scholarly journals Complement-Mediated Differential Immune Response of Human Macrophages to Sporothrix Species Through Interaction With Their Cell Wall Peptidorhamnomannans

2021 ◽  
Vol 12 ◽  
Author(s):  
Gabriela W. P. Neves ◽  
Sarah Sze Wah Wong ◽  
Vishukumar Aimanianda ◽  
Catherine Simenel ◽  
J. Iñaki Guijarro ◽  
...  
Keyword(s):  
Immune Response ◽  
Complement System ◽  
Sporothrix Schenckii ◽  
Direct Interaction ◽  
Pathogenic Fungi ◽  
Human Monocyte ◽  
Yeast Cells ◽  
Complement Protein ◽  
Sporothrix Brasiliensis ◽  
Complement Receptor 3

In this study, the human immune response mechanisms against Sporothrix brasiliensis and Sporothrix schenckii, two causative agents of human and animal sporotrichosis, were investigated. The interaction of S. brasiliensis and S. schenckii with human monocyte-derived macrophages (hMDMs) was shown to be dependent on the thermolabile serum complement protein C3, which facilitated the phagocytosis of Sporothrix yeast cells through opsonization. The peptidorhamnomannan (PRM) component of the cell walls of these two Sporothrix yeasts was found to be one of their surfaces exposed pathogen-associated molecular pattern (PAMP), leading to activation of the complement system and deposition of C3b on the Sporothrix yeast surfaces. PRM also showed direct interaction with CD11b, the specific component of the complement receptor-3 (CR3). Furthermore, the blockade of CR3 specifically impacted the interleukin (IL)-1β secretion by hMDM in response to both S. brasiliensis and S. schenckii, suggesting that the host complement system plays an essential role in the inflammatory immune response against these Sporothrix species. Nevertheless, the structural differences in the PRMs of the two Sporothrix species, as revealed by NMR, were related to the differences observed in the host complement activation pathways. Together, this work reports a new PAMP of the cell surface of pathogenic fungi playing a role through the activation of complement system and via CR3 receptor mediating an inflammatory response to Sporothrix species.

scholarly journals Synthesis of Melanin-Like Pigments by Sporothrix schenckii In Vitro and during Mammalian Infection

2003 ◽  
Vol 71 (7) ◽  
pp. 4026-4033 ◽  
Author(s):  
Rachael Morris-Jones ◽  
Sirida Youngchim ◽  
Beatriz L. Gomez ◽  
Phil Aisen ◽  
Roderick J. Hay ◽  
...  
Keyword(s):  
Fungal Pathogens ◽  
Proteolytic Enzymes ◽  
Sporothrix Schenckii ◽  
Brain Heart Infusion ◽  
Pathogenic Fungi ◽  
Yeast Cells ◽  
Important Virulence Factor ◽  
Mammalian Infection

ABSTRACT Melanin has been implicated in the pathogenesis of several important human fungal pathogens. Existing data suggest that the conidia of the dimorphic fungal pathogen Sporothrix schenckii produce melanin or melanin-like compounds; in this study we aimed to confirm this suggestion and to demonstrate in vitro and in vivo production of melanin by yeast cells. S. schenckii grown on Mycosel agar produced visibly pigmented conidia, although yeast cells grown in brain heart infusion and minimal medium broth appeared to be nonpigmented macroscopically. However, treatment of both conidia and yeast cells with proteolytic enzymes, denaturant, and concentrated hot acid yielded dark particles similar in shape and size to the corresponding propagules, which were stable free radicals consistent with identification as melanins. Melanin particles extracted from S. schenckii yeast cells were used to produce a panel of murine monoclonal antibodies (MAbs) which labeled pigmented conidia, yeast cells, and the isolated particles. Tissue from hamster testicles infected with S. schenckii contained fungal cells that were labeled by melanin-binding MAbs, and digestion of infected hamster tissue yielded dark particles that were also reactive. Additionally, sera from humans with sporotrichosis contained antibodies that bound melanin particles. These findings indicate that S. schenckii conidia and yeast cells can produce melanin or melanin-like compounds in vitro and that yeast cells can synthesize pigment in vivo. Since melanin is an important virulence factor in other pathogenic fungi, this pigment may have a similar role in the pathogenesis of sporotrichosis.

Recognition of Fungal Components by the Host Immune System

2020 ◽  
Vol 21 (3) ◽  
pp. 245-264 ◽  
Author(s):  
Laura C. García-Carnero ◽  
José A. Martínez-Álvarez ◽  
Luis M. Salazar-García ◽  
Nancy E. Lozoya-Pérez ◽  
Sandra E. González-Hernández ◽  
...  
Keyword(s):  
Immune System ◽  
Histoplasma Capsulatum ◽  
Paracoccidioides Brasiliensis ◽  
Sporothrix Schenckii ◽  
Clinical Importance ◽  
Pathogenic Fungi ◽  
Diagnostic Tools ◽  
Future Research ◽  
Host Immune System ◽  
Fungal Antigens

: By being the first point of contact of the fungus with the host, the cell wall plays an important role in the pathogenesis, having many molecules that participate as antigens that are recognized by immune cells, and also that help the fungus to establish infection. The main molecules reported to trigger an immune response are chitin, glucans, oligosaccharides, proteins, melanin, phospholipids, and others, being present in the principal pathogenic fungi with clinical importance worldwide, such as Histoplasma capsulatum, Paracoccidioides brasiliensis, Aspergillus fumigatus, Candida albicans, Cryptococcus neoformans, Blastomyces dermatitidis, and Sporothrix schenckii. Knowledge and understanding of how the immune system recognizes and responds to fungal antigens are relevant for the future research and development of new diagnostic tools and treatments for the control of mycosis caused by these fungi.

Synthesis and Antifungal Activity of Coumarins Derivatives Against Sporothrix spp.

2018 ◽  
Vol 18 (2) ◽  
pp. 164-171 ◽  
Author(s):  
Luana da S.M. Forezi ◽  
Luana Pereira Borba-Santos ◽  
Mariana F.C. Cardoso ◽  
Vitor F. Ferreira ◽  
Sonia Rozental ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Antifungal Agents ◽  
Sporothrix Schenckii ◽  
Public Health Problem ◽  
Domestic Animals ◽  
Coumarin Derivatives ◽  
Sporothrix Brasiliensis ◽  
Synthetic Routes ◽  
Effective Drugs

Sporotrichosis is a serious public health problem in Brazil that affects human patients and domestic animals, mainly cats. Thus, the search for new antifungal agents is required also due to the emergence and to the lack of effective drugs available in the therapeutic arsenal. The aim of this study was to evaluate the in vitro antifungal profile of two synthetic series of coumarin derivatives against Sporothrix schenckii and Sporothrix brasiliensis. The three-components synthetic routes used for the preparation of coumarin derivatives have proved to be quite efficient and compounds 16 and 17 have been prepared in good yields. The inhibitory activity of nineteen synthetic coumarins derivatives 16a-i and 17a-j were evaluated against Sporothrix spp. yeasts and the most potent compounds were 16b and 17i. However, according to concentrations able to inhibit (minimum inhibitory concentrations) and kill (minimum fungicidal concentrations) the cells, 17i was more effective than 16b against Sporothrix spp. Thus, 17i exhibited good antifungal activity against S. brasiliensis and S. schenckii, suggesting that it is an important scaffold for the development of novel antifungal agents.

scholarly journals Halting targeted and collateral damage to red blood cells by the complement system

2021 ◽  
Author(s):  
M. Jalink ◽  
E. C. W. de Boer ◽  
D. Evers ◽  
M. Q. Havinga ◽  
J. M. I. Vos ◽  
...  
Keyword(s):  
Red Blood Cells ◽  
Complement System ◽  
Blood Cells ◽  
Defense Mechanism ◽  
Standard Of Care ◽  
Complement Protein ◽  
Complement Inhibition ◽  
Complement Inhibitors ◽  
The Complement System ◽  
Patient Burden

AbstractThe complement system is an important defense mechanism against pathogens; however, in certain pathologies, the system also attacks human cells, such as red blood cells (RBCs). In paroxysmal nocturnal hemoglobinuria (PNH), RBCs lack certain complement regulators which sensitize them to complement-mediated lysis, while in autoimmune hemolytic anemia (AIHA), antibodies against RBCs may initiate complement-mediated hemolysis. In recent years, complement inhibition has improved treatment prospects for these patients, with eculizumab now the standard of care for PNH patients. Current complement inhibitors are however not sufficient for all patients, and they come with high costs, patient burden, and increased infection risk. This review gives an overview of the underlying pathophysiology of complement-mediated hemolysis in PNH and AIHA, the role of therapeutic complement inhibition nowadays, and the high number of complement inhibitors currently under investigation, as for almost every complement protein, an inhibitor is being developed. The focus lies with novel therapeutics that inhibit complement activity specifically in the pathway that causes pathology or those that reduce costs or patient burden through novel administration routes.

scholarly journals Replicative Aging in Pathogenic Fungi

2020 ◽  
Vol 7 (1) ◽  
pp. 6
Author(s):  
Somanon Bhattacharya ◽  
Tejas Bouklas ◽  
Bettina C. Fries
Keyword(s):  
Cell Division ◽  
Candida Glabrata ◽  
Asymmetric Cell Division ◽  
Pathogenic Fungi ◽  
Yeast Cells ◽  
Candida Auris ◽  
Replicative Aging ◽  
Yeast Saccharomyces Cerevisiae ◽  
Phenotypic Variations ◽  
Systemic Infections

Candida albicans, Candida auris, Candida glabrata, and Cryptococcus neoformans are pathogenic yeasts which can cause systemic infections in immune-compromised as well as immune-competent individuals. These yeasts undergo replicative aging analogous to a process first described in the nonpathogenic yeast Saccharomyces cerevisiae. The hallmark of replicative aging is the asymmetric cell division of mother yeast cells that leads to the production of a phenotypically distinct daughter cell. Several techniques to study aging that have been pioneered in S. cerevisiae have been adapted to study aging in other pathogenic yeasts. The studies indicate that aging is relevant for virulence in pathogenic fungi. As the mother yeast cell progressively ages, every ensuing asymmetric cell division leads to striking phenotypic changes, which results in increased antifungal and antiphagocytic resistance. This review summarizes the various techniques that are used to study replicative aging in pathogenic fungi along with their limitations. Additionally, the review summarizes some key phenotypic variations that have been identified and are associated with changes in virulence or resistance and thus promote persistence of older cells.

PS3-02 Neutralization of endogenous IL-12 inhibits the T-helper Type 1 immune response in experimental Sporothrix SchenckII infection

Cytokine ◽  
2010 ◽  
Vol 52 (1-2) ◽  
pp. 82
Author(s):  
Aurelio Flores-Garcı´a ◽  
Vicente Garibaldi-Becerra ◽  
Martha Barba-Barajas ◽  
Jesus S. Velarde-Félix ◽  
Luis E. Wong-Ley-Madero ◽  
...  
Keyword(s):  
Immune Response ◽  
Sporothrix Schenckii ◽  
T Helper ◽  
Helper Type

Transient Foxp3(+) regulatory T-cell depletion enhances protective Th1/Th17 immune response in murine sporotrichosis caused by Sporothrix schenckii

Immunobiology ◽  
2020 ◽  
Vol 225 (5) ◽  
pp. 151993 ◽  
Author(s):  
Alexander Batista-Duharte ◽  
Damiana Téllez-Martínez ◽  
Cleverton Roberto de Andrade ◽  
Marisa Campos Polesi ◽  
Deivys Leandro Portuondo ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cell ◽  
Regulatory T Cell ◽  
Sporothrix Schenckii ◽  
Cell Depletion ◽  
T Cell Depletion

scholarly journals Activation of the complement system by pathogenic fungi.

1996 ◽  
Vol 9 (1) ◽  
pp. 34-46 ◽  
Author(s):  
T R Kozel
Keyword(s):  
Complement System ◽  
Host Resistance ◽  
Molecular Mechanisms ◽  
Fungal Infections ◽  
Pathogenic Fungi ◽  
Complement Cascade ◽  
Experimental Animals ◽  
Molecular Bases ◽  
The Complement System

Fungi have been studied as prototype activators of the complement cascade since the early 1900s. More recently, attention has focused on the role of the complement system in the pathogenesis of fungal infections. The interactions of Cryptococcus neoformans and Candida albicans with the complement system are the most widely characterized; however, all pathogenic fungi examined to date have the ability to initiate the complement cascade. The molecular mechanisms for initiation and regulation of the complement cascade differ from one fungus to another, most likely reflecting differences in the structure of the outer layers of the cell wall. The molecular bases for such differences remain to be identified. Studies of mycoses in experimental animals with induced or congenital deficiencies in the complement system demonstrate that complement is an important innate system for control of fungal infection. Contributions to host resistance include opsonization and generation of inflammatory mediators. Inflammation induced by chemotactic products of the complement system may contribute to the pathogenesis of some fungal infections.

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