Engineered donor cells aim to shield transplant patients from dangerous viruses

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: Participants must meet all of the following criteria: * Patients undergoing allogeneic hematopoietic stem cell transplantation (any conditioning regimen or graft source is allowed). * Presence of at least one high-risk factor for post-transplant viral infection (any of the following): * Age ≥50 years or ≤14 years * Non-sibling matched transplantation * In vivo or ex vivo T-cell depletion * Myeloablative conditioning * Conditioning containing radiotherapy * Second transplantation * CMV IgG or EBV IgG donor/recipient mismatch (donor positive, recipient negative) * History of grade II or higher acute graft-versus-host disease (aGVHD) after transplantation and use of high-dose corticosteroids (prednisone equivalent ≥1 mg/kg/day) * Availability of a suitable lymphocyte donor (see "Donor Selection Criteria"). * Adequate organ function meeting the following laboratory criteria: * Liver function: ALT and AST ≤10× upper limit of normal (ULN); total bilirubin ≤5× ULN * Renal function: BUN and creatinine ≤1.25× ULN * No cardiac dysfunction on electrocardiogram or echocardiogram * Pulmonary function: oxygen saturation \>90% without supplemental oxygen * The patient or legal guardian has the desire and request to receive treatment, signs the informed consent form before treatment, and is willing to comply with the treatment plan, follow-up schedule, and laboratory tests. Exclusion Criteria: Patients meeting any of the following criteria will be excluded from this study: * Active grade II-IV acute graft-versus-host disease (aGVHD) * Active aGVHD requiring prednisone or equivalent corticosteroid \>0.5 mg/kg/day * Active viral infection * Uncontrolled or relapsed malignancy * Other serious acute or chronic physical or psychiatric conditions, or laboratory abnormalities, that may compromise patient safety or compliance, or affect informed consent, study participation, follow-up, or interpretation of results.