In Vivo Evaluation of 111In-Labeled T-Lymphocyte Homing in Experimental Colitis

Blockade of lymphocyte recruitment to the intestinal mucosa is considered a useful therapy for inflammatory bowel disease (IBD) and anti-4 antibodies have clinical benefit in patients with active Crohn’s disease. The aim of this study was to evaluate a scintigraphic technique to assess lymphocyte homing to the colon in 2,4,6-trinitrobenzenesulfonic acid (TNBS)–induced ex-perimental colitis (TNBS colitis) in vivo. Methods: TNBS-sensi-tized and nonsensitized murine total lymphocytes or CD4 lym-phocytes were radiolabeled with 111In-oxinate. Cells were injected into control mice (n 5) or mice with TNBS colitis (n 5). Specific abdominal radioactive uptake was determined by SPECT using a dedicated pinhole system 48 h after cell transfer. Radioactive colon uptake was correlated with histology and colon weight as parameters of inflammation. Results: The ra-dioactive colon uptake was most evident in mice with TNB