Antigen-specific Cytotoxic T Cells in the Treatment of Opportunistic Infections

Inclusion Criteria: Subjects with or without hematopoietic stem cell transplantation / organ transplant recipients need to meet the following conditions: * Evidence of CMV, EBV, ADV, BKV or known pathogen infection (viral DNA, immunohistochemical cytology positive); contraindications or invalid to anti-microbial drugs. * Subjects with virus DNA increased in the 2 consecutive peripheral blood samples (≥ 1000 genomic copies/ml blood) at least 24 hours apart. * Initial hematopoietic reconstitution: neutrophils (ANC) ≥ 0.5x109 / L, platelet (PLT) ≥ 20x109 / L. * Patients with pahogen disease (organ/ tissue infiltration) symptoms, fever, diarrhea, or lymphadenopathy, regardless of the level of peripheral blood virus DNA, and confirmed by the presence of viral DNA or microbial antigens within body fluid or biopsy. * The subject / guardian has signed a written consent form before any trial begins. Proper renal and hepatic functions (ULN denotes "upper limit of normal range"): * Creatinine ≤ 2\*ULN. * Bilirubin ≤ 2\*ULN. * SGOT ≤ 3\*ULN. * SGPT≤ 3\*ULN. If CTL is not from the patient's own, then the provider of CTLs needs to meet the following criteria: * Did not receive chemotherapy or radiotherapy within 4 weeks prior to blood collection, and did not take any steroids for the previous week, did not use Penicillin or β-lactam antibiotics, or the lowest dose of other antibiotics. * White blood cells ≥ 3,500 / μl, lymphocytes ≥ 750 / μl. * Obtain a signed informed consent from the patient and / or the guardian or the donor of the BMT recipient. * Human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV) or tuberculosis (TB) test is negative. * Physical examination in line with the standard of healthy blood donors. Exclusion Criteria: * Subject infected with HCV (HCV antibody positive), HBV (HBsAg positive), HIV (HIV antibody positive), or HTLV (HTLV antibody positive). * GVHD (graft-versus-host disease) performance score at II-IV. * Subject is albumin-intolerant. * Subject with life expectancy less than 4 weeks. * Subject participated in other investigational somatic cell therapies within past 30 days. * Subject with positive pregnancy test result.