Search results for "api"
showing 10 items of 8586 documents
DNA-induced structural changes in the papillomavirus capsid.
2001
ABSTRACT 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.
Human Papillomavirus Types 16, 18, and 31 Share Similar Endocytic Requirements for Entry
2013
ABSTRACT Human papillomavirus type 18 (HPV18), one of the HPVs with malignant potential, enters cells by an unknown endocytic mechanism. The key cellular requirements for HPV18 endocytosis were tested in comparison to those for HPV16 and -31 endocytoses. HPV18 (like HPV16 and -31) entry was independent of clathrin, caveolin, dynamin, and lipid rafts but required actin polymerization and tetraspanin CD151, and the viruses were routed to the same LAMP-1-positive compartment. Hence, the viruses shared similar cellular requirements for endocytic entry.
Papillomavirus assembly requires trimerization of the major capsid protein by disulfides between two highly conserved cysteines.
1998
ABSTRACT We have used viruslike particles (VLPs) of human papillomaviruses to study the structure and assembly of the viral capsid. We demonstrate that mutation of either of two highly conserved cysteines of the major capsid protein L1 to serine completely prevents the assembly of VLPs but not of capsomers, whereas mutation of all other cysteines leaves VLP assembly unaffected. These two cysteines form intercapsomeric disulfides yielding an L1 trimer. Trimerization comprises about half of the L1 molecules in VLPs but all L1 molecules in complete virions. We suggest that trimerization of L1 is indispensable for the stabilization of intercapsomeric contacts in papillomavirus capsids.
Human Papillomavirus Type 16 E7 Peptide-Directed CD8+ T Cells from Patients with Cervical Cancer Are Cross-Reactive with the Coronavirus NS2 Protein
2003
ABSTRACTHuman papillomavirus type 16 (HPV16) E6 and E7 oncoproteins are required for cellular transformation and represent candidate targets for HPV-specific and major histocompatibility complex class I-restricted CD8+-T-cell responses in patients with cervical cancer. Recent evidence suggests that cross-reactivity represents the inherent nature of the T-cell repertoire. We identified HLA-A2 binding HPV16 E7 variant peptides from human, bacterial, or viral origin which are able to drive CD8+-T-cell responses directed against wild-type HPV16 E7 amino acid 11 to 19/20 (E711-19/20) epitope YMLDLQPET(T) in vitro. CD8+T cells reacting to the HLA-A2-presented peptide from HPV16 E711-19(20)recogni…
Evaluation of HBs, HBc, and frCP virus-like particles for expression of human papillomavirus 16 E7 oncoprotein epitopes.
2002
<i>Objectives:</i> In an attempt to develop virus-like particles (VLPs) as experimental vaccine against human papilloma virus (HPV)-induced tumours, the HPV16 E7 oncoprotein epitopes spanning amino acid (aa) residues 35–98 were expressed on three proteins capable of VLP formation: hepatitis B virus (HBV) surface (HBs) and core (HBc) antigens, and RNA phage fr coats (frCP). <i>Methods:</i> The profile of immunoglobulin isotypes induced in Balb/C mice after immunization with purified chimeric proteins was studied. <i>Results:</i> The HBs*-E7(35–54) protein expressing E7 residues 35–54 between residues 139 and 142 of the HBs carrier formed HBs-like particles…
A short introduction to papillomavirus biology.
2003
In this report, the tropism of papillomaviruses, the structure of virions, the function of viral proteins and the use of pseudovirions for the analysis of the immune response against papillomaviruses and the search for the viral receptor are briefly described.
Clathrin- and Caveolin-Independent Entry of Human Papillomavirus Type 16—Involvement of Tetraspanin-Enriched Microdomains (TEMs)
2008
BACKGROUND: Infectious entry of human papillomaviruses into their host cells is an important step in the viral life cycle. For cell binding these viruses use proteoglycans as initial attachment sites. Subsequent transfer to a secondary receptor molecule seems to be involved in virus uptake. Depending on the papillomavirus subtype, it has been reported that entry occurs by clathrin- or caveolin-mediated mechanisms. Regarding human papillomavirus type 16 (HPV16), the primary etiologic agent for development of cervical cancer, clathrin-mediated endocytosis was described as infectious entry pathway. METHODOLOGY/PRINCIPAL FINDINGS: Using immunofluorescence and infection studies we show in contra…
Conception en technologie CMOS d'un Système de Vision dédié à l'Imagerie Rapide et aux Traitements d'Images
2008
Our work presented in this thesis focuses on the design, testing and implementation of monolithics CMOS image smart sensors : The principle, performance and limitations. The hardware implementation of a vision smart system is the central link. HISIC is High Speed Image Capture with processing at pixel level. An experimental platform for instrumentation and evaluation of retina operators was conducted during this thesis. After a state of the smart sensors and CMOS retinas, the second part is dedicated to the study and design of the pixel image sensor HISIC. Two circuits were realized in CMOS technology. The first identied a new type of photo-detector, and the second, to create a prototype em…
Guia de Prácticas de Optometría II. Tema 8
2021
Este guion de prácticas describe cómo realizar una terapia de la visión. Se analiza la selección del caso, la secuencia de rehabilitación apropiada, y la motivación y cumplimiento del paciente. This chapter describes how to perform vision therapy. The selection of the case, the appropriate rehabilitation sequence, and the motivation and compliance of the patient are analyzed.
Jaunākās skolas vecuma bērnu radošās darbības sekmēšana vizuālās mākslas nodarbībās sākumskolā
2018
Darba autors ir Evita Jakovļeva. Pētījuma nosaukums “Jaunākās skolas vecuma bērnu radošās darbības sekmēšana vizuālās mākslas nodarbībās sākumskolā”. Pētījuma mērķis ir pētīt jaunākās skolas vecuma bērnu radošās darbības sekmēšanas iespējas vizuālās mākslas stundās sākumskolā. 1.nodaļā tiek aprakstītas un apkopotas pedagogu un psihologu atziņas un viedokļi par radošumu, tā būtību, kritērijiem un rādītājiem, par radošo darbību, kad tā veidojas. 2.nodaļā tiek aprakstīts jaunākās skolas vecuma bērnu psiholoģiskais radošuma attīstības raksturojums, kā arī tiek aprakstīts bērnu radošuma un radošās darbības psiholoģiskais raksturojums. 3.nodaļā tiek aprakstīts un analizēts radošās darbības sekmēš…