Novel Innate Immune Functions Revealed by Dynamic, Real-Time Live Imaging of Bacterial Infections

2010 ◽  
Vol 30 (2) ◽  
pp. 107-117 ◽  
Author(s):  
Keira Melican ◽  
Jorrit Boekel ◽  
Monica Ryden-Aulin ◽  
Agneta Richter-Dahlfors
Keyword(s):  
Real Time ◽  
Bacterial Infections ◽  
Live Imaging ◽  
Innate Immune ◽  
Immune Functions

scholarly journals Bacterial Infections Affect Male Fertility: A Focus on the Oxidative Stress-Autophagy Axis

2021 ◽  
Vol 9 ◽  
Author(s):  
Sutian Wang ◽  
Kunli Zhang ◽  
Yuchang Yao ◽  
Jianhao Li ◽  
Shoulong Deng
Keyword(s):  
Oxidative Stress ◽  
Reproductive System ◽  
Bacterial Infections ◽  
Reproductive Organs ◽  
Innate Immune ◽  
Male Reproductive System ◽  
Pathogenic Microorganisms ◽  
Immune Functions ◽  
Molecular Patterns ◽  
Multiple Signaling

Numerous factors trigger male infertility, including lifestyle, the environment, health, medical resources and pathogenic microorganism infections. Bacterial infections of the male reproductive system can cause various reproductive diseases. Several male reproductive organs, such as the testicles, have unique immune functions that protect the germ cells from damage. In the reproductive system, immune cells can recognize the pathogen-associated molecular patterns carried by pathogenic microorganisms and activate the host’s innate immune response. Furthermore, bacterial infections can lead to oxidative stress through multiple signaling pathways. Many studies have revealed that oxidative stress serves dual functions: moderate oxidative stress can help clear the invaders and maintain sperm motility, but excessive oxidative stress will induce host damage. Additionally, oxidative stress is always accompanied by autophagy which can also help maintain host homeostasis. Male reproductive system homeostasis disequilibrium can cause inflammation of the genitourinary system, influence spermatogenesis, and even lead to infertility. Here, we focus on the effect of oxidative stress and autophagy on bacterial infection in the male reproductive system, and we also explore the crosslink between oxidative stress and autophagy during this process.

scholarly journals The E3 ligase RNF115 regulates phagosome maturation and host response to bacterial infection

2021 ◽  
Author(s):  
Orsolya Bilkei-Gorzo ◽  
Tiaan Heunis ◽  
Daniela Fabrikova ◽  
Jose-Luis Marin Rubio ◽  
Julien Peltier ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Inflammatory Responses ◽  
Innate Immune ◽  
Immune Functions ◽  
Ubiquitin Chain ◽  
Knock Out ◽  
Phagosomal Maturation ◽  
Ifn Γ ◽  
Knock Out Mice

Phagocytosis as a key process in innate immunity and homeostasis. After uptake, newly formed phagosomes mature by acquisition of endo-lysosomal enzymes. Macrophage activation by interferon-gamma (IFN-γ) increases microbicidal activity, but delays phagosomal maturation by an unknown mechanism. Using quantitative proteomics, we show that phagosomal proteins harbour high levels of typical and atypical ubiquitin chain types. Moreover, phagosomal ubiquitylation of vesicle trafficking proteins is substantially enhanced upon IFN-γ activation of macrophages, suggesting a role in regulating phagosomal functions. Furthermore, we identified the E3 ubiquitin ligase RNF115, which is enriched on phagosomes of IFN-γ activated macrophages, as an important regulator of phagosomal maturation. Loss of RNF115 protein or ligase activity enhanced phagosomal maturation and increased cytokine responses to Staphylococcus aureus, suggesting that both innate immune signalling from the phagosome and phagolysosomal trafficking are controlled through ubiquitylation. RNF115 knock-out mice show less tissue damage in response to S. aureus infection, indicating a role of RNF115 in inflammatory responses in vivo. In conclusion, RNF115 and phagosomal ubiquitylation are important regulators of innate immune functions during bacterial infections.

Real-time live imaging to study bacterial infections in vivo

2009 ◽  
Vol 12 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Keira Melican ◽  
Agneta Richter-Dahlfors
Keyword(s):  
Real Time ◽  
Bacterial Infections ◽  
Live Imaging

scholarly journals Role of the Inflammasome, IL-1β, and IL-18 in Bacterial Infections

2011 ◽  
Vol 11 ◽  
pp. 2037-2050 ◽  
Author(s):  
Manoranjan Sahoo ◽  
Ivonne Ceballos-Olvera ◽  
Laura del Barrio ◽  
Fabio Re
Keyword(s):  
Bacterial Infections ◽  
Innate Immune ◽  
Host Responses ◽  
Inflammasome Activation ◽  
Different Types ◽  
Molecular Aspects ◽  
Immune Pathway ◽  
Innate Immune Pathway ◽  
Receptor Family

The inflammasome is an important innate immune pathway that regulates at least two host responses protective against infections: (1) secretion of the proinflammatory cytokines IL-1βand IL-18 and (2) induction of pyroptosis, a form of cell death. Inflammasomes, of which different types have been identified, are multiprotein complexes containing pattern recognition receptors belonging to the Nod-like receptor family or the PYHIN family and the protease caspase-1. The molecular aspects involved in the activation of different inflammasomes by various pathogens are being rapidly elucidated, and their role during infections is being characterized. Production of IL-1βand IL-18 and induction of pyroptosis of the infected cell have been shown to be protective against many infectious agents. Here, we review the recent literature concerning inflammasome activation in the context of bacterial infections and identify important questions to be answered in the future.

scholarly journals Brevinin-2 Drug Family—New Applied Peptide Candidates Against Methicillin-Resistant Staphylococcus aureus and Their Effects on Lys-7 Expression of Innate Immune Pathway DAF-2/DAF-16 in Caenorhabditis elegans

2018 ◽  
Vol 8 (12) ◽  
pp. 2627
Author(s):  
Hui Xie ◽  
Yonghua Zhan ◽  
Xueli Chen ◽  
Qi Zeng ◽  
Dan Chen ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Survival Rate ◽  
Caenorhabditis Elegans ◽  
Antimicrobial Peptides ◽  
Real Time ◽  
Innate Immune ◽  
C Elegans ◽  
New Drug ◽  
Immune Pathway ◽  
Innate Immune Pathway

The issue of Staphylococcus aureus (MRSA) developing a resistance to drugs such as methicillin has long been the focus for new drug development. In recent years, antimicrobial peptides, such as small molecular peptides with broad-spectrum antibacterial activity and special antibacterial mechanism, have shown a strong medicinal potential. In particular, the Brevinin-2 family has been shown to have a significant inhibitory effect against gram-positive bacteria (G+). In this study, we researched the influence of MRSA on the behavior and survival rate of nematodes. We established an assay of Caenorhabditis elegans–MRSA antimicrobial peptides to screen for new potent anti-infective peptides against MRSA. From the Brevinin-2 family, 13 peptides that had shown strong effects on G+ were screened for their ability to prolong the lifespan of infected worms. Real-time Polymerase Chain Reaction (PCR) tests were used to evaluate the effect on the innate immune pathway dauer formation defective (DAF)-2/DAF-16 of C. elegans. The assay successfully screened and filtered out four of the 13 peptides that significantly improved the survival rate of MRSA-infected worms. The result of real-time PCR indicated that the mRNA and protein expression levels of lys-7 were consistently upregulated by being treated with four of the Brevinin-2 family. The Brevinin-2 family peptides, including Brevinin-2, Brevinin-2-OA3, Brevinin-2ISb, and Brevinin-2TSa, also played an active role in the DAF-2/DAF-16 pathway in C. elegans. We successfully demonstrated the utility of anti-infective peptides that prolong the survival rate of the MRSA-infected host and discovered the relationship between antibacterial peptides and the innate immune system of C. elegans. We demonstrated the antimicrobial effects of Brevinin-2 family peptides, indicating their potential for use as new drug candidates against MRSA infections.

scholarly journals Selective Uropathogenic E. coli Detection Using Crossed Surface-Relief Gratings

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3634 ◽  
Author(s):  
Srijit Nair ◽  
Juan Gomez-Cruz ◽  
Ángel Manjarrez-Hernandez ◽  
Gabriel Ascanio ◽  
Ribal Sabat ◽  
...  
Keyword(s):  
Urinary Tract ◽  
Real Time ◽  
Surface Relief ◽  
Bacterial Infections ◽  
Dynamic Range ◽  
Incident Light ◽  
Public Healthcare ◽  
Label Free Detection ◽  
Surface Relief Gratings ◽  
Tract Infections

Urinary tract infections (UTIs) are one of the major burdens on public healthcare worldwide. One of the primary causes of UTIs is the invasion of the urinary tract by uropathogenic Escherichia coli (UPEC). Improper treatment of bacterial infections like UTIs with broad-spectrum antibiotics has contributed to the rise of antimicrobial resistance, necessitating the development of an inexpensive, rapid and accurate detection of UPEC. Here, we present real-time, selective and label-free detection of UPEC using crossed surface-relief gratings (CSRGs) as nanometallic sensors incorporated into an optical sensing platform. CSRGs enable real-time sensing due to their unique surface plasmon resonance (SPR)-based light energy exchange, resulting in detection of a very-narrow-bandwidth SPR signal after the elimination of residual incident light. The platform’s sensing ability is experimentally demonstrated by the detection of bulk refractive index (RI) changes, with a bulk sensitivity of 382.2 nm/RIU and a resolution in the order of 10−6 RIU. We also demonstrate, for the first time, CSRG-based real-time selective capture and detection of UPEC in phosphate-buffered saline (PBS) solution, in clinically relevant concentrations, as opposed to other UTI-causing Gram-negative bacteria. The platform’s detection limit is calculated to be 105 CFU/mL (concentration on par with the clinical threshold for UTI diagnosis), with a dynamic range spanning four orders of magnitude. This work paves the way for the development of inexpensive point-of-care diagnosis devices focusing on effective treatment of UTIs, which are a burden on public healthcare due to the rise in the number of cases and their recurrences in the recent past.

scholarly journals Recent insights into the implications of metabolism in plasmacytoid dendritic cell innate functions: Potential ways to control these functions

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 456 ◽  
Author(s):  
Philippe Saas ◽  
Alexis Varin ◽  
Sylvain Perruche ◽  
Adam Ceroi
Keyword(s):  
Dendritic Cells ◽  
Lipid Metabolism ◽  
Nuclear Receptors ◽  
Immune Cells ◽  
Transforming Growth Factor ◽  
Plasmacytoid Dendritic Cell ◽  
Innate Immune ◽  
Type I ◽  
Innate Immune Cells ◽  
Immune Functions

There are more and more data concerning the role of cellular metabolism in innate immune cells, such as macrophages or conventional dendritic cells. However, few data are available currently concerning plasmacytoid dendritic cells (PDC), another type of innate immune cells. These cells are the main type I interferon (IFN) producing cells, but they also secrete other pro-inflammatory cytokines (e.g., tumor necrosis factor or interleukin [IL]-6) or immunomodulatory factors (e.g., IL-10 or transforming growth factor-β). Through these functions, PDC participate in antimicrobial responses or maintenance of immune tolerance, and have been implicated in the pathophysiology of several autoimmune diseases. Recent data support the idea that the glycolytic pathway (or glycolysis), as well as lipid metabolism (including both cholesterol and fatty acid metabolism) may impact some innate immune functions of PDC or may be involved in these functions after Toll-like receptor (TLR) 7/9 triggering. Some differences may be related to the origin of PDC (human versus mouse PDC or blood-sorted versus FLT3 ligand stimulated-bone marrow-sorted PDC). The kinetics of glycolysis may differ between human and murine PDC. In mouse PDC, metabolism changes promoted by TLR7/9 activation may depend on an autocrine/paracrine loop, implicating type I IFN and its receptor IFNAR, explaining a delayed glycolysis. Moreover, PDC functions can be modulated by the metabolism of cholesterol and fatty acids. This may occur via the production of lipid ligands that activate nuclear receptors (e.g., liver X receptor [LXR]) in PDC or through limiting intracellular cholesterol pool size (by statins or LXR agonists) in these cells. Finally, lipid-activated nuclear receptors (i.e., LXR or peroxisome proliferator activated receptor) may also directly interact with pro-inflammatory transcription factors, such as NF-κB. Here, we discuss how glycolysis and lipid metabolism may modulate PDC functions and how this may be harnessed in pathological situations where PDC play a detrimental role.

Sign in / Sign up

Export Citation Format

Share Document