KILR CD16 Effector Cells are single donor-derived human primary effector cells, which are engineered for stable CD16 expression. When used in any ADCC assay, these effector cells produce very low background, resulting in robust assay windows, making these cells well-suited for discovery, characterization, and lot release assays.
KILR CD16 Effector Cells Advantages
- Eliminate Donor Variability - Primary effector cells from a single donor
- Fit for Long-Term QC Testing - High lot-to-lot reproducibility with frozen ready-to-use cells
- Measure Target Cell Death - Biologically relevant measure of ADCC and TCR
KILR CD16 Effector Cells are added to the plated target cells expressing the receptor antigen, which have been engineered to stably express a housekeeping protein that is tagged with enhanced ProLabel® (ePL), a smaller β-galactosidase (β-gal) enzyme fragment using the KILR Retroparticles. When the stable target cell line is used in a cytotoxicity assay, and its membrane is compromised due to cell death, the cells will release the tagged reporter protein into the media. The assay can then detect this reporter protein by the addition of detection reagents containing the larger enzyme acceptor (EA) fragment of the β-gal enzyme. This leads to the formation of the active β-gal enzyme, which hydrolyzes the substrate to give a chemiluminescent output, detected on any bench top luminescence reader.
In healthy cells (left image) with immune effector cells, chemiluminescence is not detected as the reporter protein does not leak out through an intact cell membrane into the media. Alternatively, in cancer cells that are killed by the KILR CD16 Effector Cells, chemiluminescence can be detected directly since cells release the reporter protein into the media and this chemiluminescent signal is proportional to the number of dead cells. Death of any other cell type, including the KILR CD16 Effector Cells present within the co-culture will not affect the assay output, giving the KILR Cytotoxicity assay an unparalleled specificity to detect target cell death within a co-culture system.
KILR Cytotoxicity Assays Have Broad Applications in:
Higher Signal:Background Ratios Deliver Better Accuracy and Linear Range
The KILR CD16 Effector Cells provide a significantly larger assay window in comparison to PBMCs. A killing- resistant HER2+ cell line, SKOV-3 was opsonized with trastuzumab and incubated with the effector cells for 3 hours. A 16-fold larger assay window was observed relative to PBMCs in this SKOV-3 cell model. These effector cells have much lower background with higher S:B ratios, resulting in better analysis of the antibody activity.
Obtain Highly ADCC Reproducibility Using KILR CD16 Effector Cells
High repeatability of ADDC using KILR Raji bioassay target cells. Dose response of the anti-CD20 antibody rituximab was evaluated by a single analyst on 3 different days using KILR CD16 Effector Cells (E:T = 10:1). Each day represents an independent vial of the target bioassay cells.