Search results for "Cmv"
showing 10 items of 57 documents
Analysis of T and NK cell subsets in Sicilian population from young to supercentenarian: the role of age and gender
2021
Summary Ageing dramatically affects number and function of both innate and adaptive arms of immune system, particularly T cell subsets, contributing to reduced vaccination efficacy, decreased resistance to infections and increased prevalence of cancer in older people. In the present paper, we analysed the age‐related changes in the absolute number of lymphocytes in 214 Sicilian subjects, and in the percentages of T and natural killer (NK) cells in a subcohort of donors. We compared these results with the immunophenotype of the oldest living Italian supercentenarian (aged 111 years). The results were also sorted by gender. The correlation between number/percentage of cells and age in all ind…
Role of Immunogenetics in the Outcome of HCMV Infection: Implications for Ageing
2019
The outcome of host-virus interactions is determined by a number of factors, some related to the virus, others to the host, such as environmental factors and genetic factors. Therefore, different individuals vary in their relative susceptibility to infections. Human cytomegalovirus (HCMV) is an important pathogen from a clinical point of view, as it causes significant morbidity and mortality in immunosuppressed or immunosenescent individuals, such as the transplanted patients and the elderly, respectively. It is, therefore, important to understand the mechanisms of virus infection control. In this review, we discuss recent advances in the immunobiology of HCMV-host interactions, with partic…
NKG2D stimulation of CD8(+) T cells during priming promotes their capacity to produce cytokines in response to viral infection in mice
2017
NKG2D is an activating receptor that is expressed on most cytotoxic cells of the immune system, including NK cells, γδ and CD8+ T cells. It is still a matter of debate whether and how NKG2D mediates priming of CD8+ T cells in vivo, due to a lack of studies where NKG2D is eliminated exclusively in these cells. Here we studied the impact of NKG2D on effector CD8+ T-cell formation. NKG2D-deficiency that is restricted to murine CD8+ T cells did not impair antigen-specific T-cell expansion following mCMV and LCMV infection, but reduced their capacity to produce cytokines. Upon infection, conventional dendritic cells induce NKG2D ligands, which drive cytokine production on CD8+ T cells via the Da…
Early Post-Transplant Torquetenovirus Viremia Predicts Cytomegalovirus Reactivations In Solid Organ Transplant Recipients.
2018
AbstractMonitoring the human virome has been recently suggested as a promising and novel area of research for identifying new biomarkers which would help physicians in the management of transplant patients. Imbalance of the immune system in transplant recipients has a significant impact on replication of Torquetenovirus (TTV), the most representative and abundant virus of human virome. TTV kinetic was studied by real-time PCR in 280 liver or kidney transplant recipients who underwent different drug regimens to maintain immunosuppression. During one-year post-transplant follow-up, TTV viremia fluctuated irrespective of transplanted organ type but consistent with the immunosuppression regimen…
The Mouse Cytomegalovirus Gene m42 Targets Surface Expression of the Protein Tyrosine Phosphatase CD45 in Infected Macrophages
2016
The receptor-like protein tyrosine phosphatase CD45 is expressed on the surface of cells of hematopoietic origin and has a pivotal role for the function of these cells in the immune response. Here we report that following infection of macrophages with mouse cytomegalovirus (MCMV) the cell surface expression of CD45 is drastically diminished. Screening of a set of MCMV deletion mutants allowed us to identify the viral gene m42 of being responsible for CD45 down-modulation. Moreover, expression of m42 independent of viral infection upon retroviral transduction of the RAW264.7 macrophage cell line led to comparable regulation of CD45 expression. In immunocompetent mice infected with an m42 del…
Cytomegalovirus vector expressing RAE-1γ induces enhanced anti-tumor capacity of murine CD8+ T cells
2017
Designing of CD8 T cell vaccines which would provide protection against tumors is still considered a great challenge in immunotherapy. Here we show a robust potential of a cytomegalovirus (CMV) vector expressing the NKG2D ligand RAE-1γ as CD8 T cell-based vaccine against malignant tumors. Immunization with the CMV vector expressing RAE-1γ delayed tumor growth or even provided complete protection against tumor challenge in both prophylactic and therapeutic settings. Moreover, a potent tumor control in mice vaccinated with this vector can be further enhanced by blocking the immune checkpoints TIGIT and PD-1. Expression of RAE-1γ by the CMV vector potentiated expansion of KLRG1+ CD8 T cells wi…
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…
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…