Recognition of the ALL-specific BCR-ABL junction in P190bcr-abl by monoclonal antibody ER-FP1.
The pH chromosome, resulting from the t(9;22) translocation, is the most frequently observed cytogenetic aberration in acute lymphoblastic leukemia (ALL). Two genes, bcr and abl, are involved in this translocation. As a consequence, parts of the bcr and abl genes are fused, resulting in chimeric bcr-abl genes encoding chimeric BCR-ABL proteins. Three bcr-abl genes and proteins have been identified: e1-a2 P190bcr-abl, b2-a2 P210bcr-abl, and b3-a2 P210bcr-abl. Since these chimeric proteins only occur in Ph-chromosome-positive leukemic cells, they are by definition tumor-specific markers. Ph-chromosome-positive ALL is correlated with a bad prognosis, therefore the detection of chimeric BCR-ABL proteins is of prime importance in ALL diagnosis. In the present study, we report on the generation of a monoclonal antibody termed ER-FP1, raised against the tumor-specific e1-a2 BCR-ABL junction in P190bcr-abl. We show that ER-FP1 reacts highly specifically with e1-a2 P190bcr-abl in different assays. The reactivity of ER-FP1 with e1-a2 P190bcr-abl in soluble form was analyzed in an immunoprecipitation assay; specificity was confirmed by peptide inhibition studies. Binding of ER-FP1 to e1-a2 P190bcr-abl at the single cell level was detected by using immunofluorescence techniques. Immunological double-staining experiments using ER-FP1 and a monoclonal antibody recognizing all BCR-ABL proteins confirmed the specificity of ER-FP1 for the e1-a2 fusion point.
van Denderen
J
J
Department of Immunology, Erasmus University, Rotterdam, The Netherlands.
ten Hacken
P
P
Berendes
P
P
Zegers
N
N
Boersma
W
W
Grosveld
G
G
van Ewijk
W
W
D000328:Adult; D000911:Antibodies, Monoclonal / Q000276:immunology; D000918:Antibody Specificity; D002892:Chromosomes, Human, Pair 22; D002899:Chromosomes, Human, Pair 9; D005455:Fluorescent Antibody Technique; D016044:Fusion Proteins, bcr-abl / Q000235:genetics* / Q000276:immunology; D016313:Genes, abl; D006801:Humans; D008297:Male; D008875:Middle Aged; D010677:Philadelphia Chromosome; D011233:Precipitin Tests; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000175:diagnosis / Q000235:genetics* / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000276:immunology; D014178:Translocation, Genetic
D000911:Antibodies, Monoclonal; D011505:Protein-Tyrosine Kinases; D016044:Fusion Proteins, bcr-abl