Amino acid sequences of 60B8 antigens induced in HL-60 cells by 1,25-dihydroxyvitamin D3. The antigens are identical with macrophage-related protein-14 and -8

A differentiation antigen 60B8 appeared in human promyelocytic leukemia HL-60 cells which had been induced to differentiate into macrophage-like cells by treatment with 1,25-dihydroxyvitamin D3. The antigen was purified by immunoaffinity chromatography and separated into two proteins, 60B8-A and -B antigens, by reverse-phase high performance liquid chromatography (HPLC). Both proteins were digested with proteases, and the resulting peptides were subjected to amino acid sequence analysis after purification by reverse-phase HPLC. The amino acid sequences of 60B8-A and -B antigens were identical with those of the proteins MRP-14 and -8, respectively, which were recently predicted from the nucleotide sequences of their complementary deoxyribonucleic acid (cDNA) clones by Odink et al. (Nature (London), 330, 80 (1987)). Although they did not characterize the chemical properties of the two proteins, our results clearly indicate that macrophage-related protein (MRP)-14 and -8 are expressed without post-translational modification, except that the amino-terminus of MRP-14 is blocked, in differentiated HL-60 cells.