32 research outputs found

    Diclidophora luscae (Monogenea: Diclidophoridae) in pouting, Trisopterus luscus (Linnaeus, 1758) from the northeast Atlantic; epidemiology, morphology, molecular and phylogenetic analysis

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    Diclidophora (Monogenea) species are gill parasites with a stenoxenic specifcity occurring only in Gadiformes. Epidemiologi‑cal, morphological, molecular and phylogenetic studies were performed on 594 Diclidophora specimens collected from 213 Trisopterus luscus captured in the northeast Atlantic of the Portuguese coast during 2012, 2013 and 2020. Prevalence, parasite abundance and infection intensity were determined. Positive correlation between fsh weight and length and infection intensity was observed. The efects of preservation on the parasite morphological features were studied, highlighting that specimen’s identifcation should be reinforced by molecular studies. A sequence of D. luscae capelanii from T. capelanus captured in the Mediterranean Sea included in the 28S rDNA molecular analysis was nested within a robust D. luscae clade. Data analysis suggested that this species is in fact D. luscae, which is compatible with T. luscus and T. capelanus. The identity of fsh hosts was confrmed by barcoding. For the frst time, data on the infection parameters is shown, highlighting the importance of including this parasite in the monitoring plans for a holistic approach with possible efects for the management of pouting resources aiming of attaining sustainable development and biodiversity conservation measures, according to the 14th objective of the 2030 agendainfo:eu-repo/semantics/publishedVersio

    from in uterus to elderly

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    Immune system recognize and fight back foreign microorganisms and inner modifications that lead to deficient cell and tissue functions. During a dog's life, the immune system needs to adapt to different physiological conditions, assuring surveillance and protection in a careful and controlled way. Pregnancy alters normal homeostasis, requiring a balance between immunity and tolerance. The embryos and fetus should be protected from infections, while the female dog must tolerate the growing of semi-allografts in her uterus. After birth, newborn puppies are at great risk of developing infectious diseases, because their immune system is in development and immune memory is absent. Passive transfer of immunity through colostrum is fundamental for puppy survival in the first weeks of life, but hampers the development of an active immune response to vaccination. At the end of life, dogs experience a decline in the structure and functional competence of the immune system, compromising the immune responses to novel antigenic challenges, such as infections and vaccines. Therefore, the current article reviews the general processes related to the development of the dog´s immune system, providing an overview of immune activity throughout the dog's life and its implications in canine health, and highlighting priority research goals.publishersversionpublishe

    The Facial Reconstruction of a Mesolithic Dog, Muge, Portugal

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    This paper presents the facial reconstruction of a Mesolithic dog whose skeleton was recovered from the Muge shell middens (Portugal) in the 19th century. We used the anatomical deformation approach based on a collection of computer tomography images as an attempt to reconstruct the Muge dog’s head appearance. We faced a few challenges due to the level of bone displacement and the absence of some cranium anatomical parts, as well as accurate information on soft tissue thickness for modern dogs. This multidisciplinary study combined anatomical, veterinary, zooarchaeological, artistic and graphic aspects to allow for the facial reconstruction of the Muge dog. Albeit an approximation, it confers a recognition to this prehistoric finding.info:eu-repo/semantics/publishedVersio

    New Insights on Innate Immune Response by Blood Macrophages and Liver Kupffer Cells to Leishmania infantum Parasites

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    Funding Information: Funding: This study was supported by FCT-Foundation for Science and Technology, I.P., through research grant PTDC/CVT-CVT/28908/2017 and PTDC/CVT-CVT/0228/2020, and by national funds within the scope of Centro de Investigação Interdisciplinar em Sanidade Animal (CIISA, UIDB/00276/2020) and Global Health and Tropical Medicine (GHTM, UID/04413/2020). Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.L. infantum is the aetiological agent of zoonotic visceral leishmaniasis (ZVL), a disease that affects humans and dogs. Leishmania parasites are well adapted to aggressive conditions inside the phagolysosome and can control the immune activation of macrophages (MØs). Although MØs are highly active phagocytic cells with the capacity to destroy pathogens, they additionally comprise the host cells for Leishmania infection, replication, and stable establishment in the mammal host. The present study compares, for the first time, the innate immune response to L. infantum infection of two different macrophage lineages: the blood macrophages and the liver macrophages (Kupffer cells, KC). Our findings showed that L. infantum takes advantage of the natural predisposition of blood-MØs to phagocyte pathogens. However, parasites rapidly subvert the mechanisms of MØs immune activation. On the other hand, KCs, which are primed for immune tolerance, are not extensively activated and can overcome the dormancy induced by the parasite, exhibiting a selection of immune mechanisms, such as extracellular trap formation. Altogether, KCs reveal a different pattern of response in contrast with blood-MØs when confronting L. infantum parasites. In addition, KCs response appears to be more efficient in managing parasite infection, thus contributing to the ability of the liver to naturally restrain Leishmania dissemination.publishersversionpublishe

    Collagen and microvascularization in placentas from young and older mares

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    Research Areas: Veterinary SciencesIn older mares, increasing collagen fibers (fibrosis) in the endometrium and oviduct predisposes to sub-fertility and infertility. In this study, (i) gene transcription of collagen (qPCR: COL1A1, COL1A2, COL3A1, COL5A1); (ii) total collagen protein (hydroxyproline); (iii) collagen distribution (Picrosirius red staining; polarized light microscopy); and (iv) microvascular density (Periodic acid-Schiff staining), were evaluated in mares’ placenta, and related to mares age, and placenta and neonate weights. Samples were collected from the gravid horn, non-gravid horn, and body of the placenta from younger (n = 7), and older mares (n = 9) of different breeds. Transcripts of COL1A1, COL3A1 and COL5A1, total collagen protein, chorionic plate connective tissue thickness, and microvascularization increased in the gravid horn of older mares’ placentas, compared to the youngest (P < 0.05). Although in other species placenta fibrosis may indicate placental insufficiency and reduced neonate weight, this was not observed here. It appears that older fertile mares, with more parities, may develop a heavier, more vascularized functional placenta with more collagen, throughout a longer gestation, which enables the delivery of heavier foals. Thus, these features might represent morphological and physiological adaptations of older fertile mares’ placentas to provide the appropriate nutrition to the equine fetus.info:eu-repo/semantics/publishedVersio

    Insights on Host–Parasite Immunomodulation Mediated by Extracellular Vesicles of Cutaneous Leishmania shawi and Leishmania guyanensis

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    Funding Information: This study was supported by FCT-Foundation for Science and Technology, I.P., through research grant PTDC/CVT-CVT/28908/2017 and PTDC/CVT-CVT/0228/2020 and by national funds within the scope of Centro de Investigação Interdisciplinar em Sanidade Animal (CIISA, UIDB/00276/2020) and Global Health and Tropical Medicine (GHTM, UID/04413/2020). Publisher Copyright: © 2023 by the authors.Leishmaniasis is a parasitic disease caused by different species of Leishmania and transmitted through the bite of sand flies vector. Macrophages (MΦ), the target cells of Leishmania parasites, are phagocytes that play a crucial role in the innate immune microbial defense and are antigen-presenting cells driving the activation of the acquired immune response. Exploring parasite–host communication may be key in restraining parasite dissemination in the host. Extracellular vesicles (EVs) constitute a group of heterogenous cell-derived membranous structures, naturally produced by all cells and with immunomodulatory potential over target cells. This study examined the immunogenic potential of EVs shed by L. shawi and L. guyanensis in MΦ activation by analyzing the dynamics of major histocompatibility complex (MHC), innate immune receptors, and cytokine generation. L. shawi and L. guyanensis EVs were incorporated by MΦ and modulated innate immune receptors, indicating that EVs cargo can be recognized by MΦ sensors. Moreover, EVs induced MΦ to generate a mix of pro- and anti-inflammatory cytokines and favored the expression of MHCI molecules, suggesting that EVs antigens can be present to T cells, activating the acquired immune response of the host. Since nano-sized vesicles can be used as vehicles of immune mediators or immunomodulatory drugs, parasitic EVs can be exploited by bioengineering approaches for the development of efficient prophylactic or therapeutic tools for leishmaniasis.publishersversionpublishe

    Immunophenotyping of peripheral blood, lymph node, and bone marrow T lymphocytes during canine leishmaniosis and the impact of antileishmanial chemotherapy

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    Dogs are a major reservoir of Leishmania infantum, etiological agent of canine leishmaniosis (CanL) a zoonotic visceral disease of worldwide concern. Therapeutic protocols based on antileishmanial drugs are commonly used to treat sick dogs and improve their clinical condition. To better understand the impact of Leishmania infection and antileishmanial drugs on the dog's immune response, this study investigates the profile of CD4+ and CD8+ T cell subsets in peripheral blood, lymph node, and bone marrow of sick dogs and after two different CanL treatments. Two CanL groups of six dogs each were treated with either miltefosine or meglumine antimoniate combined with allopurinol. Another group of 10 clinically healthy dogs was used as control. Upon diagnosis and during the following 3 months of treatment, peripheral blood, popliteal lymph node, and bone marrow mononuclear cells were collected, labeled for surface markers CD45, CD3, CD4, CD8, CD25, and intracellular nuclear factor FoxP3, and T lymphocyte subpopulations were immunophenotyped by flow cytometry. CanL dogs presented an overall increased frequency of CD8+ and CD4+CD8+ double-positive T cells in all tissues and a decreased frequency of CD4+ T cells in the blood. Furthermore, there was a higher frequency of CD8+ T cells expressing CD25+FoxP3+ in the blood and bone marrow. During treatment, these subsets recovered to levels similar to those of healthy dogs. Nevertheless, antileishmanial therapy caused an increase of CD4+CD25+FoxP3+ T cells in all tissues, associated with the decrease of CD8+CD25−FoxP3− T cell percentages. These findings may support previous studies that indicate that L. infantum manipulates the dog's immune system to avoid the development of a protective response, ensuring the parasite's survival and the conditions that allow the completion of Leishmania life cycle. Both treatments used appear to have an effect on the dog's immune response, proving to be effective in promoting the normalization of T cell subsets.publishersversionpublishe

    CkP1 bacteriophage, a S16-like myovirus that recognizes Citrobacter koseri lipopolysaccharide through its long tail fibers

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    The online version contains supplementary material available at https://doi.org/10.1007/s00253-023-12547-8.Citrobacter koseri is an emerging Gram-negative bacterial pathogen, which causes urinary tract infections. We isolated and characterized a novel S16-like myovirus CKP1 (vB\_CkoM\\_CkP1), infecting C. koseri. CkP1 has a host range covering the whole C. koseri species, i.e., all strains that were tested, but does not infect other species. Its linear 168,463-bp genome contains 291 coding sequences, sharing sequence similarity with the Salmonella phage S16. Based on surface plasmon resonance and recombinant green florescence protein fusions, the tail fiber (gp267) was shown to decorate C. koseri cells, binding with a nanomolar affinity, without the need of accessory proteins. Both phage and the tail fiber specifically bind to bacterial cells by the lipopolysaccharide polymer. We further demonstrate that CkP1 is highly stable towards different environmental conditions of pH and temperatures and is able to control C. koseri cells in urine samples. Altogether, CkP1 features optimal in vitro characteristics to be used both as a control and detection agent towards drug-resistant C. koseri infections.Open access funding provided by FCT|FCCN (b-on). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit. DB is supported by the Research Foundation – Flanders (FWO), grant number 1S69520N. JO received a predoctoral fellowship from the UAB and a FEMS research and training grant.info:eu-repo/semantics/publishedVersio

    Extracellular vesicles shed by trypanosoma brucei brucei manipulate host mononuclear cells

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    Funding Information: Funding: This study was supported by FCT—Foundation for Science and Technology, I.P., through research grant PTDC/CVT-CVT/28908/2017 and by national funds within the scope of Centro de Investigação Interdisciplinar em Sanidade Animal (CIISA, UIDB/00276/2020) and Global Health and Tropical Medicine (GHTM, UID/04413/2020). Funding Information: This study was supported by FCT?Foundation for Science and Technology, I.P., through research grant PTDC/CVT-CVT/28908/2017 and by national funds within the scope of Centro de Investiga??o Interdisciplinar em Sanidade Animal (CIISA, UIDB/00276/2020) and Global Health and Tropical Medicine (GHTM, UID/04413/2020). Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.African trypanosomiasis or sleeping sickness is a zoonotic disease caused by Trypanosoma brucei, a protozoan parasite transmitted by Glossina spp. (tsetse fly). Parasite introduction into mammal hosts triggers a succession of events, involving both innate and adaptive immunity. Macrophages (MΦ) have a key role in innate defence since they are antigen-presenting cells and have a micro-bicidal function essential for trypanosome clearance. Adaptive immune defence is carried out by lymphocytes, especially by T cells that promote an integrated immune response. Like mammal cells, T. b. brucei parasites release extracellular vesicles (TbEVs), which carry macromolecules that can be transferred to host cells, transmitting biological information able to manipulate cell immune response. However, the exact role of TbEVs in host immune response remains poorly understood. Thus, the current study examined the effect elicited by TbEVs on MΦ and T lymphocytes. A combined approach of microscopy, nanoparticle tracking analysis, multiparametric flow cytometry, colourimetric assays and detailed statistical analyses were used to evaluate the influence of TbEVs in mouse mononuclear cells. It was shown that TbEVs can establish direct communication with cells of innate and adaptative immunity. TbEVs induce the differentiation of both M1-and M2-MΦ and elicit the expansion of MHCI+, MHCII+ and MHCI+ MHCII+ MΦ subpopulations. In T lymphocytes, TbEVs drive the overexpression of cell-surface CD3 and the nuclear factor FoxP3, which lead to the differentiation of regulatory CD4+ and CD8+ T cells. Moreover, this study indicates that T. b. brucei and TbEVs seem to display opposite but complementary effects in the host, establishing a balance between parasite growth and controlled immune response, at least during the early phase of infection.publishersversionpublishe
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