Final answer:
The characteristic of T cell mediated response related to transplant rejection that is delayed and reversible is known as Delayed (Type IV) Hypersensitivity. This immune response involves T cell sensitization and activation leading to macrophage recruitment and potential tissue damage but can be managed with proper medical intervention.
Step-by-step explanation:
The characteristic of the T cell mediated response that occurs days to weeks after transplant and is reversible is known as Delayed (Type IV) Hypersensitivity. This type of immune response involves T cells that are sensitized upon the first exposure to an antigen. On subsequent re-exposure, the sensitized T cells secrete cytokines that recruit macrophages and other phagocytes to the site of the antigen, which can lead to transplant rejection. The time frame for this response is typically 24 to 72 hours after re-exposure, making the reaction a delayed one compared to other hypersensitivity types.
Type IV hypersensitivity reactions can be mediated by both CD4 T helper cells and CD8 cytotoxic T lymphocytes. These reactions can cause tissue damage mediated by activated macrophages or cytotoxic T cells. In transplant cases, for instance, CTL-mediated reaction targets transplanted tissue cells that display foreign antigens from the donor. This is part of the body's immune response, aiming to eradicate perceived foreign invaders.