Heterogeneous expression of a novel MPC-1 antigen on myeloma cells: possible involvement of MPC-1 antigen in the adhesion of mature myeloma cells to bone marrow stromal cells.
Recent immunophenotypic analysis has shown that the heterogeneous expression of the adhesion molecule VLA-5 classifies myeloma cells into VLA-5+ mature and VLA-5- immature subpopulations. To further clarify the two myeloma subpopulations, we generated a monoclonal antibody, MPC-1, by immunizing mice with an adherent human myeloma cell line, KMS-5. The MPC-1 antibody recognized a 48-Kd surface antigen on KMS-5 but not on U-266, a nonadherent human myeloma cell line. Specificity characterization showed that MPC-1 antigen was expressed on mature myeloma cells, normal plasma cells, and mature B cells, whereas pre-B cells and germinal center B cells lacked its expression. Monocytes and a human bone marrow stromal cell line, KM102, also expressed this antigen. Two subclones of MPC-1+ VLA-5+ (KMS-5Ad) and MPC-1-VLA-5+ (KMS-5NAd) were separated from the KMS-5 cell line. The KMS-5NAd adhered to KM102 more tightly than did the KMS-5NAd, and the U-266 (MPC-1-VLA-5-) displayed almost no adherence to the KM102. The adhesion of the KMS-5Ad was partially inhibited by the MPC-1 antibody. These results, taken together, suggest that the MPC-1 antigen serves as a differentiation marker for B-lineage cells, including plasma cells, and may function as an adhesion molecule involved in the interaction of mature myeloma cells with bone marrow stromal cells.
Huang
N
N
Department of Internal Medicine, Hiroshima University, Japan.
Kawano
M M
MM
Harada
H
H
Harada
Y
Y
Sakai
A
A
Kuramoto
A
A
Niwa
O
O
D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D000954:Antigens, Surface / Q000032:analysis / Q000096:biosynthesis; D015153:Blotting, Western; D001853:Bone Marrow / Q000502:physiology*; D001854:Bone Marrow Cells; D002448:Cell Adhesion / Q000502:physiology*; D002460:Cell Line; D002999:Clone Cells; D005434:Flow Cytometry; D006801:Humans; D051379:Mice; D008970:Molecular Weight; D009000:Monocytes / Q000502:physiology; D009101:Multiple Myeloma / Q000473:pathology / Q000503:physiopathology*; D009363:Neoplasm Proteins / Q000032:analysis / Q000096:biosynthesis* / Q000276:immunology; D017469:Receptors, Fibronectin / Q000502:physiology; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; C084913:MPC-1 antigen; D009363:Neoplasm Proteins; D017469:Receptors, Fibronectin