title: Use of direct fluorescence labeling and confocal microscopy to determine the biodistribution of two protein therapeutics, Cerezyme and Ceredase.
abstract: Efficient targeting of therapeutic reagents to tissues and cell types of interest is critical to achieving therapeutic efficacy and avoiding unwanted side effects due to offtarget uptake. To increase assay efficiency and reduce the number of animals used per experiment during preclinical development, we used a combination of direct fluorescence labeling and confocal microscopy to simultaneously examine the biodistribution of two therapeutic proteins, Cerezyme and Ceredase, in the same animals. We show that the fluorescent tags do not interfere with protein uptake and localization. We are able to detect Cerezyme and Ceredase in intact cells and organs and demonstrate colocalization within target cells using confocal microscopy. In addition, the relative amount of protein internalized by different cell types can be quantified using cell type-specific markers and morphometric analysis. This approach provides an easy and straightforward means of assessing the tissue and cell type-specific biodistribution of multiple protein therapeutics in target organs using a minimal number of animals.
authors: Department of Pathology, Genzyme Corporation, Framingham, Massachusetts 01701-9322, USA. peter.piepenhagen@genzyme.com
authors: Peter A
authors: PA
authors: Piepenhagen
authors: Scott
authors: S
authors: Vanpatten
authors: Heather
authors: H
authors: Hughes
authors: James
authors: J
authors: Waire
authors: James
authors: J
authors: Murray
authors: Laura
authors: L
authors: Andrews
authors: Tim
authors: T
authors: Edmunds
authors: Michael
authors: M
authors: O'Callaghan
authors: Beth L
authors: BL
authors: Thurberg
mesh_terms: D000825:Animal Structures / Q000737:chemistry / Q000166:cytology; D000818:Animals; D056947:Enzyme Replacement Therapy / Q000379:methods*; D005453:Fluorescence; D005962:Glucosylceramidase / Q000008:administration & dosage / Q000493:pharmacokinetics*; D007275:Injections, Intravenous; D051379:Mice; D008810:Mice, Inbred C57BL; D018613:Microscopy, Confocal / Q000379:methods*; D013194:Staining and Labeling / Q000379:methods*
chemical_list: C070292:alglucerase; D005962:Glucosylceramidase; C090568:imiglucerase