SUMMARYHuman lung alveolar epithelial cells constitutively express class II major histocompatibility complex ( MHC). Human lung microvascular endothelial and small airway epithelial cells can be induced to express class II MHC by stimulation with the pro-inflammatory cytokine interferonc. The levels of class II MHC on lung epithelial and endothelial cells were comparable to those seen on an Epstein-Barr virus (EBV )-transformed B-cell line. However, the costimulatory molecules B7-1 and B7-2 were not expressed. The ability of the class II MHC expressing human lung parenchymal cells to present alloantigen to CD4+ T lymphocytes was investigated. Freshly isolated human alveolar epithelial cells (type II pneumocytes) and monolayers of interferon-cstimulated small airway epithelial and lung microvascular endothelial cells were co-cultured with allogeneic CD4+ T lymphocytes and proliferation determined by [3H ]thymidine incorporation. A clear diÂerence was observed between eÂects of the epithelial and endothelial cells on CD4+ T-lymphocyte activation. Alveolar and small airway epithelial cells failed to stimulate the proliferation of allogeneic CD4+ T lymphocytes whereas lung microvascular endothelial cells did stimulate proliferation. This diÂerence could not be explained by the levels of class II MHC or the lack of B7-1 and B7-2 solely. Microvascular endothelial cells, and not alveolar or small airway epithelial cells, possess B7-independent costimulatory pathways.
Acute allograft rejection is characterized by infiltration of the donor organ by host lymphoid cells, predominantly T lymphocytes. However, the site of proliferation and clonal expansion of alloreactive T lymphocytes is not well defined in man. A group of normal transbronchial biopsies (TBB, n=9) from clinically well lung transplant recipients was compared to TBB showing acute rejection (at least grade A2, n=9), using CD3- and Ki67-specific antibodies to double-label proliferating T lymphocytes. Few double-labeled lymphocytes were present in the normal biopsies (range, 0-3 cells). However, five of the rejection biopsies contained significant numbers of proliferating T lymphocytes (range, 19-47; Fisher's exact test; P=0.029). Furthermore, this positive group contained all three cases of grade A3 rejection in the study, as well as a case with persistent grade A2 rejection on follow-up biopsy. These data demonstrate that T lymphocytes do proliferate in transplanted human lungs; such proliferation is associated with more severe rejection.
This thesis explores the concepts and frames of living kidney donors through the use of recorded and transcribed conversations between living kidney donor patients and their transplant team. It offers insight into the expectations of living kidney donors as they prepare themselves to gift a kidney to someone they know.Living kidney donor frames are represented as particularly resilient and well-defined, shielding them from messages delivered by their transplant team. Those frames incorporate their acceptance as living kidney donors, the risk to themselves and their own personal definitions of autonomy and choice.With the intention of using phenomenological discourse analysis to examine the recorded and transcribed data, ten potential living kidney donors and their recipients were invited to take part in a PhD project entitled the Living Donor Study at the Princess Alexandra Hospital, in Queensland Australia. Transcriptions were analysed using line-by-line and axial coding and living donor transcripts were repeatedly compared with one another in order to reach an appropriate level of saturation and provide evidence of re-emerging concepts and frames.Data for the Living Donor Study were obtained during the living kidney donor's initial transplant assessment clinic visit. The purpose of this project was to examine prospective accounts of the living donation experience using conversations with their transplant team as opposed to using retrospective questionnaires and interviewing methods. By eliminating much of the subjectivity that is common in ex post facto interviews, I was able to identify many of the concepts that assist living kidney donors in framing their experience and how those frames impact upon their expectations of the transplant assessment clinic and their upcoming donation.
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