High-dimensional analysis of 16 SARS-CoV-2 vaccine combinations reveals lymphocyte signatures correlating with immunogenicity

The range of vaccines developed against severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) provides a unique opportunity to study immunization across different platforms. In a single-center cohort, we analyzed the humoral and cellular immune compartments following five coronavirus disease 2019 (COVID-19) vaccines spanning three technologies (adenoviral, mRNA and inactivated virus) administered in 16 combinations. For adenoviral and inactivated-virus vaccines, heterologous combinations were generally more immunogenic compared to homologous regimens. The mRNA vaccine as the second dose resulted in the strongest antibody response and induced the highest frequency of spike-binding memory B cells irrespective of the priming vaccine. Priming with the inactivated-virus vaccine increased the SARS-CoV-2-specific T cell response, whereas boosting did not. Distinct immune signatures were elicited by the different vaccine combinations, demonstrating that the immune response is shaped by the type of vaccines applied and the order in which they are delivered. These data provide a framework for improving future vaccine strategies against pathogens and cancer

High-Dimensional Flow Cytometry of Tumor and Immune Cell Marker in High Grade Glioma

High grade glioma and particular glioblastoma are malignant brain tumors with a poor prognosis. Median overall survival with current standard therapy is only 14 months. Although immunotherapy revolutionized the treatment of other types of cancer with many ongoing trials, major advances have not yet been made in the treatment of malignant brain tumors. Recent studies have shown that the tumor microenvironment is dominated by myeloid cells with an immune suppressive phenotype, programmed by the tumor, which promotes tumor progression. T cells on the other hand are often not efficiently primed, are terminally exhausted, or inactivated by immune checkpoints. The aim of this study was to identify targetable surface markers on tumor cells and macrophages in high grade glioma. We first performed a screen using spectral flow cytometry to identify surface markers expressed on four human glioblastoma cell lines. Initially, 361 surface markers expressed on tumor cell lines were identified. Using various databases and survival data from the Cancer Genome Atlas, this list was narrowed down to markers that correlated with a negative impact on survival in glioblastoma patients. Further analysis using single-cell RNA sequencing datasets helped to determine which markers were specifically expressed on tumor cells and macrophages, while excluding those highly expressed on normal brain cells or other normal tissues. After creating and testing panels of brain tumor and immune cell surface markers, samples from 46 patients with high grade glioma were analyzed by high dimensional spectral flow cytometry. By comparing surface marker expression between IDH mutant and IDH wild-type high grade gliomas, we identified specific tumor cell and macrophage subpopulations that are more abundant in IDH wildtype tumors. The signature on tumor cells included the expression of GPR56, CD271, CD71, CD112, CD323, CD146, CD276, PDL1, CD56, CD151, CD51, CD304, CD63 and PDL2. Correlation of our signature with survival revealed a significant association with shorter survival comparing IDH mutant and IDH wildtype patients in our cohort. Various immunosuppressive macrophage subsets were more abundant in IDH-wildtype tumors. Higher frequency of exhausted CD8 T cells were associated with longer survival, whereas immunosuppressive macrophage subsets including FOLR2+CD39+CD163+MoMacs, cycling CD169+MERTK+CD163+CD206+MoMacs, and CD39+CX3CR1+ microglia were associated with shorter survival. These MoMacs co-expressed markers that were also present on our tumor samples, such as CD39, CD112, CD31, CD276, PDL1, HLADR, CD116, CD63, CD51, CD304 and PDL2. Endothelial cells in our samples distinguished themselves by the expression of CD146, CD138 and CD151. Overall, our study was able to generate a specific surface marker atlas with signatures for brain tumor cells, microglia, and monocyte derived macrophages as well as endothelial cells in high grade glioma. Our study reveals potential new targets for development of immunotherapies, such as for example antibody cytokine fusions or CAR-macrophages, particularly for the more aggressive IDH wildtype glioblastoma

Adaptive Hybrid Surgery Experiences in Benign Skull Base Tumors

Background: The treatment of benign skull base tumors remains challenging. These tumors are often located in close relationship to critical structures. Therefore, radical resection of these tumors can be associated with high morbidity. Multimodal treatment concepts, including controlled partial tumor resection followed by radiosurgery, should be considered. Methods: Adaptive hybrid surgery analysis (AHSA) is an intraoperative tool that has been introduced for the automatic assessment of tumor properties, and virtual real-time radiosurgical treatment simulation and continuous feasibility analysis of adjuvant radiosurgery. The AHSA method (Brainlab®, Munich, Germany) was applied to five patients who underwent partial resection of a benign skull base tumor. Tumor volumetry was obtained on pre- and postoperative MR scans. Organs at risk were, preoperative, automatically delineated with atlas mapping software (Elements® Segmentation Cranial), and adaptations were made if necessary. Results: Five patients with benign skull base lesions underwent planned partial tumor resection in a multimodal therapeutic surgery followed by radiosurgery. The preoperative tumor volumes ranged between 8.52 and 25.2 cm3. The intraoperative residual tumor volume measured with the AHSA® software ranged between 2.13–12.17 cm3 (25–52% of the preoperative tumor volume). The intraoperative automatic AHSA plans of the remaining tumor volume suggested, in all five patients, that safe hypofractionated radiation was feasible. Patients were followed for 69.6 ± 1.04 months, and no complications occurred after the patients were treated with radiation. Conclusions: Intraoperative SRS planning based on volumetric assessments during resection of skull base tumors using AHSA® is feasible and safe. The AHSA method allows the neurosurgeon to continuously evaluate the feasibility of adjuvant radiosurgery while planning and performing a surgical resection. This method supports the treatment strategy of a complementary approach during surgical resection of complex skull base tumors and might contribute to preventing surgical and radiosurgical complications