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. 2017 Oct 5;8:42–51. doi: 10.1016/j.omtm.2017.09.008

Figure 1.

Figure 1

Distribution of Fluorescent-Labeled rhIDU

Distribution of rhIDU labeled with Alexa Fluor 680 (rhIDU-AF680) in naive, antibody-negative (anti-rhIDU IgG antibody < 1 OD U/μL), and antibody-positive (anti-rhIDU IgG antibody > 3 OD U/μL) MPS I mice. (A) False color ex vivo imaging of internal organs from a representative mouse from two untreated MPS I mice (MPS I No Tx; top row) and a representative mouse from six rhIDU-AF680-treated MPS I mice (AF680; bottom row) 24 hr after injection of labeled enzyme. Autofluorescence was apparent in some tissues (arrows). (B) Fluorescence intensity in vivo in the whole mouse. Naive MPS I mice (i.e., mice that had no previous rhIDU exposure; filled circles; n = 6) are compared to untreated MPS I control mice (open circles; n = 2). (C) Distribution of rhIDU to internal organs ex vivo in six naive MPS I mice (Naive), six antibody-negative MPS I mice (AB Neg), five antibody-positive MPS I mice (AB Pos), and two untreated MPS I mice (MPS I NoTx). Average fluorescence intensity was measured 24 hr after injection of rhIDU-AF680. Signals in untreated MPS I mice (MPS I No Tx) represent autofluorescence. (D) IDU enzymatic activity in internal organs of antibody-positive- and antibody-negative-treated MPS I mice (n = 5 per group) after 16 weeks of rhIDU treatment compared to untreated MPS I control mice (n = 10). Untreated normal control mice (we used wild-type littermates) received no treatment (n = 10; Normal No Tx). Error bars represent SD. *p < 0.05.