The Risks and Opportunities of Homeostatic Repopulation

ABSTRACT – Overall The NHP kidney transplant model offers unique and important pathways to the improved understanding and implementation of novel therapies for human transplant patients. Being an outbred, large animal model with close genetic similarities to humans allows more accurate modeling of mechanisms and drugs/drug combinations, and virtually all recently approvedimmunosuppressive agents and strategies have beenevaluated in a NHP model. Our group has contributed to these advances substantially for approximately three decades, resulting in over five clinical trials arising from our NHP research. Now we propose to focus on novel strategies to promote donor-specific tolerance, to further develop our understanding of the interrelationship between CMV infection and alloimmunity, and to advance our strategies for addressing the T and B cell response to alloantigens. We have developed a collaboration that allows us to interrogate the T cell and B cell receptor repertoire of macaques and their changes in response to immune interventions. This novel tool will greatly enhance our ability to measure the impact of therapies at the cellular level in rhesus monkeys. In addition, we have pioneered methodologies to assess the immune response within lymph nodes of rhesus monkeys and measure germinal center changes and changes of T follicular helper cells as a means of better understanding the B cell response to allotransplantation. We plan to use our collective experience in rhesus monkey kidney transplantation and biology to evaluate therapies that are translatable to human kidney transplantation and will also use mechanistic assays that can be performed in humans. In addition to the translational benefits of the proposed work such as donor-specific regulatory T cell augmentation, we expect to gain fundamental new insights into B cell memory durability and the breadth of T and B cell repertoires to alloantigens and how these change with therapy and during rejection or infection. Our proposal involves many academic and industry collaborations that are ongoing as attested by letters of support. We will continue to train individuals who plan careers in transplant medicine, surgery, and immunology such that they will be prepared to lead the future of our field. The impact of this proposal has broad implications that may benefit U.S. citizens affected by end stage renal failure or by immune-mediated illnesses or infections.