Inducible Regulatory T Cells (iTregs) in Non-Myeloablative Sibling Donor Peripheral Blood Stem Cell Transplantation

Inclusion Criteria: * 18 - 75 years of age with an HLA-identical sibling donor * One of the following disease categories: * Acute myelogenous leukemia - high risk CR1 (as evidenced by preceding MDS, intermediate to high risk cytogenetics, ≥ 2 cycles to obtain CR, erythroblastic or megakaryocytic leukemia; CR2+. All patients must be in CR as defined by hematological recovery (ANC \> 0.5x 109/L), AND \<5% blasts by light microscopy within the bone marrow with a cellularity of ≥15%. * Acute lymphocytic leukemia - high risk CR1 \[t(9;22), t (1:19), t(4;11) or other MLL rearrangements\] or \>1cycle to obtain CR; CR2+. All patients must be in CR as defined by hematological recovery (ANC \> 0.5x 109/L), AND \<5% blasts by light microscopy within the bone marrow with a cellularity of ≥15%. * Chronic myelogenous leukemia all types except blast crisis (note treated blast crisis in chronic phase is eligible) * Non-Hodgkin lymphoma or Hodgkin lymphoma demonstrating chemosensitive disease * Myelodysplastic syndrome with severe pancytopenia, leading to either transfusion dependency or increased risk for infections * Performance status: Karnofsky ≥ 60% * Adequate organ function within 28 days of study enrollment defined as: * Liver: SGOT and SGPT \< 5.0 x ULN; total bilirubin \< 3 x ULN * Renal: serum creatinine \< 2.0 mg/dl or glomerular filtration rate (GFR) \> 40 mL/min/1.73m2. Patients with a creatinine \> 1.2 mg/dl or a history of renal dysfunction must have glomerular filtration rate (GFR) \> 40 mL/min/1.73m2 * Albumin: \> 2.5 g/dL * Cardiac: No decompensated CHF or uncontrolled arrhythmia; ejection fraction \> 35% within 6 weeks prior to study enrollment * Pulmonary: No O2 requirements; DLCO \> 30% predicted within 6 weeks prior to study enrollment * If recent mold infection (e.g. aspergillus) must have minimum of 30 days of therapy and responsive disease and be cleared by Infectious Disease * Sexually active females of child bearing potential and males must agree to use effective contraception for the duration of the transplant period * Voluntary written consent Exclusion Criteria: * Pregnancy or breast feeding - women of childbearing potential must have a negative pregnancy test within 28 days of study enrollment. * Prior myeloablative transplant within previous 3 months of study enrollment. * Evidence of HIV infection or known HIV positive serology. * Active serious infection.