scholarly journals Chitin, Chitinase Responses, and Invasive Fungal Infections

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Karina Vega ◽  
Markus Kalkum
Keyword(s):  
Immune Responses ◽  
Fungal Infections ◽  
Pathogenic Fungi ◽  
Therapeutic Approaches ◽  
Human Immune System ◽  
Cell Wall Component ◽  
Diagnostic Assays ◽  
Host Immune Responses ◽  
Human Immune ◽  
Novel Therapeutic

The human immune system is capable of recognizing and degrading chitin, an important cell wall component of pathogenic fungi. In the context of host-immune responses to fungal infections, herein we review the particular contributions and interplay of fungus and chitin recognition, and chitin-degrading enzymes, known as chitinases. The mechanisms of host chitinase responses may have implications for diagnostic assays as well as novel therapeutic approaches for patients that are at risk of contracting fatal fungal infections.

Should we Try to Alleviate Immunosenescence and Inflammaging - Why, How and to What Extent?

2019 ◽  
Vol 25 (39) ◽  
pp. 4154-4162 ◽  
Author(s):  
Jacek M. Witkowski ◽  
Ewa Bryl ◽  
Tamas Fulop
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Immune Cells ◽  
Malignant Neoplasm ◽  
Human Beings ◽  
Therapeutic Approaches ◽  
Human Immune System ◽  
Immune Systems ◽  
Human Immune

With advancing age, immune responses of human beings to external pathogens, i.e., bacteria, viruses, fungi and parasites, and to internal pathogens - malignant neoplasm cells - become less effective. Two major features in the process of aging of the human immune system are immunosenescence and inflammaging. The immune systems of our predecessors co-evolved with pathogens, which led to the occurrence of effective immunity. However, the otherwise beneficial activity may pose problems to the organism of the host and so it has builtin brakes (regulatory immune cells) and - with age - it undergoes adaptations and modifications, examples of which are the mentioned inflammaging and immunosenescence. Here we describe the mechanisms that first created our immune systems, then the consequences of their changes associated with aging, and the mechanisms of inflammaging and immunosenescence. Finally, we discuss to what extent both processes are detrimental and to what extent they might be beneficial and propose some therapeutic approaches for their wise control.

scholarly journals An Invertebrate Host to Study Fungal Infections, Mycotoxins and Antifungal Drugs: Tenebrio molitor

2018 ◽  
Vol 4 (4) ◽  
pp. 125 ◽  
Author(s):  
Patrícia Canteri de Souza ◽  
Carla Custódio Caloni ◽  
Duncan Wilson ◽  
Ricardo Sergio Almeida
Keyword(s):  
Immune Responses ◽  
Potential Model ◽  
Fungal Infections ◽  
Pathogenic Fungi ◽  
Tenebrio Molitor ◽  
Antifungal Drugs ◽  
Innate Immune ◽  
Fungal Virulence ◽  
Host Immune Responses ◽  
Evolutionarily Conserved

Faced with ethical conflict and social pressure, researchers have increasingly chosen to use alternative models over vertebrates in their research. Since the innate immune system is evolutionarily conserved in insects, the use of these animals in research is gaining ground. This review discusses Tenebrio molitor as a potential model host for the study of pathogenic fungi. Larvae of T. molitor are known as cereal pests and, in addition, are widely used as animal and human feed. A number of studies on mechanisms of the humoral system, especially in the synthesis of antimicrobial peptides, which have similar characteristics to vertebrates, have been performed. These studies demonstrate the potential of T. molitor larvae as a model host that can be used to study fungal virulence, mycotoxin effects, host immune responses to fungal infection, and the action of antifungal compounds.

scholarly journals The Squeaky Yeast Gets Greased: The Roles of Host Lipids in the Clearance of Pathogenic Fungi

2020 ◽  
Vol 6 (1) ◽  
pp. 19
Author(s):  
Gaelen Guzman ◽  
Patrick Niekamp ◽  
Fikadu Geta Tafesse
Keyword(s):  
Immune System ◽  
Immune Cells ◽  
Fungal Pathogens ◽  
Fungal Infections ◽  
Pathogenic Fungi ◽  
Innate Immune ◽  
High Morbidity ◽  
Human Immune System ◽  
Human Immune ◽  
Phagocytic Uptake

Fungal infections remain a global health threat with high morbidity and mortality. The human immune system must, therefore, perpetually defend against invasive fungal infections. Phagocytosis is critical for the clearance of fungal pathogens, as this cellular process allows select immune cells to internalize and destroy invading fungal cells. While much is known about the protein players that enable phagocytosis, the various roles that lipids play during this fundamental innate immune process are still being illuminated. In this review, we describe recent discoveries that shed new light on the mechanisms by which host lipids enable the phagocytic uptake and clearance of fungal pathogens.

scholarly journals Development of a new patient-derived xenograft humanised mouse model to study human-specific tumour microenvironment and immunotherapy

Gut ◽  
2018 ◽  
Vol 67 (10) ◽  
pp. 1845-1854 ◽  
Author(s):  
Yue Zhao ◽  
Timothy Wai Ho Shuen ◽  
Tan Boon Toh ◽  
Xue Ying Chan ◽  
Min Liu ◽  
...  
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Immune Checkpoint ◽  
Drug Testing ◽  
Checkpoint Inhibitors ◽  
Tumour Microenvironment ◽  
Human Immune System ◽  
Patient Derived Xenograft ◽  
Human Immune ◽  
Human Specific

ObjectiveAs the current therapeutic strategies for human hepatocellular carcinoma (HCC) have been proven to have limited effectiveness, immunotherapy becomes a compelling way to tackle the disease. We aim to provide humanised mouse (humice) models for the understanding of the interaction between human cancer and immune system, particularly for human-specific drug testing.DesignPatient-derived xenograft tumours are established with type I human leucocyte antigen matched human immune system in NOD-scid Il2rg−/− (NSG) mice. The longitudinal changes of the tumour and immune responses as well as the efficacy of immune checkpoint inhibitors are investigated.ResultsSimilar to the clinical outcomes, the human immune system in our model is educated by the tumour and exhibits exhaustion phenotypes such as a significant declination of leucocyte numbers, upregulation of exhaustion markers and decreased the production of human proinflammatory cytokines. Notably, cytotoxic immune cells decreased more rapidly compared with other cell types. Tumour infiltrated T cells have much higher expression of exhaustion markers and lower cytokine production compared with peripheral T cells. In addition, tumour-associated macrophages and myeloid-derived suppressor cells are found to be highly enriched in the tumour microenvironment. Interestingly, the tumour also changes gene expression profiles in response to immune responses by upregulating immune checkpoint ligands. Most importantly, in contrast to the NSG model, our model demonstrates both therapeutic and side effects of immune checkpoint inhibitors pembrolizumab and ipilimumab.ConclusionsOur work provides a model for immune-oncology study and a useful parallel-to-human platform for anti-HCC drug testing, especially immunotherapy.

scholarly journals Fungal Extracellular Vesicles as Potential Targets for Immune Interventions

mSphere ◽  
2019 ◽  
Vol 4 (6) ◽  
Author(s):  
Mateus Silveira Freitas ◽  
Vânia Luiza Deperon Bonato ◽  
Andre Moreira Pessoni ◽  
Marcio L. Rodrigues ◽  
Arturo Casadevall ◽  
...  
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Nucleic Acids ◽  
Extracellular Vesicles ◽  
Fungal Pathogen ◽  
Fungal Infections ◽  
Pathogenic Fungi ◽  
Therapeutic Strategies ◽  
Host Immune System ◽  
Immunomodulatory Properties

ABSTRACT The release of extracellular vesicles (EVs) by fungi is a fundamental cellular process. EVs carry several biomolecules, including pigments, proteins, enzymes, lipids, nucleic acids, and carbohydrates, and are involved in physiological and pathological processes. EVs may play a pivotal role in the establishment of fungal infections, as they can interact with the host immune system to elicit multiple outcomes. It has been observed that, depending on the fungal pathogen, EVs can exacerbate or attenuate fungal infections. The study of the interaction between fungal EVs and the host immune system and understanding of the mechanisms that regulate those interactions might be useful for the development of new adjuvants as well as the improvement of protective immune responses against infectious or noninfectious diseases. In this review, we describe the immunomodulatory properties of EVs produced by pathogenic fungi and discuss their potential as adjuvants for prophylactic or therapeutic strategies.

scholarly journals Characterization of Human Antiviral Adaptive Immune Responses during Hepatotropic Virus Infection in HLA-Transgenic Human Immune System Mice

2013 ◽  
Vol 191 (4) ◽  
pp. 1753-1764 ◽  
Author(s):  
Eva Billerbeck ◽  
Joshua A. Horwitz ◽  
Rachael N. Labitt ◽  
Bridget M. Donovan ◽  
Kevin Vega ◽  
...  
Keyword(s):  
Immune System ◽  
Virus Infection ◽  
Immune Responses ◽  
Human Immune System ◽  
Adaptive Immune Responses ◽  
Adaptive Immune ◽  
Human Immune

scholarly journals Production of Eicosanoids and Other Oxylipins by Pathogenic Eukaryotic Microbes

2003 ◽  
Vol 16 (3) ◽  
pp. 517-533 ◽  
Author(s):  
Mairi C. Noverr ◽  
John R. Erb-Downward ◽  
Gary B. Huffnagle
Keyword(s):  
Immune Responses ◽  
Pathogenic Fungi ◽  
Host Cells ◽  
Chemokine Production ◽  
Host Immune Responses ◽  
Potential Link ◽  
Leukocyte Chemotaxis ◽  
Eukaryotic Microbes ◽  
Precise Role

SUMMARY Oxylipins are oxygenated metabolites of fatty acids. Eicosanoids are a subset of oxylipins and include the prostaglandins and leukotrienes, which are potent regulators of host immune responses. Host cells are one source of eicosanoids and oxylipins during infection; however, another potential source of eicosanoids is the pathogen itself. A broad range of pathogenic fungi, protozoa, and helminths produce eicosanoids and other oxylipins by novel synthesis pathways. Why do these organisms produce oxylipins? Accumulating data suggest that phase change and differentiation in these organisms are controlled by oxylipins, including prostaglandins and lipoxygenase products. The precise role of pathogen-derived eicosanoids in pathogenesis remains to be determined, but the potential link between pathogen eicosanoids and the development of TH2 responses in the host is intriguing. Mammalian prostaglandins and leukotrienes have been studied extensively, and these molecules can modulate Th1 versus Th2 immune responses, chemokine production, phagocytosis, lymphocyte proliferation, and leukocyte chemotaxis. Thus, eicosanoids and oxylipins (host or microbe) may be mediators of a direct host-pathogen “cross-talk” that promotes chronic infection and hypersensitivity disease, common features of infection by eukaryotic pathogens.

scholarly journals Recent advances in understanding inherited deficiencies in immunity to infections

F1000Research ◽  
2020 ◽  
Vol 9 ◽  
pp. 243 ◽  
Author(s):  
Gregory M. Constantine ◽  
Michail S. Lionakis
Keyword(s):  
Immune Responses ◽  
Host Defense ◽  
Fungal Infections ◽  
Microbial Pathogens ◽  
Host Immune Responses ◽  
Vaccination Strategies ◽  
The World ◽  
Human Immunity ◽  
Immune Pathways ◽  
Resistance To Infection

The immune system is central to our interactions with the world in which we live and importantly dictates our response to potential allergens, toxins, and pathogens to which we are constantly exposed. Understanding the mechanisms that underlie protective host immune responses against microbial pathogens is vital for the development of improved treatment and vaccination strategies against infections. To that end, inherited immunodeficiencies that manifest with susceptibility to bacterial, viral, and/or fungal infections have provided fundamental insights into the indispensable contribution of key immune pathways in host defense against various pathogens. In this mini-review, we summarize the findings from a series of recent publications in which inherited immunodeficiencies have helped illuminate the interplay of human immunity and resistance to infection.

scholarly journals Mathematical model of a personalized neoantigen cancer vaccine and the human immune system

2021 ◽  
Vol 17 (9) ◽  
pp. e1009318
Author(s):  
Marisabel Rodriguez Messan ◽  
Osman N. Yogurtcu ◽  
Joseph R. McGill ◽  
Ujwani Nukala ◽  
Zuben E. Sauna ◽  
...  
Keyword(s):  
Mathematical Model ◽  
T Cells ◽  
Immune System ◽  
Immune Responses ◽  
Cancer Vaccine ◽  
Tumor Size ◽  
Cancer Vaccines ◽  
Patient Specific ◽  
Human Immune System ◽  
Human Immune

Cancer vaccines are an important component of the cancer immunotherapy toolkit enhancing immune response to malignant cells by activating CD4+ and CD8+ T cells. Multiple successful clinical applications of cancer vaccines have shown good safety and efficacy. Despite the notable progress, significant challenges remain in obtaining consistent immune responses across heterogeneous patient populations, as well as various cancers. We present a mechanistic mathematical model describing key interactions of a personalized neoantigen cancer vaccine with an individual patient’s immune system. Specifically, the model considers the vaccine concentration of tumor-specific antigen peptides and adjuvant, the patient’s major histocompatibility complexes I and II copy numbers, tumor size, T cells, and antigen presenting cells. We parametrized the model using patient-specific data from a clinical study in which individualized cancer vaccines were used to treat six melanoma patients. Model simulations predicted both immune responses, represented by T cell counts, to the vaccine as well as clinical outcome (determined as change of tumor size). This model, although complex, can be used to describe, simulate, and predict the behavior of the human immune system to a personalized cancer vaccine.

scholarly journals Diagnosis and treatment of invasive Candida infections – a review article

2019 ◽  
Vol 73 (1) ◽  
pp. 47
Author(s):  
Marta Dąbrowska ◽  
Monika Sienkiewicz ◽  
Paweł Kwiatkowski ◽  
Michał Dąbrowski
Keyword(s):  
Immune Responses ◽  
Fungal Infections ◽  
Review Article ◽  
Source Control ◽  
Candida Spp ◽  
Common Cause ◽  
Host Immune Responses ◽  
Invasive Infections ◽  
Candida Infections ◽  
Short Time

<p>Candida albicans is the most common cause of fungal infections worldwide. Invasive candidiasis comprises candidemia and deep-seated candidiasis. Most yeast invasive infections are endogenous with a high mortality. Pathogenesis of candidiasis depends on avoiding host immune responses, as well as the virulence factors of the fungus enabling colonization and invasion of tissues. Adequate source control and antifungal therapy administered within a short time is critical to get a better prognosis. The emergence of drug resistance and the side effects of currently available antifungals are becoming the major problem in the management of Candida spp. infection.</p>

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