Immunity: explain question

A patient with kidney failure receives a kidney transplant from an unrelated donor. Despite careful tissue matching, the recipient's immune system eventually recognises the donated kidney as foreign and mounts an immune response.

Explain how the immune system distinguishes between self and non-self antigens, and describe the sequence of events that occur during the primary immune response against the transplanted kidney. In your answer, include the roles of macrophages, B-lymphocytes (including plasma cells), T-helper cells, and T-killer cells. Also explain how memory cells contribute to long-term immunity if a second transplant from the same donor were attempted later.