Detection of local inflammation induced by repeated exposure to contact allergens by use of IVIS SpectrumCT analyses.

Background. Contact allergy is characterized by local skin inflammation that, in some cases, can result in systemic immune activation. Objectives. To investigate whether IVIS Spectrum CT analyses can be used to detect the immune response induced by contact allergens. Methods. Mice were repeatedly exposed to vehicle or allergens on the ears. The local and systemic responses were analysed at different times with the ProSense 750 FAST probe in IVIS SpectrumCT measurements. In addition, changes in ear thickness, cytokine profile in the skin and immunological phenotype in the draining lymph nodes and spleen were determined. Results. Local inflammation was detected by ProSense 750 FAST and correlated with changes in ear thickness, cytokine profile and immunological phenotype following exposure to the strong contact allergen 2,4-dinitrofluorobenzene. Analysis of the systemic response with ProSense 750 FAST did not show any difference between allergen-exposed and control mice, although fluorescence-activated cell sorting analysis of the spleen showed increased numbers of gamma delta T cells and CD11b(+) CD11c(+) MHCII+ cells in allergen-treated mice. Conclusions. IVIS SpectrumCT analyses with ProSense 750 FAST as the probe can be used to detect local immune responses induced by contact allergens.