50 research outputs found
Human Papillomavirus Type 16 Entry: Retrograde Cell Surface Transport along Actin-Rich Protrusions
The lateral mobility of individual, incoming human papillomavirus type 16 pseudoviruses (PsV) bound to live HeLa cells was studied by single particle tracking using fluorescence video microscopy. The trajectories were computationally analyzed in terms of diffusion rate and mode of motion as described by the moment scaling spectrum. Four distinct modes of mobility were seen: confined movement in small zones (30–60 nm in diameter), confined movement with a slow drift, fast random motion with transient confinement, and linear, directed movement for long distances. The directed movement was most prominent on actin-rich cell protrusions such as filopodia or retraction fibres, where the rate was similar to that measured for actin retrograde flow. It was, moreover, sensitive to perturbants of actin retrograde flow such as cytochalasin D, jasplakinolide, and blebbistatin. We found that transport along actin protrusions significantly enhanced HPV-16 infection in sparse tissue culture, cells suggesting a role for in vivo infection of basal keratinocytes during wound healing
Essential Roles for Soluble Virion-Associated Heparan Sulfonated Proteoglycans and Growth Factors in Human Papillomavirus Infections
A subset of human papillomavirus (HPV) infections is causally related to the development of human epithelial tumors and cancers. Like a number of pathogens, HPV entry into target cells is initiated by first binding to heparan sulfonated proteoglycan (HSPG) cell surface attachment factors. The virus must then move to distinct secondary receptors, which are responsible for particle internalization. Despite intensive investigation, the mechanism of HPV movement to and the nature of the secondary receptors have been unclear. We report that HPV16 particles are not liberated from bound HSPG attachment factors by dissociation, but rather are released by a process previously unreported for pathogen-host cell interactions. Virus particles reside in infectious soluble high molecular weight complexes with HSPG, including syndecan-1 and bioactive compounds, like growth factors. Matrix mellatoproteinase inhibitors that block HSPG and virus release from cells interfere with virus infection. Employing a co-culture assay, we demonstrate HPV associated with soluble HSPG-growth factor complexes can infect cells lacking HSPG. Interaction of HPV-HSPG-growth factor complexes with growth factor receptors leads to rapid activation of signaling pathways important for infection, whereas a variety of growth factor receptor inhibitors impede virus-induced signaling and infection. Depletion of syndecan-1 or epidermal growth factor and removal of serum factors reduce infection, while replenishment of growth factors restores infection. Our findings support an infection model whereby HPV usurps normal host mechanisms for presenting growth factors to cells via soluble HSPG complexes as a novel method for interacting with entry receptors independent of direct virus-cell receptor interactions
Emerging concepts in biomarker discovery; The US-Japan workshop on immunological molecular markers in oncology
Supported by the Office of International Affairs, National Cancer Institute (NCI), the "US-Japan Workshop on Immunological Biomarkers in Oncology" was held in March 2009. The workshop was related to a task force launched by the International Society for the Biological Therapy of Cancer (iSBTc) and the United States Food and Drug Administration (FDA) to identify strategies for biomarker discovery and validation in the field of biotherapy. The effort will culminate on October 28th 2009 in the "iSBTc-FDA-NCI Workshop on Prognostic and Predictive Immunologic Biomarkers in Cancer", which will be held in Washington DC in association with the Annual Meeting. The purposes of the US-Japan workshop were a) to discuss novel approaches to enhance the discovery of predictive and/or prognostic markers in cancer immunotherapy; b) to define the state of the science in biomarker discovery and validation. The participation of Japanese and US scientists provided the opportunity to identify shared or discordant themes across the distinct immune genetic background and the diverse prevalence of disease between the two Nations
Adenovirus vectors based on human adenovirus type 19a have high potential for human muscle-directed gene therapy.
Until recently, adenovirus-based gene therapy has been almost exclusively based on human adenovirus serotype 5 (Ad5). The aim of this study was to systematically compare the efficiency of transduction of primary muscle cells from various species by two adenoviral vectors from subgroups C and D. Transduction of a panel of myoblasts demonstrated a striking specificity of an Ad19a-based replication-defective E1-deleted vector (Ad19aEGFP) for human cells, whereas the Ad5-based vector had high affinity for nonhuman primate myoblasts. Transgene expression correlated well with cell-associated vector genomes. Up to 6.59% of the initially applied Ad19aEGFP vector particles were taken up by human myoblasts, as compared with 0.1% of the corresponding Ad5 vector. Remarkably, Ad19aEGFP but not Ad5EGFP efficiently transduced differentiated human myotubes, an in vitro model for skeletal muscle transduction. Uptake of Ad19aEGFP vector particles in human myotubes was 12-fold more efficient than that of Ad5EGFP. Moreover, both vectors demonstrated an early block at the level of vector uptake in mouse myoblasts and rat L6 cells. Investigation of the underlying mechanism for binding and uptake of the two vectors by human myoblasts showed high susceptibility for Ad19a to neuraminidase and wheat germ agglutinin (WGA) lectin, whereas Ad5-mediated transduction was dependent on binding to the coxsackie-adenovirus receptor (CAR) and sensitive to soluble RGD peptide and heparin. Our study offers insights into species-dependent factors that determine Ad tropism and, moreover, provides a basis for application of the novel Ad19a-based vector for gene transfer into human skeletal muscle
Using the framework of corporate culture in “mergers” to support the development of a cultural basis for integrative medicine – guidance for building an integrative medicine department or service
Claudia M Witt,1–3 Marion Pérard,2 Brian Berman,3,4 Susan Berman,4 Timothy C Birdsall,5 Horst Defren,6 Sherko Kümmel,7 Gary Deng,8 Gustav Dobos,9 Atje Drexler,10 Christine Holmberg,2 Markus Horneber,11 Robert Jütte,9 Lori Knutson,12 Christopher Kummer,13 Susanne Volpers,14 David Schweiger15 1University Hospital Zurich, Institute for Complementary and Integrative Medicine, Zurich, Switzerland; 2Institute for Social Medicine, Epidemiology and Health Economics, Charité-Universitätsmedizin, Berlin, Germany; 3University of Maryland School of Medicine, Center for Integrative Medicine, Baltimore, Maryland, USA; 4The Institute for Integrative Health, Baltimore, USA; 5Cancer Treatment Centers of America, Goodyear, Arizona, USA, 6Kliniken Essen Mitte, Evang, Huyssen-Stiftung/Knappschaft GmbH Patientenmanagement, Essen, Germany; 7Department of Senology, Breast Center, Kliniken Essen-Mitte, Evang. Huyssens Stiftung, Knappschaft GmbH, Essen, Germany; 8Memorial Sloan-Kettering Cancer Center, New York, USA; 9Department of Internal and Integrative Medicine, Kliniken Essen-Mitte, Academic Teaching Hospital of the University of Duisburg-Essen, Germany; 10Robert Bosch Foundation GmbH, Stuttgart, Germany; 11Department of Internal Medicine, Division of Oncology and Hematology, Paracelsus Medical University, Klinikum Nürnberg, Germany; 12Integrative Healthcare Solutions, Minneapolis, Minnesota, USA; 13Institute of Mergers, Acquisitions and Alliances (IMAA), Zurich, Switzerland; 14Frauenselbsthilfe nach Krebs, Bonn, Germany; 15Schweiger, Schweiger & Associates, Hilton Head Island, South Carolina, USA Background: An increasing number of clinics offer complementary or integrative medicine services; however, clear guidance about how complementary medicine could be successfully and efficiently integrated into conventional health care settings is still lacking. Combining conventional and complementary medicine into integrative medicine can be regarded as a kind of merger. In a merger, two or more organizations - usually companies - are combined into one in order to strengthen the companies financially and strategically. The corporate culture of both merger partners has an important influence on the integration.Purpose: The aim of this project was to transfer the concept of corporate culture in mergers to the merging of two medical systems.Methods: A two-step approach (literature analyses and expert consensus procedure) was used to develop practical guidance for the development of a cultural basis for integrative medicine, based on the framework of corporate culture in “mergers,” which could be used to build an integrative medicine department or integrative medicine service.Results: Results include recommendations for general strategic dimensions (definition of the medical model, motivation for integration, clarification of the available resources, development of the integration team, and development of a communication strategy), and recommendations to overcome cultural differences (the clinic environment, the professional language, the professional image, and the implementation of evidence-based medicine).Conclusion: The framework of mergers in corporate culture provides an understanding of the difficulties involved in integrative medicine projects. The specific recommendations provide a good basis for more efficient implementation. Keywords: integrative medicine, mergers, corporate cultur
Human Papillomavirus Capsid Protein-pREP in Schizosaccharomyces pombe: Efficient Assembly of the Viral Capsid Protein in S. pombe and S. cerevisiae
DNA-Induced Structural Changes in the Papillomavirus Capsid
Human papillomavirus capsid assembly requires intercapsomeric disulfide bonds between molecules of the major capsid protein L1. Virions isolated from naturally occurring lesions have a higher degree of cross-linking than virus-like particles (VLPs), which have been generated in eukaryotic expression systems. Here we show that DNA encapsidation into VLPs leads to increased cross-linking between L1 molecules comparable to that seen in virions. A higher trypsin resistance, indicating a tighter association of capsomeres through DNA interaction, accompanies this structural change