Isolation and characterization of two monoclonal antibodies that recognize different epitopes of the human c-kit receptor.
After immunizing mice with a human megakaryoblastic leukemia cell line, M-MOK, we obtained two monoclonal antibodies which recognize the human c-kit receptor. The monoclonal antibodies, designated MTK1 and MTK2, were found to specifically recognize Balb/3T3 cells transfected with human c-kit cDNA and not parent Balb/3T3 cells while showing different immunological, biochemical and biological behaviors. Both allowed visualization of the 140 kDa c-kit protein by Western blot analysis, but MTK1 detected only positive band with non-reducing conditions for sodium dodecyl sulfate-polyacrylamide gel electrophoresis. MTK1 partially inhibited the stem cell factor (SCF) induced proliferation of M-MOK cells, whereas, MTK2 was without effect. MTK1 also inhibited the bone marrow derived colony forming unit granulocyte/macrophage (CFU-GM) formed by granulocyte-macrophage colony stimulating factor (GM-CSF) and SCF. Not only anti-CD34 antibodies (HPCA-1) but also MTK1 could be shown to concentrate bone marrow CFU-GM and burst forming unit erythroid (BFU-E) effectively. The presently described monoclonal antibodies may therefore be useful for functional analysis of the ligand binding domain of the human c-kit receptor, as well as for further classification of hematopoietic stem cells in addition to the CD34 positive cells.
Morita
S
S
Department of Pediatric Oncology, Tohoku University, Sendai.
Tsuchiya
S
S
Fujie
H
H
Itano
M
M
Ohashi
Y
Y
Minegishi
M
M
Konno
T
T
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology* / Q000302:isolation & purification; D018952:Antigens, CD34 / Q000276:immunology; D015153:Blotting, Western; D001854:Bone Marrow Cells; D002455:Cell Division / Q000502:physiology; D002469:Cell Separation; D002478:Cells, Cultured; D000939:Epitopes / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000276:immunology / Q000378:metabolism; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D009000:Monocytes / Q000276:immunology / Q000502:physiology; D019009:Proto-Oncogene Proteins c-kit / Q000276:immunology*
D000911:Antibodies, Monoclonal; D018952:Antigens, CD34; D000939:Epitopes; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D019009:Proto-Oncogene Proteins c-kit