RESUMO
BACKGROUND: Gills monogenean infestation causes significant mortalities in cultured fishes as a result of respiratory manifestation. Medicinal plants are currently being heavily emphasized in aquaculture due to their great nutritional, therapeutic, antimicrobial activities, and financial value. METHODS: The current study is designed to assess the effect of garlic (Allium sativum) and onion (Allium cepa) extracts as a water treatment on the hematological profile, innate immunity, and immune cytokines expression besides histopathological features of gills of Nile tilapia (Oreochromis niloticus L.) infected with gills monogenetic trematodes (Dactylogyrus sp.). Firstly, the 96-hour lethal concentration 50 (96 h-LC50) of garlic extract (GE) and onion extract (OE) were estimated to be 0.4 g/ L and 3.54 g/ L for GE and OE, respectively. Moreover, the in-vitro anti-parasitic potential for (GE) was found between 0.02 and 0.18 mg/mL and 0.4 to 1.8 mg/mL for OE. For the therapeutic trial, fish (n = 120; body weight: 40-60 g) were randomly distributed into four groups in triplicates (30 fish/group, 10 fish/replicate) for 3 days. Group1 (G1) was not infected or treated and served as control. G2 was infected with Dactylogyrus spp. and not exposed to any treatment. G3, G4 were infected with Dactylogyrus sp. and treated with 1/10 and 1/5 of 96 h LC50 of OE, respectively. G5, G6 were infected with Dactylogyrus sp. and treated with 1/10 and 1/5 of 96 h LC50 of GE, respectively. RESULTS: No apparent signs or behaviors were noted in the control group. Dactylogyrus spp. infected group suffered from clinical signs as Pale color and damaged tissue. Dactylogyrus spp. infection induced lowering of the hematological (HB, MCH, MCHC and WBCs), and immunological variables (lysozyme, nitric oxide, serum Anti- protease activities, and complement 3). the expression of cytokine genes IL-ß and TNF-α were modulated and improved by treatment with A. sativum and A. cepa extracts. The obtained histopathological alterations of the gills of fish infected with (Dactylogyrus spp.) were hyperplasia leading to fusion of the gill filament, lifting of epithelial tissue, aneurism and edema. The results indecated that G4 and G5 is more regenarated epithelium in compare with the control group. CONCLUSION: A. sativum and A. cepa extracts enhance the blood profile and nonspecific immune parameters, and down-regulated the expression level of (IL-1ß and TNF-α).
Assuntos
Ciclídeos , Citocinas , Doenças dos Peixes , Alho , Brânquias , Cebolas , Extratos Vegetais , Trematódeos , Infecções por Trematódeos , Animais , Brânquias/parasitologia , Brânquias/patologia , Brânquias/efeitos dos fármacos , Doenças dos Peixes/parasitologia , Doenças dos Peixes/tratamento farmacológico , Doenças dos Peixes/imunologia , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Ciclídeos/imunologia , Ciclídeos/parasitologia , Alho/química , Citocinas/genética , Citocinas/metabolismo , Infecções por Trematódeos/veterinária , Infecções por Trematódeos/tratamento farmacológico , Infecções por Trematódeos/parasitologia , Infecções por Trematódeos/imunologia , Trematódeos/efeitos dos fármacos , Imunidade Inata/efeitos dos fármacosRESUMO
Introduction: Parasite-mediated selection is considered one of the potential mechanisms contributing to the coexistence of asexual-sexual complexes. Gibel carp (Carassius gibelio), an invasive fish species in Europe, often forms populations composed of gynogenetic and sexual specimens. Methods: The experimental infection was induced in gynogenetic and sexual gibel carp using eye-fluke Diplostomum pseudospathaceum (Trematoda), and the transcriptome profile of the spleen as a major immune organ in fish was analyzed to reveal the differentially expressed immunity-associated genes related to D. pseudospathaceum infection differing between gynogenetic and sexual gibel carp. Results: High parasite infection was found in gynogenetic fish when compared to genetically diverse sexuals. Although metacercariae of D. pseudospathaceum are situated in an immune-privileged organ, our results show that eye trematodes may induce a host immune response. We found differential gene expression induced by eye-fluke infection, with various impacts on gynogenetic and sexual hosts, documenting for the majority of DEGs upregulation in sexuals, and downregulation in asexuals. Differences in gene regulation between gynogenetic and sexual gibel carp were evidenced in many immunity-associated genes. GO analyses revealed the importance of genes assigned to the GO terms: immune function, the Notch signaling pathway, MAP kinase tyrosine/threonine/phosphatase activity, and chemokine receptor activity. KEGG analyses revealed the importance of the genes involved in 12 immunity-associated pathways - specifically, FoxO signaling, adipocytokine signaling, TGF-beta signaling, apoptosis, Notch signaling, C-type lectin receptor signaling, efferocytosis, intestinal immune network for IgA production, insulin signaling, virion - human immunodeficiency virus, Toll-like receptor signaling, and phosphatidylinositol signaling system. Discussion: Our study indicates the limited potential of asexual fish to cope with higher parasite infection (likely a loss of capacity to induce an effective immune response) and highlights the important role of molecular mechanisms associated with immunity for the coexistence of gynogenetic and sexual gibel carp, potentially contributing to its invasiveness.
Assuntos
Doenças dos Peixes , Espécies Introduzidas , Trematódeos , Infecções por Trematódeos , Animais , Trematódeos/fisiologia , Doenças dos Peixes/imunologia , Doenças dos Peixes/parasitologia , Infecções por Trematódeos/veterinária , Infecções por Trematódeos/imunologia , Infecções por Trematódeos/parasitologia , Transcriptoma , Interações Hospedeiro-Parasita/imunologia , Regulação da Expressão Gênica , Carpas/parasitologia , Carpas/imunologia , Carpas/genética , Feminino , Perfilação da Expressão Gênica , Reprodução/imunologiaRESUMO
Aporocotylids (Trematoda: Digenea), also known as fish blood flukes infect the circulatory system of fish leading to serious health problems and mortality. Aporocotylids are a particular concern for farmed fish as infection intensity can increase within the farming environment and lead to mortalities. In the context of managing these infections, one of the most crucial aspects to consider is the host response of the infected fish against these blood flukes. Understanding the response is essential to improving current treatment strategies that are largely based on the use of anthelmintic praziquantel to manage infections in aquaculture. This review focuses on the current knowledge of farmed fish host responses against the different life stages of aporocotylids. New treatment strategies that are able to provide protection against reinfections should be a long-term goal and is not possible without understanding the fish response to infection and the interactions between host and parasite.
Assuntos
Aquicultura , Doenças dos Peixes , Peixes , Trematódeos , Infecções por Trematódeos , Animais , Infecções por Trematódeos/veterinária , Infecções por Trematódeos/imunologia , Infecções por Trematódeos/parasitologia , Infecções por Trematódeos/tratamento farmacológico , Doenças dos Peixes/imunologia , Doenças dos Peixes/parasitologia , Trematódeos/fisiologia , Peixes/imunologia , Peixes/parasitologia , Interações Hospedeiro-Parasita , Anti-Helmínticos/uso terapêutico , Anti-Helmínticos/farmacologiaRESUMO
Intestinal trematodes constitute a major group of helminths that parasitize humans and animals with relevant morbidity and mortality. Despite the importance of the intestinal trematodes in medical and veterinary sciences, immunology and pathology of these helminth infections have been neglected for years. Apart from the work focused on the members of the family Echnistomatidae, there are only very isolated and sporadic studies on the representatives of other families of digeneans, which makes a compilation of all these studies necessary. In the present review, the most salient literature on the immunology and pathology of intestinal trematodes in their definitive hosts in examined. Emphasis will be placed on members of the echinostomatidae family, since it is the group in which the most work has been carried out. However, we also review the information on selected species of the families Brachylaimidae, Diplostomidae, Gymnophallidae, and Heterophyidae. For most of these families, coverage is considered under the following headings: (i) Background; (ii) Pathology of the infection; (iii) Immunology of the infection; and (iv) Human infections.
Assuntos
Enteropatias Parasitárias , Trematódeos , Infecções por Trematódeos , Animais , Humanos , Trematódeos/fisiologia , Trematódeos/imunologia , Infecções por Trematódeos/parasitologia , Infecções por Trematódeos/imunologia , Infecções por Trematódeos/veterinária , Enteropatias Parasitárias/imunologia , Enteropatias Parasitárias/parasitologia , Intestinos/parasitologia , Intestinos/patologia , Intestinos/imunologia , Interações Hospedeiro-Parasita/imunologiaRESUMO
Improperly cooked fish, carrying active metacercariae (MCs), can pose a significant risk for transmitting fish-borne zoonotic trematodes (FBZTs) to human consumers. This study aimed to enhance our understanding of FBZTs by conducting a comprehensive cross-sectional analysis involving various fish species, such as Nile tilapia (Oreochromis niloticus), African catfish (Clarias gariepinus), and red-belly tilapia (Tilapia zillii). These fish specimens were collected from distinct Egyptian governorates, specifically Giza, Kafr al-Shaykh, and Fayoum. The recovered flukes from experimentally infected domestic pigeons were identified as Prohemistomum vivax, Haplorchis pumilio, and Pygidiopsis genata based on morphological features. Furthermore, the identity of the retrieved adult flukes was confirmed using three species-specific primers for PCR amplification and sequencing analysis of the ITS rDNA region and have been deposited in GenBank with the following accession numbers: P. vivax (OR291421.1 and OR291422.1), P. genata (OP099561.1), and H. pumilio (OM439581.1-OP090510.1). Quantitative real-time PCR targeting the immunological genes Tumor Necrosis Factor-alpha (TNF-alpha) and Interleukin-1 (IL-1Β) was employed to compare the cellular immune response between infected with EMCs and uninfected O. niloticus. The results indicated a significant increase in TNF- and IL-1Β levels in FBZTs-infected vs un-infected fishes. Importantly, the presence of adult flukes and EMCs led to substantial histological alterations in both experimentally infected pigeons and naturally infected fish tissues. These changes included the necrosis of fish muscle bundles and a pronounced inflammatory reaction with muscular necrosis in the digestive tracts of experimentally infected pigeons.
Assuntos
Doenças dos Peixes , Infecções por Trematódeos , Animais , Estudos Transversais , Doenças dos Peixes/parasitologia , Doenças dos Peixes/imunologia , Infecções por Trematódeos/veterinária , Infecções por Trematódeos/parasitologia , Infecções por Trematódeos/imunologia , Zoonoses/parasitologia , Metacercárias , Ciclídeos/parasitologia , Ciclídeos/imunologia , Egito , Água Doce , Peixes-Gato/parasitologia , Tilápia/parasitologia , TrematódeosRESUMO
Helminth neuroinfections represent serious medical conditions, but the diversity of the host-parasite interplay within the nervous tissue often remains poorly understood, partially due to the lack of laboratory models. Here, we investigated the neuroinvasion of the mouse spinal cord by Trichobilharzia regenti (Schistosomatidae). Active migration of T. regenti schistosomula through the mouse spinal cord induced motor deficits in hindlimbs but did not affect the general locomotion or working memory. Histological examination of the infected spinal cord revealed eosinophilic meningomyelitis with eosinophil-rich infiltrates entrapping the schistosomula. Flow cytometry and transcriptomic analysis of the spinal cord confirmed massive activation of the host immune response. Of note, we recorded striking upregulation of the major histocompatibility complex II pathway and M2-associated markers, such as arginase or chitinase-like 3. Arginase also dominated the proteins found in the microdissected tissue from the close vicinity of the migrating schistosomula, which unselectively fed on the host nervous tissue. Next, we evaluated the pathological sequelae of T. regenti neuroinvasion. While no demyelination or blood-brain barrier alterations were noticed, our transcriptomic data revealed a remarkable disruption of neurophysiological functions not yet recorded in helminth neuroinfections. We also detected DNA fragmentation at the host-schistosomulum interface, but schistosomula antigens did not affect the viability of neurons and glial cells in vitro. Collectively, altered locomotion, significant disruption of neurophysiological functions, and strong M2 polarization were the most prominent features of T. regenti neuroinvasion, making it a promising candidate for further neuroinfection research. Indeed, understanding the diversity of pathogen-related neuroinflammatory processes is a prerequisite for developing better protective measures, treatment strategies, and diagnostic tools.
Assuntos
Arginase/metabolismo , Eosinófilos/metabolismo , Schistosomatidae/imunologia , Medula Espinal/parasitologia , Infecções por Trematódeos/imunologia , Infecções por Trematódeos/metabolismo , Animais , Biomarcadores/metabolismo , Quimiocinas/metabolismo , Modelos Animais de Doenças , Feminino , Perfilação da Expressão Gênica , Interações Hospedeiro-Parasita , Imunidade , Complexo Principal de Histocompatibilidade , Camundongos , Camundongos Endogâmicos C57BL , Neuroglia/parasitologia , Neurônios/parasitologia , Infecções por Trematódeos/patologiaRESUMO
Paramphistomosis, caused by the rumen fluke, Calicophoron daubneyi, is a parasitic infection of ruminant livestock, which has seen a rapid rise in prevalence throughout Western Europe in recent years. After ingestion of metacercariae (parasite cysts) by the mammalian host, newly excysted juveniles (NEJs) emerge and invade the duodenal submucosa, which causes significant pathology in heavy infections. The immature flukes then migrate upward, along the gastrointestinal tract, and enter the rumen where they mature and begin to produce eggs. Despite their emergence, and sporadic outbreaks of acute disease, we know little about the molecular mechanisms used by C. daubneyi to establish infection, acquire nutrients, and avoid the host immune response. Here, transcriptome analysis of four intramammalian life-cycle stages, integrated with secretome analysis of the NEJ and adult parasites (responsible for acute and chronic diseases, respectively), revealed how the expression and secretion of selected families of virulence factors and immunomodulators are regulated in accordance with fluke development and migration. Our data show that while a family of cathepsins B with varying S2 subsite residues (indicating distinct substrate specificities) is differentially secreted by NEJs and adult flukes, cathepsins L and F are secreted in low abundance by NEJs only. We found that C. daubneyi has an expanded family of aspartic peptidases, which is upregulated in adult worms, although they are under-represented in the secretome. The most abundant proteins in adult fluke secretions were helminth defense molecules that likely establish an immune environment permissive to fluke survival and/or neutralize pathogen-associated molecular patterns such as bacterial lipopolysaccharide in the microbiome-rich rumen. The distinct collection of molecules secreted by C. daubneyi allowed the development of the first coproantigen-based ELISA for paramphistomosis which, importantly, did not recognize antigens from other helminths commonly found as coinfections with rumen fluke.
Assuntos
Proteínas de Helminto/genética , Proteínas de Helminto/metabolismo , Paramphistomatidae/genética , Paramphistomatidae/metabolismo , Animais , Antígenos de Helmintos/genética , Antígenos de Helmintos/imunologia , Antígenos de Helmintos/metabolismo , Bovinos , Cisteína Proteases/genética , Cisteína Proteases/metabolismo , Fezes/parasitologia , Proteínas de Helminto/imunologia , Estágios do Ciclo de Vida , Paramphistomatidae/crescimento & desenvolvimento , Rúmen/parasitologia , Secretoma , Transcriptoma , Infecções por Trematódeos/diagnóstico , Infecções por Trematódeos/imunologia , Infecções por Trematódeos/parasitologiaRESUMO
Skin mucus is considered the first barrier against diseases in fish. The skin mucus protein profile of the greater amberjack (Seriola dumerili) and its changes due to experimental infection with Neobenedenia girellae were studied by combining 2-DE-MS/MS and gel-free LC-MS/MS proteomic approaches. The 2-DE results led to the identification of 69 and 55 proteins in noninfected and infected fish, respectively, and revealed that keratins were specifically cleaved in parasitized fish. Therefore, the skin mucus of the infected fish showed a higher protease activity due to, at least in part, an increase of metal-dependent protease and serine-type protease activities. Additionally, through a gel-free LC-MS/MS analysis, 1377 and 1251 different proteins were identified in the skin mucus of healthy and parasitized fish, respectively. The functional analysis of these proteins demonstrated a statistical overrepresentation of ribosomal proteins (a well-known source of antimicrobial peptides) in N. girellae-infected fish. In contrast, the components of membranes and protein transport GO categories were underrepresented after infection. Immune system process-related proteins constituted 2.5% of the total skin mucosal proteins. Among these skin mucosal proteins, 14 and 15 proteins exclusive to non-parasitized and parasitized fish were found, respectively, including specific serine-type proteases and metalloproteases in the parasitized fish. Moreover, the finding of tryptic peptides exclusive to some bacterial genera, obtained by gel-free LC-MS/MS, allowed us to construct a preliminary map of the microbiota living in the mucus of S. dumerili, with Pseudomonas and Paracoccus the most represented genera in both noninfected and infected fish.
Assuntos
Doenças dos Peixes/imunologia , Proteínas de Peixes/imunologia , Peixes/imunologia , Peptídeo Hidrolases/imunologia , Proteoma/imunologia , Pele/enzimologia , Animais , Doenças dos Peixes/parasitologia , Microbiota , Muco/enzimologia , Muco/metabolismo , Muco/microbiologia , Pele/metabolismo , Pele/microbiologia , Trematódeos/fisiologia , Infecções por Trematódeos/imunologia , Infecções por Trematódeos/parasitologia , Infecções por Trematódeos/veterináriaRESUMO
BACKGROUND: The cytokine interleukin-25 (IL-25) is recognized as the most relevant initiator of protective T helper 2 (Th2) responses in intestinal helminth infections. This cytokine induces resistance against several species of intestinal helminths, including the trematode Echinostoma caproni. E. caproni has been extensively used as an experimental model to study the factors determining resistance to intestinal infections. In the study reported here, we assessed the role of IL-25 in the generation of resistance in mice infected with E. caproni. METHODS: The factors that determine the production of IL-25 in mice experimentally infected with E. caproni were determined, as were the consequences of IL-25 production in terms of polarization of the immune response and resistance to infection. RESULTS: Our results show that the role of IL-25 in the polarization of the immune response differs between the primary and secondary immune responses. IL-25 is required for the development of a Th2 phenotype in primary E. caproni infections, but it can also promote the differentiation to Th2 memory cell subsets that enhance type-2 immunity in memory responses. However, the development of Th2 responses does not induce resistance to infection. The Th2 phenotype does not elicit resistance, and IL-25 is responsible for the resistance regardless of its type-2 cytokine activity and activation of signal transducer and activator of transcription (STAT6). Alternative activation of macrophages induced by IL-25 can be implicated in the resistance to infection. CONCLUSIONS: In contrast to primary infection, secondary infection elicits a type-2 immune response even in the absence of IL-25 expression. Despite the development of a type-2 response, mice are susceptible to secondary infection associated with the lack of IL-25. Resistance to infection is due to the production of IL-25, which acts autonomously from Th2 response in terms of parasite clearance.
Assuntos
Citocinas/metabolismo , Interleucina-17/metabolismo , Interleucina-17/uso terapêutico , Infecções por Trematódeos/tratamento farmacológico , Infecções por Trematódeos/imunologia , Animais , Anticorpos Anti-Helmínticos , Modelos Animais de Doenças , Resistência a Medicamentos , Echinostoma , Equinostomíase/parasitologia , Expressão Gênica , Helmintíase/imunologia , Imunidade , Imunoglobulina G , Interleucina-17/genética , Enteropatias Parasitárias/imunologia , Intestinos/parasitologia , Camundongos , RNA Mensageiro , Fator de Transcrição STAT6 , Células Th2 , Infecções por Trematódeos/parasitologiaRESUMO
Southern Bluefin Tuna (SBT), Thunnus maccoyii, is ranched off Port Lincoln, South Australia and is Australia's second largest economic finfish aquaculture industry. The biggest threats to SBT health identified by the industry are the blood flukes Cardicola forsteri and C. orientalis (Trematoda: Aporocotylidae). Melanomacrophage centres (MMCs) are aggregations of pigmented macrophage like cells present in spleen, kidney and liver of teleost fish. The aim of this study was to quantify MMCs in SBT anterior kidney, liver and spleen to investigate changes in relation to Cardicola spp. Infection. Samples were collected at the end of ranching from pontoons where SBT were treated with PZQ and pontoons with untreated SBT. SBT MMC percentage of surface area cover was highest in SBT spleen and lowest in the liver. Significant positive correlations were identified between SBT MMC area and SBT size in all three organs (p < 0.05). MMC area and parasite infection showed significant positive correlations in the kidney and spleen for Cardicola spp. gill egg counts, and in the kidney for C. forsteri DNA from SBT hearts and gills (p < 0.05). MMCs area increased with increased intensity of Cardicola spp. Infection and MMCs have the potential to be used as an indicator to assess health effects that Cardicola spp. have on SBT.
Assuntos
Doenças dos Peixes/imunologia , Fagócitos/imunologia , Trematódeos , Infecções por Trematódeos/imunologia , Atum/imunologia , Animais , Doenças dos Peixes/parasitologia , Rim/citologia , Rim/imunologia , Rim/parasitologia , Fígado/citologia , Fígado/imunologia , Fígado/parasitologia , Baço/citologia , Baço/imunologia , Baço/parasitologia , Infecções por Trematódeos/parasitologia , Infecções por Trematódeos/veterinária , Atum/parasitologiaRESUMO
The transcriptome of the caenogastropod mollusk Littorina littorea was scanned for the presence of sequences encoding Toll-like receptors (TLRs) and corresponding proteins involved in downstream TLR signaling pathway. In the transcriptomic snapshots of hemocytes and kidney tissues, 45 complete TLRs encoded by 35 genes were identified. Out of the 59 non-TLR molecules involved in a canonical TLR signaling pathway, 35 genes were classified as homologous and could be placed within the TLR-mediated MyD88-and MAPK-dependent circuitries. No reference vertebrate adapters TIRAP, TRIF and TRAM were identified in the transcriptome. The results of RNA-seq experiments with an immune challenge (rediae of the digenean Himasthla elongata) indicate that four TLRs (LlTLR1, 3, 5 and 8) and a set of upregulated genes involved in signal transduction (LlMyd88, LlTNFα, LlCASP8, LlFADD, LlNFKBIA (IkBα), LlIRAK1, LlSTAT1, LlMAPK14 (P38), LlMAP2K1 (MEK1/2), LlIRF3 and LlIRF5) may participate in the anti-digenean immune response of L. littorea.
Assuntos
Gastrópodes/genética , Gastrópodes/imunologia , Receptores Toll-Like/genética , Receptores Toll-Like/imunologia , Animais , Gastrópodes/parasitologia , Transdução de Sinais , Transcriptoma , Trematódeos , Infecções por Trematódeos/genética , Infecções por Trematódeos/imunologia , Infecções por Trematódeos/veterináriaRESUMO
Monogenean Gyrodactylus cichlidarum can cause severe mortality of Nile tilapia (Oreochromis niloticus) fry. To date, reports about mucosal immunity of O. niloticus against this parasite have been rare. In order to explore the mucosal immunity of Nile tilapia against G. cichlidarum infection, the expressions of six adaptive immune-related genes and the contents of specific immunoglobulin IgM and IgT in the skin-associated lymphoid tissues (SALT) were dynamically analyzed after primary and secondary infections. The abundances of G. cichlidarum on the hosts after secondary infection were lower than those after primary parasite infection, which implied that hosts could initiate immune protection against G. cichlidarum reinfection to some degree. The transcription levels of TCR-ß and CD4 genes in the skin tissue were significantly up-regulated after primary G. cichlidarum infection, while genes pIgR and IgT were only detected with significant up-regulations during secondary infection. With the exception of pIgR, which had remarkably higher expression in the fish with low parasite loads, all other genes studied tended to have higher mRNA level in the fish with higher parasite loads. The specific IgM content in the skin mucus increased significantly on the 2nd day after the primary exposure, higher than the corresponding value during the secondary exposure, and had significantly positive correlation with the parasite loads during the first parasite infection. These results manifested that acquired immune responses in the SALT of Nile tilapia participated in the resistance against G. cichlidarum infection, underscoring the involvement of mucosal immunity in fish against monogenean infection, and suggesting potential prophylactic treatment of gyrodactylid disease of tilapia.
Assuntos
Ciclídeos , Doenças dos Peixes/imunologia , Imunidade nas Mucosas , Trematódeos/fisiologia , Infecções por Trematódeos/veterinária , Animais , Doenças dos Peixes/parasitologia , Infecções por Trematódeos/imunologia , Infecções por Trematódeos/parasitologiaRESUMO
Heterobothrium okamotoi, a monogenean gill parasite, exhibits high host specificity for the tiger puffer, Takifugu rubripes, and it has been experimentally verified that the parasite cannot colonize either closely related species such as the grass puffer Takifugu niphobles or distantly related fish such as the red seabream Pagrus major. Previously, we demonstrated in T. rubripes that immunoglobulin M (IgM) with d-mannose affinity induced deciliation of the oncomiracidia, the first step of parasitism, indicating that the parasite utilizes the molecule as a receptor for infection. In the present study, we purified mannose-specific IgM from 2 nonhost species, T. niphobles and P. major, by affinity and gel-filtration chromatography techniques and compared their deciliation-inducing activity against H. okamotoi oncomiracidia. The IgM of the former showed activity, whereas the latter had no effect, suggesting that in addition to d-mannose-binding ability, the crystallizable fragment domain of IgM, which is not part of the antigen-binding domain, plays an important role in host recognition by the oncomiracidia, such as direct binding to the parasites. It also suggests that the host specificity of H. okamotoi is relatively low upon initial recognition, and the specificity is established by exclusion in nonhosts during a later stage.
Assuntos
Ectoparasitoses/veterinária , Doenças dos Peixes/parasitologia , Imunoglobulina M/fisiologia , Manose/imunologia , Platelmintos/imunologia , Takifugu/parasitologia , Sequência de Aminoácidos , Animais , Western Blotting , Cílios/imunologia , Clonagem Molecular , DNA Complementar/genética , DNA Complementar/imunologia , Ectoparasitoses/imunologia , Ectoparasitoses/parasitologia , Eletroforese em Gel de Poliacrilamida , Doenças dos Peixes/imunologia , Expressão Gênica , Brânquias/parasitologia , Especificidade de Hospedeiro , Concentração de Íons de Hidrogênio , Imunoglobulina M/sangue , Imunoglobulina M/genética , Imunoglobulina M/isolamento & purificação , Mucosa/química , Mucosa/imunologia , Mucosa/parasitologia , Platelmintos/patogenicidade , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Takifugu/imunologia , Infecções por Trematódeos/imunologia , Infecções por Trematódeos/parasitologia , Infecções por Trematódeos/veterináriaRESUMO
Trichobilharzia regenti (Schistosomatidae) percutaneously infects birds and mammals and invades their central nervous system (CNS). Here, we characterized the peripheral immune response of infected mice and showed how it was influenced by the parasite-induced inflammation in the skin and the CNS. As revealed by flow cytometry, T cells expanded in the spleen and the CNS-draining lymph nodes 7-14 days post-infection. Both T-bet+ and GATA-3+ T cells were markedly elevated suggesting a mixed type 1/2 immune response. However, it dropped after 7 dpi most likely being unaffected by the neuroinflammation. Splenocytes from infected mice produced a high amount of IFN-γ and, to a lesser extent, IL-10, IL-4 and IL-17 after in vitro stimulation by cercarial homogenate. Nevertheless, it had only a limited capacity to alter the maturation status of bone marrow-derived dendritic cells (BMDCs), contrary to the recombinant T. regenti cathepsin B2, which also strongly augmented expression of Ccl5, Cxcl10, Il12a, Il33 and Il10 by BMDCs. Taken together, mice infected with T. regenti developed the mixed type 1/2 immune response, which was driven by the early skin inflammation rather than the late neuroinflammation. Parasite peptidases might play an active role in triggering the host immune response.
Assuntos
Cercárias/imunologia , Dermatite/parasitologia , Schistosomatidae/imunologia , Linfócitos T/imunologia , Infecções por Trematódeos/imunologia , Animais , Catepsina B/metabolismo , Citocinas/imunologia , Células Dendríticas/imunologia , Dermatite/imunologia , Dermatite/patologia , Feminino , Inflamação/parasitologia , Inflamação/patologia , Camundongos , Camundongos Endogâmicos C57BL , Pele/imunologia , Pele/parasitologia , Pele/patologia , Infecções por Trematódeos/parasitologiaRESUMO
Hosts have two general strategies for mitigating the fitness costs of parasite exposure and infection: resistance and tolerance. The resistance-tolerance framework has been well developed in plant systems, but only recently has it been applied to animal-parasite interactions. However, difficulties associated with estimating fitness, controlling parasite exposure, and quantifying parasite burden have limited application of this framework to animal systems. Here, we used an experimental approach to quantify the relative influence of variation among host individuals and genetic families in determining resistance and tolerance within an amphibian-trematode system. Importantly, we used multiple, alternative metrics to assess each strategy, and employed a Bayesian analytical framework to compare among responses while incorporating uncertainty. Relative to unexposed hosts, exposure to the pathogenic trematode (Ribeiroia ondatrae) reduced the survival and growth of California newts (Taricha torosa) (survival: 93% vs. 74%; growth: 0.29 vs. -0.5 vs mm day -1). Similarly, parasite infection success (the inverse of resistance) ranged from 8% to 100%. Yet despite this broad variation in host resistance and tolerance among individual newts, we found no evidence for transmissable, among-family variation in any of the resistance or tolerance metrics. This suggests that opportunities for evolution of these traits is limited, likely requiring significant increases in mutation, gene flow, or environmental heterogeneity. Our study provides a quantitative framework for evaluating the importance of alternative metrics of resistance and tolerance across multiple time points in the study of host-parasite interactions in animal systems.
Assuntos
Echinostomatidae/patogenicidade , Salamandridae/parasitologia , Infecções por Trematódeos/veterinária , Animais , Teorema de Bayes , Distribuição Binomial , Resistência à Doença , Echinostomatidae/imunologia , Interações Hospedeiro-Parasita , Lagoas , Salamandridae/genética , Salamandridae/crescimento & desenvolvimento , Salamandridae/fisiologia , Caramujos/parasitologia , Infecções por Trematódeos/genética , Infecções por Trematódeos/imunologia , Infecções por Trematódeos/parasitologiaRESUMO
Serine peptidases are involved in many physiological processes including digestion, haemostasis and complement cascade. Parasites regulate activities of host serine peptidases to their own benefit, employing various inhibitors, many of which belong to the Kunitz-type protein family. In this study, we confirmed the presence of potential anticoagulants in protein extracts of the haematophagous monogenean Eudiplozoon nipponicum which parasitizes the common carp. We then focused on a Kunitz protein (EnKT1) discovered in the E. nipponicum transcriptome, which structurally resembles textilinin-1, an antihemorrhagic snake venom factor from Pseudonaja textilis. The protein was recombinantly expressed, purified and biochemically characterised. The recombinant EnKT1 did inhibit in vitro activity of Factor Xa of the coagulation cascade, but exhibited a higher activity against plasmin and plasma kallikrein, which participate in fibrinolysis, production of kinins, and complement activation. Anti-coagulation properties of EnKT1 based on the inhibition of Factor Xa were confirmed by thromboelastography, but no effect on fibrinolysis was observed. Moreover, we discovered that EnKT1 significantly impairs the function of fish complement, possibly by inhibiting plasmin or Factor Xa which can act as a C3 and C5 convertase. We localised Enkt1 transcripts and protein within haematin digestive cells of the parasite by RNA in situ hybridisation and immunohistochemistry, respectively. Based on these results, we suggest that the secretory Kunitz protein of E. nipponicum has a dual function. In particular, it impairs both haemostasis and complement activation in vitro, and thus might facilitate digestion of a host's blood and protect a parasite's gastrodermis from damage by the complement. This study presents, to our knowledge, the first characterisation of a Kunitz protein from monogeneans and the first example of a parasite Kunitz inhibitor that impairs the function of the complement.
Assuntos
Proteínas do Sistema Complemento/imunologia , Doenças dos Peixes/imunologia , Proteínas de Helminto/imunologia , Hemostasia , Trematódeos/imunologia , Infecções por Trematódeos/veterinária , Sequência de Aminoácidos , Animais , Anticoagulantes/química , Anticoagulantes/imunologia , Antifibrinolíticos/química , Antifibrinolíticos/imunologia , Carpas/sangue , Carpas/imunologia , Carpas/parasitologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/imunologia , Fator Xa/imunologia , Inibidores do Fator Xa/química , Inibidores do Fator Xa/imunologia , Fibrinolisina/imunologia , Doenças dos Peixes/sangue , Doenças dos Peixes/parasitologia , Proteínas de Helminto/química , Proteínas de Helminto/genética , Interações Hospedeiro-Parasita , Calicreína Plasmática/antagonistas & inibidores , Calicreína Plasmática/imunologia , Alinhamento de Sequência , Trematódeos/química , Trematódeos/genética , Infecções por Trematódeos/sangue , Infecções por Trematódeos/imunologia , Infecções por Trematódeos/parasitologiaRESUMO
The immune system of snails is highly sensitive to pollutants, which can suppress its immune response. We investigated the effects of exposure to the glyphosate-based herbicide Roundup® Original on the snail Biomphalaria glabrata infected by the platyhelminth Echinostoma paraensei by evaluating changes in the snail's internal defense system. Four cohorts were studied: control group, infected snails, snails treated with Roundup®, and snails infected and treated with Roundup®. The hemocyte viability was assessed, morphological differentiation of cells was observed and flow cytometry was performed to determine the morphology, viability and the lectin expression profiles. The frequencies of dead hemocytes were lower in the infected group and higher in both pesticide treated groups. Three cell types were identified: blast-like cells, hyalinocytes and granulocytes. The highest number of all types of hemocytes, as well as the highest number of dead cells, were observed in the infected, pesticide-treated group. The association between infection and herbicide exposure greatly increased the frequency of dead hemocytes, suggesting that this condition impairs the internal defense system of B. glabrata making the snails more vulnerable to parasitic infections.
Assuntos
Biomphalaria/imunologia , Glicina/análogos & derivados , Hemócitos/citologia , Herbicidas/toxicidade , Imunidade Celular/efeitos dos fármacos , Infecções por Trematódeos/imunologia , Animais , Biomphalaria/parasitologia , Echinostoma/parasitologia , Citometria de Fluxo , Glicina/toxicidade , Hemócitos/efeitos dos fármacos , Hemócitos/metabolismo , Interações Hospedeiro-Parasita/efeitos dos fármacos , Sistema Imunitário/efeitos dos fármacos , Sistema Imunitário/patologia , Lectinas/efeitos dos fármacos , Lectinas/metabolismo , GlifosatoRESUMO
The main objective of this study was to determine the effect of two forms of mannan oligosaccharides (MOS: Bio-Mos® and cMOS: Actigen®, Alltech Inc, USA) and their combination on greater amberjack (Seriola dumerili) growth performance and feed efficiency, immune parameters and resistance against ectoparasite (Neobenedenia girellae) infection. Fish were fed for 90 days with 5â¯gâ¯kg-1 MOS, 2â¯gâ¯kg-1 cMOS or a combination of both prebiotics, in a Seriola commercial base diet (Skretting, Norway). At the end of the feeding period, no differences were found in growth performance or feed efficiency. Inclusion of MOS also had no effect on lysozyme activity in skin mucus and serum, but the supplementation of diets with cMOS induced a significant increase of serum bactericidal activity. Dietary cMOS also reduced significantly greater amberjack skin parasite levels, parasite total length and the number of parasites detected per unit of fish surface following a cohabitation challenge with N. girellae, whereas no effect of MOS was detected on these parameters. Of 17 immune genes studied cMOS dietary inclusion up-regulated hepcidin, defensin, Mx protein, interferon-γ (IFNγ), mucin-2 (MUC-2), interleukin-1ß (IL-1B), IL-10 and immunoglobulin-T (IgT) gene expression in gills and/or skin. MOS supplementation had a larger impact on spleen and head kidney gene expression, where piscidin, defensin, iNOS, Mx protein, interferons, IL-1ß, IL-10, IL-17 and IL-22 were all upregulated. In posterior gut dietary MOS and cMOS both induced IL-10, IgM and IgT, but with MOS also increasing piscidin, MUC-2, and IL-1ß whilst cMOS induced hepcidin, defensin and IFNγ. In general, the combination of MOS and cMOS resulted in fewer or lower increases in all tissues, possibly due to an overstimulation effect. The utilization of cMOS at the dose used here has clear benefits on parasite resistance in greater amberjack, linked to upregulation of a discrete set of immune genes in mucosal tissues.
Assuntos
Suplementos Nutricionais , Ectoparasitoses/veterinária , Peixes/imunologia , Regulação da Expressão Gênica/imunologia , Oligossacarídeos/farmacologia , Ração Animal , Animais , Dieta/veterinária , Ectoparasitoses/imunologia , Ectoparasitoses/parasitologia , Regulação da Expressão Gênica/efeitos dos fármacos , Prebióticos , Distribuição Aleatória , Trematódeos , Infecções por Trematódeos/imunologia , Infecções por Trematódeos/parasitologia , Infecções por Trematódeos/veterinária , Regulação para CimaRESUMO
Cercarial dermatitis (CD) is an allergic skin disease that rises in consequence of infection by invasive stages (cercariae) of trematodes of the family Schistosomatidae. CD has been considered a re-emerging disease, human cases have been reported from all continents, and tourism-threatening outbreaks occur even in frequented recreational areas. Although the symptoms of CD are generally known, the data on immune response in human patients are sporadic and incomprehensive. In the present study, we attempted to correlate the symptoms, personal history, and time course of CD in human patients with differential cell counts, dynamics of selected cytokines, and dynamics and quality of antibody response. By a systematic follow-up, we obtained a uniquely complex dataset from ten persons accidentally and concurrently infected by the same parasite species in the same locality. The onset of CD was significantly faster, and the symptoms were heavier in participants with a history of CD if compared to naive ones, who, however, also developed some of the symptoms. The repeatedly infected persons had elevated proportion of eosinophils 1 week post exposure (p.e.) and a stronger specific IgG but not IgM response, whereas specific IgE response was not observed. Increased serum levels of IL-4 occurred 1 and 3 week(s) p.e. in all participants. There was high variability in individual immunoblot patterns of IgG response, and no antigen with a universal diagnostic potential was confirmed. The presented analyses suggested that a complex approach can improve the accuracy of the diagnosis of CD, but component data should be interpreted carefully.
Assuntos
Anticorpos Antiprotozoários/sangue , Dermatite/imunologia , Dermatite/parasitologia , Schistosomatidae/imunologia , Infecções por Trematódeos/imunologia , Adulto , Animais , República Tcheca , Surtos de Doenças , Feminino , Seguimentos , Humanos , Imunoglobulina E/sangue , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Interleucina-4/sangue , Masculino , Pessoa de Meia-Idade , Lagoas/parasitologia , Inquéritos e Questionários , Infecções por Trematódeos/diagnóstico , Infecções por Trematódeos/parasitologia , Adulto JovemRESUMO
Dactylogyrus ctenopharyngodonid and Ichthyophthirius multifiliis are 2 important ectoparasites of fish. Both parasites can induce an immune response in fish that leads to a decrease in parasitic infection intensity and the development of resistance against parasitic reinfection. The present study evaluated whether grass carp Ctenopharyngodon idella that survived a D. ctenopharyngodonid infection could develop immunity against infection by D. ctenopharyngodonid and I. multifiliis. The results demonstrated that when grass carp were infected with D. ctenopharyngodonid, the number of red blood cells and the percentages of thrombocytes, monocytes, and neutrophils in the white blood cells increased significantly in the early stage of infection. The percentage of lymphocytes increased over time following parasitic infection. The mean infection intensity of D. ctenopharyngodonid decreased to 0 on Day 28. The activities of serum acid phosphatase, alkaline phosphatase, lysozyme, and superoxide dismutase increased significantly after D. ctenopharyngodonid infection. In addition, the grass carp that survived a previous D. ctenopharyngodonid infection could completely resist D. ctenopharyngodonid reinfection and partially resist I. multifiliis infection.