Standardization of the Human Cytomegalovirus Antigenemia Assay by Means of In Vitro-Generated pp65-Positive Peripheral Blood Polymorphonuclear Leukocytes

Reviews in Medical Virology

2010

Self Cite

128

111

Human cytomegalovirus (HCMV) has been routinely isolated from and propagated in vitro in human embryonic lung fibroblast (HELF) cell cultures, while in vivo it is known to infect predominantly endothelial and epithelial cells. In recent years, genetic determinants of the HCMV tropism for endothelial/epithelial cells were identified in the UL131A/UL130/UL128 locus of HCMV genome of wild-type strains. UL131A-UL128 gene products form a complex with glycoprotein H (gH) and L (gL) resulting in a gH/gL/UL131A-UL128 complex that is required for HCMV entry into endothelial/epithelial cells. In contrast, virus entry into fibroblasts has its genetic determinants in the complex gH/gL/gO (or gH/gL). During primary HCMV infection, the neutralising antibody response measured in endothelial cells (EC) is potent, occurs very early and is directed mostly against combinations of two or three gene products of the UL131A-128 locus. On the contrary, neutralising antibodies measured in fibroblasts appear late, are relatively weak in potency and are directed against gH and gB. The T-cell immune response to UL131A-UL128 gene products remains to be investigated. Recently, a role has been proposed for neutralising antibody in conferring prevention/protection against HCMV infection/disease in pregnant women with primary HCMV infection. However, the level of cooperation between humoral immunity and the well-established T-cell protection remains to be defined.

Section: In Vivo Hcmv Cell Tropismmentioning

confidence: 99%

Section: Genetic Determinants Of Hcmv Tropism For Endothelial/ Epithementioning

confidence: 99%

Human cytomegalovirus tropism for endothelial/epithelial cells: scientific background and clinical implications

Revello

Reviews in Medical Virology

2010

Self Cite

128

111

“…HCMV DNA was quantified by real-time PCR using a primer pair selected from the US8 gene (nt 226-290) [15]. Antigenemia was determined by counting the number of pp65-positive leukocytes/2 × 10 5 leukocytes isolated from peripheral blood (16,17).…”

Section: Virological Follow-upmentioning

confidence: 99%

Positive Cross-Match Living Donor Kidney Transplantation: Longer-Term Outcomes

American Journal of Transplantation

Lilleri

Rognoni

et al. 2009

The incidence and treatment of both systemic and pulmonary human cytomegalovirus (HCMV) infection as well as HCMV-specific T-cell immune responses were investigated in 57 consecutive lung transplant recipients (LTR) by using as cutoffs for preemptive therapy: 300 000 DNA copies/mL whole blood for systemic infections and 100 000 DNA copies/mL bronchoalveolar lavage fluid for lung infections. Results showed that out of 29/57 LTR (50.9%) needing preemptive antiviral therapy, 15 (51.7%) reached the blood cutoff, 8 (27.6%) the pulmonary cutoff and 6 (20.7%) both the blood and the lung cutoff (3 simultaneously and 3 subsequently). Recovery of HCMV-specific T-cell immune responses was achieved much earlier for CD8 + than CD4 + T cells. However, protection from HCMV reactivation was conferred by the presence of both arms of the Tcell response. In two LTR reaching the pulmonary cutoff and not preemptively treated, a full HCMV-specific CD4 + and CD8 + T-cell response was associated with resolution of lung infection. Antirejection steroid therapy suppressed T-cell immune responses, thus facilitating HCMV reactivation. In conclusion, in LTR, monitoring HCMV infection in both blood and lungs, may improve preemptive therapy efficacy. In addition, monitoring the HCMV-specific T-cell immune response appears useful for predicting control of HCMV infection in the posttransplant period.

“…Patients examined in this immunological study were included in a randomized controlled study aimed at evaluating a DNAemia cutoff for pre-emptive therapy of HCMV infections in comparison with the antigenemia cutoff in use in our department for several years. Thus, patients were randomly selected from each of the two arms using as a guide for pre-emptive therapy either antigenemia (20,21), with a cutoff of 100 pp65-positive leukocytes/2 × 10 5 leukocytes examined (22), or DNAemia (23) with a cutoff of 300 000 copies/mL whole blood (24). Antigenemia and DNAemia were performed once a week during the first 3 months post-transplant in the absence of HCMV infection, and twice a week during episodes of HCMV infection.…”

Section: Hcmv Infection Diagnosis and Treatmentmentioning

confidence: 99%

Monitoring of Human Cytomegalovirus-Specific CD4+ and CD8+ T-Cell Immunity in Patients Receiving Solid Organ Transplantation

American Journal of Transplantation

Lilleri

Fornara

et al. 2006

156

111

Absolute and human cytomegalovirus (HCMV)-specific CD4+ and CD8 + T-cell counts were monitored in 38 solid organ (20 heart, 9 lung and 9 kidney) transplant recipients during the first year after transplantation by a novel assay based on T-cell stimulation with HCMV-infected autologous dendritic cells. According to the pattern of T-cell restoration occurring either within the first month after transplantation or later, patients were classified as either early (n = 21) or late responders (n = 17). HCMV-specific CD4 + and CD8+ T-cell counts were consistently lower in late compared to early responders from baseline through 6 months after transplantation. In addition, in late responders, while HCMV infection preceded immune restoration, HCMV-specific CD4 + restoration was significantly delayed with respect to CD8 + T-cell restoration. The number of HCMV-specific CD4 + and CD8+ T-cells detected prior to transplantation significantly correlated with time to T-cell immunity restoration, in that higher HCMV-specific T-cell counts predicted earlier immune restoration. Clinically, the great majority of early responders (18/21, 85.7%) underwent self-resolving HCMV infections (p = 0.004), whereas the great majority of late responders (13/17, 76.5%) were affected by HCMV infections requiring antiviral treatment (p = <0.0001). Simultaneous monitoring of HCMV infection and HCMV-specific T-cell immunity predicts T-cell-mediated control of HCMV infection.