Epitope mapping of new monoclonal antibodies recognizing distinct human FcRII (CD32) isoforms.
The class II Fc gamma receptors are widely distributed on cells of the immune system. Nevertheless, the exact cell type distribution of the FcRII isoforms is still unclear because of the lack of appropriate antibodies that discriminate between the various isoforms. In this study we describe the generation and characterization of three monoclonal antibodies (MAbs) raised against recombinant human FcRIIb2 as well as a synthetic peptide (amino acids 30-39) of this receptor. Analyses of the isoform specificity of these antibodies using ELISA and Western blots revealed that the MAbs II1A5 (mIgG1) and ID2.7 (mIgM) are pan FcRII antibodies recognizing all known FcRII isoforms. In contrast, the MAb II8D2 (mIgG1) specifically reacts with FcRIIb but not with FcRIIa. The observed antibody reactivities could be confirmed by examination of the exact epitopes using overlapping 15-mer peptides spanning the entire FcRIIb2. So far these antibodies are the only ones described that detect FcRII in Western blots. Moreover, they can be used to analyze the cellular FcRII isoform distribution at the protein level, which was otherwise not possible.
Weinrich
V
V
Universität Bielefeld, Fakultät für Chemie-Biochemie II, Germany.
Sondermann
P
P
Bewarder
N
N
Wissel
K
K
Frey
J
J
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis; D000918:Antibody Specificity; D018604:Epitope Mapping; D004926:Escherichia coli / Q000235:genetics; D006801:Humans; D006825:Hybridomas / Q000276:immunology; D051379:Mice; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000235:genetics / Q000276:immunology; D017452:Receptors, IgG / Q000235:genetics*; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D017386:Sequence Homology, Amino Acid
D000911:Antibodies, Monoclonal; D010446:Peptide Fragments; D017452:Receptors, IgG; D011994:Recombinant Proteins