Abstract
The effect of 406, a novel fusion protein between the N-terminal sequence of the insect insulin-like peptide, bombyxin, human insulin-like growth factor II and mouse interleukin 3 was investigated in its capacity to abrogate the toxic effects of azidothymidine (AZT) in C57BL/6 mice. Mice receiving 2.5 mg/ml AZT in their drinking water were concurrently treated with daily s.c. injections of 14, 140 or 1400 ng 406 for 4 wk. AZT-treated mice had a lower total weight, hemoglobin content and white blood cells than non treated controls. 406 significantly increased the number of circulating white blood cells at all doses, and the optimal effects were observed at a dose of 140 ng/mouse. Using this optimal dose, 406 completely abrogated the AZT-mediated weight loss. The effects on erythroid cells depended on the severity of the AZT-induced anemia. The amounts of hemoglobin were equal or slightly lower than those of controls under conditions of mild anemia, but were significantly higher than controls under conditions of severe anemia. 406 significantly increased the number of all hematopoietic colony-forming cells in bone marrow and spleen, but the effects were particularly striking in granulocyte-macrophage precursors. Blood glucose levels did not change at optimal or suboptimal 406 doses but increased at a dose of 1.4 μg/mouse. These experiments demonstrate the usefulness of these IGF-cytokine fusion proteins, whose low cost production represents a significant advantage for future in vivo studies.
Footnotes
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Send reprint requests to: Dr. L. F. Congote, Endocrine Laboratory, Royal Victoria Hospital, 687 av. des pins, ouest, Montreal, Canada H3A 1A1
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↵1 This study was supported by the Kidney Foundation of Canada and the Quebec Heart and Stroke Foundation. M.R.D. is a recipient of a Studentship of the Research Institute of the Royal Victoria Hospital and L.D. was partially supported by the program Challenge 1996 from the Federal Government of Canada.
- Abbreviations:
- AIDS
- acquired immunodeficiency syndrome. AZT, 3′-azido-3′-deoxythymidine IGF, insulin-like growth factor
- BOMIGF
- NQPQMVHTY-hIGF II(9–67)
- IL-3
- interleukin 3
- GM-CSF
- granulocyte-macrophage colony stimulating factor
- BFU-E
- burst-forming unit, erythroid
- CFU-GM
- granulocyte, macrophage and granulocyte-macrophage colony forming units
- Received April 22, 1997.
- Accepted October 6, 1997.
- The American Society for Pharmacology and Experimental Therapeutics
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