Immunity Illuminated

Procedure for Cyclex's Luminetics T cell activation assay

The T-cell immune status of patients with conditions such as AIDS indicates disease progression. One way to evaluate T-cell immune health is to measure the proliferation of a patient's T cells in response to stimulation with an antigen or mitogen. However, these measurements typically require long incubation times and radioactive isotopes, making them unsuitable for clinical applications. Columbia, Md.-based Cylex Inc. has designed a convenient alternative with its Luminetics Assay for T Cell Activation, a rapid, whole blood-based assay that combines paramagnetic particle separation with luminescence detection. While cell proliferation assays provide similar information, the Luminetics Assay is unique in that it obtains results in hours rather than days; a typical assay takes less than 24 hours.

In the Luminetics Assay, T cells are stimulated with an antigen or mitogen first, followed by separation of specific T-cell subsets. Monoclonal antibodies attached to paramagnetic particles recognize specific cell surface markers, and T cells are isolated when the sample is placed in a magnetic field. Because increased intracellular ATP accumulation is associated with T-cell activation, a luminescent ATP assay employing firefly luciferase measures the level of activation among isolated cells. As Peter Sottong, vice president and director of operations at Cylex, explains, "By comparing the activated to the unstimulated cells, you can get a sense of the health of the immune system itself."

Researchers can use the Luminetics Assay for a variety of applications, including AIDS, autoimmune disease, cancer, and organ transplantation research. In addition, simply changing the monoclonal antibodies attached to the magnetic beads enables study of other lymphocyte subsets.

--Aileen Constans (aconstans@the-scientist.com)

For More Information
Cylex, Inc.
(410) 964-0236
www.cylex.net