scholarly journals A Histoplasma capsulatum lipid metabolic map identifies antifungal targets and virulence factors

2020 ◽  
Author(s):  
Daniel Zamith-Miranda ◽  
Heino M. Heyman ◽  
Meagan C. Burnet ◽  
Sneha P. Couvillion ◽  
Xueyun Zheng ◽  
...  
Keyword(s):  
Immune Response ◽  
Drug Development ◽  
Cell Biology ◽  
Histoplasma Capsulatum ◽  
Platelet Activating Factor ◽  
Interleukin 10 ◽  
Antifungal Drugs ◽  
New Drugs ◽  
Fungal Cell ◽  
Factor Α

AbstractLipids play a fundamental role in fungal cell biology, being components of the cell membrane as well as targets of antifungal drugs. A deeper knowledge of lipid metabolism is key for developing new drugs and a better understanding of fungal pathogenesis. Here we built a comprehensive map of the Histoplasma capsulatum lipid metabolic pathway by integrating proteomic and lipidomic analyses. The map led to the identification of both the fatty acid desaturation and the sphingolipid biosynthesis pathways as targets for drug development. We also found that H. capsulatum produces analogs of platelet-activating factor, a potent regulator of the human immune response. The H. capsulatum platelet-activating factor analogs induced platelet aggregation and stimulated the production of the cytokines interleukin-10 and tumor necrosis factor-α by J774 macrophages. Overall, this lipid metabolic map revealed pathways that can be targeted for drug development, in addition to identifying a regulator of the host immune response.

scholarly journals 3D-Hepatocyte Culture Applied to Parasitology: Immune Activation of Canine Hepatic Spheroids Exposed to Leishmania infantum

Biomedicines ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 628
Author(s):  
Armanda V. Rodrigues ◽  
Graça Alexandre-Pires ◽  
Ana Valério-Bolas ◽  
David Santos-Mateus ◽  
Mariana Rafael-Fernandes ◽  
...  
Keyword(s):  
Gene Expression ◽  
Immune Response ◽  
Leishmania Infantum ◽  
Three Dimensional ◽  
Interleukin 10 ◽  
Health Concern ◽  
Canine Leishmaniasis ◽  
No Production ◽  
Effector Cells ◽  
Factor Α

The application of innovative three-dimensional (3D) spheroids cell culture strategy to Parasitology offers the opportunity to closely explore host–parasite interactions. Here we present a first report on the application of 3D hepatic spheroids to unravel the immune response of canine hepatocytes exposed to Leishmania infantum. The liver, usually considered a major metabolic organ, also performs several important immunological functions and constitutes a target organ for L. infantum infection, the etiological agent of canine leishmaniasis (CanL), and a parasitic disease of major veterinary and public health concern. 3D hepatic spheroids were able to sense and immunologically react to L. infantum parasites, generating an innate immune response by increasing nitric oxide (NO) production and enhancing toll-like receptor (TLR) 2 and interleukin-10 gene expression. The immune response orchestrated by canine hepatocytes also lead to the impairment of several cytochrome P450 (CYP450) with possible implications for liver natural xenobiotic metabolization capacity. The application of meglumine antimoniate (MgA) increased the inflammatory response of 3D hepatic spheroids by inducing the expression of Nucleotide oligomerization domain (NOD) -like receptors 1 and NOD2 and TLR2, TLR4, and TLR9 and enhancing gene expression of tumour necrosis factor α. It is therefore suggested that hepatocytes are key effector cells and can activate and orchestrate the immune response to L. infantum parasites.

The Chemistry of Drugs to Treat Candida albicans

2019 ◽  
Vol 19 (28) ◽  
pp. 2554-2566 ◽  
Author(s):  
Aurelio Ortiz ◽  
Estibaliz Sansinenea
Keyword(s):  
Candida Species ◽  
Antifungal Drugs ◽  
New Drugs ◽  
Drug Classes ◽  
Life Threatening ◽  
Antifungal Substances ◽  
High Level ◽  
Systemic Infections ◽  
New Compounds ◽  
Level Resistance

Background:: Candida species are in various parts of the human body as commensals. However, they can cause local mucosal infections and, sometimes, systemic infections in which Candida species can spread to all major organs and colonize them. Objective:: For the effective treatment of the mucosal infections and systemic life-threatening fungal diseases, a considerably large number of antifungal drugs have been developed and used for clinical purposes that comprise agents from four main drug classes: the polyenes, azoles, echinocandins, and antimetabolites. Method: : The synthesis of some of these drugs is available, allowing synthetic modification of the molecules to improve the biological activity against Candida species. The synthetic methodology for each compound is reviewed. Results: : The use of these compounds has caused a high-level resistance against these drugs, and therefore, new antifungal substances have been described in the last years. The organic synthesis of the known and new compounds is reported. Conclusion: : This article summarizes the chemistry of the existing agents, both the old drugs and new drugs, in the treatment of infections due to C. albicans, including the synthesis of the existing drugs.

Efficacy of Novel Schiff base Derivatives as Antifungal Compounds in Combination with Approved Drugs Against Candida Albicans

2019 ◽  
Vol 15 (6) ◽  
pp. 648-658 ◽  
Author(s):  
Manzoor Ahmad Malik ◽  
Shabir Ahmad Lone ◽  
Parveez Gull ◽  
Ovas Ahmad Dar ◽  
Mohmmad Younus Wani ◽  
...  
Keyword(s):  
Schiff Base ◽  
Candida Albicans ◽  
Antifungal Activity ◽  
Fungal Infections ◽  
Total Sterol ◽  
Antifungal Drugs ◽  
New Drugs ◽  
Ergosterol Biosynthesis ◽  
Dependent Manner ◽  
Schiff Base Derivatives

Background: The increasing incidence of fungal infections, especially caused by Candida albicans, and their increasing drug resistance has drastically increased in recent years. Therefore, not only new drugs but also alternative treatment strategies are promptly required. Methods: We previously reported on the synergistic interaction of some azole and non-azole compounds with fluconazole for combination antifungal therapy. In this study, we synthesized some non-azole Schiff-base derivatives and evaluated their antifungal activity profile alone and in combination with the most commonly used antifungal drugs- fluconazole (FLC) and amphotericin B (AmB) against four drug susceptible, three FLC resistant and three AmB resistant clinically isolated Candida albicans strains. To further analyze the mechanism of antifungal action of these compounds, we quantified total sterol contents in FLC-susceptible and resistant C. albicans isolates. Results: A pyrimidine ring-containing derivative SB5 showed the most potent antifungal activity against all the tested strains. After combining these compounds with FLC and AmB, 76% combinations were either synergistic or additive while as the rest of the combinations were indifferent. Interestingly, none of the combinations was antagonistic, either with FLC or AmB. Results interpreted from fractional inhibitory concentration index (FICI) and isobolograms revealed 4-10-fold reduction in MIC values for synergistic combinations. These compounds also inhibit ergosterol biosynthesis in a concentration-dependent manner, supported by the results from docking studies. Conclusion: The results of the studies conducted advocate the potential of these compounds as new antifungal drugs. However, further studies are required to understand the other mechanisms and in vivo efficacy and toxicity of these compounds.

Predictivity/Translatability of Toxicities Observed in Nonclinical Toxicology Studies to Clinical Safety Outcomes in Drug Development: Case Examples

2019 ◽  
Vol 39 (2) ◽  
pp. 141-150
Author(s):  
Nicola J. Stagg ◽  
Hanan N. Ghantous ◽  
Robert Roth ◽  
Kenneth L. Hastings
Keyword(s):  
Drug Development ◽  
Annual Meeting ◽  
Clinical Studies ◽  
Early Termination ◽  
New Drugs ◽  
Clinical Safety ◽  
Case Examples ◽  
Palm Springs ◽  
Starting Dose ◽  
Good Concordance

Nonclinical toxicology studies are conducted to characterize the potential toxicities and establish a safe starting dose for new drugs in clinical studies, but the question remains as to how predictable/translatable the nonclinical safety findings are to humans. In many cases, there is good concordance between nonclinical species and patients. However, there are cases for which there is a lack of predictivity or translatability that led to early termination of clinical studies due to unanticipated toxicities or early termination of programs before making it to the clinic due to unacceptable nonclinical toxicities assumed to be translatable. A few case examples of safety findings that are translatable versus safety findings that are not translatable and why they are not translateable were presented as a symposium at the 38th Annual Meeting of the American College of Toxicology in Palm Springs, California, and are discussed in this article.

scholarly journals Cathepsin L plays a key role in SARS-CoV-2 infection in humans and humanized mice and is a promising target for new drug development

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Miao-Miao Zhao ◽  
Wei-Li Yang ◽  
Fang-Yuan Yang ◽  
Li Zhang ◽  
Wei-Jin Huang ◽  
...  
Keyword(s):  
Drug Development ◽  
Cathepsin L ◽  
Human Cells ◽  
New Drugs ◽  
Disease Course ◽  
Promising Target ◽  
First Time

AbstractTo discover new drugs to combat COVID-19, an understanding of the molecular basis of SARS-CoV-2 infection is urgently needed. Here, for the first time, we report the crucial role of cathepsin L (CTSL) in patients with COVID-19. The circulating level of CTSL was elevated after SARS-CoV-2 infection and was positively correlated with disease course and severity. Correspondingly, SARS-CoV-2 pseudovirus infection increased CTSL expression in human cells in vitro and human ACE2 transgenic mice in vivo, while CTSL overexpression, in turn, enhanced pseudovirus infection in human cells. CTSL functionally cleaved the SARS-CoV-2 spike protein and enhanced virus entry, as evidenced by CTSL overexpression and knockdown in vitro and application of CTSL inhibitor drugs in vivo. Furthermore, amantadine, a licensed anti-influenza drug, significantly inhibited CTSL activity after SARS-CoV-2 pseudovirus infection and prevented infection both in vitro and in vivo. Therefore, CTSL is a promising target for new anti-COVID-19 drug development.

scholarly journals Lights and Shadows in Immuno-Oncology Drug Development

Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 691
Author(s):  
Milana Bergamino Sirvén ◽  
Sonia Pernas ◽  
Maggie C. U. Cheang
Keyword(s):  
Drug Development ◽  
Checkpoint Inhibitors ◽  
Late Phase ◽  
New Drugs ◽  
Successful Outcome ◽  
Different Types ◽  
Cancer Types ◽  
Clinical Trial Designs ◽  
Oncology Drug Development ◽  
Critical Aspects

The rapidly evolving landscape of immuno-oncology (IO) is redefining the treatment of a number of cancer types. IO treatments are becoming increasingly complex, with different types of drugs emerging beyond checkpoint inhibitors. However, many of the new drugs either do not progress from phase I-II clinical trials or even fail in late-phase trials. We have identified at least five areas in the development of promising IO treatments that should be redefined for more efficient designs and accelerated approvals. Here we review those critical aspects of IO drug development that could be optimized for more successful outcome rates in all cancer types. It is important to focus our efforts on the mechanisms of action, types of response and adverse events of these novel agents. The use of appropriate clinical trial designs with robust biomarkers of response and surrogate endpoints will undoubtedly facilitate the development and subsequent approval of these drugs. Further research is also needed to establish biomarker-driven strategies to select which patients may benefit from immunotherapy and identify potential mechanisms of resistance.

scholarly journals Lymphocytes are detrimental during the early innate immune response against Listeria monocytogenes

2006 ◽  
Vol 203 (4) ◽  
pp. 933-940 ◽  
Author(s):  
Javier A. Carrero ◽  
Boris Calderon ◽  
Emil R. Unanue
Keyword(s):  
Immune Response ◽  
Listeria Monocytogenes ◽  
Innate Immune Response ◽  
Early Stage ◽  
Bacterial Pathogen ◽  
Interleukin 10 ◽  
Innate Immune ◽  
Type I ◽  
Phagocytic Cells ◽  
Immunodeficient Mice

Mice deficient in lymphocytes are more resistant than normal mice to Listeria monocytogenes infection during the early innate immune response. This paradox remains unresolved: lymphocytes are required for sterilizing immunity, but their presence during the early stage of the infection is not an asset and may even be detrimental. We found that lymphocyte-deficient mice, which showed limited apoptosis in infected organs, were resistant during the first four days of infection but became susceptible when engrafted with lymphocytes. Engraftment with lymphocytes from type I interferon receptor–deficient (IFN-αβR−/−) mice, which had reduced apoptosis, did not confer increased susceptibility to infection, even when the phagocytes were IFN-αβR+/+. The attenuation of innate immunity was due, in part, to the production of the antiinflammatory cytokine interleukin 10 by phagocytic cells after the apoptotic phase of the infection. Thus, immunodeficient mice were more resistant relative to normal mice because the latter went through a stage of lymphocyte apoptosis that was detrimental to the innate immune response. This is an example of a bacterial pathogen creating a cascade of events that leads to a permissive infective niche early during infection.

Role of Platelet-Activating Factor in Cardiovascular Pathophysiology

2000 ◽  
Vol 80 (4) ◽  
pp. 1669-1699 ◽  
Author(s):  
Giuseppe Montrucchio ◽  
Giuseppe Alloatti ◽  
Giovanni Camussi
Keyword(s):  
Cardiovascular System ◽  
Cell Biology ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Critical Role ◽  
Experimental Studies ◽  
Platelet Activating Factor ◽  
Biologically Active ◽  
Endothelial Cell Migration

Platelet-activating factor (PAF) is a phospholipid mediator that belongs to a family of biologically active, structurally related alkyl phosphoglycerides. PAF acts via a specific receptor that is coupled with a G protein, which activates a phosphatidylinositol-specific phospholipase C. In this review we focus on the aspects that are more relevant for the cell biology of the cardiovascular system. The in vitro studies provided evidence for a role of PAF both as intercellular and intracellular messenger involved in cell-to-cell communication. In the cardiovascular system, PAF may have a role in embryogenesis because it stimulates endothelial cell migration and angiogenesis and may affect cardiac function because it exhibits mechanical and electrophysiological actions on cardiomyocytes. Moreover, PAF may contribute to modulation of blood pressure mainly by affecting the renal vascular circulation. In pathological conditions, PAF has been involved in the hypotension and cardiac dysfunctions occurring in various cardiovascular stress situations such as cardiac anaphylaxis and hemorrhagic, traumatic, and septic shock syndromes. In addition, experimental studies indicate that PAF has a critical role in the development of myocardial ischemia-reperfusion injury. Indeed, PAF cooperates in the recruitment of leukocytes in inflamed tissue by promoting adhesion to the endothelium and extravascular transmigration of leukocytes. The finding that human heart can produce PAF, expresses PAF receptor, and is sensitive to the negative inotropic action of PAF suggests that this mediator may have a role also in human cardiovascular pathophysiology.

Recent advances in the synthesis of fungal antigenic oligosaccharides

2017 ◽  
Vol 89 (7) ◽  
pp. 885-898 ◽  
Author(s):  
Vadim B. Krylov ◽  
Lucia Paulovičová ◽  
Ema Paulovičová ◽  
Yury E. Tsvetkov ◽  
Nikolay E. Nifantiev
Keyword(s):  
Immune Response ◽  
Cell Wall ◽  
Cell Adhesion ◽  
Driving Force ◽  
Efficient Solutions ◽  
Carbohydrate Chemistry ◽  
Fungal Cell ◽  
Synthetic Methodologies ◽  
Novel Strategy ◽  
Constant Improvement

AbstractThe driving force for the constant improvement and development of new synthetic methodologies in carbohydrate chemistry is a growing demand for biologically important oligosaccharide ligands and neoglycoconjugates thereof for numerous biochemical investigations such as cell-to-pathogen interactions, immune response, cell adhesion, etc. Here we report our syntheses of the spacer-armed antigenic oligosaccharides related to three groups of the polysaccharides of the fungal cell-wall including α- and β-mannan, α- and β-glucan and galactomannan chains, which include new rationally designed synthetic blocks, efficient solutions for the stereoselective construction of glycoside bonds, and novel strategy for preparation of furanoside-containing oligosaccharides based on recently discovered pyranoside-into-furanoside (PIF) rearrangement.

scholarly journals Targeted Deletion of Class A Macrophage Scavenger Receptor Increases the Risk of Cardiac Rupture After Experimental Myocardial Infarction

Circulation ◽  
2007 ◽  
Vol 115 (14) ◽  
pp. 1904-1911 ◽  
Author(s):  
Kenichi Tsujita ◽  
Koichi Kaikita ◽  
Takanori Hayasaki ◽  
Tsuyoshi Honda ◽  
Hironori Kobayashi ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Tumor Necrosis Factor Α ◽  
Interleukin 10 ◽  
Experimental Myocardial Infarction ◽  
Cardiac Rupture ◽  
Infarcted Myocardium ◽  
Factor Α ◽  
Necrosis Factor

Background— Class A macrophage scavenger receptor (SR-A) is a macrophage-restricted multifunctional molecule that optimizes the inflammatory response by modulation of the activity of inflammatory cytokines. This study was conducted with SR-A–deficient (SR-A −/− ) mice to evaluate the relationship between SR-A and cardiac remodeling after myocardial infarction. Methods and Results— Experimental myocardial infarction (MI) was produced by ligation of the left coronary artery in SR-A −/− and wild-type (WT) male mice. The number of mice that died within 4 weeks after MI was significantly greater in SR-A −/− mice than in WT mice ( P =0.03). Importantly, death caused by cardiac rupture within 1 week after MI was 31% (17 of 54 mice) in SR-A −/− mice and 12% (6 of 51 mice) in WT mice ( P =0.01). In situ zymography demonstrated augmented gelatinolytic activity in the infarcted myocardium in SR-A −/− mice compared with WT mice. Real-time reverse transcription–polymerase chain reaction at day 3 after MI showed that the expression of matrix metalloproteinase-9 mRNA increased significantly in the infarcted myocardium in SR-A −/− mice compared with WT mice. Furthermore, SR-A −/− mice showed augmented expression of tumor necrosis factor-α and reduction of interleukin-10 in the infarcted myocardium at day 3 after MI. In vitro experiments also demonstrated increased tumor necrosis factor-α and decreased interleukin-10 expression in activated SR-A −/− macrophages. Conclusions— The present findings suggest that SR-A deficiency might cause impairment of infarct remodeling that results in cardiac rupture via insufficient production of interleukin-10 and enhanced expression of tumor necrosis factor-α and of matrix metalloproteinase-9. SR-A might contribute to the prevention of cardiac rupture after MI.

Sign in / Sign up

Export Citation Format

Share Document