Lung transplantation in the rat: a model for study of the cellular mechanisms of allograft rejection.

Single-lung transplantation in the rat has been shown to provide an effective model for the study of cellular events associated with allograft rejection. It is possible to recover sufficient viable immune cells for functional immunological studies by lavage of the broncho-alveolar space of the grafts with tissue-culture medium. These cells are representative of the population within the parenchymal infiltrate, but are not exposed to harsh, potentially damaging, physical and chemical conditions during their extraction. Lavage-derived cells from non-immunosuppressed recipients showed donor-specific cytotoxicity, were clonable by limiting dilution culture, and proliferated in response to 24-hr stimulation with recombinant IL-2. Administration of Cyclosporin A (CsA) prevented pulmonary rejection and was also shown to block the formation of specific cytotoxic effector cells and the development of responsiveness to IL-2.