e. the control group, there was significantly higher localisation of neutrophils in the liver, spleen and lungs compared to the DSS recipient mice (Fig. 5b). However, in contrast to the DSS recipients, there was no bioluminescence signal evident in the naive colons (Fig. 5a). In both human and experimental IBD, PMN invasion of the intestinal lamina propria and crypts correlates with tissue damage and clinical symptoms, suggesting that targeting neutrophil recruitment is a viable therapeutic strategy for IBD. This study presents a robust model to analyse the

biology of neutrophil trafficking that can also be used in preclinical studies to evaluate new therapeutic Fulvestrant solubility dmso compounds aimed specifically at blocking neutrophil recruitment. The first step in developing the model was to characterise the purity and functional properties of the neutrophil population from thioglycollate-induced peritonitis. Phenotypic analysis of the peritoneal exudate isolated 12 h post-i.p. administration of thioglycollate, revealed 80% neutrophil purity. In addition, the cells were activated and NVP-LDE225 cell line functionally responsive to recombinant KC in vitro, and their chemotaxis was inhibited by the presence of an anti-KC antibody. These results showed that the post-thioglycollate peritoneal exudate population of neutrophils was appropriate for the adoptive transfer

model. Bioluminescence imaging of whole-body and ex vivo organs was C-X-C chemokine receptor type 7 (CXCR-7) used to track and quantify neutrophil trafficking following adoptive transfer of luc+ peritoneal exudate cells from transgenic donors. This is a non-invasive technology allowing real-time detection of tagged cells in vivo using CCD cameras due to the detection of visible light produced by luciferase-catalysed reactions [31]. In contrast to other imaging modalities, such as positron emission

tomography (PET), single photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI), bioluminescence imaging is less complicated, less labour-intensive and relatively low cost while still providing quantitative, spatial and temporal data. In addition, bioluminescence overcomes the problems encountered commonly with using fluorescent labels such as carboxyfluorescein succinimidyl ester (CFSE) and green fluorescent protein (GFP), namely the exponentially decreasing light intensity with tissue depth and the limited sensitivity and specificity as a result of endogenous tissue autofluorescence [32,33]. So far, bioluminescence has been used to monitor infection progression, transgene expression, tumour growth and metastasis, transplantation, toxicology and gene therapy [31]. In the context of cell tracking, Sheikh et al. successfully used bioluminescence imaging to track bone marrow mononuclear cell homing in ischaemic myocardium [34], while Costa et al. used a retroviral vector containing luciferase and GFP to illuminate the migratory patterns of CD4+ T cells in a mouse model of multiple sclerosis [35].