scholarly journals Fungal Dimorphism and Virulence: Molecular Mechanisms for Temperature Adaptation, Immune Evasion, and In Vivo Survival

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Gregory M. Gauthier
Keyword(s):  
Phase Transition ◽  
Immune Evasion ◽  
Molecular Mechanisms ◽  
Temperature Adaptation ◽  
Dimorphic Fungi ◽  
Fungal Dimorphism ◽  
Recent Advances ◽  
Immune Defenses ◽  
Yeast Phase

The thermally dimorphic fungi are a unique group of fungi within the Ascomycota phylum that respond to shifts in temperature by converting between hyphae (22–25°C) and yeast (37°C). This morphologic switch, known as the phase transition, defines the biology and lifestyle of these fungi. The conversion to yeast within healthy and immunocompromised mammalian hosts is essential for virulence. In the yeast phase, the thermally dimorphic fungi upregulate genes involved with subverting host immune defenses. This review highlights the molecular mechanisms governing the phase transition and recent advances in how the phase transition promotes infection.

scholarly journals Molecular mechanisms of antibody-mediated neutralisation of flavivirus infection

2008 ◽  
Vol 10 ◽  
Author(s):  
Theodore C. Pierson ◽  
Michael S. Diamond
Keyword(s):  
Virus Infection ◽  
Molecular Mechanisms ◽  
Vaccine Development ◽  
Clinical Importance ◽  
Small Animal ◽  
Antibody Recognition ◽  
Recent Advances ◽  
Flavivirus Infection

AbstractFlaviviruses are a group of positive-stranded RNA viruses that cause a spectrum of severe illnesses globally in more than 50 million individuals each year. While effective vaccines exist for three members of this group (yellow fever, Japanese encephalitis, and tick-borne encephalitis viruses), safe and effective vaccines for several other flaviviruses of clinical importance, including West Nile and dengue viruses, remain in development. An effective humoral immune response is critical for protection against flaviviruses and an essential goal of vaccine development. The effectiveness of virus-specific antibodies in vivo reflects their capacity to inhibit virus entry and spread through several mechanisms, including the direct neutralisation of virus infection. Recent advances in our understanding of the structural biology of flaviviruses, coupled with the use of small-animal models of flavivirus infection, have promoted significant advances in our appreciation of the factors that govern antibody recognition and inhibition of flaviviruses in vitro and in vivo. In this review, we discuss the properties that define the potency of neutralising antibodies and the molecular mechanisms by which they inhibit virus infection. How recent advances in this area have the potential to improve the development of safe and effective vaccines and immunotherapeutics is also addressed.

scholarly journals The circular RNA circDLG1 promotes gastric cancer progression and anti-PD-1 resistance through the regulation of CXCL12 by sponging miR-141-3p

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Dong-Liang Chen ◽  
Hui Sheng ◽  
Dong-Sheng Zhang ◽  
Ying Jin ◽  
Bai-Tian Zhao ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cancer Progression ◽  
Immune Evasion ◽  
Molecular Mechanisms ◽  
Circular Rnas ◽  
Gastric Cancer Cells ◽  
Cancer Tissues ◽  
Gastric Cancer Progression

Abstract Background Dysregulation of circular RNAs (circRNAs) plays an important role in the development of gastric cancer; thus, revealing the biological and molecular mechanisms of abnormally expressed circRNAs is critical for identifying novel therapeutic targets in gastric cancer. Methods A circRNA microarray was performed to identify differentially expressed circRNAs between primary and distant metastatic tissues and between gastric cancer tissues sensitive or resistant to anti-programmed cell death 1 (PD-1) therapy. The expression of circRNA discs large homolog 1 (DLG1) was determined in a larger cohort of primary and distant metastatic gastric cancer tissues. The role of circDLG1 in gastric cancer progression was evaluated both in vivo and in vitro, and the effect of circDLG1 on the antitumor activity of anti-PD-1 was evaluated in vivo. The interaction between circDLG1 and miR-141-3p was assessed by RNA immunoprecipitation and luciferase assays. Results circDLG1 was significantly upregulated in distant metastatic lesions and gastric cancer tissues resistant to anti-PD-1 therapy and was associated with an aggressive tumor phenotype and adverse prognosis in gastric cancer patients treated with anti-PD-1 therapy. Ectopic circDLG1 expression promoted the proliferation, migration, invasion, and immune evasion of gastric cancer cells. Mechanistically, circDLG1 interacted with miR-141-3p and acted as a miRNA sponge to increase the expression of CXCL12, which promoted gastric cancer progression and resistance to anti-PD-1-based therapy. Conclusions Overall, our findings demonstrate how circDLG1 promotes gastric cancer cell proliferation, migration, invasion and immune evasion and provide a new perspective on the role of circRNAs during gastric cancer progression.

scholarly journals Cytomegalovirus Misleads Its Host by Priming of CD8 T Cells Specific for an Epitope Not Presented in Infected Tissues

2003 ◽  
Vol 199 (1) ◽  
pp. 131-136 ◽  
Author(s):  
Rafaela Holtappels ◽  
Jürgen Podlech ◽  
Marcus-Folker Pahl-Seibert ◽  
Markus Jülch ◽  
Doris Thomas ◽  
...  
Keyword(s):  
T Cells ◽  
Immune Evasion ◽  
Cd8 T Cells ◽  
Molecular Mechanisms ◽  
Antigenic Peptide ◽  
Long Term Memory ◽  
Antigenic Peptides ◽  
Cross Presentation ◽  
Antigen Presenting

Cytomegaloviruses (CMVs) code for several proteins that inhibit the presentation of antigenic peptides to CD8 T cells. Although the molecular mechanisms of CMV interference with the major histocompatibility complex class I pathway are long understood, surprisingly little evidence exists to support a role in vivo. Here we document the first example of the presentation of an antigenic peptide being blocked by a CMV immune evasion protein in organs relevant to CMV disease. Although this Db-restricted peptide, which is derived from the antiapoptotic protein M45 of murine CMV (mCMV), is classified as an immunodominant peptide based on response magnitude and long-term memory, adoptive transfer of M45 epitope-specific CD8 T cells did not protect against infection with wild-type mCMV. Notably, the same cells protected C57BL/6 mice infected with an mCMV mutant in which immune evasion protein m152/gp40 is deleted. These data indicate that direct presentation or cross-presentation of an antigenic peptide by professional antigen-presenting cells can efficiently prime CD8 T cells that fail in protection against CMV organ disease because m152/gp40 prevents presentation of this peptide in pathogenetically relevant tissue cells.

Abstract 16596: Immune Evasion by Human Neonatal Cardiac Mesenchymal Stem Cells Demonstrates Therapeutic Application in Myocardial Infarction

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Muthukumar Gunasekaran ◽  
Rachana Mishra ◽  
Progyaparamita Saha ◽  
Aakash Shah ◽  
Lauren Davidson ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Immune Evasion ◽  
Molecular Mechanisms ◽  
Cell Retention ◽  
Over Expression ◽  
And Function

Immune rejection of transplanted stem cells is a major stumbling block in designing effective therapy for myocardial infarction. Human neonatal cardiac mesenchymal stem cells (nMSCs) showed superior cardiac functional recovery compared to adult MSCs in immune competent rat MI model. However, molecular mechanisms underlying immune evasion by transplanted nMSCs in the infarcted myocardium remain unexplored. In this investigation, we demonstrate for the first-time the expression, regulation and function of CD47 in human nMSCs and its novel mechanism of immune evasion increases its regenerative potential in rat MI model. Transplanted nMSCs showed significant increased cell retention, reduced phagocytosis and CD68 + cells compared to aMSCs in rat MI model. Comparative proteomic analysis by LC-MS/MS on nMSCs and aMSCs showed that CD47 higher in nMSCs. Increased CD47 expression in nMSCs inhibited phagocytosis compared to aMSCs in vitro and in vivo . Further, CD47 blockade in nMSCs using anti-CD47, siRNA and shRNA lentiviral based approaches increased in vitro , in vivo phagocytosis, CD68 + cells and reduced cell retention and MI recovery in vivo . Microarray analysis and validation showed miR-34a was significantly higher in aMSCs than nMSCs. To unravel CD47 regulation in aMSCs, we performed target scan analysis that predicted miR-34a binds on CD47. Further, miR-34a over expression in nMSCs reduced CD47 expression, increased in vitro and in vivo phagocytosis and reduced cell retention and MI recovery. In conclusion, increased CD47 expression in nMSCs inhibit phagocytosis by CD47/SIRPα immune regulatory axis to demonstrates its immune evasion potential and its therapeutic applications in myocardial infarction.

Flavonoids as P-gp Inhibitors: A Systematic Review of SARs

2019 ◽  
Vol 26 (25) ◽  
pp. 4799-4831 ◽  
Author(s):  
Jiahua Cui ◽  
Xiaoyang Liu ◽  
Larry M.C. Chow
Keyword(s):  
Molecular Mechanisms ◽  
Metastatic Cancer ◽  
Drug Candidates ◽  
Chemical Structures ◽  
Transporter Family ◽  
Promising Area ◽  
New Generation ◽  
Nontoxic Inhibitors

P-glycoprotein, also known as ABCB1 in the ABC transporter family, confers the simultaneous resistance of metastatic cancer cells towards various anticancer drugs with different targets and diverse chemical structures. The exploration of safe and specific inhibitors of this pump has always been the pursuit of scientists for the past four decades. Naturally occurring flavonoids as benzopyrone derivatives were recognized as a class of nontoxic inhibitors of P-gp. The recent advent of synthetic flavonoid dimer FD18, as a potent P-gp modulator in reversing multidrug resistance both in vitro and in vivo, specifically targeted the pseudodimeric structure of the drug transporter and represented a new generation of inhibitors with high transporter binding affinity and low toxicity. This review concerned the recent updates on the structure-activity relationships of flavonoids as P-gp inhibitors, the molecular mechanisms of their action and their ability to overcome P-gp-mediated MDR in preclinical studies. It had crucial implications on the discovery of new drug candidates that modulated the efflux of ABC transporters and also provided some clues for the future development in this promising area.

The Mechanisms Behind the Biological Activity of Flavonoids

2019 ◽  
Vol 26 (39) ◽  
pp. 6976-6990 ◽  
Author(s):  
Ana María González-Paramás ◽  
Begoña Ayuda-Durán ◽  
Sofía Martínez ◽  
Susana González-Manzano ◽  
Celestino Santos-Buelga
Keyword(s):  
Gene Expression ◽  
Biological Activity ◽  
Phenolic Compounds ◽  
Intracellular Signaling ◽  
Molecular Mechanisms ◽  
Radical Scavenging ◽  
Model Organism ◽  
Stress Theory ◽  
Radical Scavenging Properties

: Flavonoids are phenolic compounds widely distributed in the human diet. Their intake has been associated with a decreased risk of different diseases such as cancer, immune dysfunction or coronary heart disease. However, the knowledge about the mechanisms behind their in vivo activity is limited and still under discussion. For years, their bioactivity was associated with the direct antioxidant and radical scavenging properties of phenolic compounds, but nowadays this assumption is unlikely to explain their putative health effects, or at least to be the only explanation for them. New hypotheses about possible mechanisms have been postulated, including the influence of the interaction of polyphenols and gut microbiota and also the possibility that flavonoids or their metabolites could modify gene expression or act as potential modulators of intracellular signaling cascades. This paper reviews all these topics, from the classical view as antioxidants in the context of the Oxidative Stress theory to the most recent tendencies related with the modulation of redox signaling pathways, modification of gene expression or interactions with the intestinal microbiota. The use of C. elegans as a model organism for the study of the molecular mechanisms involved in biological activity of flavonoids is also discussed.

Targeting PPARalpha in Alzheimer's Disease

2018 ◽  
Vol 15 (4) ◽  
pp. 345-354 ◽  
Author(s):  
Barbara D'Orio ◽  
Anna Fracassi ◽  
Maria Paola Cerù ◽  
Sandra Moreno
Keyword(s):  
Oxidative Stress ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Molecular Mechanisms ◽  
Redox Homeostasis ◽  
Antioxidant Response ◽  
Peroxisome Proliferator ◽  
Prevailing Paradigm

Background: The molecular mechanisms underlying Alzheimer's disease (AD) are yet to be fully elucidated. The so-called “amyloid cascade hypothesis” has long been the prevailing paradigm for causation of disease, and is today being revisited in relation to other pathogenic pathways, such as oxidative stress, neuroinflammation and energy dysmetabolism. The peroxisome proliferator-activated receptors (PPARs) are expressed in the central nervous system (CNS) and regulate many physiological processes, such as energy metabolism, neurotransmission, redox homeostasis, autophagy and cell cycle. Among the three isotypes (α, β/δ, γ), PPARγ role is the most extensively studied, while information on α and β/δ are still scanty. However, recent in vitro and in vivo evidence point to PPARα as a promising therapeutic target in AD. Conclusion: This review provides an update on this topic, focussing on the effects of natural or synthetic agonists in modulating pathogenetic mechanisms at AD onset and during its progression. Ligandactivated PPARα inihibits amyloidogenic pathway, Tau hyperphosphorylation and neuroinflammation. Concomitantly, the receptor elicits an enzymatic antioxidant response to oxidative stress, ameliorates glucose and lipid dysmetabolism, and stimulates autophagy.

Novel Findings of Anti-cancer Property of Propofol

2018 ◽  
Vol 18 (2) ◽  
pp. 156-165 ◽  
Author(s):  
Jiaqiang Wang ◽  
Chien-shan Cheng ◽  
Yan Lu ◽  
Xiaowei Ding ◽  
Minmin Zhu ◽  
...  
Keyword(s):  
General Anesthesia ◽  
Cancer Progression ◽  
Molecular Mechanisms ◽  
Intravenous Anesthetic ◽  
The Past ◽  
Anti Cancer ◽  
Underlying Mechanisms ◽  
Recent Attention

Background: Propofol, a widely used intravenous anesthetic agent, is traditionally applied for sedation and general anesthesia. Explanation: Recent attention has been drawn to explore the effect and mechanisms of propofol against cancer progression in vitro and in vivo. Specifically, the proliferation-inhibiting and apoptosis-inducing properties of propofol in cancer have been studied. However, the underlying mechanisms remain unclear. Conclusion: This review focused on the findings within the past ten years and aimed to provide a general overview of propofol's malignance-modulating properties and the potential molecular mechanisms.

Sign in / Sign up

Export Citation Format

Share Document