Andreas Brandl

Donor CD4(+)Foxp3(+) regulatory T cells (T reg cells) suppress graft-versus-host disease (GvHD) after allogeneic hematopoietic stem cell transplantation (HCT [allo-HCT]). Current clinical study protocols rely on the ex vivo expansion of donor T reg cells and their infusion in high numbers. In this study, we present a novel strategy for inhibiting GvHD that is based on the in vivo expansion of recipient T reg cells before allo-HCT, exploiting the crucial role of tumor necrosis factor receptor 2 (TNFR2) in T reg cell biology. Expanding radiation-resistant host T reg cells in recipient mice using a mouse TNFR2-selective agonist before allo-HCT significantly prolonged survival and reduced GvHD severity in a TNFR2- and T reg cell-dependent manner. The beneficial effects of transplanted T cells against leukemia cells and infectious pathogens remained unaffected. A corresponding human TNFR2-specific agonist expanded human T reg cells in vitro. These observations indicate the potential of our strategy to protect allo-HCT patients from acute GvHD by expanding T reg cells via selective TNFR2 activation in vivo.

PURPOSE In patients with peritoneal metastasis (PM) from gastric cancer (GC), chemotherapy is the treatment of choice. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are still being debated. This randomized, controlled, open-label, multicenter phase III trial (EudraCT 2006-006088-22; ClinicalTrials.gov identifier: NCT02158988 ) explored the impact on overall survival (OS) of HIPEC after CRS. PATIENTS AND METHODS Adult patients with GC and histologically proven PM were randomly assigned (1:1) to perioperative chemotherapy and CRS alone (CRS-A) or CRS plus HIPEC (CRS + H). HIPEC comprised mitomycin C 15 mg/m 2 and cisplatin 75 mg/m 2 in 5 L of saline perfused for 60 minutes at 42°C. The primary end point was OS; secondary endpoints included progression-free survival (PFS), other distant metastasis-free survival (MFS), and safety. Analyses followed the intention-to-treat principle. RESULTS Between March 2014 and June 2018, 105 patients were randomly assigned (53 patients to CRS-A and 52 patients to CRS + H). The trial stopped prematurely because of slow recruitment. In 55 patients, treatment stopped before CRS mainly due to disease progression/death. Median OS was the same for both groups (CRS + H, 14.9 [97.2% CI, 8.7 to 17.7] months v CRS-A, 14.9 [97.2% CI, 7.0 to 19.4] months; P = .1647). The PFS was 3.5 months (95% CI, 3.0 to 7.0) in the CRS-A group and 7.1 months (95% CI, 3.7 to 10.5; P = .047) in the CRS + H group. The CRS + H group showed better MFS (10.2 months [95% CI, 7.7 to 14.7] v CRS-A, 9.2 months [95% CI, 6.8 to 11.5]; P = .0286). The incidence of grade ≥3 adverse events (AEs) was similar between groups (CRS-A, 38.1% v CRS + H, 43.6%; P = .79). CONCLUSION This study showed no OS difference between CRS + H and CRS-A. PFS and MFS were significantly better in the CRS + H group, which needs further exploration. HIPEC did not increase AEs.

Bioactive glass (BG) scaffolds are being investigated for bone tissue engineering applications because of their osteoconductive and angiogenic nature. However, to increase the in vivo performance of the scaffold, including enhancing the angiogenetic growth into the scaffolds, some researchers use different modifications of the scaffold including addition of inorganic ionic components to the basic BG composition. In this study, we investigated the in vitro biocompatibility and bioactivity of Cu2+-doped BG derived scaffolds in either BMSC (bone-marrow derived mesenchymal stem cells)-only culture or co-culture of BMSC and human dermal microvascular endothelial cells (HDMEC). In BMSC-only culture, cells were seeded either directly on the scaffolds (3D or direct culture) or were exposed to ionic dissolution products of the BG scaffolds, kept in permeable cell culture inserts (2D or indirect culture). Though we did not observe any direct osteoinduction of BMSCs by alkaline phosphatase (ALP) assay or by PCR, there was increased vascular endothelial growth factor (VEGF) expression, observed by PCR and ELISA assays. Additionally, the scaffolds showed no toxicity to BMSCs and there were healthy live cells found throughout the scaffold. To analyze further the reasons behind the increased VEGF expression and to exploit the benefits of the finding, we used the indirect method with HDMECs in culture plastic and Cu2+-doped BG scaffolds with or without BMSCs in cell culture inserts. There was clear observation of increased endothelial markers by both FACS analysis and acetylated LDL (acLDL) uptake assay. Only in presence of Cu2+-doped BG scaffolds with BMSCs, a high VEGF secretion was demonstrated by ELISA; and typical tubular structures were observed in culture plastics. We conclude that Cu2+-doped BG scaffolds release Cu2+, which in turn act on BMSCs to secrete VEGF. This result is of significance for the application of BG scaffolds in bone tissue engineering approaches.