Inventors:
Beverly Packard - Rockville MD, US
Martin Brown - Germantown MD, US
Mark Feinberg - Atlanta GA, US
Luzheng Liu - Brookline MA, US
Guido Silvestri - Decatur GA, US
Ann Chahroudi - Atlanta GA, US
Akira Komoriya - Rockville MD, US
International Classification:
C12Q001/70, G01N033/53, G01N033/567, C12Q001/37
US Classification:
435/007200, 435/023000, 435/005000
Abstract:
This invention provides a non-radioactive assay to monitor and quantify the target-cell killing activities mediated by cytotoxic T lymphocytes (CTLs). This assay is predicated on the discovery that apoptosis pathway activation and, in particular, caspase activity, provides a measure of cytotoxic effector cell activity. In one embodiment, measurement of CTL-induced caspase activation in target cells is achieved through detection of the specific cleavage of fluorogenic caspase substrates. This assay reliably detects antigen-specific CTL killing of target cells, and provides a more sensitive, more informative and safer alternative to the standard Cr-release assay most often used to quantify CTL responses. The assay can be used to study CTL-mediated killing of primary host target cells of different cell lineages, and enables the study of antigen-specific cellular immune responses in real time at the single-cell level. As such, the assay can provide a valuable tool for studies of infectious disease pathogenesis and development of new vaccines and immunotherapies.