Publications by authors named "Barry van der Strate"

21 Publications

  • Page 1 of 1

EBF recommendation on practical management of critical reagents for antidrug antibody ligand-binding assays.

Bioanalysis 2019 10 28;11(19):1787-1798. Epub 2019 Oct 28.

European Bioanalysis Forum, Havenlaan 86c b204, 1000 Brussels, Belgium.

Immunogenicity assays are required to measure antidrug antibodies that are generated against biotherapeutic modalities. As for any ligand-binding assays, critical reagents (CR) play a crucial role in immunogenicity assays, as the robustness and reliability of an assay are defined by the quality and long-term availability of these reagents. The current regulatory guidelines do not provide clear directions on how to implement and verify lot-to-lot changes of CR during an assay life cycle, or the acceptance criteria that should be used when implementing new lots of CR. These aspects were extensively discussed within the European Bioanalysis Forum community. In this paper, CR for immunogenicity assays are identified and the minimum requirements for introducing new lots of CR in immunogenicity assays are described.
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http://dx.doi.org/10.4155/bio-2019-0248DOI Listing
October 2019

Incurred sample reproducibility: 10 years of experiences: views and recommendations from the European Bioanalysis Forum.

Bioanalysis 2018 Nov 6;10(21):1723-1732. Epub 2018 Nov 6.

European Bioanalysis Forum, Brussels, Belgium.

With 10 years of experiences on incurred sample reanalysis (ISR) as an integrated part of regulated bioanalysis, the European Bioanalysis Forum has reflected on the implementation and the use of ISR. Three surveys were conducted in 2016 and 2017 as a revisit of the ISR experiences within European pharmaceutical industry and contract research organizations: has ISR become a tool for postvalidation and process check of a bioanalytical method performance and has ISR become a routine in our laboratories? Do we agree on the interpretation of guidelines/guidance and are we aligned in our approach - among others?
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http://dx.doi.org/10.4155/bio-2018-0194DOI Listing
November 2018

EBF recommendation on practical management of critical reagents for PK ligand-binding assays.

Bioanalysis 2018 Oct 18;10(19):1557-1565. Epub 2018 Sep 18.

European Bioanalysis Forum, Havenlaan 86c b204, 1000 Brussels, Belgium.

Critical reagents play a crucial role in ligand-binding assays; the robustness and reliability of an assay is defined by the quality and long-term availability of these reagents. However, neither regulatory guidelines nor relevant scientific papers provide clear directions for set-up, life cycle management and, more importantly, the acceptance criteria required for the testing of the critical reagents for pharmacokinetic, biomarker and immunogenicity assays. The ambiguity from current guidelines can be a challenge for the bioanalytical community. Members of the European Bioanalysis Forum community undertook a more pragmatic approach on how to assess the impact of critical reagents. In this paper, a review and corresponding gap analysis of the current guidelines and relevant papers will be provided as well as decision trees proposed for lot-to-lot changes of critical reagents for pharmacokinetic assays.
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http://dx.doi.org/10.4155/bio-2018-0230DOI Listing
October 2018

11th GCC Closed Forum: cumulative stability; matrix stability; immunogenicity assays; laboratory manuals; biosimilars; chiral methods; hybrid LBA/LCMS assays; fit-for-purpose validation; China Food and Drug Administration bioanalytical method validation.

Bioanalysis 2018 Apr 27;10(7):433-444. Epub 2018 Apr 27.

Worldwide Clinical Trials, Austin, TX, USA.

The 11th Global CRO Council Closed Forum was held in Universal City, CA, USA on 3 April 2017. Representatives from international CRO members offering bioanalytical services were in attendance in order to discuss scientific and regulatory issues specific to bioanalysis. The second CRO-Pharma Scientific Interchange Meeting was held on 7 April 2017, which included Pharma representatives' sharing perspectives on the topics discussed earlier in the week with the CRO members. The issues discussed at the meetings included cumulative stability evaluations, matrix stability evaluations, the 2016 US FDA Immunogenicity Guidance and recent and unexpected FDA Form 483s on immunogenicity assays, the bioanalytical laboratory's role in writing PK sample collection instructions, biosimilars, CRO perspectives on the use of chiral versus achiral methods, hybrid LBA/LCMS assays, applications of fit-for-purpose validation and, at the Global CRO Council Closed Forum only, the status and trend of current regulated bioanalytical practice in China under CFDA's new BMV policy. Conclusions from discussions of these topics at both meetings are included in this report.
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http://dx.doi.org/10.4155/bio-2018-0014DOI Listing
April 2018

2017 White Paper on recent issues in bioanalysis: a global perspective on immunogenicity guidelines & biomarker assay performance (Part 3 - LBA: immunogenicity, biomarkers and PK assays).

Bioanalysis 2017 Dec 5;9(24):1967-1996. Epub 2017 Dec 5.

BioMarin Pharmaceutical, San Rafael, CA, USA.

The 2017 11th Workshop on Recent Issues in Bioanalysis took place in Los Angeles/Universal City, California, on 3-7 April 2017 with participation of close to 750 professionals from pharmaceutical/biopharmaceutical companies, biotechnology companies, contract research organizations and regulatory agencies worldwide. WRIB was once again a 5-day, week-long event - a full immersion week of bioanalysis, biomarkers and immunogenicity. As usual, it was specifically designed to facilitate sharing, reviewing, discussing and agreeing on approaches to address the most current issues of interest including both small- and large-molecule analysis involving LC-MS, hybrid ligand-binding assay (LBA)/LC-MS and LBA approaches. This 2017 White Paper encompasses recommendations emerging from the extensive discussions held during the workshop, and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to enable advances in scientific excellence, improved quality and better regulatory compliance. Due to its length, the 2017 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 3) covers the recommendations for large-molecule bioanalysis, biomarkers and immunogenicity using LBA. Part 1 (LC-MS for small molecules, peptides and small molecule biomarkers) and Part 2 (hybrid LBA/LC-MS for biotherapeutics and regulatory agencies' inputs) are published in volume 9 of Bioanalysis, issues 22 and 23 (2017), respectively.
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http://dx.doi.org/10.4155/bio-2017-4974DOI Listing
December 2017

Best practices in performing flow cytometry in a regulated environment: feedback from experience within the European Bioanalysis Forum.

Bioanalysis 2017 Aug 2;9(16):1253-1264. Epub 2017 Aug 2.

Novo Nordisk A/S, Måløv, Denmark.

Flow cytometry is a powerful tool that can be used for the support of (pre)clinical studies. Although various white papers are available that describe the set-up and validation of the instrumentation (the flow cytometer) and validation of flow cytometry methods, to date no guidelines exist that address the requirements for performing flow cytometry in a regulated environment. In this manuscript, the European Bioanalysis Forum presents additional practice guidance on the use of flow cytometry in the support of drug development programs and addresses areas that are not covered in the previous publications. The concepts presented here are based on the consensus of discussions in the European Bioanalysis Forum Topic Team 32, in meetings in Barcelona, Limelette and multiple telephone conferences.
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http://dx.doi.org/10.4155/bio-2017-0093DOI Listing
August 2017

Method transfer: a CRO perspective.

Bioanalysis 2017 Aug 1;9(15):1131-1134. Epub 2017 Aug 1.

PRA Health Sciences Bioanalytical Laboratory, Amerikaweg 18, Assen, The Netherlands.

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http://dx.doi.org/10.4155/bio-2017-0078DOI Listing
August 2017

The 10th GCC Closed Forum: rejected data, GCP in bioanalysis, extract stability, BAV, processed batch acceptance, matrix stability, critical reagents, ELN and data integrity and counteracting fraud.

Bioanalysis 2017 Apr 24;9(7):505-516. Epub 2017 Mar 24.

WuXi Apptec, Plainsboro, NJ, USA.

The 10th Global CRO Council (GCC) Closed Forum was held in Orlando, FL, USA on 18 April 2016. In attendance were decision makers from international CRO member companies offering bioanalytical services. The objective of this meeting was for GCC members to meet and discuss scientific and regulatory issues specific to bioanalysis. The issues discussed at this closed forum included reporting data from failed method validation runs, GCP for clinical sample bioanalysis, extracted sample stability, biomarker assay validation, processed batch acceptance criteria, electronic laboratory notebooks and data integrity, Health Canada's Notice regarding replicates in matrix stability evaluations, critical reagents and regulatory approaches to counteract fraud. In order to obtain the pharma perspectives on some of these topics, the first joint CRO-Pharma Scientific Interchange Meeting was held on 12 November 2016, in Denver, Colorado, USA. The five topics discussed at this Interchange meeting were reporting data from failed method validation runs, GCP for clinical sample bioanalysis, extracted sample stability, processed batch acceptance criteria and electronic laboratory notebooks and data integrity. The conclusions from the discussions of these topics at both meetings are included in this report.
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http://dx.doi.org/10.4155/bio-2017-5000DOI Listing
April 2017

Role of receptor occupancy assays by flow cytometry in drug development.

Cytometry B Clin Cytom 2016 Mar 16;90(2):110-6. Epub 2016 Feb 16.

Covance Central Laboratory Services, Indianapolis, Indiana, 46214.

The measurement of the binding of a biotherapeutic to its cellular target, receptor occupancy (RO), is increasingly important in development of biologically-based therapeutic agents. Receptor occupancy (RO) assays by flow cytometry describe the qualitative and/or quantitative assessment of the binding of a therapeutic agent to its cell surface target. Such RO assays can be as simple as measuring the number of cell surface receptors bound by an antireceptor therapeutic agent or can be designed to address more complicated scenarios such as internalization or shedding events once a receptor engages the administered therapeutic agent. Data generated from RO assays can also be used to model whether given doses of an experimental therapeutic agent and their administration schedules lead to predicted levels of receptor occupancy and whether the receptor is modulated (up or down) on cells engaged by the therapeutic agent. There are a variety of approaches that can be used when undertaking RO assays and with the ability to measure distinct subsets in heterogeneous populations, flow cytometry is ideally suited to RO measurements. This article highlights the importance of RO assays on the flow cytometric platform in the development of biotherapeutic agents.
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http://dx.doi.org/10.1002/cyto.b.21355DOI Listing
March 2016

Recommendations for the development and validation of flow cytometry-based receptor occupancy assays.

Cytometry B Clin Cytom 2016 Mar 22;90(2):141-9. Epub 2016 Feb 22.

Covance Central Laboratory Services, 8211 SciCor Dr, Indianapolis, Indiana, 46214.

Receptor occupancy measurements demonstrate the binding of a biotherapeutic agent to its extra-cellular target and represent an integral component of the pharmacodynamic (PD) portfolio utilized to advance the development and commercialization of a therapeutic agent. Coupled with traditional pharmacokinetic (PK) assessments derived from serum drug concentration, receptor occupancy data can be used to model PK/PD relationships and validate dose selection decisions throughout the drug development lifecycle. Receptor occupancy assays can be even more challenging to develop than other flow cytometric methods (e.g. surface immunophenotyping). In addition to typical considerations regarding stability of the cell type of interest, stability of the target-bound therapeutic agent and stability of the target receptor must be taken into account. Reagent selection is also challenging as reagents need to be evaluated for the potential to compete with the therapeutic agent and bind with comparable affinity. This article provides technical guidance for the development and validation of cytometry-based receptor occupancy assays.
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http://dx.doi.org/10.1002/cyto.b.21339DOI Listing
March 2016

8th GCC: consolidated feedback to US FDA on the 2013 draft FDA guidance on bioanalytical method validation.

Bioanalysis 2014 ;6(22):2957-63

Covance Laboratories, Chantilly, VA, USA.

The 8th GCC Closed Forum for Bioanalysis was held in Baltimore, MD, USA on 5 December 2013, immediately following the 2013 AAPS Workshop (Crystal City V): Quantitative Bioanalytical Methods Validation and Implementation--The 2013 Revised FDA Guidance. This GCC meeting was organized to discuss the contents of the draft revised FDA Guidance on bioanalytical method validation that was published in September 2013 and consolidate the feedback of the GCC members. In attendance were 63 senior-level participants, from seven countries, representing 46 bioanalytical CRO companies/sites. This event represented a unique opportunity for CRO bioanalytical experts to share their opinions and concerns regarding the draft FDA Guidance, and to build unified comments to be provided to the FDA.
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http://dx.doi.org/10.4155/bio.14.287DOI Listing
July 2015

Scavenger receptor A: a new route for adenovirus 5.

Mol Pharm 2009 Mar-Apr;6(2):366-74

Department of Therapeutic Gene Modulation, Groningen University Institute for Drug Exploration, University of Groningen, The Netherlands.

Adenoviruses are common pathogens associated with respiratory diseases, gastrointestinal illnesses and/or conjunctivitis. Currently, this virus is used as a vector in gene therapy trials. The promise of viral gene therapy applications is substantially reduced because the virus is cleared by liver macrophages upon systemic administration. The mechanism underlying adenoviral tropism to and degradation in macrophages is poorly understood. We identified a new adenoviral receptor, the scavenger receptor A (SR-A), responsible for uptake of the virus in macrophages. CHO cells expressing SR-A showed increased viral transgene expression when compared with wild type cells. Preincubation of J774 macrophage cells with SR-A ligands decreased significantly adenoviral uptake. Electron-microscopy analysis of infected J774 cells showed activation of a viral degradation pathway. Infection of mice with adenovirus resulted in a substantial decrease of the virus in liver macrophages when SR-A was blocked. Our data provide a basis for understanding of the adenoviral uptake and degradation mechanism in macrophages in vitro and in vivo. Inhibition of adenoviral SR-A uptake can be utilized in gene therapy applications to increase its efficiency and efficacy.
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http://dx.doi.org/10.1021/mp8000974DOI Listing
September 2009

Heme oxygenase-1 prevents smoke induced B-cell infiltrates: a role for regulatory T cells?

Respir Res 2008 Feb 6;9:17. Epub 2008 Feb 6.

Department of Pulmonary Diseases, University Medical Center Groningen, University of Groningen, P,O, Box 30,001, 9700 RB, Groningen, The Netherlands.

Background: Smoking is the most important cause for the development of COPD. Since not all smokers develop COPD, it is obvious that other factors must be involved in disease development. We hypothesize that heme oxygenase-1 (HO-1), a protective enzyme against oxidative stress and inflammation, is insufficiently upregulated in COPD. The effects of HO-1 modulation on cigarette smoke induced inflammation and emphysema were tested in a smoking mouse model.

Methods: Mice were either exposed or sham exposed to cigarette smoke exposure for 20 weeks. Cobalt protoporphyrin or tin protoporphyrin was injected during this period to induce or inhibit HO-1 activity, respectively. Afterwards, emphysema development, levels of inflammatory cells and cytokines, and the presence of B-cell infiltrates in lung tissue were analyzed.

Results: Smoke exposure induced emphysema and increased the numbers of inflammatory cells and numbers of B-cell infiltrates, as well as the levels of inflammatory cytokines in lung tissue. HO-1 modulation had no effects on smoke induced emphysema development, or the increases in neutrophils and macrophages and inflammatory cytokines. Interestingly, HO-1 induction prevented the development of smoke induced B-cell infiltrates and increased the levels of CD4+CD25+ T cells and Foxp3 positive cells in the lungs. Additionally, the CD4+CD25+ T cells correlated positively with the number of Foxp3 positive cells in lung tissue, indicating that these cells were regulatory T cells.

Conclusion: These results support the concept that HO-1 expression influences regulatory T cells and indicates that this mechanism is involved in the suppression of smoke induced B-cell infiltrates. The translation of this interaction to human COPD should now be pursued.
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http://dx.doi.org/10.1186/1465-9921-9-17DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2254411PMC
February 2008

Dependence of neovascularization mechanisms on the molecular microenvironment.

Tissue Eng 2007 Dec;13(12):2913-21

Medical Biology Section, University of Groningen, University Medical Center, the Netherlands.

In vivo vascularization of implanted (bio)artificial constructs is essential for their proper function. Vascularization may rely on sprouting angiogenesis, vascular incorporation of bone marrow-derived endothelial cells (BMDECs), or both. Here we investigated the relative contribution of these 2 mechanisms to neovascularization in a mouse model of a foreign body reaction (FBR) to subcutaneously implanted Dacron and in hind limb ischemia (HLI) in relation to the molecular microenvironment at these neovascularization sites. Neovascularization was studied in C57Bl/6 mice reconstituted with enhanced green fluorescent protein (EGFP) transgenic bone marrow. Sprouting angiogenesis, detected using nuclear incorporation of bromodeoxyuridine in endothelial cells was present in both models, whereas vascular incorporation of EGFP(+) BMDECs was restricted to HLI. In HLI, the presence of a pro-angiogenic molecular microenvironment comprising vascular endothelial growth factor, fibroblast growth factor 2, and granulocyte colony-stimulating factor corroborated the importance of these factors for vascular BMDEC incorporation, whereas this microenvironment was absent in FBR. Enhanced mobilization of BMDECs by granulocyte-macrophage colony-stimulating factor administration or by combining HLI and FBR with Dacron did not induce incorporation of BMDECs in FBR neovessels. We conclude that the efficacy of BMDEC-based therapy is not generally warranted, but it depends on the molecular microenvironment in the targeted tissue.
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http://dx.doi.org/10.1089/ten.2007.0031DOI Listing
December 2007

Reduced inflammatory response in cigarette smoke exposed Mrp1/Mdr1a/1b deficient mice.

Respir Res 2007 Jul 7;8:49. Epub 2007 Jul 7.

Pulmonology Department, University Medical Center Groningen and University of Groningen, The Netherlands.

Background: Tobacco smoke is the principal risk factor for chronic obstructive pulmonary disease (COPD), though the mechanisms of its toxicity are still unclear. The ABC transporters multidrug resistance-associated protein 1 (MRP1) and P-glycoprotein (P-gp/MDR1) extrude a wide variety of toxic substances across cellular membranes and are highly expressed in bronchial epithelium. Their impaired function may contribute to COPD development by diminished detoxification of noxious compounds in cigarette smoke.

Methods: We examined whether triple knock-out (TKO) mice lacking the genes for Mrp1 and Mdr1a/1b are more susceptible to develop COPD features than their wild-type (WT) littermates. TKO and WT mice (six per group) were exposed to 2 cigarettes twice daily by nose-only exposure or room air for 6 months. Inflammatory infiltrates were analyzed in lung sections, cytokines and chemokines in whole lung homogenates, emphysema by mean linear intercept. Multiple linear regression analysis with an interaction term was used to establish the statistical significances of differences.

Results: TKO mice had lower levels of interleukin (IL)-7, KC (mouse IL-8), IL-12p70, IL-17, TNF-alpha, G-CSF, GM-CSF and MIP-1-alpha than WT mice independent of smoke exposure (P < 0.05). IL-1-alpha, IL-6, IL-8, IL-13, IL-17, TNF-alpha, G-CSF, GM-CSF and MCP-1 increased after smoke exposure in both groups, but the increase in IL-8 was lower in TKO than WT mice (P < 0.05) with a same trend for G-CSF (P < 0.10). Smoke-induced increase in pulmonary inflammatory cells in WT mice was almost absent in TKO mice. The mean linear intercept was not different between groups.

Conclusion: Mrp1/Mdr1a/1b knock-out mice have a reduced inflammatory response to cigarette smoke. In addition, the expression levels of several cytokines and chemokines were also lower in lungs of Mrp1/Mdr1a/1b knock-out mice independent of smoke exposure. Further studies are required to determine whether dysfunction of MRP1 and/or P-gp contribute to the pathogenesis of COPD.
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http://dx.doi.org/10.1186/1465-9921-8-49DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1950505PMC
July 2007

Circulating CD34+ progenitor cells modulate host angiogenesis and inflammation in vivo.

J Mol Cell Cardiol 2006 Jul 14;41(1):86-96. Epub 2006 Jun 14.

Department of Pathology and Laboratory Medicine, Medical Biology Section, University Medical Centre, University of Groningen, Room Z 2.7, Hanzeplein 1, 9713 GZ Groningen, The Netherlands.

Within the phenotypically and functionally heterogeneous group of circulating progenitor cells (CPC), a subclass of cells with vascular repair potential have been identified. These CPC are detected and isolated based on single or combined expression of CD34, CD133 and VEGFR-2, and referred to as endothelial progenitor cells. Here we asked whether CPC subsets defined by single expression of these markers exhibit functional heterogeneity. As functional parameters, we chose the capacity of CPC to differentiate into endothelial cells. Moreover, we studied their role in remodeling by recruitment of inflammatory cells, an aspect that has been little explored. We established an in vivo model in which the intrinsic functional capacity of these human CPC subsets was studied. Human CD34+ CPC, but not CD133+ or VEGFR-2+ CPC, seeded in Matrigel pellets and transplanted subcutaneously in a nude mouse host, contributed little to donor-derived neovascularization. However, host angiogenesis in the Matrigel implant, as demonstrated by the presence of capillaries containing erythrocytes and expressing mouse CD31, was strong in response to implantation of human CD34+ CPC and significantly lower in response to the other two CPC subsets. Moreover, the CD34+ CPC subset was significantly superior to CD133+ CPC and VEGFR-2+ CPC in the recruitment of host monocytes/macrophages. These three CPC populations were further dissected into seven discrete subsets, based on three-parameter flow cytometry analysis of combined expression patterns of CD34, CD133 and VEGFR-2. In conclusion, in our system, CD34+ CPC contribute marginally to neovascularization by differentiation but are potent regulators of the host angiogenic and pro-inflammatory response, suggesting a possible role for these cells in the remodeling of vascular lesions.
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http://dx.doi.org/10.1016/j.yjmcc.2006.04.021DOI Listing
July 2006

Cigarette smoke-induced emphysema: A role for the B cell?

Am J Respir Crit Care Med 2006 Apr 6;173(7):751-8. Epub 2006 Jan 6.

Department of Respiratory Medicine, University Medical Center Groningen, Postbox 30.001, NL-9700-RB Groningen, The Netherlands.

Rationale: Little is known about what drives the inflammatory reaction in the development of chronic obstructive lung disease. B cells have been found.

Objective: To study the involvement of B cells in the development of emphysema.

Methods: The presence of B-cell follicles and their interaction with other cells were investigated in lungs of patients with chronic obstructive pulmonary disease and of smoking mice. B cells were isolated from lymphoid follicles by laser microdissection and analyzed for the presence of immunoglobulin rearrangements and somatic mutations.

Main Results: Lymphoid follicles consisting of B cells and follicular dendritic cells with adjacent T cells were demonstrated both in the parenchyma and in bronchial walls of patients with emphysema. A clonal process was observed in all follicles and the presence of ongoing somatic mutations was observed in 75% of the follicles, indicating oligoclonal, antigen-specific proliferation. Similar lymphoid follicles were detected in mice that had developed pulmonary inflammation and progressive alveolar airspace enlargement after smoking. The increase in the number of B-cell follicles was progressive with time and correlated with the increase in mean linear intercept. Specific bacterial or viral nucleic acids could not be detected.

Conclusions: B-cell follicles with an oligoclonal, antigen-specific reaction were found in men and mice with emphysema. In mice, the development was progressive with time and correlated with the increase in airspace enlargement. We hypothesize that these B cells contribute to the inflammatory process and/or the development and perpetuation of emphysema by producing antibodies against either tobacco smoke residues or extracellular matrix components.
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http://dx.doi.org/10.1164/rccm.200504-594OCDOI Listing
April 2006

Inhibition of cytomegalovirus infection by lactoferrin in vitro and in vivo.

Antiviral Res 2004 Sep;63(3):197-208

Department of Pharmacokinetics and Drug Delivery, University Center for Pharmacy, Groningen University Institute for Drug Exploration (GUIDE), Ant. Deusinglaan 1, 9713 AV Groningen, The Netherlands,

Lactoferrin is an antimicrobial agent, that, amongst other viruses, inhibits cytomegalovirus (CMV). In this study, we addressed the mechanism(s) by which lactoferrin interacts with CMV and its target cells to inhibit infection. We also studied the antiviral activity of lactoferrin in vivo in rat CMV models with and without immune suppression. We cationized a protein of similar molecular weight, i.e. human serum albumin (HSA), as well as a protein with a smaller molecular weight (beta-lactoglobulin). While HSA itself displayed no anti-CMV activity in vitro, cationic HSA inhibited CMV replication to a similar extent as lactoferrin. Time-of-addition assays indicated that all cationic proteins interacted with an early event in the infection and pre-incubation of cells rather than of virus significantly reduced CMV replication. Rats were treated with lactoferrin (4, 40 or 160 mg/kg, intravenously), beginning at 6h after CMV administration. Subsequently, the rats were treated three times a week. As a positive control, CMV-infected rats were treated with cidofovir, and this agent proved to be highly active in the rat models for CMV. Treatment with lactoferrin was beneficial when infection was initiated with cell-free virus, but not with virus-infected leukocytes. Lactoferrin treatment led to a 10-fold reduction in the final virus titers (salivary glands) at 4 weeks after infection in the immunocompromised rats. Lactoferrin exerted its effects via inhibition of cell entry rather than via stimulation of the immune system.
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http://dx.doi.org/10.1016/j.antiviral.2004.05.002DOI Listing
September 2004

Short-term smoke exposure attenuates ovalbumin-induced airway inflammation in allergic mice.

Am J Respir Cell Mol Biol 2004 Jun 12;30(6):880-5. Epub 2004 Jan 12.

Department of Pathology and Laboratory Medicine, University Hospital Groningen, P.O. Box 30.001, 9700 RB, Groningen, The Netherlands.

Little is known about effects of smoking on airway inflammation in asthma. We tested the hypothesis that smoking enhances established airway inflammation in a mouse model of allergic asthma. C57Bl/6j mice were sensitized to ovalbumin (OVA) and challenged with OVA (OVA-mice) or sham-sensitized to phosphate-buffered saline (PBS) and challenged with PBS aerosols (PBS-mice) for 7 wk. At 4 wk, mice were additionally exposed to air (nonsmoking controls) or mainstream smoke for 3 wk. Using whole body plethysmography, we found OVA-induced bronchoconstriction to be significantly inhibited in smoking OVA-mice as compared with nonsmoking OVA-mice (1 +/- 2% increase versus 22 +/- 6% increase in enhanced pause, respectively). Smoking did not change airway hyperresponsiveness (AHR) to methacholine in PBS-mice, yet significantly attenuated AHR in OVA-mice 24 h after OVA challenge as compared with nonsmoking mice. This was accompanied by reduced eosinophil numbers in lung lavage fluid and tissue of smoking OVA-mice compared with nonsmoking OVA-mice. In contrast to our hypothesis, short-term smoking reduced responsiveness to OVA and methacholine in OVA-mice and decreased airway inflammation when compared with nonsmoking mice. This effect of smoking may be different for long-term smoking, in which remodeling effects of smoking can be expected to interrelate with remodeling changes caused by asthmatic disease.
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http://dx.doi.org/10.1165/rcmb.2003-0178OCDOI Listing
June 2004

Synergy of bovine lactoferrin with the anti-cytomegalovirus drug cidofovir in vitro.

Antiviral Res 2003 Apr;58(2):159-65

Department of Pharmacokinetics and Drug Delivery, Groningen University Institute for Drug Exploration (GUIDE), University Centre for Pharmacy, Ant Deusinglaan 1, 9713 AV, Groningen, The Netherlands.

Unlabelled: Human cytomegalovirus (HCMV) causes severe morbidity and mortality in immunocompromised patients. Treatment of HCMV infections with conventional antiviral drugs like ganciclovir and cidofovir has major drawbacks (i.e. serious side effects). Therefore, combination therapies using drugs with different antiviral mechanisms should be envisaged. Potential synergy between lactoferrin (LF), an antibacterial, antimycotic and antiviral protein, and the antiviral drugs acyclovir, ganciclovir, foscarnet and cidofovir was investigated, using an in vitro test system with the recombinant RC256 HCMV strain.

Results: Combination of LF with acyclovir and foscarnet resulted in antagonism. When LF and ganciclovir were combined, neither synergy nor antagonism was observed. Strikingly, the combination of LF with cidofovir resulted in marked synergy. The synergistic effect could be explained by inhibition of two subsequent steps in the viral replication cycle: HCMV penetration into the target cells and intracellular synthesis of HCMV DNA. In conclusion, LF might be a potential candidate for combination therapy with cidofovir.
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http://dx.doi.org/10.1016/s0166-3542(02)00211-5DOI Listing
April 2003

The antiviral protein human lactoferrin is distributed in the body to cytomegalovirus (CMV) infection-prone cells and tissues.

Pharm Res 2002 Jan;19(1):54-62

Department of Pharmacokinetics and Drug Delivery, University Center for Pharmacy, Groningen University Institute for Drug Exploration, The Netherlands.

Purpose: Lactoferrin has anti-Cytomegalovirus (CMV) and -HIV properties in vitro. However, the pharmacokinetic behavior of the 80-kD protein has not been well defined. We, therefore, assessed the plasma decay and body distribution of lactoferrin after intravenous administration to freely moving rats. Furthermore, the systemic availability of lactoferrin after intraperitoneal dosing was determined.

Methods And Results: After intravenous injection, human lactoferrin (hLF) was rapidly cleared from the plasma, but higher doses resulted in prolonged plasma levels. Immunohistochemical analysis revealed a pronounced distribution of hLF to endothelial cells in the liver whereas diffuse staining in hepatocytes indicated the presence of considerable amounts in this large cell population. This endothelial association, which also was found in other organ/tissues, including blood vessels. was confirmed by in vitro cell-binding studies. In addition, leukocytes in plasma that were infiltrated in various organs showed binding of hLF. A small fraction of hLF was transported into the lymphatic system. Western blot analysis revealed that hLF, present in the various organs. mainly consisted of an 80-kD protein. After intraperitoneal administration, small amounts of 80-kD hLF distributed to the general circulation. The bioavailability was 0.6% but increased to 3.6% after multiple administrations.

Conclusions: The affinity of hLF for endothelial cells and leukocytes, and its penetration into the lymphatic system, indicates that this protein reaches target cells and body compartments that are crucial for CMV and HIV replication. The ability to reach the blood compartment after intraperitoneal dosing offers opportunities for parenteral administration of the protein in future studies on its antiviral effects in vivo.
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http://dx.doi.org/10.1023/a:1013655315969DOI Listing
January 2002