Search results for "Cytomegalovirus infections"
showing 10 items of 153 documents
Polyethylenimine is a strong inhibitor of human papillomavirus and cytomegalovirus infection.
2012
ABSTRACT Polyethylenimines are cationic polymers with potential as delivery vectors in gene therapy and with proven antimicrobial activity. However, the antiviral activity of polyethylenimines has not been addressed in detail thus far. We have studied the inhibitory effects of a linear 25-kDa polyethylenimine on infections with human papillomaviruses and human cytomegaloviruses. Preincubation of cells with polyethylenimine blocked primary attachment of both viruses to cells, resulting in a significant reduction of infection. In addition, the dissemination of human cytomegalovirus in culture cells was efficiently reduced by recurrent administration of polyethylenimine. Polyethylenimine conce…
Frequent coinfection of cells explains functional in vivo complementation between cytomegalovirus variants in the multiply infected host.
2005
In contrast to many other virus infections, primary cytomegalovirus (CMV) infection does not fully protect against reinfection. Accordingly, clinical data have revealed a coexistence of multiple human CMV variants/ strains in individual patients. Notably, the phenomenon of multiple infection was found to correlate with increased virus load and severity of CMV disease. Although of obvious medical relevance, the mechanism underlying this correlation is unknown. A weak immune response in an individual could be responsible for a more severe disease and for multiple infections. Alternatively, synergistic contributions of variants that differ in their biological properties can lead to qualitative…
Shedding light on the elusive role of endothelial cells in cytomegalovirus dissemination.
2011
Cytomegalovirus (CMV) is frequently transmitted by solid organ transplantation and is associated with graft failure. By forming the boundary between circulation and organ parenchyma, endothelial cells (EC) are suited for bidirectional virus spread from and to the transplant. We applied Cre/loxP-mediated green-fluorescence-tagging of EC-derived murine CMV (MCMV) to quantify the role of infected EC in transplantation-associated CMV dissemination in the mouse model. Both EC- and non-EC-derived virus originating from infected Tie2-cre + heart and kidney transplants were readily transmitted to MCMV-naïve recipients by primary viremia. In contrast, when a Tie2-cre + transplant was infected by pri…
Cell types infected in human cytomegalovirus placentitis identified by immunohistochemical double staining
1993
Chronic villitis is almost always present in intrauterine infection with human cytomegalovirus (HCMV). The inflammatory response to this virus has been described in detail. However, little is known about the types of placental cells that may be infected by HCMV and six cases of HCMV placentitis were thus investigated to identify the vulnerable cell types. Immunohistochemical double staining analyses were performed using antibodies to HCMV immediate early antigens and to specific cellular marker proteins. Fixed connective tissue cells could be demonstrated to be the predominantly infected cell type in each placental tissue. Endothelial cells and macrophages were also found to be infected in …
Human cytomegalovirus glycoprotein B genotypes in immunocompetent, immunocompromised, and congenitally infected Italian populations
2003
Human cytomegalovirus (HCMV) strains, obtained from immunocompetent and immunocompromised Italian hosts, were typed with glycoprotein B (gB) gene restriction analysis. A predominant circulation of HCMV strains with gB type 2 and 3 was detected in both the immunocompetent host with a primary HCMV infection and the immunocompromised host with or without HCMV disease. No association between gB types and subjects with different risks of developing HCMV disease was found. All four gB genotypes were capable of causing congenital infection in Italian babies, with gB type 1 accounting for 50% of the strains examined in symptomatic infants and a remarkable incidence of gB type 4 viruses.
An antigen fragment encompassing the AD2 domains of glycoprotein B from two different strains is sufficient for differentiation of primary vs. recurr…
2001
Primary human cytomegalovirus (HCMV) infection during pregnancy is a frequent cause of fatal damage in populations with low prevalence of HCMV. Differentiation of primary vs. recurrent HCMV infection is an important issue in prenatal counseling. Antibodies specific for viral glycoproteins become detectable only with considerable delay with relation to HCMV infection or IgG seroconversion. Thus, lack of glycoprotein specific (gp-specific) antibodies can serve as a convenient indicator to identify those pregnant women that bear an elevated risk for HCMV transplacental transmission and fetal sequelae. In the opposite case, presence of gp-specific antibodies virtually excludes HCMV primary infe…
Suppression of CD8+ T cell recognition in the immediate-early phase of human cytomegalovirus infection.
2012
Human cytomegalovirus (HCMV) interferes with MHC class I-restricted antigen presentation and thereby reduces recognition by CD8+ T-cells. This interference is mediated primarily by endoplasmic reticulum-resident glycoproteins that are encoded in the US2–11 region of the viral genome. Such a suppression of recognition would be of particular importance immediately after infection, because several immunodominant viral antigens are already present in the cell in this phase. However, which of the evasion proteins gpUS2–11 interfere(s) with antigen presentation to CD8+ T-cells at this time of infection is not known. Here we address this question, using recombinant viruses (RV) that express only o…
Identification of a Conserved HLA-A2-Restricted Decapeptide from the IE1 Protein (pUL123) of Human Cytomegalovirus
2002
Abstract Control of human cytomegalovirus (HCMV) infection is predominantly mediated by cytolytic CD8 + T lymphocytes (CTL). Among the roughly 200 HCMV-encoded polypeptides, the tegument protein pp65 (ppUL83) and the nonstructural IE1 protein are considered to be dominant CTL targets. Yet the importance of CTL against IE1 for protective immunity against HCMV reactivation and disease has remained elusive. Analyses have been difficult, as all MHC class I presented peptides of IE1 defined so far are located in parts of the protein that are variable between viral strains. In this study a conserved decameric peptide from IE1 (P6, IE1 354–363 ) that bound to HLA-A2 was identified. Using peptide-p…
Non-redundant and redundant roles of cytomegalovirus gH/gL complexes in host organ entry and intra-tissue spread
2015
Herpesviruses form different gH/gL virion envelope glycoprotein complexes that serve as entry complexes for mediating viral cell-type tropism in vitro; their roles in vivo, however, remained speculative and can be addressed experimentally only in animal models. For murine cytomegalovirus two alternative gH/gL complexes, gH/gL/gO and gH/gL/MCK-2, have been identified. A limitation of studies on viral tropism in vivo has been the difficulty in distinguishing between infection initiation by viral entry into first-hit target cells and subsequent cell-to-cell spread within tissues. As a new strategy to dissect these two events, we used a gO-transcomplemented ΔgO mutant for providing the gH/gL/gO…
Evaluating Human T-Cell Therapy of Cytomegalovirus Organ Disease in HLA-Transgenic Mice
2015
Reactivation of human cytomegalovirus (HCMV) can cause severe disease in recipients of hematopoietic stem cell transplantation. Although preclinical research in murine models as well as clinical trials have provided 'proof of concept' for infection control by pre-emptive CD8 T-cell immunotherapy, there exists no predictive model to experimentally evaluate parameters that determine antiviral efficacy of human T cells in terms of virus control in functional organs, prevention of organ disease, and host survival benefit. We here introduce a novel mouse model for testing HCMV epitope-specific human T cells. The HCMV UL83/pp65-derived NLV-peptide was presented by transgenic HLA-A2.1 in the conte…