The overall goal of our proposal is to develop therapy for patients with multiple myeloma. We combine a vaccine strategy with stem cell transplantation from healthy donors. These tumor cells express a tumor-specific antigen termed "idiotype." Healthy donors are immunized with this protein, activating immune cells that can recognize and eliminate tumor cells when transplanted into myeloma patients. We propose testing whether immunity against the idiotype protein can be transferred from donor to recipient. We will also characterize the immune cells engineered to kill tumor cells. Collectively, these studies will enable us to optimize therapy for multiple myeloma.