Identification of soluble APO-1 in supernatants of human B- and T-cell lines and increased serum levels in B- and T-cell leukemias.
The cell-surface protein APO-1 is a member of the nerve growth factor (NGF)/tumor necrosis factor (TNF) receptor superfamily. APO-1 mediates apoptosis in susceptible cells upon stimulation with the monoclonal antibody anti-APO-1 or upon binding of its natural ligand. Soluble receptors had previously been identified for most members of the NGF/TNF receptor superfamily. Recently, a soluble form of APO-1 (sAPO-1) was described. We established a sandwich enzyme-linked immunosorbent assay to detect sAPO-1 in culture supernatants of human cell lines and in human sera. sAPO-1 was found in culture supernatants of different human B- and T-cell lines. Molecular weights of sAPO-1 and membrane APO-1 were similar. In addition, in comparison to healthy donors, sera from patients with different high- and low-grade malignant B- and T-cell leukemias and lymphomas contained increased levels of sAPO-1. These findings may have implications for the growth of leukemias and the diagnostic monitoring of individual patients.
Knipping
E
E
Tumorimmunology Program, German Cancer Research Center, Heidelberg.
Debatin
K M
KM
Stricker
K
K
Heilig
B
B
Eder
A
A
Krammer
P H
PH
D000818:Animals; D000954:Antigens, Surface / Q000097:blood*; D001402:B-Lymphocytes / Q000737:chemistry*; D002460:Cell Line; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D015448:Leukemia, B-Cell / Q000097:blood*; D015458:Leukemia, T-Cell / Q000097:blood*; D008297:Male; D011817:Rabbits; D013601:T-Lymphocytes / Q000737:chemistry*; D019014:fas Receptor
D000954:Antigens, Surface; D019014:fas Receptor