scholarly journals Human Cytomegalovirus Infection of Endothelial Cells Triggers Platelet Adhesion and Aggregation

2005 ◽  
Vol 79 (4) ◽  
pp. 2211-2220 ◽  
Author(s):  
Afsar Rahbar ◽  
Cecilia Söderberg-Nauclér
Keyword(s):  
Endothelial Cells ◽  
Human Cytomegalovirus ◽  
Hcmv Infection ◽  
Thrombus Formation ◽  
Blood Platelets ◽  
Atherosclerotic Disease ◽  
Viral Gene ◽  
Platelet Adherence ◽  
Infected Cells

ABSTRACT Human cytomegalovirus (HCMV) is an opportunistic pathogen that has been implicated in the pathogenesis of vascular diseases. HCMV infection of endothelial cells may lead to vascular damage in vitro, and acute-phase HCMV infection has been associated with thrombosis. We hypothesized that viral infection of endothelial cells activates coagulation cascades and contributes to thrombus formation and acute vascular catastrophes in patients with atherosclerotic disease. To assess the effects of HCMV on thrombogenesis, we examined the adhesion and aggregation of blood platelets to uninfected and HCMV-infected endothelial cells. At 7 days after infection, platelet adherence and aggregation were greater in infected than in uninfected cultures (2,000 platelets/100 cells and 225 ± 15 [mean ± standard error of the mean] aggregates/five microscopic fields versus 100 platelets/100 cells and no aggregates). von Willebrand factor (vWF), ICAM-1, and VCAM-1 but not collagen IV, E-selectin, P-selectin, CD13, and CD31 were expressed at higher levels on infected cells than on uninfected cells. Platelet aggregation was inhibited by blocking of platelet GPIb (with blocking antibodies) or GPIIb/IIIa (with ReoPro) or by blocking of vWF (with polyclonal antibodies to vWF). Furthermore, blocking of vWF, platelet GPIb, and ICAM-1 but not of the endothelial cell marker CD13, α5β3-integrin, or HCMV glycoprotein B reduced platelet adherence to infected cells by 75% ± 5%, 74% ± 5%, or 18% ± 5%, respectively. The increased thrombogenicity was dependent on active virus replication and could be inhibited by foscarnet and ganciclovir; these results suggest that a late viral gene may be mediating this phenomenon, which may contribute to vascular catastrophes in patients with atherosclerotic disease.

scholarly journals Human Cytomegalovirus-Encoded pUL7 Is a Novel CEACAM1-Like Molecule Responsible for Promotion of Angiogenesis

mBio ◽  
2014 ◽  
Vol 5 (6) ◽  
Author(s):  
Jason D. MacManiman ◽  
Andrew Meuser ◽  
Sara Botto ◽  
Patricia P. Smith ◽  
Fenyong Liu ◽  
...  
Keyword(s):  
Human Cytomegalovirus ◽  
Map Kinases ◽  
Hcmv Infection ◽  
Present Report ◽  
Immunoglobulin Superfamily ◽  
Viral Gene ◽  
Cellular Machinery ◽  
Infected Cells ◽  
Cell Adhesion Molecule 1 ◽  
First Time

ABSTRACT Persistent human cytomegalovirus (HCMV) infection has been linked to several diseases, including atherosclerosis, transplant vascular sclerosis (TVS), restenosis, and glioblastoma. We have previously shown that factors secreted from HCMV-infected cells induce angiogenesis and that this process is due, at least in part, to increased secretion of interleukin-6 (IL-6). In order to identify the HCMV gene(s) responsible for angiogenesis promotion, we constructed a large panel of replication-competent HCMV recombinants. One HCMV recombinant deleted for UL1 to UL10 was unable to induce secretion of factors necessary for angiogenesis. Fine mapping using additional HCMV recombinants identified UL7 as a viral gene required for production of angiogenic factors from HCMV-infected cells. Transient expression of pUL7 induced phosphorylation of STAT3 and ERK1/2 MAP kinases and production of proangiogenic factors, including IL-6. Addition of recombinant pUL7 to cells was sufficient for angiogenesis and was again associated with increased IL-6 expression. Analysis of the UL7 structure revealed a conserved domain similar to the immunoglobulin superfamily domain and related to the N-terminal V-like domain of carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1). Our report therefore identifies UL7 as a novel HCMV-encoded molecule that is both structurally and functionally related to cellular CEACAM1, a proangiogenic factor highly expressed during vasculogenesis. IMPORTANCE A hallmark of cytomegalovirus (CMV) infection is its ability to modulate the host cellular machinery, resulting in the secretion of factors associated with long-term diseases such as vascular disorders and cancer. We previously demonstrated that HCMV infection alters the types and quantities of bioactive proteins released from cells (designated the HCMV secretome) that are involved in the promotion of angiogenesis and wound healing. A key proangiogenic and antiapoptotic factor identified from a proteomic-based approach was IL-6. In the present report, we show for the first time that HCMV UL7 encodes a soluble molecule that is a structural and functional homologue of the CEACAM1 proangiogenic cellular factor. This report thereby identifies a critical component of the HCMV secretome that may be responsible, at least in part, for the vascular dysregulation associated with persistent HCMV infection.

scholarly journals Viral Regulation of RANTES Expression during Human Cytomegalovirus Infection of Endothelial Cells

2001 ◽  
Vol 75 (7) ◽  
pp. 3383-3390 ◽  
Author(s):  
Marcella Billstrom Schroeder ◽  
G. Scott Worthen
Keyword(s):  
Endothelial Cells ◽  
Human Cytomegalovirus ◽  
Hcmv Infection ◽  
Mononuclear Cells ◽  
Viral Gene Expression ◽  
Inflammatory Cells ◽  
Viral Gene ◽  
Circulating Cells ◽  
A Site ◽  
Parenchymal Cells

ABSTRACT Human cytomegalovirus (HCMV) evades healthy immune responses during infection, and this evasion may allow HCMV to establish latency in the host. The human vasculature has been recognized as a site of HCMV infection and may also be a site of latent HCMV infection. As the interface between circulating cells and underlying parenchymal cells, the vascular endothelium provides signals for local reaction of inflammatory cells. We propose that HCMV down-regulates expression of the proinflammatory chemokine RANTES from the infected endothelium, which may result in reduced recruitment of mononuclear cells to the site of infection. Abortive HCMV infection of primary endothelial cells with the clinical isolate HCMV 4010, under conditions in which viral gene expression could not occur, induced high levels of RANTES expression. Replicative HCMV infection, however, induced cells in parallel cultures to express significantly lower levels of RANTES. Expression of the chemokines interleukin 8 and MCP-1 by endothelial cells was found to be unaffected by replicative HCMV infection and thus may not play an important role during early HCMV infection of the endothelium. HCMV may regulate RANTES expression from endothelial cells as a mechanism to evade the local immune response to infection.

scholarly journals In vitro selection of human cytomegalovirus variants unable to transfer virus and virus products from infected cells to polymorphonuclear leukocytes and to grow in endothelial cells

2001 ◽  
Vol 82 (6) ◽  
pp. 1429-1438 ◽  
Author(s):  
M. Grazia Revello ◽  
Fausto Baldanti ◽  
Elena Percivalle ◽  
Antonella Sarasini ◽  
Luciana De-Giuli ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Human Cytomegalovirus ◽  
Polymorphonuclear Leukocytes ◽  
In Vitro Selection ◽  
Biological Properties ◽  
Lung Fibroblasts ◽  
Human Embryonic Lung ◽  
Infected Cells ◽  
Selection Of

Four human cytomegalovirus (HCMV) isolates from different clinical sources were extensively propagated in human embryonic lung fibroblasts (HELF). Plaque isolates from each of the four virus strains were evaluated for their ability to be transferred to polymorphonuclear leukocytes (PMNL) and to grow in endothelial cells (EC). While all four of the clinical strains were found to be both PMNL- and EC-tropic, variants were identified from each of the four strains that lacked both biological properties, while three of the four parental strains lost their transfer capacity before passage 50 in HELF. It was demonstrated that one of the four field isolates (VR6110) and its transfer-deficient variant were genetically related, but showed different curves of virus yield in HELF. In addition, neither the immediate-early (IE) mRNA nor the IE protein p72 were found to be transferred to PMNL before 72 h post-infection (late in infection) or in the presence of viral DNA replication inhibitors. These findings link EC and PMNL tropism and suggest that PMNL tropism is a late HCMV function.

scholarly journals Human Cytomegalovirus Subverts the Functions of Monocytes, Impairing Chemokine-Mediated Migration and Leukocyte Recruitment

2006 ◽  
Vol 80 (15) ◽  
pp. 7578-7589 ◽  
Author(s):  
Giada Frascaroli ◽  
Stefania Varani ◽  
Barbara Moepps ◽  
Christian Sinzger ◽  
Maria Paola Landini ◽  
...  
Keyword(s):  
Gene Expression ◽  
Human Cytomegalovirus ◽  
Chemokine Receptors ◽  
Viral Gene Expression ◽  
Viral Gene ◽  
Host Immune System ◽  
Infected Cells ◽  
And Function ◽  
A Site

ABSTRACT Despite their role in innate and adaptive immunity, during human cytomegalovirus (HCMV) infection, monocytes are considered to be an important target of infection, a site of latency, and vehicles for virus dissemination. Since chemokine receptors play crucial roles in monocyte activation and trafficking, we investigated the effects of HCMV on their expression and function. By using endotheliotropic strains of HCMV, we obtained high rates (roughly 50%) of in vitro-infected monocytes but only restricted viral gene expression. At 24 h after infection, while the chemokine receptors CX3CR and CCR7 were unaffected, CCR1, CCR2, CCR5, and CXCR4 were downmodulated on the cell surface and retained intracellularly. Structural components of the viral particles, but not viral gene expression or soluble factors released from infected cells, accounted for the changed localization of the receptor molecules and for the block of chemokine-driven migration. HCMV-infected monocytes indeed became unresponsive to inflammatory and homeostatic chemokines, although the basal cell motility and responsiveness to N-formyl-Met-Leu-Phe were unaffected or slightly increased. The production of inflammatory mediators responsible for the recruitment of other immune cells was also hampered by HCMV. Whereas endothelial and fibroblast cells infected by HCMV efficiently recruited leukocytes, infected monocytes were unable to recruit lymphocytes, monocytes, and neutrophils. Our data further highlight the complex level of interference exerted by HCMV on the host immune system.

scholarly journals Direct infection of primary endothelial cells with human cytomegalovirus prevents angiogenesis and migration

2015 ◽  
Vol 96 (12) ◽  
pp. 3598-3612 ◽  
Author(s):  
Rasmus K. L. Gustafsson ◽  
Hannah C. Jeffery ◽  
Koon-Chu Yaiw ◽  
Vanessa Wilhelmi ◽  
Ourania N. Kostopoulou ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Human Cytomegalovirus ◽  
Clinical Symptoms ◽  
Congenital Infection ◽  
Viral Gene ◽  
Natural Hosts ◽  
And Migration ◽  
Tube Assembly

Human cytomegalovirus (hCMV) is a beta herpesvirus that establishes lifelong infection. Although the virus does not usually cause overt clinical symptoms in immunocompetent individuals it can have deleterious effects in immunocompromised patients, such as those on post-transplant medication or with HIV infection. hCMV is the most common congenital infection and can lead to serious fetal sequelae. Endothelial cells (ECs) are natural hosts for hCMV in vivo, therefore, investigations of how this cell type is modulated by infection are key to understanding hCMV pathogenesis. Previous studies have examined the effect of secretomes from hCMV-infected cells on EC angiogenesis, whereas the effect of direct infection on this process has not been so well investigated. Here, we show that placental ECs are viral targets during congenital infection and that vessels in infected tissue appear morphologically abnormal. We demonstrate that the clinical hCMV strain VR1814 impaired EC tube assembly in in vitro angiogenesis assays and inhibited wound healing ability in scratch assays. Secretomes from infected cultures did not impair angiogenesis of uninfected ECs, suggesting that cell-intrinsic changes, as opposed to secreted factors, were responsible. We observed viral gene transcription dependent downregulation of the expression of angiogenesis-associated genes, including angiopoietin-2, TEK receptor and vascular endothelial growth factor receptors. An alternative clinical hCMV stain, TB40E showed similar effects on EC angiogenesis. Together, our data indicate that direct infection with hCMV can induce an anti-migratory and anti-angiogenic EC phenotype, which could have a detrimental effect on the vasculature development in infected tissues.

scholarly journals Efficient Lytic Infection of Human Arterial Endothelial Cells by Human Cytomegalovirus Strains

2000 ◽  
Vol 74 (16) ◽  
pp. 7628-7635 ◽  
Author(s):  
M. Kahl ◽  
D. Siegel-Axel ◽  
S. Stenglein ◽  
G. ◽  
Jahn ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Human Cytomegalovirus ◽  
Umbilical Vein ◽  
Lytic Infection ◽  
Vascular Bed ◽  
Complete Lysis ◽  
Infected Cells ◽  
Arterial Endothelial Cells

ABSTRACT Endothelial cells (EC) are common targets of permissive infection by human cytomegalovirus (HCMV) in vivo during acute disease. However, studies of HCMV-EC interactions in vitro have generated discordant results. While lytic infection of cultured venous EC has been well established, Fish et al. (K. N. Fish, C. Soderberg Naucler, L. K. Mills, S. Stenglein, and J. A. Nelson, J. Virol. 72:5661–5668) have reported noncytopathic persistence of the virus in cultured aortic EC. We propose that interstrain differences in viral host cell tropism rather than the vascular bed of origin of infected EC might account for these discrepancies. In the present investigation we compared the responses of EC derived from human adult iliac artery, placental microvasculature, and umbilical vein to infection with various HCMV strains. Regardless of the vascular bed of origin, infection with EC-propagated HCMV strains induced 100% efficient cytopathic change progressing to complete lysis of inoculated monolayers. While fibroblast-propagated strains persisted at low titer in infected arterial EC cultures, they were also cytolytic for individual infected cells. The finding of cytopathic lytic infection of arterial EC by HCMV implicates a mechanism of vascular injury in the pathogenesis of HCMV infection.

scholarly journals Human Cytomegalovirus Inhibits Differentiation of Monocytes into Dendritic Cells with the Consequence of Depressed Immunological Functions

2003 ◽  
Vol 77 (20) ◽  
pp. 10943-10956 ◽  
Author(s):  
Sara Gredmark ◽  
Cecilia Söderberg-Nauclér
Keyword(s):  
Dendritic Cells ◽  
Human Cytomegalovirus ◽  
Hcmv Infection ◽  
Costimulatory Molecule ◽  
T Cell Response ◽  
Immune Reactivity ◽  
Immune Recognition ◽  
Dendritic Cell Differentiation ◽  
Infected Cells

ABSTRACT Human cytomegalovirus (HCMV) infections in immunocompromised patients are associated with impaired immunological functions. Blood monocytes, which can differentiate into dendritic cells upon cytokine stimulation, play a central role in adequate immune reactivity and are believed to carry latent HCMV. We demonstrate here that HCMV infection of monocytes results in a block in the cytokine-induced differentiation of monocytes into functionally active CD1a-positive dendritic cells, which exhibited severely depressed immunological functions in vitro. The HCMV-infected cells exhibited a significantly reduced ability to endocytose fluorescein isothiocyanate-labeled dextran particles as well as a more than 90% reduced ability to migrate in response to the chemoattractant factors RANTES, MIP-1α, and MIP-3β. Interestingly, HCMV-infected cells expressed high levels of the costimulatory molecule CD86, in contrast to the low levels of expression that was observed on uninfected monocytes and uninfected immature dendritic cells. Furthermore, HCMV-infected CD1a-negative cells were unable to induce a T-cell response. Thus, these observations suggest that HCMV infection of monocytes in vitro blocks cytokine-induced dendritic cell differentiation, and since dendritic cells play a central role in initiating immune responses, these findings suggest a powerful tactic to avoid immune recognition and to blunt the immune response at early phases of infection.

Differential outcomes of human cytomegalovirus infection in primitive hematopoietic cell subpopulations

Blood ◽  
2004 ◽  
Vol 104 (3) ◽  
pp. 687-695 ◽  
Author(s):  
Felicia Goodrum ◽  
Craig T. Jordan ◽  
Scott S. Terhune ◽  
Kevin High ◽  
Thomas Shenk
Keyword(s):  
Human Cytomegalovirus ◽  
Hcmv Infection ◽  
Viral Gene Expression ◽  
Cell Phenotype ◽  
Viral Gene ◽  
Viral Genomes ◽  
Differential Outcomes ◽  
Infected Cells ◽  
Human Cytomegalovirus Infection ◽  
Cell Subpopulations

AbstractThe cellular reservoir for latent human cytomegalovirus (HCMV) in the hematopoietic compartment, and the mechanisms governing a latent infection and reactivation from latency are unknown. Previous work has demonstrated that HCMV infects CD34+ progenitors and expresses a limited subset of viral genes. The outcome of HCMV infection may depend on the cell subpopulations infected within the heterogeneous CD34+ compartment. We compared HCMV infection in well-defined CD34+ cell subpopulations. HCMV infection inhibited hematopoietic colony formation from CD34+/CD38– but not CD34+/c-kit+ cells. CD34+/CD38– cells transiently expressed a large subset of HCMV genes that were not expressed in CD34+/c-kit+ cells or cells expressing more mature cell surface phenotypes. Although viral genomes were present in infected cells, viral gene expression was undetectable by 10 days after infection. Importantly, viral replication could be reactivated by coculture with permissive fibroblasts only from the CD34+/CD38– population. Strikingly, a subpopulation of CD34+/CD38– cells expressing a stem cell phenotype (lineage–/Thy-1+) supported a productive HCMV infection. These studies demonstrate that the outcome of HCMV infection in the hematopoietic compartment is dependent on the nature of the cell subpopulations infected and that CD34+/CD38– cells support an HCMV infection with the hallmarks of latency.

scholarly journals Revisiting Ehrlichia ruminantium Replication Cycle Using Proteomics: The Host and the Bacterium Perspectives

2021 ◽  
Vol 9 (6) ◽  
pp. 1144
Author(s):  
Isabel Marcelino ◽  
Philippe Holzmuller ◽  
Ana Coelho ◽  
Gabriel Mazzucchelli ◽  
Bernard Fernandez ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Host Cell ◽  
Cell Metabolism ◽  
Replication Cycle ◽  
Host Cells ◽  
Ehrlichia Ruminantium ◽  
Host Interaction ◽  
Infected Cells ◽  
Related Proteins

The Rickettsiales Ehrlichia ruminantium, the causal agent of the fatal tick-borne disease Heartwater, induces severe damage to the vascular endothelium in ruminants. Nevertheless, E. ruminantium-induced pathobiology remains largely unknown. Our work paves the way for understanding this phenomenon by using quantitative proteomic analyses (2D-DIGE-MS/MS, 1DE-nanoLC-MS/MS and biotin-nanoUPLC-MS/MS) of host bovine aorta endothelial cells (BAE) during the in vitro bacterium intracellular replication cycle. We detect 265 bacterial proteins (including virulence factors), at all time-points of the E. ruminantium replication cycle, highlighting a dynamic bacterium–host interaction. We show that E. ruminantium infection modulates the expression of 433 host proteins: 98 being over-expressed, 161 under-expressed, 140 detected only in infected BAE cells and 34 exclusively detected in non-infected cells. Cystoscape integrated data analysis shows that these proteins lead to major changes in host cell immune responses, host cell metabolism and vesicle trafficking, with a clear involvement of inflammation-related proteins in this process. Our findings led to the first model of E. ruminantium infection in host cells in vitro, and we highlight potential biomarkers of E. ruminantium infection in endothelial cells (such as ROCK1, TMEM16K, Albumin and PTPN1), which may be important to further combat Heartwater, namely by developing non-antibiotic-based strategies.

Interactions Between Blood Platelets and Vascular Endothelium in vitro Studies

1979 ◽  
Author(s):  
M.A. Gimbrone ◽  
K.D. Curwen ◽  
R. I. Handin
Keyword(s):  
Platelet Aggregation ◽  
Vascular Endothelium ◽  
Potent Inhibitor ◽  
Platelet Reactivity ◽  
Blood Platelets ◽  
Primary Cultures ◽  
Adenosine Diphosphate ◽  
Human Platelets ◽  
Platelet Adherence

Endothelial cells (EC) can actively influence the hemostatic response at sites of vascular injury through multiple mechanisms. For example, EC can degrade adenosine diphosphate, release plasminogen activator, and synthesize prostacyclin (PGI2), a potent inhibitor of platelet aggregation. We have examined whether PGI2 also might account for the normal lack of platelet adherence to the uninjured EC surface. In a monolayer adherence assay, radiolabeled human platelets in citrated plasma showed minimal interaction with primary cultures of human EC (<1 platelet adhering per cell). Platelets from aspirin-treated and untreated donors behaved similarly. However, aspirin pretreatment of EC consistently resulted in ~2-fold increases in platelet adherence which could be completely abolished by exogenous PGI2 (0.5–1.0 μg/ml). SV40-transformed human EC (SVHEC), which are deficient in PGI2 production compared to primary EC, showed 10-30 times more platelet adherence. Exogenous PGI2 produced a dose - related (.001-1.0 μg/ml) decrease in platelet adherence to SVHEC but did not result in the basal levels observed with normal EC monolayers. These data suggest that : 1) In addition to its effects on platelet aggregation, PGI2 can influence platelet endothelial cell interactions; 2) The increased platelet reactivity of transformed EC is associated with, but not completely attributable, to decreased PGI2 production; and 3) Factors other than PGI2 may play a role in the thromboresistance of normal vascular endothelium.

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