Subset & Target Phenotyping

T-Cell Subset Characterization

• CD3 — defines the total T-cell population
• CD4 — identifies helper T-cell subsets
• CD8 — identifies cytotoxic T-cell subsets
• CD45RA / CD45RO / CCR7 / CD62L — memory-subset classification

CD4⁺ and CD8⁺ T cells play distinct roles in TCE-mediated immune responses. CD8⁺ T cells are the primary cytotoxic effector cells, while CD4⁺ T cells support and sustain CD8⁺ function through cytokine secretion. In healthy-donor PBMCs, CD8⁺ cells typically account for 20–40% of T cells; if the post-sort CD8⁺ proportion is too low (e.g., <10%), cytotoxicity assays may fail to distinguish candidate activity differences due to insufficient effector cells.

Memory-subset markers provide a differentiation context for interpreting T-cell exhaustion: naive T cells, central memory T cells, effector memory T cells, and terminally differentiated effector memory T cells respond differently to repeated stimulation, and the same inhibitory-receptor expression level carries different meanings across subsets.

Target-Cell Phenotyping (must be confirmed before cytotoxicity assays)

• Whether the target antigen is expressed, and whether antigen-positive and antigen-negative populations are clearly separated;
• Whether the antigen density falls within the expected range, and whether the target cells are in a state suitable for functional assays.

Antigen-density quantitation: Target-antigen density is always recorded as antibodies per cell (ABC, calibrated against standardized beads). Before each experiment, confirm a positive rate >95% and that ABC falls within the historical benchmark range for the cell line. The negative/positive cutoff, batch release, and candidate comparisons are all based on ABC. The key to this step is choosing validated, multicolor-compatible flow antibodies; clone number, fluorochrome pairing, and titrated concentration all affect gating accuracy, and clones already validated in multicolor panels are preferred.

Product list

Select the validated flow antibodies for subset gating and target-antigen quantitation.

Blinatumomab Reference Data

Data Validation

ABC quantitation standard: target-antigen density is recorded as antibodies per cell (ABC, calibrated against standardized beads). CD20 ABC on Raji cells is expected to be stable, with >95% positivity and between-batch CV controlled within an acceptable range.

Expected performance in epcoritamab functional evaluation: using SOLIDEX^®-CDEx CD4/CD8 antibodies for subset gating is expected to show no MFI decay. Memory-subset gating (CD45RA/CCR7) is expected to be clearly resolved, providing a reliable differentiation context for exhaustion interpretation.