This is a new platform in non-myeloablative allogeneic stem cell transplantation to improve survival by harnessing the immunologic potential of donor T-cells to induce and maintain long-term remissions in patients with hematologic malignancies without undue toxicity. This study involves is the first study in humans directed at optimizing the graft vs leukemia effect by infusing activated T-cells from healthy donors prophylactically, months after recovery from the initial transplant. Investigators are studying whether the activation of donor cells prior to infusion will enhance the patient's ability to "seek and destroy" residual malignant cells while also helping the immune system to fight infection without increasing the immune reaction against the host.

Patient-related Parameters:

• Patients must have a healthy histocompatible donor (A, B and DR match); either sibling or unrelated volunteer identified through the NMDP
• Age between 18 and 70 years old
• Life expectancy greater than 3 months.
• ECOG performance status 0-1.
• Patients must have acceptable organ function:
• total bilirubin <2.0
• AST and ALT < 3 x normal, unless increases are thought to be either from non-hepatic causes (i.e hemolysis) or related to underlying disease (such as liver involvement with leukemia);
• creatinine <2.0 or creatinine clearance >40 ml/min (calculated or collected);
• Cardiac: An ejection fraction >40% on MUGA or echocardiogram;
• Pulmonary: corrected DLCO >50%

Exclusion Criteria:

Subjects:

• Patients who have had chemotherapy or radiotherapy within 4 weeks prior to entering the study. Patients must have recovered from adverse events due to agents administered more than 4 weeks earlier.
• Patients with uncontrolled or untreated central nervous system involvement
• Patients with uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements.
• HIV positive patients are excluded
• Pregnant women
• Patients who are breastfeeding

Donors:

• Sibling donors will be evaluated according to the standard practice of the University of Pennsylvania Bone Marrow and Stem Cell Transplant Program
• Unrelated donor evaluations and consent will be performed by an NMDP donor center according to standard guidelines and procedures.