CD25 (IL-2Rα) is expressed on both Tregs and recently activated effector T cells — depleting CD25⁺ cells would eliminate the very effector T cells needed for anti-tumor immunity. CTLA-4 is expressed on both Tregs and activated effectors. CCR8 is selectively expressed on tumor-infiltrating Tregs but not on activated effectors or peripheral Tregs. This means anti-CCR8 ADCC-enhanced antibodies can deplete immunosuppressive Tregs in the tumor while preserving effector T-cell function and systemic immune homeostasis — a much wider therapeutic window.

CCR8 is a seven-transmembrane GPCR — it cannot be expressed as a soluble extracellular domain (ECD) protein the way single-pass receptors like PD-1 or CD47 can. The antibody-binding epitopes span multiple extracellular loops and the N-terminus, which only adopt the correct conformation when embedded in the cell membrane. This is why anti-CCR8 antibody development relies heavily on cell-based immunization (DNA immunization + cell-based boost) and screening against CCR8-overexpressing cell lines rather than recombinant protein.

Gate on live CD3⁺CD4⁺CD25⁺CD127⁻/low (Treg gate), then analyze CCR8 surface expression using a PE- or APC-conjugated anti-CCR8 antibody. In tumor tissue, typically 30-80% of intratumoral Tregs are CCR8⁺, whereas <5% of peripheral blood Tregs are CCR8⁺. Include FoxP3 intracellular staining for definitive Treg confirmation. For fresh tumor tissue, enzymatic digestion (Collagenase IV + DNase I) is recommended before staining.

Anti-CCR8 therapeutic antibodies work primarily through Fc-mediated effector functions — ADCC (antibody-dependent cellular cytotoxicity) by NK cells and ADCP (antibody-dependent cellular phagocytosis) by macrophages — to physically deplete CCR8⁺ Tregs in the tumor. This is distinct from checkpoint blockade (which releases brakes on existing T cells). Most clinical candidates use afucosylated or Fc-engineered IgG1 to maximize ADCC potency. Some candidates additionally block CCL1-mediated Treg recruitment, providing a dual mechanism.

Yes. Mouse CCR8 shows the same tumor-selective Treg expression pattern as human CCR8, making syngeneic mouse tumor models (CT26, MC38, B16) valid for preclinical anti-CCR8 efficacy studies. However, human and mouse CCR8 share only ~71% sequence identity, so cross-reactive antibodies are rare — most programs develop separate human and mouse surrogate antibodies. Our catalog includes both human and mouse CCR8 reagents for translational research.