Development of a Sensitive Anti-Mouse CCR5 Monoclonal Antibody for Flow Cytometry.

C-C chemokine receptor 5 (CCR5), a member of the G protein-coupled receptor family, is the most common coreceptor for the human immunodeficiency virus type 1. CCR5 is also involved in the pathogenesis of tumors and inflammatory diseases. The CCR5 antagonists including monoclonal antibodies (mAbs) have been developed and evaluated in clinical trials. In this study, we developed novel mAbs for mouse CCR5 (mCCR5) using the Cell-Based Immunization and Screening (CBIS) method. One of the established anti-mCCR5 mAbs, C 5 Mab-2 (rat IgG 2b , kappa), reacted with mCCR5-overexpressed Chinese hamster ovary-K1 (CHO/mCCR5) and an endogenously mCCR5-expressing cell line (L1210) by flow cytometry. Using flow cytometry, the dissociation constant ( K D ) of C 5 Mab-2 for CHO/mCCR5 was determined as 4.3 × 10 -8 M. These results indicated that C 5 Mab-2 is useful for the detection of mCCR5 in flow cytometry and may be applicable to obtain the proof of concept in preclinical studies.