Development of Monoclonal Antibodies Specific to Either CD300A^R111 or CD300A^Q111 or Both

CD300A is a member of the CD300 immunoglobulin (Ig)-like receptor family consisting of eight molecules in humans, all of which contain one Ig-like domain in the extracellular portion. Upon binding its ligand phosphatidylserine or phosphatidylethanolamine, CD300A mediates an inhibitory signal through the immunoreceptor tyrosine-based inhibitory motif in the cytoplasmic portion. The CD300 family molecules are highly homologous to each other. In addition, CD300A has a single nucleotide polymorphism (rs2272111), which is a nonsense mutation encoding glutamine (CD300A^Q111) instead of arginine (CD300A^R111) at residue 111 in the Ig-like domain of CD300A. In this study, we successfully generated monoclonal antibodies (mAbs) specific to either CD300A^R111 or CD300A^Q111 or both. These mAbs are useful for the analysis of CD300A genotype by flow cytometry and the development of an antibody drug for the treatment of various diseases.