Detection of activated lymphocytes in endocrine pancreas of BB/W rats by injection of 123I-interleukin-2: an early sign of type 1 diabetes.
Recombinant interleukin-2 (IL2) was labelled with iodine-123 by a modified chloramine T method. The labelled IL2, which had a high specific activity (100-150 microCi/microgram) and retained its capacity for binding to the IL2 receptor on activated lymphocytes in vitro, was injected intravenously int...
Main Authors: | , , , , |
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Format: | Journal article |
Language: | English |
Published: |
1987
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Summary: | Recombinant interleukin-2 (IL2) was labelled with iodine-123 by a modified chloramine T method. The labelled IL2, which had a high specific activity (100-150 microCi/microgram) and retained its capacity for binding to the IL2 receptor on activated lymphocytes in vitro, was injected intravenously into BB/W diabetes-prone and normal rats. Combined immunoperoxidase staining and autoradiography of organ sections revealed that labelled IL2 bound specifically in vivo to IL2-receptor-positive cells in the spleen of both normal and BB/W rats and to activated lymphocytes infiltrating the pancreas of BB/W rats. The severity of lymphocytic infiltration correlated with the degree of radioactivity in the pancreas of BB/W rats. Time-activity curves, generated over organs of injected rats after gamma camera imaging, confirmed that radioactivity was greater in the pancreas of diabetes-prone than in normal rats. 123I is a suitable isotope for gamma camera imaging, so the intravenous injection of IL2 labelled with iodine-123 may be valuable for the in-vivo visualisation of activated lymphocytes in tissues infiltrated by lymphocytes. |
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