Imaging of human leukemic T-cell xenografts in nude mice by radiolabeled monoclonal antibodies and F(ab')2 fragments.
Monoclonal antibodies (MoAb) that react with the T-lymphocyte markers called cluster of differentiation CD5 and CD2 were labeled with iodine 131 (131I) and were injected intravenously in nude mice bearing solid subcutaneous xenografts derived from the human T-cell leukemia line Ichikawa. Both MoAb anti-CD5 and anti-CD2 yielded favorable mean tumor to whole-body ratios of 3.8 and 5.1, respectively. These ratios were further increased up to 10.0 for MoAb anti-CD5 and 15.5 for MoAb anti-CD2 by using their F(ab')2 fragments. The tumors could be imaged clearly by external scanning after injection of F(ab')2 fragments from both MoAb. F(ab')2 fragments from MoAb anti-CD2 and of a third MoAb recognizing the clonotypic determinant (Ti) of the antigen receptor expressed by the human T-cell line Jurkat were injected in mice bearing intrasplenic Jurkat xenografts. A selective localization of both fragments in tumor tissue was demonstrated with mean tumor to whole-body ratios of 7.5 and 4.1 for MoAb anti-CD2 and anti-Ti, respectively. These in vivo experimental results may provide useful information for the potential use of radiolabeled MoAb and fragments in the diagnosis and treatment of patients with T-cell lymphoma and different other forms of T-cell malignancies.
Vacca
A
A
Institute of Biochemistry, University of Lausanne, Epalinges, Switzerland.
Buchegger
F
F
Carrel
S
S
Mach
J P
JP
D000818:Animals; D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D005260:Female; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000276:immunology*; D007457:Iodine Radioisotopes; D007945:Leukemia, Lymphoid / Q000000981:diagnostic imaging / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D011877:Radionuclide Imaging; D013601:T-Lymphocytes / Q000276:immunology*; D014183:Transplantation, Heterologous
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D007140:Immunoglobulin Fab Fragments; D007457:Iodine Radioisotopes