Detecting and defining immunity to cytomegalovirus
Authors: Willis, S., Neal, R., Mantzouratou, A., Emanuela, P. and Buchan, S.
Conference: British Society for Immunology Annual Congress
Dates: 5-8 December 2023
Abstract:Human cytomegalovirus (CMV) is a ubiquitous member of the beta-herpesvirus family, infecting approximately 50% of adults worldwide. Infection is usually asymptomatic although CMV enters a life long latent state. After allogeneic haematopoietic stem cell transplant (allo-HSCT), reactivation of CMV can cause severe morbidity and mortality. T-cell mediated immunity is key in controlling CMV infection and assays designed to measure T-cell CMV-specific immunity would improve personalised management of CMV in the setting of allo-HSCT. We aimed to evaluate the performance of QuantiFERON®-CMV, a commercial assay designed to measure CMV-specific T-cell immune reconstitution post-allo-HSCT. To corroborate results and provide additional information relating to immune-cell subset frequency and phenotype, parallel flow cytometric analyses were performed. Data are from a pilot study, which pre-empts longitudinal evaluation of QuantiFERON®-CMV and flow cytometry in allo-HSCT patients. Healthy volunteers were tested for the presence of anti-CMV IgG (an indicator of prior CMV infection), and simultaneously for the presence/phenotype of CMV-specific T cells by QuantiFERON®-CMV and flow cytometry. CMV cellular immunity was detected in the 6 of 11 individuals exhibiting a humoral response to CMV. Correlation between CMV reactivity detected by QuantiFERON®-CMV and flow cytometry was observed although QuantiFERON®-CMV was the more sensitive assay. CMV-specific CD8+ T cells were enriched for TEMRA and exhibited diverse patterns of CX3CR1 expression, a marker associated with cytolytic function. These data provide a platform to evaluate QuantiFERON®-CMV as a patient management tool post allo-HSCT, and to explore the evolution of CMV-reactive CD8+ T-cell frequency, phenotype and function during immune reconstitution
Source: Manual