Inclusion Criteria:
* First 2 subjects: male and female subjects age ≥18 and \< 27 years (as of 2/16/18 the first 2 subjects were enrolled and treated); subsequent subjects \<31 years.
* Diagnosis of CD19+22+ leukemia
* Disease status:
* If post allogeneic HCT: Confirmed CD19+CD22+ leukemia recurrence defined as at least 0.01% disease following allogeneic HCT
* If relapse/refractory status with no prior history of allogeneic HCT, one of the following:
* Second or greater marrow relapse, with or without extramedullary disease
* First marrow relapse at end of first month or re-induction with marrow having at least 0.01 % blasts by morphology and/or MPF
* Primary refractory as defined as greater than 5% blasts by multi-parameter flow after at least 2 separate induction regimens.
* Subject has indication for HCT but has been deemed ineligible, inclusive of persistent MRD prior to HCT
* Asymptomatic from CNS involvement, if present, and in the opinion of the Principal Investigator with a reasonable expectation that disease burden can be controlled in the interval between enrollment and T-cell infusion. Subjects with significant neurologic deterioration will not be eligible for T-cell infusion until stabilized.
* Free from active GVHD and off immunosuppressive GVHD therapy for 4 weeks prior to enrollment
* Lansky or Karnofsky performance score of at least 50
* Life expectancy of at least 8 weeks
* Recovered from acute toxic effects of all prior chemotherapy, immunotherapy, and radiotherapy
* At least 7 days post last chemotherapy administration (excluding intrathecal maintenance chemotherapy)
* At least 7 das post last systemic corticosteroids administration (unless physiologic replacement dosing)
* No prior genetically modified cell therapy that is still detectable or virotherapy
* Adequate organ function
* Adequate laboratory values
* Willing to participate in long-term follow-up for up to 15 years, if enrolled in the study and receive T cell infusion
* Patients of childbearing/fathering potential must agree to use highly effective contraception from the time of initial T cell infusion through 12 months following the last T cell infusion
Exclusion Criteria:
* Presence of active clinically significant CNS dysfunction
* Pregnant or breast-feeding
* Unable to tolerate apheresis procedure
* Presence of active malignancy other than CD19+CD22+ leukemia
* Presence of active severe infection
* Presence of any concurrent medical condition that, in the opinion of the Principal Investigator, would prevent the patient from undergoing protocol-specified therapy
