Long-Term Outcome After Adoptive Immunotherapy With Natural Killer Cells: Alloreactive NK Cell Dose Still Matters

Recently, many reports were published supporting the clinical use of adoptivelytransferred natural killer (NK) cells as a therapeutic tool against cancer, including acutemyeloid leukemia (AML). Our group demonstrated promising clinical response usingadoptive immunotherapy with donor-derived alloreactive KIR-ligand-mismatched NK cellsin AML patients. Moreover, the antileukemic effect was correlated with the dose of infusedalloreactive NK cells (“functional NK cell dose”). Herein, we update the results of ourprevious study on a cohort of adult AML patients (median age at enrollment 64) infirstmorphological complete remission (CR), not eligible for allogeneic stem celltransplantation. After an extended median follow-up of 55.5 months, 8/16 evaluablepatients (50%) are still off-therapy and alive disease-free. Overall survival (OS) and disease-free survival (DFS) are related with the dose of infused alloreactive NK cells (≥2×105/kg

Higher numbers of blood CD14+ cells before starting conditioning regimen correlate with greater risk of acute graft-versus-host disease in allogeneic stem cell transplantation from related donors.

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Acute graft-versus-host disease and steroid treatment impair CD11c+ and CD123+ dendritic cell reconstitution after allogeneic peripheral blood stem cell transplantation

AbstractHuman dendritic cells (DC) comprise 2 subsets—plasmacytoid CD123+ and myeloid CD11c+ DC—that may have distinct roles in the regulation of immunity after allogeneic hematopoietic stem cell transplantation. In this study, we analyzed the kinetics of CD123+ DC and CD11c+ DC reconstitution in 31 patients who underwent transplantation with allogeneic granulocyte colony-stimulating factor-mobilized peripheral blood (PB) stem cells from HLA-identical sibling donors after myeloablative conditioning. Lineage marker-negative HLA-DR+ CD11c+ CD11c+ DC and lineage marker-negative HLA-DR+ CD123+ CD123+ DC, as well as monocytes and lymphoid subsets, were enumerated in donor grafts and in the PB of patients at various time points after transplantation. Reconstitution of both CD11c+ DC and CD123+ DC to normal levels occurred within 6 to 12 months and was not affected by the diagnosis, preparatory regimen, or graft composition. However, PB CD11c+ DC and CD123+ DC counts were significantly reduced in patients with acute GVHD grade II to IV (at 1 and 3 months) and grade I (at 1 month). Patients with chronic GVHD instead showed reduced CD123+ DC counts only 6 months after transplantation. Moreover, treatment with steroids (>0.1 mg/kg) was significantly associated with reduced PB CD11c+ DC and CD123+ DC counts at all time points after transplantation. In multivariate analysis, only acute GVHD affected DC reconstitution early after transplantation. These results will prompt new studies addressing whether DC reconstitution correlates with immunity against infectious agents or with graft-versus-tumor reactions after PB stem cell allotransplantation

High dose rabbit antithymocyte globulin induction in living related liver transplantation

Induction with rabbit antithymocyte globulin (RATG) has been reported to be effective in cadaveric liver transplantation. The aim of this study was to compare two immunosuppressive protocols in adult living-related liver transplantation (LRLT)

Synergism Through WEE1 and CHK1 Inhibition in Acute Lymphoblastic Leukemia

Introduction: Screening for synthetic lethality markers has demonstrated that the inhibition of the cell cycle checkpoint kinases WEE1 together with CHK1 drastically affects stability of the cell cycle and induces cell death in rapidly proliferating cells. Exploiting this finding for a possible therapeutic approach has showed efficacy in various solid and hematologic tumors, though not specifically tested in acute lymphoblastic leukemia. Methods: The efficacy of the combination between WEE1 and CHK1 inhibitors in B and T cell precursor acute lymphoblastic leukemia (B/T-ALL) was evaluated in vitro and ex vivo studies. The efficacy of the therapeutic strategy was tested in terms of cytotoxicity, induction of apoptosis, and changes in cell cycle profile and protein expression using B/T-ALL cell lines. In addition, the efficacy of the drug combination was studied in primary B-ALL blasts using clonogenic assays. Results: This study reports, for the first time, the efficacy of the concomitant inhibition of CHK1/CHK2 and WEE1 in ALL cell lines and primary leukemic B-ALL cells using two selective inhibitors: PF-0047736 (CHK1/CHK2 inhibitor) and AZD-1775 (WEE1 inhibitor). We showed strong synergism in the reduction of cell viability, proliferation and induction of apoptosis. The efficacy of the combination was related to the induction of early S-phase arrest and to the induction of DNA damage, ultimately triggering cell death. We reported evidence that the efficacy of the combination treatment is independent from the activation of the p53-p21 pathway. Moreover, gene expression analysis on B-ALL primary samples showed that Chek1 and Wee1 are significantly co-expressed in samples at diagnosis (Pearson r = 0.5770, p = 0.0001) and relapse (Pearson r= 0.8919; p = 0.0001). Finally, the efficacy of the combination was confirmed by the reduction in clonogenic survival of primary leukemic B-ALL cells. Conclusion: Our findings suggest that the combination of CHK1 and WEE1 inhibitors may be a promising therapeutic strategy to be tested in clinical trials for adult ALL

The timing of plerixafor addition to G-Csf and chemotherapy affects immunological recovery after autologous stem cell transplant in multiple myeloma

Plerixafor inhibits CXCR4, thus inducing the mobilization of hematopoietic stem/progenitor cells in lymphoma and multiple myeloma (MM) patients eligible for autologous stem cell transplantation (ASCT). However, the kinetics of plerixafor-induced mobilization of lymphocyte subsets is poorly known. Here, we evaluated the graft content, the engraftment, and the immunological reconstitution of MM patients receiving plerixafor. Thirty-seven patients undergoing one or tandem ASCT were enrolled. After mobilization with cyclophosphamide plus G-CSF, plerixafor was added at hematological recovery regardless of CD34(+) cell count. We evaluated the number of CD34(+), CD34(+)/CD38(-), CD3(+), CD4(+), CD8(+), CD19(+), CD56(+)/CD3(-), CD4(+)/CD25(+)/FOXP3(+), and CD138(+)/CD38(+) cells on each apheresis. Hematological and immunological recovery were determined at 30 days, 3, 6, 9, and 12 months after ASCT. Overall, 34/37 patients mobilized a median of 10.1\u2009 7\u200910(6) CD34(+) cells/Kg (IQ 7.7-13.4). Patients with <20/\ub5L CD34(+) cells at plerixafor administration (18/33) had a significantly higher CD34(+) cell fold increase, but not a higher absolute number, than 16/33 patients with 6520/\ub5L CD34(+) cells. A similar CD34(+) and immune graft composition was reported. A higher number of CD3(+) and CD8(+) cells/\ub5L was observed at 3 months after first ASCT (p\u2009<\u20090.05) in the group with 6520 CD34(+) cells/\ub5L. Thus, in MM patients, the timing of plerixafor administration influences immunological recovery