65 research outputs found

    A promising new ELISA diagnostic test for cattle babesiosis based on Babesia bigemina Apical Membrane Antigen-1.

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    Babesiosis due to Babesia bigemina is a relevant tick‑borne disease, affecting cattle worldwide. Many surface proteins of the pathogen including the Apical Membrane Antigen 1 (AMA‑1) ‑ have been analysed for vaccine and diagnostic purposes. This study focused on B. bigemina AMA‑1 and on its use for the assessment of diagnostic tests. After bioinformatic analyses, AMA‑1 codifying region was amplified and cloned into an expression vector used to induce protein synthesis in Escherichia coli cells. AMA‑1 was purified by affinity chromatography and used to set up the best condition for an ELISA protocol. Bovine field sera positive to B. bigemina were used to evaluate the presence of anti‑AMA‑1 antibodies. In order to verify the assay specificity, sera positive to Babesia bovis or to the piroplasm Theileria annulata were also included. Significant differences were obtained between sera negative to both B. bigemina and B. bovis and samples positive to B. bigemina, to B. bovis or to both pathogens. No significant reaction was observed with T. annulata positive sera. The results showed that AMA‑1 protein is suitable to be used as antigen in diagnostic assays for babesiosis diagnosis in cattle, as it does not show any cross reaction with anti-T. annulata antibodies

    Serological survey and molecular characterization of theileria annulata in sicilian cattle

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    Tropical theileriosis is a tick-borne disease caused by hemoprotozoan parasites with considerable veterinary and economic impact worldwide. Ticks transmitting the disease belong to the Haemaphysalis, Rhipicephalus, and Hyalomma genera. The Hyalomma genus is very common in Sicily (Italy) and represents the main Theileria annulata vector in the island. Data concerning the molecular epidemiology of this pathogen are missing in the region. In 2018–2019, blood and serum samples were collected from 480 cows in seven Sicilian farms from four different provinces. Seroprevalence in the farms ranged from 22% to 71%. Three farms were selected for molecular analysis consisting of real-time PCR targeting the almost complete 18S ribosomal RNA (rRNA). Four amplicons per farm were sequenced and phylogenetic analyses were carried out. The four sequences were identical within each farm and showed 92–99% identity with the other farms and with sequences from Genbank. According to the phylogenetic analysis, these three sequences and an additional one from a laboratory-cultured Theileria annulata strain obtained in 1999 belonged to a single T. annulata clade with good bootstrap support with other sequences from Italy, India, and Iran, indicating limited geographical and temporal genetic variability of the parasite. This study represents the first phylogenetic analysis of T. annulata in Sicily, which will be useful to improve the strategies for theileriosis control and prevention

    Detection of natural killer T cells in mice infected with Rickettsia conorii

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    Little information is available regarding the role of natural killer T (NKT) cells during the early stage of Rickettsia conorii infection. Herein, C3H/HeN mice were infected with the Malish 7 strain of R. conorii. Splenocytes from these mice were analysed in the early stage of the infection by flow cytometry and compared with uninfected controls. Our results showed an increase in NKT cells in infected mice. Additionally, NKT interleukin (IL)-17(+) cells increased three days after infection, together with a concurrent decrease in the relative amount of NKT interferon (IFN)-\u3b3(+) cells. We also confirmed a higher amount of NK IFN-\u3b3(+) cells in infected mice. Taken together, our data showed that NKT cells producing Il-17 increased during the early stage of rickettsial infection. These results suggest a connection between IL-17(+) NKT cells and vasculitis, which is the main clinical symptom of rickettsiosi

    Recent Advances on the Innate Immune Response to Coxiella burnetii.

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    Coxiella burnetii is an obligate intracellular Gram-negative bacterium and the causative agent of a worldwide zoonosis known as Q fever. The pathogen invades monocytes and macrophages, replicating within acidic phagolysosomes and evading host defenses through different immune evasion strategies that are mainly associated with the structure of its lipopolysaccharide. The main transmission routes are aerosols and ingestion of fomites from infected animals. The innate immune system provides the first host defense against the microorganism, and it is crucial to direct the infection towards a self-limiting respiratory disease or the chronic form. This review reports the advances in understanding the mechanisms of innate immunity acting during C. burnetii infection and the strategies that pathogen put in place to infect the host cells and to modify the expression of specific host cell genes in order to subvert cellular processes. The mechanisms through which different cell types with different genetic backgrounds are differently susceptible to C. burnetii intracellular growth are discussed. The subsets of cytokines induced following C. burnetii infection as well as the pathogen influence on an inflammasome-mediated response are also described. Finally, we discuss the use of animal experimental systems for studying the innate immune response against C. burnetii and discovering novel methods for prevention and treatment of disease in humans and livestock

    Innate Immune Response to Tick-Borne Pathogens: Cellular and Molecular Mechanisms Induced in the Hosts.

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    Many pathogens are transmitted by tick bites, including Anaplasma spp., Ehrlichia spp., Rickettsia spp., Babesia and Theileria sensu stricto species. These pathogens cause infectious diseases both in animals and humans. Different types of immune effector mechanisms could be induced in hosts by these microorganisms, triggered either directly by pathogen-derived antigens or indirectly by molecules released by host cells binding to these antigens. The components of innate immunity, such as natural killer cells, complement proteins, macrophages, dendritic cells and tumor necrosis factor alpha, cause a rapid and intense protection for the acute phase of infectious diseases. Moreover, the onset of a pro-inflammatory state occurs upon the activation of the inflammasome, a protein scaffold with a key-role in host defense mechanism, regulating the action of caspase-1 and the maturation of interleukin-1β and IL-18 into bioactive molecules. During the infection caused by different microbial agents, very similar profiles of the human innate immune response are observed including secretion of IL-1α, IL-8, and IFN-α, and suppression of superoxide dismutase, IL-1Ra and IL-17A release. Innate immunity is activated immediately after the infection and inflammasome-mediated changes in the pro-inflammatory cytokines at systemic and intracellular levels can be detected as early as on days 2-5 after tick bite. The ongoing research field of "inflammasome biology" focuses on the interactions among molecules and cells of innate immune response that could be responsible for triggering a protective adaptive immunity. The knowledge of the innate immunity mechanisms, as well as the new targets of investigation arising by bioinformatics analysis, could lead to the development of new methods of emergency diagnosis and prevention of tick-borne infections

    Potential roles of extracellular vesicles in brain cell-to-cell communication

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    Potential roles of extracellular vesicles in brain cell-to-cell communication Extracellular vesicles (EVs) are released into thè extracellular space from both cancer and normal brain cells, and are probably able to modify thè phenotypic properties of receiving cells1. EVs released from astrocytes and neurons contain FGF2 and VEGF2'3 and induce a 'blood-brain barrier' (BBB) phenotype in cultured brain capillary endothelial cells (BCECs, unpublished results), On thè other hand, EVs from G26/24 oligodendroglioma induce apoptosis in neurons and astrocytes4-5. These effects are probably due to Fas Ligand and TRAIL, present in G26/24 vesicles4-5. Moreover, G26/24 EVs contain extracellular matrix remodeling proteases (such as ADAMTS)6, H1.0 histone protein, and H1.0 mRNA7. In particular, we previously hypothesized that G26/24 cells, and tumor cells in generai, can escape differentiation cues, and continue to proliferate by eliminating proteins, such as thè H1° linker histone (and its mRNA)7, which could otherwise block proliferation. To study vesicle release in a System that can better resemble in vivo conditions, astrocytes and BCECs were cultured on poly-L-lactic acid (PLLA) scaffolds and tested for their ability to grow and survive on this three-dimensional structures. We analyzed in parallel thè celi growth in 2D and 3D culture systems and observed thè differences in celi morphology by fluorescence analysis: threedimensional scaffolds have thè ability to guide celi growth, provide support, encourage celi adhesion and proliferation. Astrocytes8 and BCECs (unpublished results) adapted well to these porous matrices, not only remaining on thè surface, but also penetrating inside thè scaffolds. EVs released by astrocytes in these scaffolds are probably exosomes, as suggested by transmission electron microscopy pictures, and by thè presence of intracellular structures resembling multivesicular bodies. This 3D celi culture System could be further enriched to host different brain celi types, in order to set, for example, an in vitro model of BBB, that may be useful for drug delivery studies, and for thè formulation of new therapeutic strategies for thè treatment of neurological diseases. References [1] Schiera, G., Di Liegro, C.M., Di Liegro I. Int J Mol Sci. 2017, 18(12). pii: E2774. [2] Schiera, G., Proia, P., Alberti, C., Mineo, M., Savettieri, G., Di Liegro, I., 2007. J Celi Mol Med. 2007, 111(6), 1384-94. [3] Proia, P., Schiera, G., Mineo, M., Ingrassia, A.M. Santoro, G., Savettieri, G., Di Liegro, I. Int J Mol Med. 2008, 21(1), 63-7. [4] D'Agostino, S., Salamene, M., Di Liegro, I., Vittorelli, ML, Int J Oncol. 2006, 29(5), 1075-85. [5] Lo Cicero, A., Schiera, G., Proia, P., Saladino, P., Savettieri, G., Di Liegro, C.M., Di Liegro, I. Int J Oncol. 2011,39(6): 1353-7. [6] Lo Cicero, A., Majkowska, I., Nagase, H., Di Liegro, I., Troeberg, L., Matrix Biol. 2012, 31(4), 229-33. [7] Schiera, G., Di Liegro, C.M., Saladino, P., Pitti, R., Savettieri, G., Proia, P., Di Liegro, I. Int J Oncol. 2013, 43(6), 1771-6. [8] Carfì Pavia, F., Di Bella, M.A., Brucato, V., Blanda, V., Zummo, F., Vitrano, I., Di Liegro, C.M., Ghersi, G., Di Liegro, I., Schiera, G. Mol Med Rep. 2019 [Epub ahead of print]. [9] Di Bella MA, Zummo F., Carfì Pavia F., Brucato V., Di Liegro I., Schiera G. 2017, In: Microscopy and Imaging Science: practical approaches to applied research and education, pp 260-264. Ed: A. Méndez-Vilas Publisher, Formatex Research Center (Spain), ISBN-13, 978-84-942134-9-6

    Immune response to tick-borne hemoparasites: Host adaptive immune response mechanisms as potential targets for therapies and vaccines

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    Tick-transmitted pathogens cause infectious diseases in both humans and animals. Different types of adaptive immune mechanisms could be induced in hosts by these microorganisms, triggered either directly by pathogen antigens or indirectly through soluble factors, such as cytokines and/or chemokines, secreted by host cells as response. Adaptive immunity effectors, such as antibody secretion and cytotoxic and/or T helper cell responses, are mainly involved in the late and long-lasting protective immune response. Proteins and/or epitopes derived from pathogens and tick vectors have been isolated and characterized for the immune response induced in different hosts. This review was focused on the interactions between tick-borne pathogenic hemoparasites and different host effector mechanisms of T-and/or B cell-mediated adaptive immunity, describing the efforts to define immunodominant proteins or epitopes for vaccine development and/or immunotherapeutic purposes. A better understanding of these mechanisms of host immunity could lead to the assessment of possible new immunotherapies for these pathogens as well as to the prediction of possible new candidate vaccine antigens

    Biotic and abiotic factors shape the microbiota of wild-caught populations of the arbovirus vector Culicoides imicola

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    Biting midges of the genus Culicoides are known vectors of arboviruses affecting human and animal health. However, little is known about Culicoides imicola microbiota and its influence on this insect’s biology. In this study, the impact of biotic and abiotic factors on C. imicola microbiota was characterized using shotgun-metagenomic sequencing of whole-body DNA samples. Wild-caught C. imicola adult nulliparous females were sampled in two locations from Sicily, Italy. The climatic variables of temperature and soil moisture from both localities were recorded together with potential host bloodmeal sources. Shared core microbiome among C. imicola populations included Pseudomonas, Escherichia, Halomonas, Candidatus Zinderia, Propionibacterium, and Schizosaccharomyces. Specific and unique taxa were also found in C. imicola from each location, highlighting similarities and differences in microbiome composition between the two populations. DNA and protein identification showed differences in host preferences between the two populations, with Homo sapiens and Canis lupus familiaris L. being the preferred bloodmeal source in both locations. A principal component analysis showed that the combined effect of host preferences (H. sapiens) and local soil moisture factors shape the microbiome composition of wild-caught populations of C. imicola. These results contribute to characterizing the role of the microbiome in insect adaptation and its utility in predicting geographic expansion of Culicoides species with potential implications for the control of vector-borne diseases

    Italian guidelines for primary headaches: 2012 revised version

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    The first edition of the Italian diagnostic and therapeutic guidelines for primary headaches in adults was published in J Headache Pain 2(Suppl. 1):105–190 (2001). Ten years later, the guideline committee of the Italian Society for the Study of Headaches (SISC) decided it was time to update therapeutic guidelines. A literature search was carried out on Medline database, and all articles on primary headache treatments in English, German, French and Italian published from February 2001 to December 2011 were taken into account. Only randomized controlled trials (RCT) and meta-analyses were analysed for each drug. If RCT were lacking, open studies and case series were also examined. According to the previous edition, four levels of recommendation were defined on the basis of levels of evidence, scientific strength of evidence and clinical effectiveness. Recommendations for symptomatic and prophylactic treatment of migraine and cluster headache were therefore revised with respect to previous 2001 guidelines and a section was dedicated to non-pharmacological treatment. This article reports a summary of the revised version published in extenso in an Italian version
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