. The aims of this work were to assess the effect of cooking temperatures (TC) that were lower than the water boiling point (TBW) on the main chemico‐physical quality parameters of two pasta shapes (i.e., ziti and spaghetti) cooked at the conventional and minimum water‐to‐pasta ratios, as well as their optimum cooking time (OCT), cooking energy consumption, and carbon footprint, by using a novel eco‐sustainable pasta cooker.RESULTSOnce the effect of TC on OCT had been modeled in accordance with the Bigelow model, it was possible to estimate that the energy saved to heat the cooking water from ambient temperature to a lower temperature than TBW was smaller than the extra energy needed to complete the pasta cooking phase. After several cooking trials, the water uptake, cooking loss, textural properties, and thickness of the central nerve (as observed with a scanning electronic microscope) of cooked pasta were found to be...
Pharmacological Research, 2021
Loss of retinal neurons may precede clinical signs of diabetic retinopathy (DR). We studied for t... more Loss of retinal neurons may precede clinical signs of diabetic retinopathy (DR). We studied for the first time the effects of hyperglycemia on the visual system of the fruit fly Drosophila melanogaster to characterize a model for glucose-induced retinal neurodegeneration, thus complementing more traditional vertebrate systems. Adult flies were fed with increased high-sucrose regimens which did not modify the locomotion ability, muscle phenotype and mobility after 10 days. The increased availability of dietary sucrose induced hyperglycemia and phosphorylation of Akt in fat tissue, without significant effects on adult growth and viability, consistent with the early phase of insulin signaling and a low impact on the overall metabolic profile of flies at short term. Noteworthy, high-sucrose diets significantly decreased Drosophila responsiveness to the light as a consequence of vision defects. Hyperglycemia did not alter the gross anatomical architecture of the external eye phenotype although a progressive damage of photosensitive units was observed. Appreciable levels of cleaved caspase 3 and nitrotyrosine were detected in the internal retina network as well as punctate staining of Light-Chain 3 and p62, and accumulated autophagosomes, indicating apoptotic features, peroxynitrite formation and autophagy turnover defects. In summary, our results in Drosophila support the view that hyperglycemia induced by high-sucrose diets lead to eye defects, apoptosis/autophagy dysregulation, oxidative stress, and visual dysfunctions which are evolutionarily conserved, thus offering a meaningful opportunity of using a simple in vivo model to study the pathophysiology of neuroretinal alterations that develop in patients at the early stages of DR.
Journal of Drug Delivery Science and Technology, 2020
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific r... more HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Pharmacognosy Magazine, 2018
Background: In the Mediterranean region, Salvia officinalis plant is widely used and routinely ad... more Background: In the Mediterranean region, Salvia officinalis plant is widely used and routinely added to food for a traditional culinary utilization, and moreover, from long time, it is recognized to possess pharmacological activities. Objectives: In the present study, we investigated the biological properties of S. officinalis leaf ethanol extracts and a thin layer chromatography-isolated spot on murine myeloma cells. Materials and Methods: 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide tests were carried out to determinate the EC50 of both the leaf extracts and the isolated spot; the isolated spot was also investigated by liquid chromatography-mass spectrometry (LC-MS) and nuclear magnetic resonance (NMR). Electron microscopy and immunofluorescence were used for morphological studies on treated P3X murine myeloma cells. Results: LC-MS and NMR techniques identified methyl carnosate, a methyl derivative of carnosic acid, as the main component of spot B. Moreover, scanning electron microscopy, transmission electron microscopy, and immunofluorescence investigations carried out on murine myeloma cells treated for 20 h with EC50 values of spot B revealed some changes both in the cellular morphology and in the microtubular array. Conclusions: The present studies indicate that S. officinalis extracts have biological effects on murine myeloma cells and identify methyl carnosate as an interesting molecule for further investigations on human cell lines and possibly on cancer prevention.
Natural Product Communications, 2013
Ethanolic extracts of Salvia officinalis leaves demonstrated antibacterial activity against Bacil... more Ethanolic extracts of Salvia officinalis leaves demonstrated antibacterial activity against Bacillus cereus. Fractionation of the extracts led to the isolation of the most active antibacterial compound, which, from spectroscopic and LC-MS evidence, was proved to be the diterpene, methyl carnosate.
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Papers by Anna Rita Taddei