scholarly journals Noninvasively measured immune responses reflect current parasite infections in a wild carnivore and are linked to longevity

2021 ◽  
Author(s):  
Susana C. M. Ferreira ◽  
Miguel M. Veiga ◽  
Heribert Hofer ◽  
Marion L. East ◽  
Gábor Á. Czirják
Keyword(s):  
Immune Responses ◽  
Wild Carnivore ◽  
Parasite Infections

scholarly journals The importance of the back–signal from T cells into antigen–presenting cells in determining susceptibility to parasites

1997 ◽  
Vol 352 (1359) ◽  
pp. 1327-1330 ◽  
Author(s):  
Brigitte Müller ◽  
Avrion Mitchison
Keyword(s):  
T Cells ◽  
Immune Responses ◽  
Mhc Class Ii ◽  
Class Ii ◽  
Activated T Cells ◽  
Ifn Gamma ◽  
Parasite Infections ◽  
Antigen Presenting ◽  
Mhc Class Ii Genes ◽  
Mhc Class Ii Molecules

It has long been known that certain MHC class II genes can dominantly suppress immune responses and so increase susceptibility to parasite infections, but the mechanism has been unclear. Recent work has revealed one way in which this form of suppression may operate through gating by MHC class II molecules of the back–signal from activated T cells into macrophages. The two known suppressive genes of the mouse are expressed in macrophages more extensively than are other class II genes. This is asscociated with suppresion of IL–4 production resulting, we infer, from overproduction in the macrophages of IL–12, the counter–cytokine to IL–4. The lack of IL–4 may itself be immunosuppressive, even for Th2 responses, and excess IL–12 can overinduce the antiproliferative cytokine IFN–gamma. Although this mechanism requires further substantiation, we believe that it offers a reasonable answer to an old conundrum.

scholarly journals A mechanism for the induction of type 2 immune responses by a protease allergen in the genital tract

2017 ◽  
Vol 114 (7) ◽  
pp. E1188-E1195 ◽  
Author(s):  
Ji Eun Oh ◽  
Dong Sun Oh ◽  
Hi Eun Jung ◽  
Heung Kyu Lee
Keyword(s):  
Immune Responses ◽  
Genital Tract ◽  
Primary Response ◽  
Lymphoid Cells ◽  
Genital Mucosa ◽  
Type 2 Immunity ◽  
Parasite Infections ◽  
Barrier Surface ◽  
External Stimuli

The genital mucosa is a barrier that is constantly exposed to a variety of pathogens, allergens, and external stimuli. Although both allergen exposure and parasite infections frequently occur in the genital area, the mechanism by which immune responses—particularly type 2 immunity—are induced has rarely been studied in the genital mucosa. Here, we demonstrate the induction of T helper type 2 (Th2) immunity in the genital mucosa in response to a model allergen, the protease papain. Intravaginal papain immunization induced type 2 immunity in a manner that was dependent on protease activity and the estrous phase of the mice. In addition, IL-33 was released from the vaginal epithelia after intravaginal papain immunization, leading to the activation of type 2 innate lymphoid cells (ILC2s). Moreover, the IL-33–MyD88 (myeloid differentiation primary response gene 88) signaling pathway was critical for the induction of type 2 immunity. We also found that Th2 differentiation in response to intravaginal papain treatment requires a specific dendritic cell (DC) subset that is controlled by interferon regulatory factor 4 (IRF4). These findings suggest that type 2 immunity is induced by a unique mechanism in the genital tract, which is an important, but often overlooked, barrier surface.

scholarly journals Food limitation constrains host immune responses to nematode infections

2016 ◽  
Vol 12 (9) ◽  
pp. 20160471 ◽  
Author(s):  
Kristian M. Forbes ◽  
Tapio Mappes ◽  
Tarja Sironen ◽  
Tomas Strandin ◽  
Peter Stuart ◽  
...  
Keyword(s):  
Immune Responses ◽  
Food Availability ◽  
Food Limitation ◽  
Finite Energy ◽  
Innate Immune ◽  
Food Supplementation ◽  
Boreal Winter ◽  
Intestinal Nematode ◽  
Trade Offs ◽  
Parasite Infections

Trade-offs in the allocation of finite-energy resources among immunological defences and other physiological processes are believed to influence infection risk and disease severity in food-limited wildlife populations. However, this prediction has received little experimental investigation. Here we test the hypothesis that food limitation impairs the ability of wild field voles ( Microtus agrestis ) to mount an immune response against parasite infections. We conducted a replicated experiment on vole populations maintained in large outdoor enclosures during boreal winter, using food supplementation and anthelmintic treatment of intestinal nematodes. Innate immune responses against intestinal parasite infections were compared between food-supplemented and non-supplemented voles. Voles with high food availability mounted stronger immune responses against intestinal nematode infections than food-limited voles. No food effects were seen in immune responses to intracellular coccidian parasites, possibly owing to their ability to avoid activation of innate immune pathways. Our findings demonstrate that food availability constrains vole immune responses against nematode infections, and support the concept that spatio-temporal heterogeneity in food availability creates variation in infectious disease susceptibility.

The role of chemokines and their receptors during protist parasite infections

Parasitology ◽  
2016 ◽  
Vol 143 (14) ◽  
pp. 1890-1901 ◽  
Author(s):  
FIONA M. MENZIES ◽  
DAVID MACPHAIL ◽  
FIONA L. HENRIQUEZ
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Chemokine Receptors ◽  
Drug Targeting ◽  
Scientific Literature ◽  
Parasite Survival ◽  
Recent Developments ◽  
Parasite Infections ◽  
Eukaryotic Organisms

SUMMARYProtists are a diverse collection of eukaryotic organisms that account for a significant global infection burden. Often, the immune responses mounted against these parasites cause excessive inflammation and therefore pathology in the host. Elucidating the mechanisms of both protective and harmful immune responses is complex, and often relies of the use of animal models. In any immune response, leucocyte trafficking to the site of infection, or inflammation, is paramount, and this involves the production of chemokines, small chemotactic cytokines of approximately 8–10 kDa in size, which bind to specific chemokine receptors to induce leucocyte movement. Herein, the scientific literature investigating the role of chemokines in the propagation of immune responses against key protist infections will be reviewed, focussing onPlasmodiumspecies,Toxoplasma gondii, Leishmaniaspecies andCryptosporidiumspecies. Interestingly, many studies find that chemokines can in fact, promote parasite survival in the host, by drawing in leucocytes for spread and further replication. Recent developments in drug targeting against chemokine receptors highlights the need for further understanding of the role played by these proteins and their receptors in many different diseases.

scholarly journals Schistosome-Derived Molecules as Modulating Actors of the Immune System and Promising Candidates to Treat Autoimmune and Inflammatory Diseases

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Luis Janssen ◽  
Gisele Lorranna Silva Santos ◽  
Herick Sampaio Muller ◽  
Anderson Rodrigues Araújo Vieira ◽  
Tatiana Amabile de Campos ◽  
...  
Keyword(s):  
Immune Responses ◽  
Defense Mechanisms ◽  
Inflammatory Diseases ◽  
Adaptive Responses ◽  
Immunomodulatory Effects ◽  
Larval Stages ◽  
Helminth Infections ◽  
Autoimmune And Inflammatory Diseases ◽  
Potential Applications ◽  
Parasite Infections

It is long known that some parasite infections are able to modulate specific pathways of host’s metabolism and immune responses. This modulation is not only important in order to understand the host-pathogen interactions and to develop treatments against the parasites themselves but also important in the development of treatments against autoimmune and inflammatory diseases. Throughout the life cycle of schistosomes the mammalian hosts are exposed to several biomolecules that are excreted/secreted from the parasite infective stage, named cercariae, from their tegument, present in adult and larval stages, and finally from their eggs. These molecules can induce the activation and modulation of innate and adaptive responses as well as enabling the evasion of the parasite from host defense mechanisms. Immunomodulatory effects of helminth infections and egg molecules are clear, as well as their ability to downregulate proinflammatory cytokines, upregulate anti-inflammatory cytokines, and drive a Th2 type of immune response. We believe that schistosomes can be used as a model to understand the potential applications of helminths and helminth-derived molecules against autoimmune and inflammatory diseases.

scholarly journals Infection with Toxocara canis Inhibits the Production of IgE Antibodies to α-Gal in Humans: Towards a Conceptual Framework of the Hygiene Hypothesis?

Vaccines ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 167 ◽  
Author(s):  
Adnan Hodžić ◽  
Lourdes Mateos-Hernández ◽  
Emilie Fréalle ◽  
Patricia Román-Carrasco ◽  
Pilar Alberdi ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Developmental Stages ◽  
Toxocara Canis ◽  
Hygiene Hypothesis ◽  
Parasitic Infections ◽  
Parasitic Fungi ◽  
Parasite Infections ◽  
Mammalian Meat ◽  
And Control

α-Gal syndrome (AGS) is a type of anaphylactic reaction to mammalian meat characterized by an immunoglobulin (Ig)E immune response to the oligosaccharide α-Gal (Galα1-3Galβ1-4GlcNAc-R). Tick bites seems to be a prerequisite for the onset of the allergic disease in humans, but the implication of non-tick parasites in α-Gal sensitization has also been deliberated. In the present study, we therefore evaluated the capacity of helminths (Toxocara canis, Ascaris suum, Schistosoma mansoni), protozoa (Toxoplasma gondii), and parasitic fungi (Aspergillus fumigatus) to induce an immune response to α-Gal. For this, different developmental stages of the infectious agents were tested for the presence of α-Gal. Next, the potential correlation between immune responses to α-Gal and the parasite infections was investigated by testing sera collected from patients with AGS and those infected with the parasites. Our results showed that S. mansoni and A. fumigatus produce the terminal α-Gal moieties, but they were not able to induce the production of specific antibodies. By contrast, T. canis, A. suum and T. gondii lack the α-Gal epitope. Furthermore, the patients with T. canis infection had significantly decreased anti-α-Gal IgE levels when compared to the healthy controls, suggesting the potential role of this nematode parasite in suppressing the allergic response to the glycan molecule. This rather intriguing observation is discussed in the context of the ‘hygiene hypothesis’. Taken together, our study provides new insights into the relationships between immune responses to α-Gal and parasitic infections. However, further investigations should be undertaken to identify T. canis components with potent immunomodulatory properties and to assess their potential to be used in immunotherapy and control of AGS.

Neutrophils, apoptosis and phagocytic clearance: an innate sequence of cellular responses regulating intramacrophagic parasite infections

Parasitology ◽  
2006 ◽  
Vol 132 (S1) ◽  
pp. S61-S68 ◽  
Author(s):  
F. L. RIBEIRO-GOMES ◽  
M. T. SILVA ◽  
G. A. DOSREIS
Keyword(s):  
Immune Responses ◽  
Protozoan Parasite ◽  
Cellular Responses ◽  
Death Process ◽  
Protozoan Parasites ◽  
Physiological Regulation ◽  
Cell Numbers ◽  
Parasite Infections ◽  
Cell Death Process ◽  
Neutrophils Apoptosis

In complex organisms, apoptosis is a constitutive cell death process that is involved in physiological regulation of cell numbers and that can also be induced in the course of inflammatory and immune responses. Neutrophils are among the first cells recruited during inflammation. Neutrophils constitutively die by apoptosis at inflamed sites, and are ingested by macrophages. Recent studies investigated how phagocytic clearance of senescent neutrophils influences the survival of intracellular protozoan parasites that have been phagocytosed by, or have invaded phagocytes. The results indicate that neutrophil clearance plays an unexpected role in regulation of intramacrophagic protozoan parasite infection.

scholarly journals Parasitic Infections: A Role for C-Type Lectins Receptors

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Alicia Vázquez-Mendoza ◽  
Julio César Carrero ◽  
Miriam Rodriguez-Sosa
Keyword(s):  
Dendritic Cells ◽  
Immune Responses ◽  
Innate Immune ◽  
Parasitic Infections ◽  
Dependent Manner ◽  
Innate Immune Responses ◽  
Parasite Infections ◽  
Antigen Presenting ◽  
Molecular Patterns

Antigen-presenting cells (APCs) sense the microenvironment through several types of receptors that recognize pathogen-associated molecular patterns. In particular, C-type lectins receptors (CLRs), which are expressed by distinct subsets of dendritic cells (DCs) and macrophages (MØs), recognize and internalize specific carbohydrate antigens in a Ca2+-dependent manner. The targeting of these receptors is becoming an efficient strategy for parasite recognition. However, relatively little is known about how CLRs are involved in both pathogen recognition and the internalization of parasites. The role of CLRs in parasite infections is an area of considerable interest because this research will impact our understanding of the initiation of innate immune responses, which influences the outcome of specific immune responses. This paper attempts to summarize our understanding of the effects of parasites’ interactions with CLRs.

Innate and Adaptive Immune Responses to Bacterial and Parasite Infections

2008 ◽  
pp. 153-162
Author(s):  
Valentina Medici ◽  
Lorenzo Rossaro ◽  
Sripriya Balasubramanian ◽  
Stuart H. Cohen
Keyword(s):  
Immune Responses ◽  
Adaptive Immune Responses ◽  
Adaptive Immune ◽  
Parasite Infections
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