T-Track® CMV (CE)
Anyone who has once come into contact with certain pathogens, for example viruses, forms specific T lymphocytes (memory T cells) which maintain an immunological memory for the antigen triggering the disease.
If the corresponding antigen is added to the blood of a person who has already been in contact with it, this leads to a fast restimulation of the antigen-specific memory T cells. These secrete the cytokine IFN-γ, which can be measured as a specific marker of the specific immune response.
The T-Track® tests are based on the in vitro stimulation of mononuclear cells of the peripheral blood (PBMC) with UREA-formulated, virus-specific proteins. Unlike untreated proteins, these have the ability to simultaneously restimulate a broad spectrum of clinically relevant populations of effector cells (T-helper and cytotoxic T cells and via a bystander activation NK and NKT cells) in a mostly HLA independent way.
The reactivated, IFN-γ secreting effector cells are subsequently quantified by ELISpot technology. This highly sensitive test method makes it possible to detect secreted cytokines as specific markers of the immune response on the level of individual cells.
Two different UREA-formulated proteins are used to stimulate CMV-specific blood leukocytes with the T-Track® CMV kit.
The CMV- tegument protein pp65 (phosphoprotein 65) and IE-1 (immediate early-protein 1), a protein which is formed in large amounts in the early stage of an infection, have special immunogenic properties. Stimulating the blood leukocytes with pp65 and IE-1 causes an intense reactivation of CMV-specific memory cells, which can be detected by the production of the cytokine interferon-γ (IFN-γ).
The combined application of pp65 and IE-1 allows a mostly HLA-independent measurement of the CMV-specific immune response in more than 95% of the CMV seropositive blood donors.
It is envisaged that clinical studies will provide a reliable, comprehensive determination of the CMV-specific cell-mediated immunity.