Anti-CD163 Antibody [GHI/61] (PE) (A86217)

The antibodies Ki-M8, Ber-Mac3, GHI/61 and SM4 define a human macrophage-associated antigen with a relative molecular mass of 130,000 which we designate M130. The protein was purified by immunoaffinity chromatography and an N-terminal and three internal amino acid sequences were obtained. A cDNA fragment was initially obtained by polymerase chain reaction (PCR) using reverse-translated primers. Several variant cDNA clones, derived from alternative spliced messages, were obtained from a lipopolysaccharide-stimulated human monocyte library and were sequenced. The relative abundance of these variants was evaluated by a series of overlapping PCR reactions. The size of the most representative cDNA is 3.7 kb and closely agrees with the mRNA size of 3.8 kb determined by Northern blot analysis. The membrane protein encoded contains a leader peptide of 40 residues, a putative extracellular domain of 1003 residues, followed by a hydrophobic segment of 24 residues and a cytoplasmic domain of 49 residues. The extracellular domain was found to contain nine repeating elements, of about 110 residues, which are similar to those of the scavenger receptor superfamily.

A new monoclonal antibody, GHI/61, which labels the majority of monocytes and tissue macrophages is described. This antibody recognizes an intracellular antigen of 130,000 MW (reduced) and 110,000 MW (unreduced). Using biochemical, flow cytometry and immunocytochemical studies antibody GHI/61 was shown to recognize the same antigen as the previously described antibodies Ber-MAC3, Ki-M8 and SM4. On the basis of the results obtained, antibodies GHI/61, SM4, Ber-MAC3 and Ki-M8 should form a new CD group at the next Leucocyte Typing Workshop. Since the antigen recognized by the antibody GHI/61 is relatively easy to purify, the sequencing and the isolation of the gene encoding this protein should be possible.