Search results for "Cytomegalovirus infections"

Cytomegalovirus Misleads Its Host by Priming of CD8 T Cells Specific for an Epitope Not Presented in Infected Tissues

2003

Cytomegaloviruses (CMVs) code for several proteins that inhibit the presentation of antigenic peptides to CD8 T cells. Although the molecular mechanisms of CMV interference with the major histocompatibility complex class I pathway are long understood, surprisingly little evidence exists to support a role in vivo. Here we document the first example of the presentation of an antigenic peptide being blocked by a CMV immune evasion protein in organs relevant to CMV disease. Although this Db-restricted peptide, which is derived from the antiapoptotic protein M45 of murine CMV (mCMV), is classified as an immunodominant peptide based on response magnitude and long-term memory, adoptive transfer of…

Therapeutic Vaccination of Hematopoietic Cell Transplantation Recipients Improves Protective CD8 T-Cell Immunotherapy of Cytomegalovirus Infection

2021

Reactivation of latent cytomegalovirus (CMV) endangers the therapeutic success of hematopoietic cell transplantation (HCT) in tumor patients due to cytopathogenic virus spread that leads to organ manifestations of CMV disease, to interstitial pneumonia in particular. In cases of virus variants that are refractory to standard antiviral pharmacotherapy, immunotherapy by adoptive cell transfer (ACT) of virus-specific CD8+ T cells is the last resort to bridge the “protection gap” between hematoablative conditioning for HCT and endogenous reconstitution of antiviral immunity. We have used the well-established mouse model of CD8+ T-cell immunotherapy by ACT in a setting of experimental HCT and mu…

Reconstitution of CMV pp65 and IE-1-specific IFN-γ CD8+ and CD4+ T-cell responses affording protection from CMV DNAemia following allogeneic hematopo…

2011

Threshold levels of CMV-specific T-cell populations presumably affording protection from active CMV infection in allo-SCT recipients have been proposed, but lack extensive validation. We quantified CMV pp65 and immediate-early 1-specific IFN-γ CD8(+) and CD4(+) T cell responses at days +30, +60 and +90 after transplantation in 133 patients, and established cutoff cell levels protecting from CMV DNAemia within the first 120 days after transplantation. No patients showing IFN-γ CD8(+) or IFN-γ CD4(+) T-cell counts1.0 and1.2 cells/μL, respectively, developed a subsequent episode of CMV DNAemia. Initial or recurrent episodes of CMV DNAemia occurred in the face of IFN-γ T-cell levels below defin…

Lack of prompt expansion of cytomegalovirus pp65 and IE-1-specific IFNγ CD8+ and CD4+ T cells is associated with rising levels of pp65 antigenemia an…

2009

Rising levels of cytomegalovirus (CMV) DNAemia and/or pp65 antigenemia have been observed during pre-emptive ganciclovir therapy in patients undergoing allogeneic hematopoietic stem cell transplantation (allo-SCT). We assessed the incidence of this event in our series, and investigated whether its occurrence was associated with an impairment in the CMV-specific T-cell response. A total of 36 allo-SCT recipients experienced one or more episodes of active CMV infection (n=68) that were pre-emptively treated with val(ganciclovir). Rising levels of antigenemia and DNAemia, and an isolated increase in antigenemia, were observed in 39.7 and 2.9% of all episodes, respectively. Receipt of corticost…

Chemokines: reliable markers for diagnosis of rejection and inflammation following orthotopic liver transplantation.

2001

The impact of virus population diversity on the dynamics of cytomegalovirus DNAemia in allogeneic stem cell transplant recipients

2017

Mixed cytomegalovirus (CMV) infections are associated with delayed viral clearance in solid organ transplant recipients. We investigated whether this could be extrapolated to allogeneic stem cell transplant (allo-SCT) recipients. A total of 48 plasma specimens, obtained during 29 episodes of active CMV infection in 25 non-consecutive allo-SCT patients, were analysed. Baseline blood specimens, drawn shortly prior to the inception of pre-emptive antiviral therapy (pre-treatment specimen; n=29), as well as follow-up samples obtained either after the initiation of antiviral therapy (post-treatment specimen; n=15) or during recurrent episodes (n=4) were analysed. Plasma CMV DNA loads were quanti…

Lack of evidence for a reciprocal interaction between bacterial and cytomegalovirus infection in the allogeneic stem cell transplantation setting

2016

Summary Pathogenic interactions between bacteria and cytomegalovirus (CMV) may potentially occur early after allogeneic stem cell transplantation (Allo-SCT). This possibility nevertheless has not been investigated in depth. This was a retrospective study that included 170 consecutive patients who underwent 173 Allo-SCTs. Both bacterial infection (most of which were bacteremic) and CMV DNAemia were detected in 78 Allo-SCTs (62.9%). In total, 51 and 32 episodes of bacterial infection preceded or occurred after CMV DNAemia detection, respectively. Both events were diagnosed concurrently in four Allo-SCTs. The cumulative incidence of bacterial infection (of any type) over the study period was c…

Preemptive antiviral therapy for CMV infection in allogeneic stem cell transplant recipients guided by the viral doubling time in the blood

2015

Preemptive antiviral therapy for CMV infection in allogeneic stem cell transplant recipients guided by the viral doubling time in the blood

Assessing the risk of cytomegalovirus DNAaemia in allogeneic stem cell transplant recipients by monitoring oxidative-stress markers in plasma

2017

The level of antioxidants, such as thiol-containing tripeptide glutathione (GSH), in cytomegalovirus (CMV)-infected cells is notably increased. We previously showed that GSH levels in plasma, as measured by untargeted 1H nuclear magnetic resonance, are higher in allogeneic stem cell transplant (allo-SCT) recipients who subsequently develop CMV viraemia. We hypothesized that the net level of oxidative-stress markers present in plasma may be reduced in patients who develop CMV DNAaemia compared to those who do not. We serially monitored the levels of malondialdehyde (MDA) and carbonylated proteins (CPs) early after allo-SCT and assessed whether they could predict the occurrence of CMV DNAaemi…

Dynamics of cytomegalovirus (CMV) plasma DNAemia in initial and recurrent episodes of active CMV infection in the allogeneic stem cell transplantatio…

2011

Preemptive antiviral therapy strategies for active cytomegalovirus (CMV) infection occurring in allogeneic stem cell transplant recipients should be optimized to avoid overtreatment. The current study was aimed at determining whether the analysis of the kinetics of CMV DNA load in plasma may provide useful information for the therapeutic management of active CMV infection in this setting. A total of 59 consecutive patients were included in the study, of which 40 (67.8%) developed 1 (n = 21) or more (n = 19) episodes of CMV DNAemia. The need for antiviral therapy for initial or secondary episodes of CMV DNAemia could not be predicted on the basis of the CMV DNA load value in the first plasma…