Cytotoxic T Lymphocytes in Treating Patients With Malignancies With BK and/or JC Virus

Inclusion Criteria: * Patients ≥ 2 years. English and non-English speaking patients are eligible. * Immunocompromised patients; and/or Non-immunocompromised patients with PML/JC virus Encephalitis; and/or patients with any type of malignancies; and/or HIV/AIDs; and/or history of solid organ transplant; and/or Merkel polyoma-virus related Merkel cell tumor(s) with measurable disease on imaging per RECIST criteria. * Patients with microscopic hematuria OR biopsy proven BK nephritis and urine or blood PCR positive for BK virus and/or JC viral encephalitis and/or JC end-organ disease and/or polyomavirus. * Clinical status at enrollment to allow tapering of steroids to less than 0.5 mg/kg/day of prednisone. * Patients who are currently receiving treatment with cidofovir, leflunomide, or other antiviral therapy with no response, will be eligible for CTL infusion. * Written informed consent and/or signed assent from patient, parent or guardian. Patients with cognitive impairments are eligible. * Negative pregnancy test in female patients of childbearing potential, defined as not post-menopausal for 12 months or no previous surgical sterilization. Women of child bearing potential must be willing to use an effective contraceptive measure while on study. * Patients enrolled on this study may be enrolled on other IND studies at the discretion of the PI. * Patients may be re-enrolled in the protocol should the infection re-occur, provided they meet all the other eligibility criteria at the moment of re-enrollment. Exclusion Criteria: * Patients receiving prednisone \> 0.5 mg/kg/day at time of enrollment, or have received ATG within 14 days or have received donor lymphocyte infusion (DLI) or Campath within 28 days of enrollment. * Patients with other uncontrolled infections (except HIV/AIDS). For bacterial infections, patients must be receiving definitive therapy and have no signs of progressing infection for 72 hours prior to enrollment. For fungal infections patients must be receiving definitive systemic anti-fungal therapy and have no signs of progressing infection for 1 week prior to enrollment. Progressing infection is defined as hemodynamic instability attributable to sepsis or new symptoms, worsening physical signs or radiographic findings attributable to infection. Persisting fever without other signs or symptoms will not be interpreted as progressing infection * Patients with active acute (GVHD) grades II-IV