Blood kinetics, tissue distribution, and radioimaging of anti-common chronic lymphatic leukemia antigen (cCLLa) monoclonal antibody CLL2 in mice transplanted with cCLLa-bearing human leukemia cells

Blood. 1990 May 1;75(9):1853-61.

Abstract

The blood kinetics and biodistribution of anti-common chronic lymphatic leukemia antigen (cCLLa) monoclonal antibody (MoAb) CLL2 were assessed in mice bearing cCLLa+ tumors. The cCLLa is a 69-Kd glycoprotein antigen expressed selectively by malignant B cells in human CLL, hairy cell leukemia (HCL), and prolymphocytic leukemia. Immunoreactive 125I-CLL2 (5 micrograms/mouse, specific activity 4.3 microCi/micrograms) was injected intravenously in mice bearing HCL-derived EH xenografts, and blood kinetics and biodistribution were ascertained up to 16 days postinjection. Radioimages were also obtained up to 72 hours after injecting 10 micrograms/mouse (specific activity 50.1 microCi/micrograms) of 125I-CLL2. Distinct 125I-CLL2 blood kinetics were observed in EH engrafted compared with tumor-free mice including: a longer 125I-CLL2 T 1/2 (153 hours v 72 hours), and a considerably greater blood clearance (173 mg/h v 54.7 mg/h) with biexponential rather than monoexponential configuration; and a greater volume of antibody distribution (31,483 mg v 5,729 mg). These data suggest more rapid tissue uptake by grafted tumours. Preferential 125I-CLL2 uptake by EH tumours relative to normal tissues was observed beginning 24 hours postinjection (mean ratio, 4.2) with average peak tumor 125I-CLL2 levels of 428.7 pg/mg. 125I-CLL2 uptake selectivity by EH tumor cells was also supported by: (1) negligible 125I-CLL2 uptake by cCLLa- Molt-4 xenografts (average 29.1 pg/mg 24 hours postinjection); (2) background uptake of cCLLa-irrelevant MoAb 131I-LEU1 by CD5- EH xenografts (average 31.4 pg/mg 48 hours postinjection); and (3) by scintigraphy. The EH xenograft mouse model might be useful to ascertain preclinically the anti-tumor effect of anti-cCLLa MoAbs and of their conjugated derivatives.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Antibodies, Monoclonal*
  • Antibody Specificity
  • Antigens, Neoplasm / analysis*
  • Biomarkers, Tumor / analysis*
  • Cell Line
  • Humans
  • Iodine Radioisotopes
  • Kinetics
  • Leukemia, Hairy Cell / immunology*
  • Mice
  • Mice, Nude
  • Neoplasm Transplantation
  • Tissue Distribution
  • Transplantation, Heterologous

Substances

  • Antibodies, Monoclonal
  • Antigens, Neoplasm
  • Biomarkers, Tumor
  • Iodine Radioisotopes
  • common chronic lymphatic leukemia antigen gp69, human