مجال التميز | تميز دراسي وبحثي + جائزة تفوقية |
البحوث المنشورة |
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البحث (1): | |
عنوان البحث: |
Gamma Interferon and Interleukin-17A Differentially Influence the Response of Human Macrophages and Neutrophils to Pseudomonas aeruginosa Infection |
رابط إلى البحث: | |
تاريخ النشر: |
24/01/2019 |
موجز عن البحث: |
Macrophages are important orchestrators of inflammation during bacterial infection, acting as both effector cells and regulators of neutrophil recruitment and life span. Differently activated macrophage populations with distinct inflammatory and microbicidal potentials have been described. Our previous work unveiled a positive and a negative correlation between levels of gamma interferon (IFN-) and interleukin-17A (IL-17A), respectively, and lung function in cystic fibrosis, particularly in patients chronically infected with Pseudomonas aeruginosa. This study sought to define key parameters in human antibacterial immunity under Th1- and Th17-dominated inflammatory conditions; the final aim was to identify unique characteristics that could be fine-tuned therapeutically to minimize tissue damage while maximizing bacterial clearance. Toward this aim, neutrophils were incorporated into cultures of macrophages treated with IFN- or IL-17A and infected with P. aeruginosa. The intent of this design was to model (i) initiation of inflammation by infected macrophages and (ii) delayed arrival of neutrophils and their exposure to macrophage-derived cytokines. Under these conditions, IFN- decreased bacterial killing and promoted the production of monocyte chemoattractant protein 1 (MCP-1). In contrast, IL-17A promoted bacterial killing but did not affect MCP-1 production. The level of secretion of the pyrogen IL-1 was significantly lower in the presence of IFN- than in the presence of IL-17A and correlated with levels of the IL1B transcript in infected macrophages. These findings support the validity of this model to investigate human antibacterial immunity. Based on these observations, the protective and damaging roles of IFN- and IL-17A, respectively, during P. aeruginosa infection could be caused by their contrasting effects on IL-1 and MCP-1 production. |
المؤتمرات العلمية |
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المؤتمر (1): | |
عنوان المؤتمر: |
The 5th young microbiologist symposium |
تاريخ الإنعقاد: |
27-28/08/2018 |
مكان الإنعقاد: |
Belfast, UK |
طبيعة المشاركة: |
Poster presentation |
عنوان المشاركة: |
The interaction between Pseudomonas aeruginosa biofilms and neutrophils |
ملخص المشاركة: |
Colonisation and chronic lung infection by the opportunistic pathogen Pseudomonas aeruginosa (PA) is the leading cause of morbidity and mortality in cystic fibrosis patients (CF). A critical key determinant of PA pathogenicity is the switch from planktonic to biofilm mode of growth which facilitates chronic infections and makes PA eradication extremely difficult. The overarching aim of this project is to investigate the interplay between PA and innate immune cells and how it is affected by biofilm formation. Myeloid cells express C-type lectin-like receptors (CTLR) that function as pattern recognition receptors for several classes of pathogens. Previous work in the lab has indicated that PA biofilms bind the CTLD4-7 region of the mannose receptor (MR) and extracellular region of DC-SIGN. In addition MR and DC-SIGN recognise purified Psl, a key component of the biofilm matrix (EPS). We hypothesized that Dectin-2, another important C-type lectin expressed, among others by neutrophils, might also contribute to the recognition of PA biofilms by immune cells by binding to EPS components, in particular Psl. Investigation of the interplay between PA and innate immune cells and how it is affected by biofilm formation will give us an insight into novel approaches to combat PA infection. |
المؤتمر (2): | |
عنوان المؤتمر: |
The 6th European Congress on Biofilms, EUROBIOFILMS 2019 |
تاريخ الإنعقاد: |
03/09/2019 |
مكان الإنعقاد: |
Glasgow, UK |
طبيعة المشاركة: |
Poster presentation |
عنوان المشاركة: |
Modulation of immune cell activation by Pseudomonas aeruginosa biofilms; potential role of C-type lectin receptors |
ملخص المشاركة: |
Introduction: Bacteria are ubiquitous and they may cause clinical infections (e.g., in catheters), corrosion, loss of efficiency in different processes (e.g., water process). Nowadays, many strategies are used to control microbial growth and development (e.g., antibiotics, UV light, etc.). Nevertheless, when bacteria are in the vicinity of an interface they start to grow as a biofilm, producing the extracellular polymeric substances, becoming more resistant and less susceptible to biocides and disinfectants. An alternative solution could be the utilization of visible light to inactivate microbial biofilms, in particular violet light at 400 nm. Hypothesis and aims: The interaction of photons with defined energy causes the cell death. Light produces reactive oxygen species dangerous for the cells. The goal of this work is to investigate the killing effect of a specific wavelength. The use of light emitting diodes represents a future perspective for the realization of devices based on lower consumptions that do not use chemistry. Methodology: Biofilms of P. fluorescens are grown on a polystyrene surface. They are exposed to the light treatment with a high tech device with 400 nm of wavelength. Inactivation of microorganisms is carried out and the Geeraerd et al. (2000) model is used to fit the data. Different irradiances are tested. The inactivation parameters are estimated using Geeraerd et al. (2000) model. Results: The wavelength 400 nm in the VIS region is able to inactivate P. fluorescens when it is grown as biofilm. The maximum specific inactivation rate seems not to be affected by the irradiance, while the residual population depends on the irradiance emitted by the LEDs. Conclusion: P. fluorescens biofilms can be successfully inactivated by means of 400 nm light. |
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جوائز التكريم |
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الجائزة (1): | |
مسمى الجائزة: |
School of life sciences postgraduate research symposium certificate |
الجهة المانحة: |
University of Nottingham |
تاريخ الجائزة: |
25/06/2019 |
مجال التكريم: |
The certificate was presented to the student in recognition of Outstanding research presentation. |
ياسر صالح ابراهيم المهنا
دكتوراه
الطب والخدمات الصحية
University of Nottingham