Excretory–secretory products of helminth parasites: effects on host immune responses

Parasitology ◽  
1988 ◽  
Vol 96 (S1) ◽  
pp. S123-S166 ◽  
Author(s):  
M. W. Lightowlers ◽  
M. D. Rickard
Keyword(s):  
Immune Responses ◽  
Inflammatory Responses ◽  
Helminth Parasites ◽  
Host Immune Responses ◽  
Parasitic Helminths ◽  
Protective Antigens ◽  
Helminth Infections ◽  
Secretory Products ◽  
Antigen Presenting ◽  
Host Parasite

SUMMARYParasitic helminths excrete or secrete (ES) a variety of molecules into their mammalian hosts. The effects of these ES products on the host's immune responses are reviewed. Investigations into the source of antigenic or immunoregulatory ES products have identified the cuticular and tegumental surfaces of some nematodes and trematodes respectively as being important sources of ES products; other ES molecules are released through specialized excretory or secretory organs. It is proposed that the active shedding of surface antigens may serve as an important source of parasite antigens available to the immune system in a form in which they can be taken up and processed by antigen-presenting dendritic cells, macro-phages and certain B cells for presentation to T helper cells. The ES products of nematodes, trematodes and cestodes contribute to immune evasion strategies of the parasites through mechanisms including shedding of surface-bound ligands and cells, alteration of lymphocyte, macrophage and granulocyte functions and modulation of complement and other host inflammatory responses. Immunopathology may be induced by ES products as in the development of granulomas around entrapped schistosome eggs. In some host – parasite systems ES antigens may induce host-protective immune responses and this source of protective antigens has been utilized in the successful vaccination against helminth infections, particularly against infection with trichurid nematodes and the metacestode stage of cestode parasites. The use of ES antigens in immunodiagnosis of helminth infection is also briefly discussed.

Glycans in the roles of parasitological diagnosis and host–parasite interplay

Parasitology ◽  
2019 ◽  
Vol 146 (10) ◽  
pp. 1217-1232
Author(s):  
Carolina De Marco Veríssimo ◽  
Carlos Graeff-Teixeira ◽  
Malcolm K. Jones ◽  
Alessandra L. Morassutti
Keyword(s):  
Immune Responses ◽  
Developmental Stages ◽  
Complex Molecules ◽  
Host Immune Responses ◽  
Host Parasite Interactions ◽  
Parasitological Diagnosis ◽  
Parasite Survival ◽  
Specific Receptors ◽  
Secretory Products ◽  
Host Parasite

AbstractThe investigation of the glycan repertoire of several organisms has revealed a wide variation in terms of structures and abundance of glycan moieties. Among the parasites, it is possible to observe different sets of glycoconjugates across taxa and developmental stages within a species. The presence of distinct glycoconjugates throughout the life cycle of a parasite could relate to the ability of that organism to adapt and survive in different hosts and environments. Carbohydrates on the surface, and in excretory-secretory products of parasites, play essential roles in host–parasite interactions. Carbohydrate portions of complex molecules of parasites stimulate and modulate host immune responses, mainly through interactions with specific receptors on the surface of dendritic cells, leading to the generation of a pattern of response that may benefit parasite survival. Available data reviewed here also show the frequent aspect of parasite immunomodulation of mammalian responses through specific glycan interactions, which ultimately makes these molecules promising in the fields of diagnostics and vaccinology.

scholarly journals Within-host mechanisms of immune regulation explain the contrasting dynamics of two helminth species in both single and dual infections

2020 ◽  
Vol 16 (11) ◽  
pp. e1008438
Author(s):  
Chiara Vanalli ◽  
Lorenzo Mari ◽  
Lorenzo Righetto ◽  
Renato Casagrandi ◽  
Marino Gatto ◽  
...  
Keyword(s):  
Immune Responses ◽  
Immune Regulation ◽  
General Trend ◽  
Laboratory Data ◽  
Helminth Species ◽  
Multiple Infections ◽  
Host Immune Responses ◽  
Parasitic Helminths ◽  
Helminth Infections ◽  
Dual Infections

Variation in the intensity and duration of infections is often driven by variation in the network and strength of host immune responses. While many of the immune mechanisms and components are known for parasitic helminths, how these relationships change from single to multiple infections and impact helminth dynamics remains largely unclear. Here, we used laboratory data from a rabbit-helminth system and developed a within-host model of infection to investigate different scenarios of immune regulation in rabbits infected with one or two helminth species. Model selection suggests that the immunological pathways activated against Trichostrongylus retortaeformis and Graphidium strigosum are similar. However, differences in the strength of these immune signals lead to the contrasting dynamics of infections, where the first parasite is rapidly cleared and the latter persists with high intensities. In addition to the reactions identified in single infections, rabbits with both helminths also activate new pathways that asymmetrically affect the dynamics of the two species. These new signals alter the intensities but not the general trend of the infections. The type of interactions described can be expected in many other host-helminth systems. Our immune framework is flexible enough to capture different mechanisms and their complexity, and provides essential insights to the understanding of multi-helminth infections.

scholarly journals Recognition Pattern of the Fasciola hepatica Excretome/Secretome during the Course of an Experimental Infection in Sheep by 2D Immunoproteomics

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 725
Author(s):  
David Becerro-Recio ◽  
Javier González-Miguel ◽  
Alberto Ucero ◽  
Javier Sotillo ◽  
Álvaro Martínez-Moreno ◽  
...  
Keyword(s):  
Experimental Infection ◽  
Fasciola Hepatica ◽  
Cathepsin L ◽  
Helminth Parasites ◽  
Glutathione S Transferase ◽  
Serum Samples ◽  
Secretory Products ◽  
Immunogenic Proteins ◽  
Host Parasite ◽  
First Time

Excretory/secretory products released by helminth parasites have been widely studied for their diagnostic utility, immunomodulatory properties, as well as for their use as vaccines. Due to their location at the host/parasite interface, the characterization of parasite secretions is important to unravel the molecular interactions governing the relationships between helminth parasites and their hosts. In this study, the excretory/secretory products from adult worms of the trematode Fasciola hepatica (FhES) were employed in a combination of two-dimensional electrophoresis, immunoblot and mass spectrometry, to analyze the immune response elicited in sheep during the course of an experimental infection. Ten different immunogenic proteins from FhES recognized by serum samples from infected sheep at 4, 8, and/or 12 weeks post-infection were identified. Among these, different isoforms of cathepsin L and B, peroxiredoxin, calmodulin, or glutathione S-transferase were recognized from the beginning to the end of the experimental infection, suggesting their potential role as immunomodulatory antigens. Furthermore, four FhES proteins (C2H2-type domain-containing protein, ferritin, superoxide dismutase, and globin-3) were identified for the first time as non-immunogenic proteins. These results may help to further understand host/parasite relationships in fasciolosis, and to identify potential diagnostic molecules and drug target candidates of F. hepatica.

scholarly journals Identification and partial characterization of a novel serpin from Eudiplozoon nipponicum (Monogenea, Polyopisthocotylea)

Parasite ◽  
2018 ◽  
Vol 25 ◽  
pp. 61 ◽  
Author(s):  
Pavel Roudnický ◽  
Jiří Vorel ◽  
Jana Ilgová ◽  
Michal Benovics ◽  
Adam Norek ◽  
...  
Keyword(s):  
Complement Activation ◽  
Inflammatory Responses ◽  
Thrombus Formation ◽  
Protein Structures ◽  
Factor Xa ◽  
Blood Feeding ◽  
Secretory Products ◽  
Inhibitory Potential ◽  
Host Parasite ◽  
Eudiplozoon Nipponicum

Background: Serpins are a superfamily of serine peptidase inhibitors that participate in the regulation of many physiological and cell peptidase-mediated processes in all organisms (e.g. in blood clotting, complement activation, fibrinolysis, inflammation, and programmed cell death). It was postulated that in the blood-feeding members of the monogenean family Diplozoidae, serpins could play an important role in the prevention of thrombus formation, activation of complement, inflammation in the host, and/or in the endogenous regulation of protein degradation. Results: In silico analysis showed that the DNA and primary protein structures of serpin from Eudiplozoon nipponicum (EnSerp1) are similar to other members of the serpin superfamily. The inhibitory potential of EnSerp1 on four physiologically-relevant serine peptidases (trypsin, factor Xa, kallikrein, and plasmin) was demonstrated and its presence in the worm’s excretory-secretory products (ESPs) was confirmed. Conclusion: EnSerp1 influences the activity of peptidases that play a role in blood coagulation, fibrinolysis, and complement activation. This inhibitory potential, together with the serpin’s presence in ESPs, suggests that it is likely involved in host-parasite interactions and could be one of the molecules involved in the control of feeding and prevention of inflammatory responses.

scholarly journals Helminths and microbes within the vertebrate gut – not all studies are created equal

Parasitology ◽  
2019 ◽  
Vol 146 (11) ◽  
pp. 1371-1378 ◽  
Author(s):  
Alba Cortés ◽  
Laura E. Peachey ◽  
Timothy P. Jenkins ◽  
Riccardo Scotti ◽  
Cinzia Cantacessi
Keyword(s):  
Gut Microbiota ◽  
Microbial Composition ◽  
Parasitic Helminths ◽  
The Past ◽  
Systems Research ◽  
Helminth Infections ◽  
Methodological Approaches ◽  
Host Parasite ◽  
Gi Helminths ◽  
Research Domain

AbstractThe multifaceted interactions occurring between gastrointestinal (GI) parasitic helminths and the host gut microbiota are emerging as a key area of study within the broader research domain of host-pathogen relationships. Over the past few years, a wealth of investigations has demonstrated that GI helminths interact with the host gut flora, and that such interactions result in modifications of the host immune and metabolic statuses. Nevertheless, whilst selected changes in gut microbial composition are consistently observed in response to GI helminth infections across several host-parasite systems, research in this area to date is largely characterised by inconsistent findings. These discrepancies are particularly evident when data from studies of GI helminth-microbiota interactions conducted in humans from parasite-endemic regions are compared. In this review, we provide an overview of the main sources of variance that affect investigations on helminth-gut microbiota interactions in humans, and propose a series of methodological approaches that, whilst accounting for the inevitable constraints of fieldwork, are aimed at minimising confounding factors and draw biologically meaningful interpretations from highly variable datasets.

scholarly journals Regulation of Antitumor Immune Responses by the IL-12 Family Cytokines, IL-12, IL-23, and IL-27

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Mingli Xu ◽  
Izuru Mizoguchi ◽  
Noriko Morishima ◽  
Yukino Chiba ◽  
Junichiro Mizuguchi ◽  
...  
Keyword(s):  
T Cells ◽  
Immune Responses ◽  
Th17 Cells ◽  
Antitumor Immunity ◽  
Inflammatory Responses ◽  
Memory T Cells ◽  
Th1 Cells ◽  
Signal Transducers ◽  
Th Cell ◽  
Antigen Presenting

The interleukin (IL)-12 family, which is composed of heterodimeric cytokines including IL-12, IL-23, and IL-27, is produced by antigen-presenting cells such as macrophages and dendritic cells and plays critical roles in the regulation of helper T (Th) cell differentiation. IL-12 induces IFN- production by NK and T cells and differentiation to Th1 cells. IL-23 induces IL-17 production by memory T cells and expands and maintains inflammatory Th17 cells. IL-27 induces the early Th1 differentiation and generation of IL-10-producing regulatory T cells. In addition, these cytokines induce distinct immune responses to tumors. IL-12 activates signal transducers and activator of transcription (STAT)4 and enhances antitumor cellular immunity through interferon (IFN)- production. IL-27 activates STAT1, as does IFN- and STAT3 as well, and enhances antitumor immunity by augmenting cellular and humoral immunities. In contrast, although exogenously overexpressed IL-23 enhances antitumor immunity via memory T cells, endogenous IL-23 promotes protumor immunity through STAT3 activation by inducing inflammatory responses including IL-17 production.

scholarly journals Helminth Parasites Alter Protection againstPlasmodiumInfection

2014 ◽  
Vol 2014 ◽  
pp. 1-19 ◽  
Author(s):  
Víctor H. Salazar-Castañon ◽  
Martha Legorreta-Herrera ◽  
Miriam Rodriguez-Sosa
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Immune Responses ◽  
Parasite Density ◽  
Parasitic Disease ◽  
Helminth Parasites ◽  
Helminth Infections ◽  
Helminthic Infections ◽  
Severity Of The Disease ◽  
Type Response

More than one-third of the world’s population is infected with one or more helminthic parasites. Helminth infections are prevalent throughout tropical and subtropical regions where malaria pathogens are transmitted. Malaria is the most widespread and deadliest parasitic disease. The severity of the disease is strongly related to parasite density and the host’s immune responses. Furthermore, coinfections between both parasites occur frequently. However, little is known regarding how concomitant infection with helminths andPlasmodiumaffects the host’s immune response. Helminthic infections are frequently massive, chronic, and strong inductors of a Th2-type response. This implies that infection by such parasites could alter the host’s susceptibility to subsequent infections byPlasmodium. There are a number of reports on the interactions between helminths andPlasmodium; in some, the burden ofPlasmodiumparasites increased, but others reported a reduction in the parasite. This review focuses on explaining many of these discrepancies regarding helminth-Plasmodiumcoinfections in terms of the effects that helminths have on the immune system. In particular, it focuses on helminth-induced immunosuppression and the effects of cytokines controlling polarization toward the Th1 or Th2 arms of the immune response.

scholarly journals Possible Roles of Ectophosphatases in Host-Parasite Interactions

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Marta T. Gomes ◽  
Angela H. Lopes ◽  
José Roberto Meyer-Fernandes
Keyword(s):  
Immune Responses ◽  
Active Sites ◽  
Vast Number ◽  
Host Immune Responses ◽  
Extracellular Milieu ◽  
Surface Molecules ◽  
Host Parasite Interactions ◽  
Hostile Environments ◽  
Host Parasite

The interaction and survival of pathogens in hostile environments and in confrontation with host immune responses are important mechanisms for the establishment of infection. Ectophosphatases are enzymes localized at the plasma membrane of cells, and their active sites face the external medium rather than the cytoplasm. Once activated, these enzymes are able to hydrolyze phosphorylated substrates in the extracellular milieu. Several studies demonstrated the presence of surface-located ecto-phosphatases in a vast number of pathogenic organisms, including bacteria, protozoa, and fungi. Little is known about the role of ecto-phosphatases in host-pathogen interactions. The present paper provides an overview of recent findings related to the virulence induced by these surface molecules in protozoa and fungi.

scholarly journals Functional characterization of Schistosoma mansoni fucosyltransferases in Nicotiana benthamiana plants

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Kim van Noort ◽  
Dieu-Linh Nguyen ◽  
Verena Kriechbaumer ◽  
Chris Hawes ◽  
Cornelis H. Hokke ◽  
...  
Keyword(s):  
Schistosoma Mansoni ◽  
Nicotiana Benthamiana ◽  
Expression System ◽  
Functional Characterization ◽  
Helminth Parasites ◽  
Host Interactions ◽  
Host Immune Responses ◽  
Starting Point ◽  
Host Parasite

Abstract Helminth parasites secrete a wide variety of immunomodulatory proteins and lipids to dampen host immune responses. Many of these immunomodulatory compounds are modified with complex sugar structures (or glycans), which play an important role at the host–parasite interface. As an example, the human blood fluke Schistosoma mansoni produces highly fucosylated glycan structures on glycoproteins and glycolipids. Up to 20 different S. mansoni fucosyltransferase (SmFucT) genes can be found in genome databases, but thus far only one enzyme has been functionally characterized. To unravel the synthesis of highly fucosylated N-glycans by S. mansoni, we examined the ability of ten selected SmFucTs to modify N-glycans upon transient expression in Nicotiana benthamiana plants. All enzymes were localized in the plant Golgi apparatus, which allowed us to identify the SmFucTs involved in core fucosylation and the synthesis of complex antennary glycan motifs. This knowledge provides a starting point for investigations into the role of specific fucosylated glycan motifs of schistosomes in parasite-host interactions. The functionally characterized SmFucTs can also be applied to synthesize complex N-glycan structures on recombinant proteins to study their contribution to immunomodulation. Furthermore, this plant expression system will fuel the development of helminth glycoproteins for pharmaceutical applications or novel anti-helminth vaccines.

scholarly journals Secretory Products ofTrichinella spiralisMuscle Larvae and Immunomodulation: Implication for Autoimmune Diseases, Allergies, and Malignancies

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Ljiljana Sofronic-Milosavljevic ◽  
Natasa Ilic ◽  
Elena Pinelli ◽  
Alisa Gruden-Movsesijan
Keyword(s):  
Immune Responses ◽  
Trichinella Spiralis ◽  
Model Studies ◽  
Muscle Larvae ◽  
New Type ◽  
Immunomodulatory Properties ◽  
Secretory Products ◽  
Antigen Presenting ◽  
Inflammatory Milieu ◽  
Unique Ability

Trichinella spiralishas the unique ability to make itself “at home” by creating and hiding in a new type of cell in the host body that is the nurse cell. From this immunologically privileged place, the parasite orchestrates a long-lasting molecular cross talk with the host through muscle larvae excretory-secretory products (ES L1). Those products can successfully modulate parasite-specific immune responses as well as responses to unrelated antigens (either self or nonself in origin), providing an anti-inflammatory milieu and maintaining homeostasis. It is clear, based on the findings from animal model studies, thatT. spiralisand its products induce an immunomodulatory network (which encompasses Th2- and Treg-type responses) that may allow the host to deal with various hyperimmune-associated disorders as well as tumor growth, although the latter still remains unclear. This review focuses on studies of the molecules released byT. spiralis, their interaction with pattern recognition receptors on antigen presenting cells, and subsequently provoked responses. This paper also addresses the immunomodulatory properties of ES L1 molecules and how the induced immunomodulation influences the course of different experimental inflammatory and malignant diseases.

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