β-lactam hypersensitivity reactions can be severe and are extremely difficult to predict. Drug-specific T-cells have been identified in blood of patients presenting with cutaneous and hepatic hypersensitivity reactions, indicating that they play a role in the disease pathogenesis. Animal models are highly effective tools that have been used extensively to dissect mechanisms of disease and pathways of disease progression; however, animal models of drug hypersensitivity reactions have proven

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... cult to develop. The aims of this thesis were to utilize 3 β-lactam antibiotics amoxicillin, piperacillin and flucloxacillin to explore antigen-specific T-cell responses in the mouse and to attempt to develop a model of T-cell-mediated drug-induced liver damage. The project utilized the C57/Bl6 CD4+ T-cell deficient mouse with a mutation in the αβ gene encoding for MHC class II molecules, which has previously been used to investigate skin sensitization to drugs. In initial experiments, amoxicillin-specific CD8+ T-cell responses were detected both in vivo and ex vivo. Sensitization was obtained through painting of the drug onto the skin of mice that had been depleted of CD4+ T-cells, which are thought to exert regulatory/suppressor functions. On completion of the sensitization protocol, draining lymph node cells were removed and the drug-specific T-cell response was detected through analysis of proliferation and IFN-γ release. In contrast, proliferative responses and cytokine release were not detected with cells from vehicle control mice. The study was expanded to include 3 β-lactam antibiotics. Activation of CD8+ T-cells was readily detectable following sensitization with flucloxacillin. In contrast, only weak ex-vivo proliferative responses were detected following sensitization with piperacillin, which may relate to the fact that piperacillin preferentially activates CD4+ T-cells in hypertensive human patients. Drug-specific T-cell clones from human patients were generated and tested alongside murine counterparts to provi [...]