scholarly journals Characterization of a cyclophosphamide-induced murine model of immunosuppression to study Acinetobacter baumannii pathogenesis

2013 ◽  
Vol 62 (11) ◽  
pp. 1747-1754 ◽  
Author(s):  
Swetha Manepalli ◽  
Jay A. Gandhi ◽  
Vaibhav V. Ekhar ◽  
Melissa B. Asplund ◽  
Carolina Coelho ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Murine Model ◽  
Cell Function ◽  
Immune Cell ◽  
Systemic Disease ◽  
Negative Bacterium ◽  
Airway Protection ◽  
Skin Integrity ◽  
Public Health Strategies

Acinetobacter baumannii is a Gram-negative bacterium that opportunistically infects critically ill hospitalized patients with breaches in skin integrity and airway protection, leading to significant morbidity and mortality. Considering the paucity of well-established animal models of immunosuppression to study A. baumannii pathogenesis, we set out to characterize a murine model of immunosuppression using the alkylating agent cyclophosphamide (CYP). We hypothesized that CYP-induced immunosuppression would increase the susceptibility of C57BL/6 mice to developing A. baumannii-mediated pneumonia followed by systemic disease. We demonstrated that CYP intensified A. baumannii-mediated pulmonary disease, abrogated normal immune cell function and led to altered pro-inflammatory cytokine release. The development of an animal model that mimics A. baumannii infection onset in immunosuppressed individuals is crucial for generating novel approaches to patient care and improving public health strategies to decrease exposure to infection for individuals at risk.

scholarly journals The ClpXP Protease Contributes to Staphylococcus aureus Pneumonia

2020 ◽  
Vol 222 (8) ◽  
pp. 1400-1404 ◽  
Author(s):  
Gyu-Lee Kim ◽  
Lavoisier Akoolo ◽  
Dane Parker
Keyword(s):  
Staphylococcus Aureus ◽  
Respiratory Tract ◽  
Murine Model ◽  
Protein Turnover ◽  
Immune Cell ◽  
Acute Pneumonia ◽  
Staphylococcus Aureus Pneumonia

Abstract Staphylococcus aureus is a leading cause of pneumonia. We show here that the ClpXP protease involved in protein turnover is important for pathogenesis in a murine model of acute pneumonia. Staphylococcus aureus lacking this protease is attenuated in vivo, being rapidly cleared from the airway and leading to decreased immune cell influx and inflammation. Characterization of defined mutations in vitro identified defects in intracellular survival and protection against neutrophil killing. Our results further expand on what is known about ClpXP in the pathogenesis of S. aureus to include the respiratory tract.

scholarly journals Phenotypic and molecular characterization of Acinetobacter baumannii clinical isolates in Saudi Arabia

2020 ◽  
Vol 13 (2) ◽  
pp. 327
Author(s):  
R Bawazeer ◽  
M Algoribi ◽  
T Abujamel ◽  
L Okdah ◽  
M Alzayer ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
Acinetobacter Baumannii ◽  
Molecular Characterization ◽  
Clinical Isolates

scholarly journals The Role of Cancer-Associated Fibroblasts in Tumor Progression

Cancers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1399
Author(s):  
Rushikesh S. Joshi ◽  
Samanvi S. Kanugula ◽  
Sweta Sudhir ◽  
Matheus P. Pereira ◽  
Saket Jain ◽  
...  
Keyword(s):  
Cancer Treatment ◽  
Tumor Progression ◽  
Cancer Progression ◽  
Immune Cell ◽  
Systemic Disease ◽  
Genomic Medicine ◽  
Therapeutic Targets ◽  
Therapy Resistance ◽  
Cancer Associated Fibroblasts ◽  
Breast Cancers

In the era of genomic medicine, cancer treatment has become more personalized as novel therapeutic targets and pathways are identified. Research over the past decade has shown the increasing importance of how the tumor microenvironment (TME) and the extracellular matrix (ECM), which is a major structural component of the TME, regulate oncogenic functions including tumor progression, metastasis, angiogenesis, therapy resistance, and immune cell modulation, amongst others. Within the TME, cancer-associated fibroblasts (CAFs) have been identified in several systemic cancers as critical regulators of the malignant cancer phenotype. This review of the literature comprehensively profiles the roles of CAFs implicated in gastrointestinal, endocrine, head and neck, skin, genitourinary, lung, and breast cancers. The ubiquitous presence of CAFs highlights their significance as modulators of cancer progression and has led to the subsequent characterization of potential therapeutic targets, which may help advance the cancer treatment paradigm to determine the next generation of cancer therapy. The aim of this review is to provide a detailed overview of the key roles that CAFs play in the scope of systemic disease, the mechanisms by which they enhance protumoral effects, and the primary CAF-related markers that may offer potential targets for novel therapeutics.

scholarly journals OP0013 SEX DIFFERENCES IN AUTOIMMUNE DISEASE SUSCEPTIBILITY; A MULTI-OMIC APPROACH

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 8.1-8
Author(s):  
G. Robinson ◽  
K. Waddington ◽  
J. Peng ◽  
A. Radziszewska ◽  
H. Peckham ◽  
...  
Keyword(s):  
Sex Differences ◽  
Lipid Metabolism ◽  
Sex Hormones ◽  
Cell Function ◽  
Immune Cell ◽  
Density Lipoprotein ◽  
Hormone Treatment ◽  
Immune Cell Function ◽  
Immune Cell Subsets ◽  
Males And Females

Background:Males and females have altered immune responses resulting in variation in autoimmune and cardiovascular disease risk (CVR). Recently, these differences have played a role in the inflammatory response to COVID-19. Sex differences exist in the frequency and activity of immune-cell subsets but mechanisms underlying sexual dimorphism remain unknown. Juvenile-onset systemic lupus erythematosus (JSLE) is an autoimmune disorder that commonly emerges during puberty, has a strong female prevalence (female:male ratio, 4.5:1) and results in an increased CVR. JSLE is characterised by chronic inflammation and dyslipidaemia, where cardiovascular disease is a leading cause of mortality for patients. Our previous work identified a link between immune cell function and lipid metabolism in adult-onset SLE. We hypothesised that sex hormones could influence both lipid metabolism and immune cell function and this could determine sex-specific susceptibility to JSLE and associated CVR.Objectives:We investigated the role of sex hormones in modifying systemic lipid metabolism and inflammation.Methods:Nuclear magnetic resonance spectroscopy based serum metabolomics measuring over 130 lipoproteins (14-subsets with lipid compositions), flow cytometry measuring immune-cells, and RNA-sequencing were used to assess the metabolic and immune profile in young, pre/post-pubertal males (n=10/17) and females (n=10/23) and in individuals with gender-dysphoria (GD) under cross-hormone treatment (trans-male/female, n=26/25). This analysis was also performed on a cohort of post-pubertal male (n=12) and female (n=23) JSLE patients. Data was analysed by logistic regression, balanced random forest machine learning (BRF-ML), differential gene expression (DEG) and pathway analysis.Results:Post-pubertal males had significantly reduced cardio-protective high-density lipoprotein (HDL) subsets (p<0.0001) and increased cardio-pathogenic very-low-density lipoprotein subsets (p<0.0001) compared to females. These differences were not observed pre-puberty and were reversed significantly by cross-hormone treatment in GD individuals, suggesting that sex hormones regulate lipid metabolism in-vivo.BRF-ML (28 immune-cell subsets) identified an increased frequency of anti-inflammatory regulatory T-cells (Tregs) in post-pubertal males compared to females (p=0.0097). These Tregs were also more suppressive in males compared to females. Differences in Treg frequency were seen pre-puberty and were not altered by sex hormone treatment in GD individuals. However, Treg DEGs and functional transcriptomic pathways altered between post-pubertal males and females, including those involved in inflammatory signalling, overlapped with those altered by hormones in GD, suggesting hormones may also drive Treg functional changes. In addition, HDL metabolites modified by hormones showed differential associations with Treg phenotypes between post-pubertal males and females.Strikingly, sex differences in lipoproteins and Tregs were lost in JSLE, suggesting hormone signalling could be dysregulated in the pathogenesis of autoimmunity and could increase CVR for patients.Conclusion:Sex hormones drive altered lipoprotein metabolism and functional transcriptomic pathways in Tregs. Males have a lipoprotein profile associated with increased CVR, but a more anti-inflammatory immune profile compared to females. Together, this could explain sex differences in inflammatory disease susceptibilities and inform future sex-specific therapeutic strategies for the management of both JSLE and CVR.Acknowledgements:Lupus UKRosetrees TrustVersus ArthritisNIHR UCLH Biomedical Research CentreDisclosure of Interests:None declared

scholarly journals Synthesis and Characterization of Exopolysaccharide Encapsulated PCL/Gelatin Skin Substitute for Full-Thickness Wound Regeneration

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 854
Author(s):  
Ahmad Hivechi ◽  
Peiman Brouki Milan ◽  
Khashayar Modabberi ◽  
Moein Amoupour ◽  
Kaveh Ebrahimzadeh ◽  
...  
Keyword(s):  
Cell Activity ◽  
Average Diameter ◽  
Skin Substitute ◽  
Full Thickness ◽  
Skin Integrity ◽  
Hematoxylin And Eosin ◽  
First Time ◽  
Full Thickness Wound

Loss of skin integrity can lead to serious problems and even death. In this study, for the first time, the effect of exopolysaccharide (EPS) produced by cold-adapted yeast R. mucilaginosa sp. GUMS16 on a full-thickness wound in rats was evaluated. The GUMS16 strain’s EPS was precipitated by adding cold ethanol and then lyophilized. Afterward, the EPS with polycaprolactone (PCL) and gelatin was fabricated into nanofibers with two single-needle and double-needle procedures. The rats’ full-thickness wounds were treated with nanofibers and Hematoxylin and eosin (H&E) and Masson’s Trichrome staining was done for studying the wound healing in rats. Obtained results from SEM, DLS, FTIR, and TGA showed that EPS has a carbohydrate chemical structure with an average diameter of 40 nm. Cell viability assessments showed that the 2% EPS loaded sample exhibits the highest cell activity. Moreover, in vivo implantation of nanofiber webs on the full-thickness wound on rat models displayed a faster healing rate when EPS was loaded into a nanofiber. These results suggest that the produced EPS can be used for skin tissue engineering applications.

scholarly journals Recombinant Production and Characterization of an Extracellular Subtilisin-Like Serine Protease from Acinetobacter baumannii of Fermented Food Origin

2021 ◽  
Author(s):  
Nur Syafiqah Muhammed ◽  
Nurulfarhana Hussin ◽  
Aik Siang Lim ◽  
Mohd Anuar Jonet ◽  
Shaza Eva Mohamad ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Serine Protease ◽  
Fermented Food ◽  
Recombinant Production

scholarly journals Pre-Transplant Immune Cell Function Assay as a Predictor of Early Cardiac Allograft Rejection

2021 ◽  
Vol 40 (4) ◽  
pp. S232-S233
Author(s):  
S.D. Maidman ◽  
C. Gidea ◽  
A. Reyentovich ◽  
S. Rao ◽  
T. Saraon ◽  
...  
Keyword(s):  
Allograft Rejection ◽  
Cell Function ◽  
Immune Cell ◽  
Cardiac Allograft ◽  
Immune Cell Function ◽  
Cardiac Allograft Rejection

scholarly journals 492 Integration of high dimensional datasets in an immunocompetent mammary mouse model reveals pathways of tolerance and resistance to immune checkpoint blockade

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A528-A528
Author(s):  
Lin Ma ◽  
Jian-Hua Mao ◽  
Mary Helen Barcellos-Hoff ◽  
Jade Moore
Keyword(s):  
Tumor Microenvironment ◽  
Immune Cells ◽  
Transforming Growth Factor ◽  
Immune Cell ◽  
Systemic Disease ◽  
Ct Imaging ◽  
High Dimensional ◽  
Cytokine Signaling ◽  
Immune Infiltrate ◽  
Pet Ct

BackgroundCheckpoint inhibitors can induce robust and durable responses in a subset of patients. Extending this benefit to more patients could be facilitated by better understanding of how interacts with immune cells with the tumor microenvironment, which is a critical barrier to control both local and systemic disease. The composition and pattern of the immune infiltrate associates with the likelihood of response to immunotherapy. Inflamed tumors that exhibit a brisk immune cell infiltrate are responsive, while those in which immune cells are completely or partially excluded are not. Transforming growth factor β (TGFβ) is immunosuppressive and associated with the immune excluded phenotype.MethodsUsing an immune competent mammary tumor derived transplant (mTDT) model recently developed in our lab, exhibits inflamed, excluded or deserts immune infiltrate phenotypes based on localization of CD8 lymphocytes. Using whole transcriptome deep sequencing, cytof, and PET-CT imaging, we evaluated the tumor, microenvironment, and immune pathway activation among immune infiltrate phenotypes.ResultsThree distinct inflamed tumors phenotypes were identified: ‘classically’ inflamed characterized by pathway evidence of increased CD8+ T cells and decreased PD-L1 expression, inflamed tumors with pathways indicative of neovascularization and STAT3 signaling and reduced T cell mobilization, and an inflamed tumor with increased immunosuppressive myeloid phenotypes. Excluded tumors were characterized by TGFβ gene expression and pro-inflammatory cytokine signaling (e.g. TNFα, IL1β), associated with decreased leukocytes homing and increased immune cell death of cells. We visualized and quantified TGFβ activity using PET-CT imaging of 89Zr-fresolimumab, a TGFβ neutralizing antibody. TGFβ activity was significantly increased in excluded tumors compared to inflamed or desert tumors, which was supported by quantitative pathology (Perkin Elmer) of its canonical signaling target, phosphorylated SMAD2 (pSMAD2). pSMAD2 was positively correlated with PD-L1 expression in the stroma of excluded tumors. In contrast, in inflamed tumors, TGFβ activity positively correlated with increased F4/80 positive macrophages and negatively correlated with expression of PD-L1. CyTOF analysis of tumor and spleen immune phenotypes revealed increased trafficking of myeloid cells in mice bearing inflamed tumors compared to excluded and deserts.ConclusionsThe immunocompetent mTDT provides a model that bridges the gap between the immune landscape and tumor microenvironment. Integration of these high-dimensional data with further studies of response to immunotherapies will help to identify tumor features that favor response to treatment or the means to convert those that are unresponsive.

Sign in / Sign up

Export Citation Format

Share Document