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Preemptive therapy at CMV reactivation has diminished post-transplant CMV mortality. Furthermore, recent studies suggest a favorable 'virus-versus-leukemia' effect from reactivating CMV, reducing relapse of AML after SCT. We studied the relationship of CMV reactivation with leukemic relapse in 110 patients with CML receiving HLA-identical sibling SCT between 1993 and 2008. Of these, 79 (72%) were in chronic phase, 5 in second chronic phase, 17 in accelerated phase and 9 in blast phase. A total of 97 patients (88%) received a myeloablative conditioning regimen, 97 received 4-log ex vivo T cell-depleted grafts and 13 received T-replete grafts. CMV reactivation before day 100 was observed in 72 patients (65.5%). At a median follow-up of 6.2 years, CMV reactivation < day 100 as a time-dependent covariate was an independent factor associated with decreased relapse. We conclude that CMV reactivation may contribute to a beneficial GVL effect in CML transplant recipients. [ABSTRACT FROM AUTHOR]

A human endogenous retrovirus type E (HERV-E) was recently found to be selectively expressed in most renal cell carcinomas (RCCs). Importantly, antigens derived from this provirus are immunogenic, stimulating cytotoxic T cells that kill RCC cells in vitro and in vivo. Here, we show HERV-E expression is restricted to the clear cell subtype of RCC (ccRCC) characterized by an inactivation of the von Hippel-Lindau (VHL) tumor-suppressor gene with subsequent stabilization of hypoxia-inducible transcription factors (HIFs)-1α and -2α. HERV-E expression in ccRCC linearly correlated with HIF-2α levels and could be silenced in tumor cells by either transfection of normal VHL or small interfering RNA inhibition of HIF-2α. Using chromatin immunoprecipitation, we demonstrated that HIF-2α can serve as transcriptional factor for HERV-E by binding with HIF response element (HRE) localized in the proviral 5′ long terminal repeat (LTR). Remarkably, the LTR was found to be hypomethylated only in HERV-E-expressing ccRCC while other tumors and normal tissues possessed a hypermethylated LTR preventing proviral expression. Taken altogether, these findings provide the first evidence that inactivation of a tumor suppressor gene can result in aberrant proviral expression in a human tumor and give insights needed for translational research aimed at boosting human immunity against antigenic components of this HERV-E. [ABSTRACT FROM AUTHOR]

CD3(+)CD56(-), CD4 and CD8 double negative T (DNT) cells comprise 1-3% of peripheral blood (PB) mononuclear cells. Their role in tumor immunity remains largely unknown due to their limited numbers and lack of effective methods to expand them. Here we developed a novel protocol by which DNT cells can be expanded ex vivo to therapeutic levels in 2 weeks from 13 of 16 acute myeloid leukemia (AML) patients during chemotherapy-induced complete remission. The expanded DNT cells expressed similar or higher levels of interferon-γ and tumor necrosis factor-α and Granzyme B as that seen in bulk activated CD8T cells from the same patient but significantly higher levels of perforin. The expanded DNT cells could effectively kill both allogeneic and autologous primary CD34(+) leukemic blasts isolated from PB of AML patients in a perforin-dependant manner. These results demonstrate, for the first time, that DNT cells from AML patients can be expanded ex vivo even after intensive chemotherapy, and are effective at killing both allogeneic and autologous primary leukemic blasts. These findings warrant studies further exploring the potential of DNT cells as a novel adjuvant immunotherapy to decrease the risk of relapse in patients with AML and, perhaps, other cancers. [ABSTRACT FROM AUTHOR]

Natural killer (NK) cells are the first lymphocytes to recover after allogeneic stem cell transplantation (SCT) and can exert powerful graft-versus-leukemia (GVL) effects determining transplant outcome. Conditions governing NK cell alloreactivity and the role of NK recovery in sibling SCT are not well defined. NK cells on day 30 post-transplant (NK30) were measured in 54 SCT recipients with leukemia and donor and recipient killer immunoglobulin-like receptor (KIR) genotype determined. In univariate analysis, donor KIR genes 2DL5A, 2DS1, 3DS1 (positive in 46%) and higher numbers of inhibitory donor KIR correlated with higher NK30 counts and were associated with improved transplant outcome. NK30 counts also correlated directly with the transplant CD34 cell dose and inversely with the CD3+ cell dose. In multivariate analysis, the NK30 emerged as the single independent determinant of transplant outcome. Patients with NK30 >150/μl had less relapse (HR 18.3, P=0.039), acute graft-versus-host disease (HR 3.2, P=0.03), non-relapse mortality (HR 10.7, P=0.028) and improved survival (HR 11.4, P=0.03). Results suggest that T cell-depleted SCT might be improved and the GVL effect enhanced by selecting donors with favorable KIR genotype, and by optimizing CD34 and CD3 doses.Leukemia (2007) 21, 2145–2152; doi:10.1038/sj.leu.2404892; published online 2 August 2007 [ABSTRACT FROM AUTHOR]

Summary:Reduced immunosuppression may improve immune recovery and increase the graft-versus-leukemia effect after allogeneic stem cell transplantation. Furthermore, the requirement for post-transplant immunosuppression following extensive T-cell depletion remains unclear. We therefore evaluated the role of cyclosporine (CSA) in recipients of HLA-identical T-cell-depleted peripheral blood stem cell transplants (PBSCT), followed by donor lymphocyte infusions (DLIs) scheduled on days +45 and +100. Before day+45, successive cohorts of patients received decreasing amounts of CSA: standard-dose (SD) CSA, low-dose (LD) CSA, or no CSA until day+45. LD CSA was as effective as SD CSA in preventing acute graft-versus-host disease (GVHD). However, moderate-to-severe acute GVHD was significantly more frequent before the day +45 DLI in patients receiving no CSA (33.3 vs 12.7%, P=0.036, including the only four grade III-IV cases). As a result of higher rates of early acute GVHD, more patients in the 'no CSA' group failed to receive any DLI (30.7 vs 7.1%, P=0.01). Overall, there was no difference in the incidence of acute GVHD, as patients receiving CSA developed more GVHD after DLI. Similarly, no significant differences were found in chronic GVHD, transplant-related mortality, or survival. These results define a role for CSA in preventing GVHD at low T-cell doses following PBSCT.Bone Marrow Transplantation (2003) 31, 783-788. doi:10.1038/sj.bmt.1703928 [ABSTRACT FROM AUTHOR]

Examines the use of high-dose acyclovir and pre-emptive ganciclovir to prevent cytomegalovirus (CMV) disease in myeloablative and non-myeloablative allogeneic stem cell transplantation. Transplantation approaches used in T cell-depleted stem cell transplant; Symptoms of CMV disease; Risk factors for CMV reactivation.

Nine of 56 (20% actuarial) patients receiving a T cell-depleted, HLA-identical sibling BMT for hematological malignancy developed hemorrhagic cystitis (HC) 15–368 days post BMT. Hematuria was severe and prolonged (median duration 18 days). In eight patients (89%), a viral etiology was confirmed (four adenovirus, four polyomavirus). HC was associated with significant morbidity, with all patients requiring continuous bladder irrigation and transfusion support for blood loss and thrombocytopenia. HC occurring before day 100 was significantly associated with a reduction in long-term survival: 1/7 (14.3%) patients developing HC before day 100 became long-term survivors vs 21/49 (42.8%) without HC by day 100 (P = 0.034). In univariate analysis, HC was associated with a diagnosis of multiple myeloma (P = 0.02). There was a trend towards a higher incidence of HC in patients reactivating cytomegalovirus (CMV) compared with those remaining CMV negative (18.4 vs 5.5% respectively, P = 0.17). HC was not associated with graft-versus-host disease, or with the transplant dose of CD34+ progenitors or CD3+ cells, patient age or sex. Life-threatening, viral-induced HC and the unusually high incidence of adenovirus-induced HC may have been caused by immune deficiency associated with T cell depletion in this series. [ABSTRACT FROM AUTHOR]

Discusses research which evaluated the safety and anti-leukemic efficacy of adoptive T-cell therapy with CD8[sup +] cytotoxic T lymphocytes (CTL) clones specific for tissue-restricted minor histocompatibility (H) Ags, in patients with advanced myelodysplastic syndrome and acute leukemia who relapse after hematopoietic cell transplantation from an MHC-identical donor. Generation of the CTL clones; Observation on graft-versus-tumor effects.

Discusses a study which compared patients receiving a T cell-depleted nonmyeloablative allogeneic stem cell transplant (SCT) with patients receiving a T cell-depleted myeloablative allogeneic SCT with delayed T cell addback over a 21-month period ending in September 1999. Treatments received by patients at risk for cytomegalovirus (CMV); Cases of CMV disease.