Differential impact of two doses of antithymocyte globulin conditioning on lymphocyte recovery upon haploidentical hematopoietic stem cell transplantation

Background: In vivo depletion of host T cells with antithymocyte globulin (ATG) is a common strategy for preventing graft-versus-host disease in allogeneic hematopoietic stem cell transplantation (HSCT). The total dose of ATG in conditioning regimens appears to be an important factor that influences the outcome in recipients of transplants. However, the optimal ATG dosage has not been established to date. It remains unclear whether, in the setting of haploidentical HSCT (haploHSCT), different doses of ATG might exert differential influences on the recovery of lymphocyte subpopulations. Methods: This retrospective study analyzed lymphocyte recovery and its correlation to viral infection in two groups of patients that received different doses of ATG before haploHSCT. We performed flowcytometry to determine immunophenotypes of CD19(+) B cells and CD3(+), CD4(+), CD8(+), CD4(+) CD45RA(+), CD4(+) CD45RO(+), CD4(+) CD28(+), CD8(+) CD28(+), and CD4(-)CD8(-)T cells. Results: We found that, compared to 6 mg/kg, 10 mg/kg ATG significantly hampered the recoveries of CD4+, CD4(+) CD45RA(+), and CD4(+) CD45RO(+) T cells in the first 2 months following haploHSCT. Similarly, compared to 6 mg/kg, the 10 mg/kg dose of ATG negatively influenced the recoveries of CD4(-)CD8(-) and CD8(+) CD28(+) T cells; recovery was delayed for 6 and 12 months after transplantation, respectively. Moreover, we showed that an increase in Epstein-Barr virus (EBV) infections, associated with the higher dose of ATG, was correlated with the delayed recovery of CD4(-)CD8(-)double negative T cells. Conclusions: The present study revealed a differential impact of different ATG conditioning doses on the recoveries of T cell subpopulations post-haploHSCT. This study was the first to connect the recovery of CD4-CD8-T cells to the risk of EBV infection after HSCT. These findings will facilitate optimization of the ATG conditioning dosage and improve the outcome of patients with leukemia that receive haploHSCT.Key Program of the National Natural Science Foundation of China [81230013]; National Natural Science Foundation of China [81370666]SCI(E)[email protected]

Fabrication of a composite 3D-printed titanium alloy combined with controlled in situ drug release to prevent osteosarcoma recurrence

Osteosarcoma is a malignant bone tumor occurring in adolescents. Surgery combined with adjuvant or neoadjuvant chemotherapy is the standard treatment. However, systemic chemotherapy is associated with serious side effects and a high risk of postoperative tumor recurrence, leading to a high amputation rate and mortality in cancer patients. Implant materials that can simultaneously repair large bone defects and prevent osteosarcoma recurrence are in urgent need. Herein, an intelligent system comprising 3D-printed titanium scaffold (TS) and pH-responsive PEGylated paclitaxel prodrugs was fabricated for bone defect reconstruction and recurrence prevention following osteosarcoma surgery. The drug-loaded implants exhibited excellent stability and biocompatibility for supporting the activity of bone stem cells under normal body fluid conditions and the rapid release of drugs in response to faintly acidic environments. An in vitro study demonstrated that five human osteosarcoma cell lines could be efficiently eradicated by paclitaxel released in an acidic microenvironment. Using mice models, we demonstrated that the drug-loaded TS can enable a pH-responsive treatment of postoperative tumors and effectively prevent osteosarcoma recurrence. Therefore, local implantation of this composite scaffold may be a promising topical therapeutic method to prevent osteosarcoma recurrence

Identification of potential resistance mechanisms and therapeutic targets for the relapse of BCMA CAR-T therapy in relapsed/refractory multiple myeloma through single-cell sequencing

Abstract Background BCMA CAR-T is highly effective for relapsed/refractory multiple myeloma(R/R-MM) and significantly improves the survival of patients. However, the short remission time and high relapse rate of MM patients treated with BCMA CAR-T remain bottlenecks that limit long-term survival. The immune microenvironment of the bone marrow (BM) in R/R-MM may be responsible for this. The present study aims to present an in-depth analysis of resistant mechanisms and to explore potential novel therapeutic targets for relapse of BCMA CAR-T treatment via single-cell RNA sequencing (scRNA-seq) of BM plasma cells and immune cells. Methods This study used 10X Genomic scRNA-seq to identify cell populations in R/R-MM CD45+ BM cells before BCMA CAR-T treatment and relapse after BCMA CAR-T treatment. Cell Ranger pipeline and CellChat were used to perform detailed analysis. Results We compared the heterogeneity of CD45+ BM cells before BCMA CAR-T treatment and relapse after BCMA CAR-T treatment. We found that the proportion of monocytes/macrophages increased, while the percentage of T cells decreased at relapse after BCMA CAR-T treatment. We then reclustered and analyzed the alterations in plasma cells, T cells, NK cells, DCs, neutrophils, and monocytes/macrophages in the BM microenvironment before BCMA CAR-T treatment and relapse after BCMA CAR-T treatment. We show here that the percentage of BCMA positive plasma cells increased at relapse after BCMA CAR-T cell therapy. Other targets such as CD38, CD24, SLAMF7, CD138, and GPRC5D were also found to be expressed in plasma cells of the R/R-MM patient at relapse after BCMA CAR-T cell therapy. Furthermore, exhausted T cells, TIGIT+NK cells, interferon-responsive DCs, and interferon-responsive neutrophils, increased in the R/R-MM patient at relapse after BCMA CAR-T cell treatment. Significantly, the proportion of IL1βhi Mφ, S100A9hi Mφ, interferon-responsive Mφ, CD16hi Mφ, MARCO hi Mφ, and S100A11hi Mφ significantly increased in the R/R-MM patient at relapse after BCMA CAR-T cell therapy. Cell–cell communication analysis indicated that monocytes/macrophages, especially the MIF and APRIL signaling pathway are key players in R/R-MM patient at relapse after BCMA CAR-T cell therapy. Conclusion Taken together, our data extend the understanding of intrinsic and extrinsic relapse of BCMA CAR-T treatment in R/R-MM patient and the potential mechanisms involved in the alterations of antigens and the induced immunosuppressive microenvironment, which may provide a basis for the optimization of BCMA CAR-T strategies. Further studies should be performed to confirm these findings

Automatic segmentation of high‐risk clinical target volume for tandem‐and‐ovoids brachytherapy patients using an asymmetric dual‐path convolutional neural network

PurposesPreimplant diagnostic magnetic resonance imaging is the gold standard for image-guided tandem-and-ovoids (T&O) brachytherapy for cervical cancer. However, high dose rate brachytherapy planning is typically done on postimplant CT-based high-risk clinical target volume (HR-CTVCT ) because the transfer of preimplant Magnetic resonance (MR)-based HR-CTV (HR-CTVMR ) to the postimplant planning CT is difficult due to anatomical changes caused by applicator insertion, vaginal packing, and the filling status of the bladder and rectum. This study aims to train a dual-path convolutional neural network (CNN) for automatic segmentation of HR-CTVCT on postimplant planning CT with guidance from preimplant diagnostic MR.MethodsPreimplant T2-weighted MR and postimplant CT images for 65 (48 for training, eight for validation, and nine for testing) patients were retrospectively solicited from our institutional database. MR was aligned to the corresponding CT using rigid registration. HR-CTVCT and HR-CTVMR were manually contoured on CT and MR by an experienced radiation oncologist. All images were then resampled to a spatial resolution of 0.5 × 0.5 × 1.25 mm. A dual-path 3D asymmetric CNN architecture with two encoding paths was built to extract CT and MR image features. The MR was masked by HR-CTVMR contour while the entire CT volume was included. The network put an asymmetric weighting of 18:6 for CT: MR. Voxel-based dice similarity coefficient (DSCV ), sensitivity, precision, and 95% Hausdorff distance (95-HD) were used to evaluate model performance. Cross-validation was performed to assess model stability. The study cohort was divided into a small tumor group (<20 cc), medium tumor group (20-40 cc), and large tumor group (>40 cc) based on the HR-CTVCT for model evaluation. Single-path CNN models were trained with the same parameters as those in dual-path models.ResultsFor this patient cohort, the dual-path CNN model improved each of our objective findings, including DSCV , sensitivity, and precision, with an average improvement of 8%, 7%, and 12%, respectively. The 95-HD was improved by an average of 1.65 mm compared to the single-path model with only CT images as input. In addition, the area under the curve for different networks was 0.86 (dual-path with CT and MR) and 0.80 (single-path with CT), respectively. The dual-path CNN model with asymmetric weighting achieved the best performance with DSCV of 0.65 ± 0.03 (0.61-0.70), 0.79 ± 0.02 (0.74-0.85), and 0.75 ± 0.04 (0.68-0.79) for small, medium, and large group. 95-HD were 7.34 (5.35-10.45) mm, 5.48 (3.21-8.43) mm, and 6.21 (5.34-9.32) mm for the three size groups, respectively.ConclusionsAn asymmetric CNN model with two encoding paths from preimplant MR (masked by HR-CTVMR ) and postimplant CT images was successfully developed for automatic segmentation of HR-CTVCT for T&O brachytherapy patients