Absence of pro-survival A1 has no impact on inflammatory cell survival in vivo during acute lung inflammation and peritonitis

Author(s):  
Marco Herold ◽  
Lahiru Gangoda ◽  
Robyn Schenk ◽  
Sarah Best ◽  
Christina Nedeva ◽  
...  

Abstract Inflammation is a natural defense mechanism of the body to protect against pathogens. It is induced by immune cells, such as macrophages and neutrophils, which are rapidly recruited to the site of infection, mediating host defense. The processes for eliminating inflammatory cells after pathogen clearance are critical in preventing sustained inflammation which can cause diverse pathologies. During chronic inflammation, excessive and uncontrollable activity of the immune system can cause extensive tissue damage. New therapies aimed at preventing this over-activity of the immune system could have major clinical benefit. Here, we investigated the role of the pro-survival Bcl-2 family member A1 in the survival of inflammatory cells under normal and inflammatory conditions using murine models of lung and peritoneal inflammation. Despite the robust upregulation of A1 protein levels in wild-type cells upon induction of inflammation, the survival of inflammatory cells was not impacted in A1 deficient mice compared to wild-type controls. These findings indicate that A1 does not play a major role in immune cell homeostasis during inflammation and therefore does not constitute a therapeutic target for such morbidities.

2004 ◽  
Vol 72 (7) ◽  
pp. 3849-3854 ◽  
Author(s):  
Brien L. Neudeck ◽  
Jennifer M. Loeb ◽  
Nancy G. Faith ◽  
Charles J. Czuprynski

ABSTRACT Mechanisms by which the intestinal epithelium resists invasion by food-borne pathogens such as Listeria monocytogenes are an evolving area of research. Intestinal P glycoprotein is well known to limit the absorption of xenobiotics and is believed to act as a cytotoxic defense mechanism. The aim of this study was to determine if intestinal P glycoprotein is involved in host defense against L. monocytogenes. Caco-2 cells and a P-glycoprotein-overexpressing subclone (Caco-2/MDR) were employed in addition to mdr1a−/− mice and wild-type controls. In vitro invasion assays and in vivo experiments were employed to measure bacterial invasion and dissemination. In addition, L. monocytogenes proteins were labeled with [35S]methionine, and the transepithelial transport across Caco-2 monolayers was characterized in both directions. Overexpression of P glycoprotein in Caco-2/MDR cells led to increased resistance to L. monocytogenes invasion, whereas P-glycoprotein inhibition led to increased invasion. Flux of [35S]methionine-labeled L. monocytogenes proteins was significantly greater in the basolateral-to-apical direction than in the apical-to-basolateral direction, indicating dependence on an apically located efflux transporter. Moreover, inhibiting P glycoprotein reduced the basolateral-to-apical flux of the proteins. Early dissemination of L. monocytogenes from the gastrointestinal tract was significantly greater in the mdr1a−/− mice than in wild-type controls. Expression and function of intestinal P glycoprotein is an important determinant in resistance to early invasion of L. monocytogenes.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Gheed Al-Hity ◽  
FengWei Yang ◽  
Eduard Campillo-Funollet ◽  
Andrew E. Greenstein ◽  
Hazel Hunt ◽  
...  

AbstractInvestigational in vitro models that reflect the complexity of the interaction between the immune system and tumours are limited and difficult to establish. Herein, we present a platform to study the tumour-immune interaction using a co-culture between cancer spheroids and activated immune cells. An algorithm was developed for analysis of confocal images of the co-culture to evaluate the following quantitatively; immune cell infiltration, spheroid roundness and spheroid growth. As a proof of concept, the effect of the glucocorticoid stress hormone, cortisol was tested on 66CL4 co-culture model. Results were comparable to 66CL4 syngeneic in vivo mouse model undergoing psychological stress. Furthermore, administration of glucocorticoid receptor antagonists demonstrated the use of this model to determine the effect of treatments on the immune-tumour interplay. In conclusion, we provide a method of quantifying the interaction between the immune system and cancer, which can become a screening tool in immunotherapy design.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kyle S. Feldman ◽  
Eunwon Kim ◽  
Michael J. Czachowski ◽  
Yijen Wu ◽  
Cecilia W. Lo ◽  
...  

AbstractRespiratory mucociliary clearance (MCC) is a key defense mechanism that functions to entrap and transport inhaled pollutants, particulates, and pathogens away from the lungs. Previous work has identified a number of anesthetics to have cilia depressive effects in vitro. Wild-type C57BL/6 J mice received intra-tracheal installation of 99mTc-Sulfur colloid, and were imaged using a dual-modality SPECT/CT system at 0 and 6 h to measure baseline MCC (n = 8). Mice were challenged for one hour with inhalational 1.5% isoflurane, or intraperitoneal ketamine (100 mg/kg)/xylazine (20 mg/kg), ketamine (0.5 mg/kg)/dexmedetomidine (50 mg/kg), fentanyl (0.2 mg/kg)/1.5% isoflurane, propofol (120 mg/Kg), or fentanyl/midazolam/dexmedetomidine (0.025 mg/kg/2.5 mg/kg/0.25 mg/kg) prior to MCC assessment. The baseline MCC was 6.4%, and was significantly reduced to 3.7% (p = 0.04) and 3.0% (p = 0.01) by ketamine/xylazine and ketamine/dexmedetomidine challenge respectively. Importantly, combinations of drugs containing fentanyl, and propofol in isolation did not significantly depress MCC. Although no change in cilia length or percent ciliation was expected, we tried to correlate ex-vivo tracheal cilia ciliary beat frequency and cilia-generated flow velocities with MCC and found no correlation. Our results indicate that anesthetics containing ketamine (ketamine/xylazine and ketamine/dexmedetomidine) significantly depress MCC, while combinations containing fentanyl (fentanyl/isoflurane, fentanyl/midazolam/dexmedetomidine) and propofol do not. Our method for assessing MCC is reproducible and has utility for studying the effects of other drug combinations.


1984 ◽  
Vol 4 (4) ◽  
pp. 813-816
Author(s):  
A Barkan ◽  
J E Mertz

The size distributions of polyribosomes containing each of three simian virus 40 late 16S mRNA species that differ in nucleotide sequence only within their leaders were determined. The two 16S RNA species with shorter leaders were incorporated into polysomes that were both larger (on average) and narrower in size distribution than was the predominant wild-type 16S RNA. Therefore, the nucleotide sequence of the leader can influence the number of ribosomes present on the body of an mRNA molecule. We propose a model in which the excision from leaders of sizeable translatable regions permits more frequent utilization of internally located translation initiation signals, thereby enabling genes encoded within the bodies of polygenic mRNAs to be translated at higher rates. In addition, the data provide the first direct evidence that VP1 can, indeed, be synthesized in vivo from the species of 16S mRNA that also encodes the 61-amino acid leader protein.


2021 ◽  
Author(s):  
Tania HIDALGO ◽  
Rosana Simón-Vázquez ◽  
africa González-Fernández ◽  
Patricia Horcajada

Human body is continuously in a never-ending chess game against pathogens. When the immune system, our natural defense tool, is weakened, these organisms are able to escape, collapsing the body...


2010 ◽  
Vol 10 ◽  
pp. 818-831 ◽  
Author(s):  
Hiroyuki Seki ◽  
Takaharu Sasaki ◽  
Tomomi Ueda ◽  
Makoto Arita

Inflammation is the first response of the immune system to infection or injury, but excessive or inappropriate inflammatory responses contribute to a range of acute and chronic human diseases. Clinical assessment of dietary supplementation of ω-3 polyunsaturated fatty acids (i.e., eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) indicate that they have beneficial impact on these diseases, although the mechanisms are poorly understood at the molecular level. In this decade, it has been revealed that EPA and DHA are enzymatically converted to bioactive metabolites in the course of acute inflammation and resolution. These metabolites were shown to regulate immune cell functions and to display potent anti-inflammatory actions bothin vitroandin vivo. Because of their ability to resolve an acute inflammatory response, they are referred to as proresolving mediators, or resolvins. In this review, we provide an overview of the formation and actions of these lipid mediators.


2017 ◽  
Vol 95 (1) ◽  
pp. 69-75 ◽  
Author(s):  
Kei-ichi Shimazaki ◽  
Kazuhiro Kawai

Lactoferrin is a multifunctional, iron-binding glycoprotein found in milk and other exocrine secretions. Lactoferrin in milk plays vital roles in the healthy development of newborn mammals, and is also an innate resistance factor involved in the prevention of mammary gland infection by microorganisms. Inflammation of the udder because of bacterial infection is referred to as mastitis. There have been many investigations into the relationships between lactoferrin and mastitis, which fall into several categories. The main categories are fluctuations in the lactoferrin concentration of milk, lactoferrin activity against mastitis pathogens, elucidation of the processes underlying the onset of mastitis, participation of lactoferrin in the immune system, and utilization of lactoferrin in mastitis treatment and prevention. This minireview describes lactoferrin research concerning bovine mastitis. In the 1970s, many researchers reported that the lactoferrin concentration fluctuates in milk from cows with mastitis. From the late 1980s, many studies clarified the infection-defense mechanism in the udder and the contribution of lactoferrin to the immune system. After the year 2000, the processes underlying the onset of mastitis were elucidated in vivo and in vitro, and lactoferrin was applied for the treatment and prevention of mastitis.


2018 ◽  
Vol 400 (1) ◽  
pp. 63-75 ◽  
Author(s):  
Sander Bekeschus ◽  
Christian Seebauer ◽  
Kristian Wende ◽  
Anke Schmidt

AbstractLeukocytes are professionals in recognizing and removing pathogenic or unwanted material. They are present in virtually all tissues, and highly motile to enter or leave specific sites throughout the body. Less than a decade ago, physical plasmas entered the field of medicine to deliver their delicate mix of reactive species and other physical agents for mainly dermatological or oncological therapy. Plasma treatment thus affects leukocytes via direct or indirect means: immune cells are either present in tissues during treatment, or infiltrate or exfiltrate plasma-treated areas. The immune system is crucial for human health and resolution of many types of diseases. It is therefore vital to study the response of leukocytes after plasma treatmentin vitroandin vivo. This review gathers together the major themes in the plasma treatment of innate and adaptive immune cells, and puts these into the context of wound healing and oncology, the two major topics in plasma medicine.


2003 ◽  
Vol 285 (5) ◽  
pp. H2240-H2247 ◽  
Author(s):  
Elizabeth A. Nunamaker ◽  
Hai-Ying Zhang ◽  
Yuichi Shirasawa ◽  
Joseph N. Benoit ◽  
David A. Dean

The development of inexpensive and effective approaches to transiently decrease gene expression in vivo would be useful for the study of physiological processes in living animals. DNAzymes are a novel class of DNA oligonucleotides that can catalytically cleave target mRNAs and thereby reduce protein production. However, current methods for their delivery in vivo are limited and inefficient. In this study, we show that electroporation can be used to deliver DNAzymes to the intact mesenteric vasculature of rats. With the use of PKC-ϵ as a target, a set of wild-type and mutant control DNAzymes was designed and shown to reduce both PKC-ϵ mRNA and protein levels in cultured smooth muscle cells in a specific manner. The wild-type DNAzyme reduced PKC-ϵ protein levels by 70% at 24 h in two different cell lines without decreasing the levels of the five other PKC isoforms tested. When delivered to the intact vasculature using electroporation, the DNAzyme reduced PKC-ϵ protein levels by >60% without affecting these other PKC isoforms. Electroporation was required for oligonucleotide transfer and was able to deliver the DNAzymes to multiple cell layers in the vessel wall. Protein levels were reduced maximally by 24 h postelectroporation and returned to normal by 48 h. These results suggest that electroporation can be used to deliver DNAzymes and other DNA oligonucleotides to the vasculature in vivo and can decrease gene expression for a window of time that can be used for experimental studies.


Cancers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3247
Author(s):  
Kumar Nikhil ◽  
Mohini Kamra ◽  
Asif Raza ◽  
Hanan S. Haymour ◽  
Kavita Shah

SPOP, an adaptor protein for E3 ubiquitin ligase can function as a tumor-suppressor or a tumor-enhancer. In castration-resistant prostate cancer (CRPC), it inhibits tumorigenesis by degrading many oncogenic targets, including androgen receptor (AR). Expectedly, SPOP is the most commonly mutated gene in CRPC (15%), which closely correlates with poor prognosis. Importantly, 85% of tumors that retain wild-type SPOP show reduced protein levels, indicating that SPOP downregulation is an essential step in CRPC progression. However, the underlying molecular mechanism remains unknown. This study uncovered the first mechanism of SPOP regulation in any type of cancer. We identified SPOP as a direct substrate of Aurora A (AURKA) using an innovative technique. AURKA directly phosphorylates SPOP at three sites, causing its ubiquitylation. SPOP degradation drives highly aggressive oncogenic phenotypes in cells and in vivo including stabilizing AR, ARv7 and c-Myc. Further, SPOP degrades AURKA via a feedback loop. SPOP upregulation is one of the mechanisms by which enzalutamide exerts its efficacy. Consequently, phospho-resistant SPOP fully abrogates tumorigenesis and EMT in vivo, and renders CRPC cells sensitive to enzalutamide. While genomic mutations of SPOP can be treated with gene therapy, identification of AURKA as an upstream regulator of SPOP provides a powerful opportunity for retaining WT-SPOP in a vast majority of CRPC patients using AURKA inhibitors ± enzalutamide, thereby treating the disease and inhibiting its progression.


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