Das rekruitment immunkompetenter zellen in eine transplantierte lunge ist trotz inkompletter reinnervierung nicht behindert

Background: It is not clear whether surgical intervention during lung transplantation which includes cutting vegetative nerves, lymphatic vessels and bronchial arteries, leads to alterations in immune responses. Thus, it was studied in an animal model whether an induced pulmonary immune reaction after syngenic lung transplantation was impaired without the influence of immunosuppression and rejection. The recruitment of leukocytes and the status of reinnervation was examined. Methods: Syngenic transplantation of the left lung was performed in Lewis rats without rejection and therefore without immunosuppressive therapy. In a subgroup of animals host and donor leukocytes were distinguished. An ovalbumin (OVA)-specific pulmonary immune response was induced four months after transplantation. Bronchoalveolar lavage (BAL) and interstitial leukocytes were examined using flow cytometry and immunocytology, comparing the right lung and the grafted left lung. Immunohistology was performed to detect nerve fibers on cryostat sections. Results: An induced cellular inflammation was observed in the right host lung as well as in the grafted left lung. However, the CD4 T cell numbers in the BAL were increased in the left lung. Single donor-type leukocytes could still be observed four months after transplantation. A partial reinnervation was found. Conclusions: The recruitment of immune cells into the lung interstitium and bronchoalveolar space of grafted lungs is not impaired. The incomplete reinnervation has no influence on leukocyte recruitment.