Biochemistry, Biophysics, and Structural Biology Commons^™

Immunoproteomics: The Key To Discovery Of New Vaccine Antigens Against Bacterial Respiratory Infections, Ruth Dennehy, Siobhan Mcclean

Articles

The increase in antibiotic resistance and the shortage of new antimicrobials to prevent difficult bacterial infections underlines the importance of prophylactic therapies to prevent infection by bacterial pathogens. Vaccination has reduced the incidence of many serious diseases, including respiratory bacterial infections. However, there are many pathogens for which no vaccine is available and some vaccines are not effective among all age groups or among immunocompromised individuals. Immunoproteomics is a powerful technique which has been used to identify potential vaccine candidates to protect against pathogenic bacteria. The combination of proteomics with the detection of immunoreactive antigens using serum highlights immunogenic proteins …

Inhibition Of Burkholderia Multivorans Adhesion To Lung Epithelial Cells By Bivalent Lactosides, Ciara Wight, Rosaria Leyden, Paul V. Murphy, Máire Callaghan, Trinidad Velasco-Torrijos, Siobhan Mcclean

Articles

Burkholderia cepacia complex (Bcc) is an opportunistic pathogen in cystic fibrosis patients which is inherently resistant to antimicrobial agents. The mechanisms of attachment and pathogenesis of Bcc, a group of 17 species, are poorly understood. The most commonly identified Bcc species in newly colonised patients, Burkholderia multivorans, continues to be acquired from the environment. Development of therapies which can prevent or reduce the risk of colonization on exposure to Bcc in the environment would be a better alternative to antimicrobial agents. Previously, it has been shown that Bcc strains bound to many glycolipid receptors on lung epithelia. Using a …

Interaction Of Environmental B. Cenocepacia Strains With Cystic Fibrosis And Non-Cystic Fibrosis Bronchial Epithelial Cells In Vitro., Annamaria Bevivino, Luisa Pirone, Ruth Pilkington, Noemi Cifani, Claudia Dalmastri, Máire Callaghan, Fiorentina Ascenzioni, Siobhan Mcclean

Articles

Burkholderia cenocepacia is an important human pathogen in patients with cystic fibrosis (CF). Non-clinical reservoirs may play a role in the acquisition of infections, so it is important to evaluate the pathogenic potential of environmental B. cenocepacia isolates. In this study, we investigated the interactions of two environmental B. cenocepacia strains (Mex1 and MCII-168) with two bronchial epithelial cell lines,16HBE14o- and CFBE41o-, which have a non-CF and a CF phenotype, respectively.

The environmental strains showed a significantly lower level of invasion into both CF- and non-CF cells in comparison with the clinical B. cenocepacia LMG16656^T strain. Exposure of polarized …

Bacterial Host Interactions In Cystic Fibrosis, Máire Callaghan, Siobhan Mcclean

Articles

Chronic infection is a hallmark of cystic fibrosis (CF) and the main contributor to morbidity. Microbial infection in CF is complex, due to the number of different species that colonise the CF lung. Their colonisation is facilitated by a host response that is impaired or compromised by highly viscous mucous, zones of hypoxia and the lack of the cystic fibrosis transmembrane regulator (CFTR). Successful dominant CF pathogens combine an effective arsenal to establish infection and counter-attack the host response, together with an ability to adapt readily to an unfavourable environment. Hypermutability is common among CF pathogens facilitating adaptation and as …

The Speed Of Sound And Attenuation Of An Iec Agar-Based Tissue-Mimicking Material For High Frequency Ultrasound Applications, Chao Sun, Stephen Pye, Jacinta Browne, Anna Janeczko, Bill Ellis, Mairead Butler, Vassilis Sboros, Adrain Thomson, Mark Brewin, Charles Earnshaw, Carmel Moran

Articles

No abstract provided.

Quantitative Reagent-Free Detection Of Fibrinogen Levels In Human Blood Plasma Using Raman Spectroscopy, Kelvin Poon, Fiona Lyng, Peter Knief, Orla L. Howe, Aidan Meade, James Curtin, Hugh Byrne, Joseph Vaughan

Articles

Fibrinogen assays are commonly used as part of clinical screening tests to investigate haemorrhagic states, for detection of disseminated intravascular coagulation and as a predictor of a variety of cardiovascular events. The Clauss assay, which measures thrombin clotting time, is the most commonly used method for measuring fibrinogen levels. Nevertheless, inconsistencies are present in inter-manufacturer reagent sources, calibration standards and methodologies. Automated coagulation analysers, which measure changes in optical density during the prothrombin time (PT-Fg), have found use in many hospitals. However, the PT-Fg method is found to give falsely elevated values due to varying choices of calibrants, reagents and …

Combretazet-3 A Novel Synthetic Cis-Stable Combretastatin-A4-Azetidinone Hybrid With Enhanced Stabilityand Therapeutic Efficacy In Colon Cancer, Lisa M. Greene, Shu Wang, Niamh O'Boyle, Sandra A. Bright, Jane E. Reid, Patrick Kelly, Mary J. Meegan, Daniela M. Zisterer

Articles

In recent years an extensive series of synthetic combretastatin A-4 (CA-4)-azetidinone (β-lactam) hybrids were designed and synthesised with a view to improve the stability, therapeutic efficacy and aqueous solubility of CA-4. Lead compounds containing a 3,4,5-trimethoxy aromatic ring at position 1 and a variety of substitution patterns at positions 3 and 4 of the β-lactam ring were screened in three adenocarcinoma-derived colon cancer cell lines (CT-26, Caco-2 and the CA-4 resistant cell line, HT-29). In both CT-26 and Caco-2 cells all β-lactam analogues analysed displayed potent therapeutic efficacy within the nanomolar range. Substitution of the ethylene bridge of CA-4 with …

Activation Of Mmp-9 By Human Lung Epithelial Cells In Response To The Cystic Fibrosis-Associated Pathogen Burkholderia Cenocepacia Reduced Wound Healing In Vitro, Ciara Wright ], Ruth Pilkington, Máire Callaghan, Siobhan Mcclean

Articles

Burkholderia cepacia complex is a group of bacterial pathogens that cause opportunistic infections in cystic fibrosis (CF). The most virulent of these is Burkholderia cenocepacia. Matrix metalloproteinases (MMPs) are upregulated in CF patients. The aim of this work was to examine the role of MMPs in the pathogenesis of B. cepacia complex, which has not been explored to date. Real-time PCR analysis showed that B. cenocepacia infection upregulated MMP-2 and MMP-9 genes in the CF lung cell line CFBE41o- within 1 h, whereas MMP-2, -7, and -9 genes were upregulated in the non-CF lung cell line 16HBE14o-. Conditioned media from …

Expression Of Genes Involved In A Radiation-Induced Bystander Effect, Hayley Furlong

Conference Papers

The radiation induced bystander effect is relevant to carcinogenesis, it may have significant implications for risk estimation for radiation exposure. Currently the mechanisms and cellular events are the subject of intense investigation, because little is known. It is thought that the radiation induced bystander response is due to a bystander factor secreted in the medium post irradiation. However the biological nature of this factor is currently unknown, but it is thought to be a protein of some sort that may be involved in the apoptosis cascade. Materials and Methods: HaCaT epithelial cells were used in this study and exposed to …

Differential Precipitation And Solubilization Of Proteins., Barry Ryan

Books/Book Chapters/ Proceedings

Differential protein precipitation is a rapid and economical step in protein purification and is based on exploiting the inherent physico-chemical properties of the polypeptide. Precipitation of recombinant proteins, lysed from the host cell, is commonly used to concentrate the protein of choice before further polishing steps with more selective purification columns (e.g. His-Tag, Size Exclusion etc.). Recombinant proteins can also precipitate naturally as inclusion bodies due to various influences during over-expression in the host cell. Although this phenomenon permits easier initial separation from native proteins, these inclusion bodies must carefully be differentially solubilised so as to reform functional, correctly folded …

Collagen Matrices As An Improved Model For In Vitro Study Of Live Cells Using Raman Microspectroscopy, Franck Bonnier, Peter Knief, Aidan Meade, Jennifer Dorney, Kunal Bhattacharya, Fiona Lyng, Hugh Byrne

Conference papers

Due to its high lateral resolution, Raman microspectrsocopy is rapidly becoming an accepted technique for the subcellular imaging of single cells. Although the potential of the technique has frequently been demonstrated, many improvements have still to be realised to enhance the relevancy of the data collected. Although often employed, chemical fixation of cells can cause modifications to the molecular composition and therefore influence the observations made. However, the weak contribution of water to Raman spectra offers the potential to study live cells cultured in vitro using an immersion lens, giving the possibility to record highly specific spectra from cells in …

Avoiding Proteolysis During Protein Chromatography., Barry Ryan

Books/Book Chapters/ Proceedings

All cells contain proteases which effect catalytic hydrolysis of the peptide bond between amino acids in the protein backbone. Typically, proteinases are prevented from non-specific proteolysis by regulation and physical separation into different sub-cellular compartments; however, this segregation is not retained during cell lysis to release a protein of interest. Prevention of proteolysis during protein purification often takes the form of a two-pronged approach; firstly inhibition of proteolysis in situ, followed by the separation of the protease from the protein of interest via chromatographical purification. Proteinase inhibitors are routinely used to limit the effect of the proteinases before they are …

Synthesis, Evaluation And Structural Studies Of Antiproliferative Tubulin-Targeting Azetidin-2-Ones, Niamh O'Boyle, Lisa M. Greene, Orla Bergin, Jean-Baptiste Fichet, Thomas Mccabe, David G. Lloyd, Daniela M. Zisterer, Mary J. Meegan

Articles

A series of azetidin-2-ones substituted at positions 2, 3 and 4 of the azetidinone ring scaffold were synthesised and evaluated for antiproliferative, cytotoxic and tubulin binding activity. In these compounds, the cis double bond of the vascular targeting agent combretastatin A-4 is replaced with the azetidinone ring in order to enhance the antiproliferative effects displayed by combretastatin A-4 and prevent the cis/trans isomerization that is associated with inactivation of combretastatin A-4. The series of azetidinones was synthetically accessible via the Staudinger and Reformatsky reactions. Of a diverse range of heterocyclic derivatives, 3-(2-thienyl) analogue 28 and 3-(3-thienyl) analogue 29 displayed the …

Synthesis, Biochemical And Molecular Modelling Studies Of Antiproliferative Azetidinones Causing Microtubule Disruption And Mitotic Catastrophe, Niamh O'Boyle, Miriam Carr, Lisa M. Greene, Niall O. Keely, Andrew Js Knox, Thomas Mccabe, David G. Lloyd, Daniela M. Zisterer, Mary J. Meegan

Articles

The structure-activity relationships of antiproliferative β-lactams, focusing on modifications at the 4-position of the β-lactam ring, is described. Synthesis of this series of compounds was achieved utilizing the Staudinger and Reformatsky reactions. The antiproliferative activity was assessed in MCF-7 cells, where the 4-(4-ethoxy)phenyl substituted compound 26 displayed the most potent activity with an IC₅₀ value of 0.22 μM. The mechanism of action was demonstrated to be by inhibition of tubulin. Cell exposure to combretastatin A-4 and 26 led to arrest of MCF-7 cells in the G2/M phase of the cell cycle and induction of apoptosis. Additionally, mitotic catastrophe for …

Lead Identification Of Β-Lactam And Related Imine Inhibitors Of The Molecular Caperone Heat Shock Protein 90, Niamh O'Boyle, Andrew Js Knox, Trevor P. Price, D. Clive Williams, Daniela M. Zisterer, David G. Lloyd, Mary J. Meegan

Articles

Heat shock protein 90 is an emerging target for oncology therapeutics. Inhibitors of this molecular chaperone, which is responsible for the maintenance of a number of oncogenic proteins, have shown promise in clinical trials and represent a new and exciting area in the treatment of cancer. Heat shock protein 90 inhibitors have huge structural diversity, and here we present the identification of inhibitors based on β-lactam and imine templates. β-Lactam 5 and imines 12 and 18 exhibit binding to heat shock protein 90-α with IC₅₀ values of 5.6 μM, 14.5 μM and 22.1 μM respectively. The binding affinity displayed …

Virulence Of An Emerging Respiratory Pathogen, Genus Pandoraea, In Vivo And Its Interactions With Lung Epithelial Cells, Gillian Herbert, Anne Costello, Lydia Fabunmi, Kirsten Schaffer, Kevin Kavanagh, Emma M. Caraher, Máire Callaghan, Siobhan Mcclean

Articles

Pandoraea species have emerged as opportunistic pathogens among cystic fibrosis (CF) and non-CF patients. Pandoraea pulmonicola is the predominant Pandoraea species among Irish CF patients. The objective of this study was to investigate the pathogenicity and potential mechanisms of virulence of Irish P. pulmonicola isolates and strains from other Pandoraea species. Three patients from whom the P. pulmonicola isolates were isolated have since died. The in vivo virulence of these and other Pandoraea strains was examined by determining the ability to kill Galleria mellonella larvae. The P. pulmonicola strains generally were the most virulent of the species tested, with three …

Reasons For Reducing Breastfeeding Duration Among Chinese Mothers In Ireland:A Qualitative Study, Qianling Zhou

Other resources

Introduction: The Ireland Chinese Mother Survey has revealed a remarkable decline of breastfeeding duration among Chinese mothers who gave birth in Ireland [1]. This qualitative study was undertaken to explore the reasons for such a decrease and to determine the influence of residency in Ireland on breastfeeding practices among immigrant Chinese. Methods: Purposive sampling together with the snowball technique was used to recruit immigrant Chinese women who have given birth in Ireland. Seven focus groups were conducted and thematic content analysis was performed to analyse the data. Results: Decline in breastfeeding duration was not mainly due to the formula feeding …

Strategies For The Elimination Of Matrix Effects In The Lc-Ms/Ms Analysis Of The Lipophilic Toxins Okadaic Acid And Azaspiracid-1 In Molluscan Shellfish, Jane Kilcoyne, Elie Fux

Articles

Considerable efforts are being made worldwide to replace in vivo assays with instrumental methods of analysis for the monitoring of marine biotoxins in shellfish. Analysis of these compounds by the preferred technique of LC-MS/MS is challenged by matrix effects associated with shellfish tissue components. In methods validation, assessment of matrix interferences is imperative to ensure the accuracy of analytical results. We evaluated matrix interferences in the analysis of okadaic acid (OA) and azaspiracid 1 (AZA1) in mollucscan shellfish by using a conventional acidic method on electrospray triple stage quadrapole (TSQ) and hybrid quadrupole time of flight (QToF) instruments, with matrix …

Maternal Health Behaviours During Pregnancy And Associations With Infant Feeding Factors, Roslyn Tarrant, Katherine Younger, Margaret Sheridan-Pereira, John Kearney

Other resources

Maternal health behaviours during pregnancy and associations with postnatal infant feeding practices

Objectives: To examine modifiable maternal health behaviours during pregnancy, including folic acid use peri-conceptually, smoking and alcohol consumption patterns, and relate these factors to maternal postnatal infant feeding practices.

Materials and Methods: A prospective observational study involved the recruitment of 539 pregnant women from a Dublin maternity hospital. Following application of exclusion criteria, 450 mothers were followed up at 6 weeks and 6 months postpartum. Quantitative data on folic acid use, as well as mothers’ smoking and alcohol consumption patterns during pregnancy were collected from the antenatal questionnaire. …

How To Be Successful In Exclusive Breastfeeding For Four To Six Months:Experiences Of Chinese Mothers In Ireland, Qianling Zhou

Other resources

No abstract provided.

Study Of The Efficacy, Biodistribution, And Safety Profile Of Therapeutic Gutless Adenovirus Vectors As A Prelude To A Phase I Clinical Trial For Glioblastoma, Akm Ghulam Muhammad, Mariana Puntel, Marianela Candolfi, A Salem, Kader Yagiz, C Farrokhi, Kurt Kroeger, Weidong Xiong, James Curtin, Chunyan Liu, K Lawrence, Niyati Bondale, Jonathan Lerner, G Baker, David Foulad, Robert Pechnick, Donna Palmer, Philip Ng, Pedro Lowenstein, Maria Castro

Articles

Glioblastoma multiforme (GBM) is the most common and most aggressive primary brain tumor in humans. Systemic immunity against gene therapy vectors has been shown to hamper therapeutic efficacy; however, helper-dependent high-capacity adenovirus (HC-Ad) vectors elicit sustained transgene expression, even in the presence of systemic anti-adenoviral immunity. We engineered HC-Ads encoding the conditional cytotoxic herpes simplex type 1 thymidine kinase (TK) and the immunostimulatory cytokine fms-like tyrosine kinase ligand 3 (Flt3L). Flt3L expression is under the control of the regulatable Tet-ON system. In anticipation of a phase I clinical trial for GBM, we assessed the therapeutic efficacy, biodistribution, and clinical and …

Release Of Hmgb1 In Response To Pro-Apoptotic Glioma Killing Strategies: Efficacy And Neurotoxicity, Marianela Candolfi, Kader Yagiz, David Foulad, Gabrielle Alzadeh, Matthew Tesarfreund, Akm Ghulam Muhammad, Mariana Puntel, Kurt Kroeger, Chunyan Liu, Sharon Lee, James Curtin, Gwendalyn D. King, Jonathan Lerner, Katsuaki Sato, Yohei Mineharu, Weidong Xiong, Pedro R. Lowenstein, Maria Castro

Articles

Purpose In preparation for a Phase I clinical trial utilizing a combined cytotoxic/immunotherapeutic strategy using adenoviruses expressing Flt3L (Ad-Flt3L) and thymidine kinase (Ad-TK) to treat glioblastoma (GBM), we tested the hypothesis that Ad-TK+GCV would be the optimal tumor killing agent in relation to efficacy and safety when compared to other pro-apoptotic approaches. Experimental Design and Results The efficacy and neurotoxicity of Ad-TK+GCV was compared with Ads encoding the pro-apoptotic cytokines (TNF-α, TRAIL, FasL), alone or in combination with Ad-Flt3L. In rats bearing small GBMs (day 4), only Ad-TK+GCV or Ad-FasL improved survival. In rats bearing large GBMs (day 9), the …

Genetic Connections Between Neurological Disorders And Cholesterol Metabolism, Ingemar Bjorkhem, Valerio Leoni, Steve Meaney

Articles

Cholesterol is an essential component of both the peripheral and central nervous systems of mammals. Over the last decade, evidence has accumulated that disturbances in cholesterol metabolism are associated with the development of various neurological conditions. In addition to genetically defined defects in cholesterol synthesis, which will be covered in another review in this Thematic Series, defects in cholesterol metabolism (cerebrotendinous xanthomatosis) and intracellular transport (Niemann Pick Syndrome) lead to neurological disease. A subform of hereditary spastic paresis (type SPG5) and Huntington's disease are neurological diseases with mutations in genes that are of importance for cholesterol metabolism. Neurodegeneration is generally …

Synthesis And Evaluation Of Azetidinone Analogues Of Combretastatin A-4 As Tubulin Targeting Agents, Niamh O'Boyle, Miriam Carr, Lisa M. Greene, Orla Bergin, Seema M. Nathwani, Thomas Mccabe, David G. Lloyd, Daniela M. Zisterer, Mary J. Meegan

Articles

The synthesis and antiproliferative activity of a new series of rigid analogues of combretastatin A-4 are described which contain the 1,4-diaryl-2-azetidinone (β-lactam) ring system in place of the usual ethylene bridge present in the natural combretastatin stilbene products. These novel compounds are also substituted at position 3 of the β-lactam ring with an aryl ring. A number of analogues showed potent nanomolar activity in human MCF-7 and MDA-MB-231 breast cancer cell lines, displayed in vitro inhibition of tubulin polymerization and did not cause significant cytotoxicity in normal murine breast epithelial cells. 4-(4-Methoxyaryl)-substituted compound 32, 4-(3-hydroxy-4-methoxyaryl)-substituted compounds 35 and 41 and …

Purification And Properties Of Amycolatopsis Mediterranei Dsm 43304 Lipase And Its Potential In Flavour Ester Synthesis, Dharmendra Dheeman, Gary Henehan, Jesus Maria Frias

Articles

An extracellular thermostable lipase from Amycolatopsis mediterranei DSM 43304 has been purified to homogeneity using ammonium sulphate precipitation followed by anion exchange chromatography and hydrophobic interaction chromatography. This protocol resulted in 398 fold purification with 36% final recovery. The purified A. mediterranei DSM 43304 lipase (AML) has an apparent molecular mass of 33 kDa. The N-terminal sequence, AANPYERGPDPTTASIEATR, showed highest similarity to a lipase from Streptomyces exfoliatus. The values of and for p-nitrophenyl palmitate (p-NPP) under optimal temperature (60°C) and pH (8.0) conditions were 0.10 ± 0.01 mM and 2.53 ± 0.06 mmol/minmg, respectively. The purified …

Influence Of Cultivation Conditions On The Production Of A Thermostable Extracellular Lipase From Amycolatopsis Mediterranei Dsm 43304, Dharmdendra Dheeman, Jesus Maria Frias, Gary Henehan

Articles

Among several lipase producing actinomycete strains screened, Amycolatopsis mediterranei DSM 43304 was found to produce a thermostable, extracellular lipase. Culture condition and nutrient source modification studies involving carbon sources, nitrogen sources, incubation temperature and medium pH were carried out. Lipase activity of 1.37 ± 0.103 IU/ml of culture medium was obtained in 96 h at 28 °C and pH 7.5 using linseed oil and fructose as carbon sources and a combination of phytone peptone and yeast extract (5:1) as nitrogen sources. In optimal culture conditions the lipase activity was enhanced 12-fold with a 2-fold increase in lipase specific activity. The …

Hmgb1 Mediates Endogenous Tlr2 Activation And Brain Tumor Regression, James Curtin, Naiyou Liu, Marianela Candolfi, Weidong Xiong, Hikmat Assi, Kader Yagiz, Matthew Edwards, Kathrin Michelsen, Kurt Kroeger, Chunyan Liu, Akm Ghulam Muhammad, Mary Clark, Moshe Arditi, Begonya Comin-Anduix, Antoni Ribas, Pedro Lowenstein, Maria Castro

Articles

BACKGROUND: Glioblastoma multiforme (GBM) is the most aggressive primary brain tumor that carries a 5-y survival rate of 5%. Attempts at eliciting a clinically relevant anti-GBM immune response in brain tumor patients have met with limited success, which is due to brain immune privilege, tumor immune evasion, and a paucity of dendritic cells (DCs) within the central nervous system. Herein we uncovered a novel pathway for the activation of an effective anti-GBM immune response mediated by high-mobility-group box 1 (HMGB1), an alarmin protein released from dying tumor cells, which acts as an endogenous ligand for Toll-like receptor 2 (TLR2) signaling …

Transcriptional Regulation Of Cholesterol 24-Hydroxylase By Histone Deacetylase Inhibitors., Marjan Shafaati, Riona O'Driscoll, Ingemar Bjorkhem, Steve Meaney

Articles

The mechanistic basis for the tissue specific expression of cholesterol elimination pathways is poorly understood. To gain additional insight into this phenomenon we considered it of interest to investigate if epigenetic mechanisms are involved in the regulation of the brain-specific enzyme cholesterol 24-hydroxylase (CYP46A1), a key regulator of brain cholesterol elimination. We demonstrated a marked time-dependent derepression of the expression of CYP46A1, in response to treatment with the potent histone deacetylase (HDAC) inhibitor Trichostatin A. The pattern of expression of the genes in the genomic region surrounding CYP46A1 was found to be diametrically opposite in brain and liver. Intraperitoneal injection …

Generation Of A Reporter Library Of Eralpha Interacting Dna Sequences, Cormac Jennings

Masters

Oestrogens are a group of steroid hormones of which oestradiol is the major form. Oestrogens are present in men and women and some of their main physiological roles involve female and male reproduction, bone metabolism and homeostasis. Oestrogens carry out their actions by diffusing across the cell membrane and binding to their receptor called the oestrogen receptor (ER), of which two types exist, ERα and ERβ. ERs regulate gene expression through the binding of DNA, most notably the estrogen response element (ERE). Breast cancer is the most common malignancy in women in industrialised countries and 65 percent of breast cancers …

Treg Depletion Inhibits Efficacy Of Cancer Immunotherapy: Implications For Clinical Trials., James Curtin, Marianela Candolfi, Tamer Fakhouri, Chunyan Liu, Anderson Alden, Matthew Edwards, Pedro Lowenstein, Maria Castro

Articles

BACKGROUND: Regulatory T lymphocytes (Treg) infiltrate human glioblastoma (GBM); are involved in tumor progression and correlate with tumor grade. Transient elimination of Tregs using CD25 depleting antibodies (PC61) has been found to mediate GBM regression in preclinical models of brain tumors. Clinical trials that combine Treg depletion with tumor vaccination are underway to determine whether transient Treg depletion can enhance anti-tumor immune responses and improve long term survival in cancer patients. FINDINGS: Using a syngeneic intracrabial glioblastoma (GBM) mouse model we show that systemic depletion of Tregs 15 days after tumor implantation using PC61 resulted in a decrease in Tregs …