Purpose: Novel natural killer (NK) cell-directed strategies in cancer immunotherapy aim at specifically modulating the balance between NK cell receptor signals toward tumor-specific activation. The signaling lymphocyte activation molecule-related receptor 2B4 (CD244) is an important regulator of NK cell activation. We investigated whether 2B4-enhanced activation signals can redirect the cytolytic function of human NK cells to NK cell-resistant and autologous leukemia and tumor targets. Experimental Design: In vitro-stimulated NK cells from healthy donors and pediatric leukemia patients were gene modified with CD19 or G D2 -specific chimeric receptors containing either the T-cell receptor ζ or 2B4 endodomain alone or combined. Results: Chimeric 2B4 signaling alone failed to induce interleukin-2 receptor up-regulation and cytokine secretion but triggered a specific degranulation response. Integration of the 2B4 endodomain into T-cell receptor ζ chimeric receptors significantly enhanced all aspects of the NK cell activation response to antigen-expressing leukemia or neuroblastoma cells, including CD25 up-regulation, secretion of IFN-γ and tumor necrosis factor-α, release of cytolytic granules, and growth inhibition, and overcame NK cell resistance of autologous leukemia cells while maintaining antigen specificity. Conclusion: These data indicate that the 2B4 receptor has a potent costimulatory effect in NK cells. Antigen-specific 2B4ζ-expressing NK cells may be a powerful new tool for adoptive immunotherapy of leukemia and other malignancies.

Invasive fungal infections cause substantial morbidity and mortality in immunocompromised patients, particularly in those with haematological malignancies and recipients of allogeneic haematopoietic stem cell transplantation. Difficulties in diagnosing invasive fungal infections and subsequent delays in treatment initiation lead to unfavourable outcomes and emphasise the importance of prophylaxis. Since the recommendations of the Infectious Diseases Working Party of the German Society for Haematology and Oncology in 2009, results of 14 additional clinical studies have been published comprising 2,899 patients and initiating this update. Key recommendations for adult patients are as follows: Posaconazole remains the drug of choice during remission-induction chemotherapy in acute myeloid leukaemia, myelodysplastic syndrome and allogeneic haematopoietic stem cell transplantation with graft versus host disease (AI). In the pre-engraftment period of allogeneic transplantation, several antifungals are appropriate and can be recommended with equal strength: voriconazole (BI), micafungin (BI), fluconazole (BI) and posaconazole (BII). There is poor evidence regarding antifungal prophylaxis in the post-engraftment period of allogeneic haematopoietic stem cell transplantation if no steroids for treatment of graft versus host disease are required. Aerosolised liposomal amphotericin B inhalation in conjunction with fluconazole can be used in patients with prolonged neutropenia (BII).