Lung transplantation (LTx) is the only option for patients with end-stage lung disease who have exhausted all other medical treatments. The Alfred Hospital in Melbourne performs ~100 lung transplants per year and patients have a five-year survival of 70%. Long term graft survival, however, remains limited by chronic rejection, that is, recurring immunological attacks upon the graft. Despite immunosuppressive therapies, recipients remain vulnerable to graft rejection caused in many cases by antibody-mediated rejection (AMR), largely due to human leukocyte antigen (HLA) mismatching. Although antibodies are frequently implicated in graft rejection, AMR is poorly understood and poorly characterized among LTx recipients, particularly in terms of its origin, its progression and predicting its impact on outcomes. While there is a significant correlation between the presence of antibodies to the donor HLA and worse graft survival, the critical information of how the response starts, how it progresses, what immunological processes drive it remain unknown. To address this need, we wish to identify and characterise the anti-graft antibody response, to monitor the quantity and quality of donor-specific antibodies, the processes triggering their production, their persistence and how they affect persistence and function of the graft. The global aim of this project is: To define the nature of the immune response against the graft and through this, highlight potential points of intervention to block graft rejection. This will be done by: 1. Identifying B cells, both memory and antibody secreting cells, in LTx recipients that are specific for donor antigens on the graft, particularly to donor HLA class II. 2. Investigating the nature of the antibody over the time course of the transplant in isotype, affinity, amount and binding site by molecular characterization of anti-graft Abs. 3. Determining the mechanism of tissue destruction mediated by anti-graft antibodies. 4. Mapping the exact binding sites of anti-graft antibodies and determining the correlation between epitope recognition and graft rejection. This project continues and adds to existing work on B-cell and T-cell subset representation in blood samples from a cohort of LTx recipients, divided into those that developed donor-specific antibodies (DSA+) and those that did not (DSA-) following transplantation. Technically the project involves: - isolation and analysis by flow cytometry of lymphocyte subsets in human peripheral blood and explanted tissues. - Cell culture of purified subsets for antibody production - Formulation and use of specialist staining reagents to detect donor-specific B cells. - Assessment of antibody production and antigen-specific binding by V gene sequencing and reconstitution - Statistical analysis of data to determine significant differences and correlations between experimental and clinical outcomes. This project is a collaboration between the Alfred Hospital Respiratory Medicine and Monash Department of Immunology and Pathology.
Antibody, transplantation, immune response, tissue rejection, physiology, pharmacology, microbiology, anatomy, developmental biology, molecular biology, biochemistry, immunology, human pathology, clinical
Central Clinical School » Immunology and Pathology
Top-up scholarship funding available
Alfred Research Alliance