Phase I Trial for Patients w/ Advanced Hematologic Malignancies Undergoing Allogeneic HCT

This is a Phase I trial testing a new approach to stem cell transplantation for people with blood cancers (leukemia or myelodysplastic syndrome). It uses a specialized type of immune cell called regulatory T cells (Tregs) to try to reduce dangerous transplant side effects, like graft-versus-host disease, without suppressing the beneficial anti-cancer effects of the transplant. **You may be eligible if...** - You are 18–70 years old with acute leukemia in remission, or with myelodysplastic syndrome (MDS) eligible for transplant - You have a donor who is a close (7/8) HLA match - Your heart, lungs, liver, and kidneys are functioning adequately - You have never had a prior stem cell transplant **You may NOT be eligible if...** - You have had a previous allogeneic (donor) stem cell transplant - You are currently on immune-suppressing medications (beyond low-dose steroids) - You have active uncontrolled infection, HIV, or active hepatitis B or C - You have had a heart attack or stroke in the last 6-12 months - You have another active cancer (besides non-melanoma skin cancer) Talk to your doctor to see if this trial is right for you.