C₈Mab-3: An Anti-Mouse CCR8 Monoclonal Antibody for Immunocytochemistry

The C-C motif chemokine receptor 8 (CCR8) is highly expressed in regulatory T cells. CCR8 is also expressed in many cancers and is associated with those progression. The development of monoclonal antibodies (mAbs) for CCR8 leads to cancer immunotherapy and elucidation of unknown mechanisms of CCR8-dependent cancer progression. In this study, we have developed an anti-mouse CCR8 (mCCR8) mAb (clone C₈Mab-3, rat IgG₁, kappa) using the Cell-Based Immunization and Screening (CBIS) method. We revealed that C₈Mab-3 and its recombinant antibody (recC₈Mab-3) bind to mCCR8-overexpressed Chinese hamster ovary (CHO)-K1 cells (CHO/mCCR8), but not to the parental CHO-K1 cells, in flow cytometry. In addition, C₈Mab-3 and recC₈Mab-3 reacted to P388 (a mouse lymphocyte-like cell) and J774-1 (a mouse macrophage-like cell), which express endogenous mCCR8. C₈Mab-3 also detected exogenous and endogenous mCCR8 using immunocytochemistry. These results suggest that C₈Mab-3, developed using the CBIS method, is useful for immunocytochemistry against exogenous and endogenous mCCR8.