As new immunology assays are developed, there is a need to standardize, optimize and validate them to determine whether they can contribute reliable new information about the immune response. One such assay that was recently developed is the multiplex bead array, which can simultaneously measure the concentration of several dozen analytes in a single sample, such as blood serum. This is a dramatic increase over existing technologies used in clinical trial assessments, which can only measure up to ten analytes at once. To use this new technology in a clinical trials setting, it must be thoroughly assessed for its reliability, variability and limitations, and be compared against existing assays to see whether its results are consistent with them.
VIDD staff scientist Dr. Olivier Defawe, in conjunction with co-director Dr. Julie McElrath, assistant members Drs. Youyi Fong and Nicole Frahm, associate member Dr. Stephen De Rosa and other colleagues, recently validated a version of the multiplex bead array assay for use within the HIV Vaccine Trials Network. Their version of the assay measures cytokines and chemokines, which are cell-signaling proteins secreted by and responded to by immune cells. The levels of these molecules change dramatically in response to vaccination or infection, and can trigger responses such as inflammation and migration of immune cells to the site of infection. After initial optimization experiments, the researchers assessed the limits of detection, variability in the assay between different operators and over time, how accurately it measured a known quantity of analyte, and how it compared to another assay in measuring whether vaccine recipients generated an immune response to vaccination. Overall they found the assay performed robustly and provides valuable additional information about the immune response that differs from the data obtained from existing validated assays. The cytokine multiplex bead array assay will be a useful addition for researching the immune response. Additional knowledge about which molecules are affected by vaccination will provide insight into how the immune response develops, and could lead to improved vaccine design.
Defawe OD, Fong Y, Vasilyeva E, Pickett M, Carter DK, Gabriel E, Rerks-Ngarm S, Nitayaphan S, Frahm N, McElrath MJ, De Rosa SC. Optimization and qualification of a multiplex bead array to assess cytokine and chemokine production by vaccine-specific cells. J Immunol Methods. 2012 May 22.