We adoptively transferred donor-derived cytomegalovirus (CMV)-specific T-cell lines into 8 stem cell transplant recipients lacking CMV-specific T-cell proliferation. All patients, of whom one was infected by a CMV strain that was genotypically ganciclovir resistant, had received unsuccessful antiviral chemotherapy for more than 4 weeks. CMVspecific lines had been prepared by repetitive stimulation with CMV antigen, which increased the percentage of CMV-specific T cells and ablated alloreactivity completely even against patients mismatched for 1 to 3 HLA antigens. After transfer of 10 7 T cells/m 2 at a median of 120 days (range, 79-479 days) after transplantation, no side effects were noticed. Despite cessation of antiviral chemotherapy, the CMV load dropped significantly in all 7 evaluable patients, with a maximal reduction after a median of 20 days (range, 5-31 days). In 2 patients with high virus load, the antiviral effect was only transient. One of these patients received a second T-cell infusion, which cleared the virus completely. At a median of 11 days after transfer, CMV-specific T-cell proliferation was demonstrated in 6 patients, and an increase in CMV-specific CD4 ؉ T cells was demonstrated in 5 patients. In 6 patients, 1.12 to 41 CMV-specific CD8 ؉ T cells/L blood were detected at a median of 13 days after transfer, with an increase in all patients lacking CMV-specific CD8 ؉ T cells prior to transfer. Hence, anti-CMV cellular therapy was successful in 5 of 7 patients, whereas in 2 of 7 patients, who received an intensified immune suppression at the time of or after T-cell therapy, only transient reductions in virus load were obtained. (Blood. 2002;99: 3916-3922)
NKG2D ligands (NKG2DLs) mark malignant cells for recognition by natural killer (NK) cells and cytotoxic T lymphocytes via the activating immunoreceptor NKG2D. This led to the hypothesis that NKG2DLs play a critical role in tumor immune surveillance. The human NKG2DLs MICA and MICB are expressed on tumors of epithelial origin in vivo. For the other recently described set of human NKG2DLs, the UL16-binding proteins (ULBPs), expression in vivo is as yet undefined. In this study we investigated expression and function of NKG2DLs in leukemia using a panel of newly generated NKG2DL-specific monoclonal antibodies. We report that leukemia cells from patients variously express MIC and ULBP molecules on the cell surface with MICA most frequently detected. Patient leukemia cells expressing MICA were lysed by NK cells in an NKG2D-dependent fashion. Sera of patients, but not of healthy donors, contained elevated levels of soluble MICA (sMICA). We also detected increased sMICB levels in patient sera using a newly established MICB-specific enzyme-linked immunosorbent assay. Reduction of leukemia MIC surface expression by shedding may impair NKG2D-mediated immune surveillance of leukemias. In addition, determination of sMICA and sMICB levels may be implemented as a prognostic parameter in patients with hematopoietic malignancies.
Whereas patients with pure seminomatous EGCT histology have a long-term chance of cure of almost 90% irrespective of the primary tumor site, 45% of patients with mediastinal nonseminomas are alive at 5 years. This outcome is clearly inferior compared with patients with nonseminomatous retroperitoneal primary tumors.
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