Miltenyi Biotec (Germany)

ABSTRACTTissue engineering, and in particular the development of organ‐on‐a‐chip (OOC) models, holds significant promise for advancing personalized medicine and reducing the use of animal models. The integration of microfluidics and advanced biomaterials in OOC systems provides controlled microenvironments and fosters the creation of physiologically relevant tissue models. A critical aspect of OOC models is the fabrication of perfusable chips to create vascular networks that are essential for sustaining long‐term 3D cultures. Here we show a two‐step fabrication approach that combines one‐ and two‐photon polymerization (2PP) to create a microfluidic chip capable of supporting endothelial cell (EC) angiogenesis. The chip features a 2PP‐printed sealing contour to ensure leak‐free bonding of chip parts, and an array of channel‐separating‐pillars that enable EC migration from the parent vessel into an extracellular matrix. Our results demonstrate that the developed angiogenesis‐on‐a‐chip model successfully induces EC sprouting in response to angiogenic factors. This work significantly contributes to the field by providing a versatile platform for vascular studies, highlighting the potential for its application in drug screening. The flexibility and precision of our fabrication method also allows for customizing OOC devices for various biological applications, thereby enhancing the relevance of these systems in investigation of complex tissue interactions.

Abstract Glioblastoma is a devastating brain cancer. Despite intense research, patient survival has not significantly increased over the past decades and efficient treatment is currently not available. Therefore, the fundamental understanding of the disease, based on the development of relevant animal models, combined with the development of efficient tools for their deep analysis, represents a priority. Neural Stem cells in the subventricular zone of the forebrain have been identified as cells of origin for glioblastoma, leading to the development of new somatic lineage models based on in vivo brain electroporation. While such models have been characterized in depths by sequencing approaches, systematic histological analyses are currently scarce. Here we present the multimodal histological characterization of a transgenesis independent somatic glioblastoma model in mice. Using 3D light sheet imaging we demonstrate that the model is highly reproducible, allowing quantitative evaluation of tumor growth over large cohorts. Using multiplex imaging by MICS technology we systematically characterize the cellular landscape and molecular composition of the induced tumors, as well as their micro- and macro-environments, and provide a resource of mouse compatible antibodies for cancer research. Finally, we use the model to show that tissue clearing and 3D light sheet microscopy of whole brains can be combined with subsequent multiplex imaging, allowing deep spatial characterization of the tumor proteome in pre-identified brain regions.

Background: Chimeric antigen receptor T-cell (CAR-T) therapies have been approved by the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) for the treatment of diffuse large B-cell lymphoma (DLBCL), primarily based on single-arm trials or indirect comparisons with stem cell transplantation. However, no direct head-to-head comparisons of CAR-T therapies have been conducted, largely due to their high cost. To assess their true value, indirect treatment comparisons (ITCs) are essential. These comparisons, however, are prone to confounding biases, which necessitate careful adjustments through the identification and measurement of relevant variables. Materials and Methods: This study aims to identify the variables used for adjustment in ITCs of CAR-T therapies for DLBCL and examine the methodologies employed to select them. A rapid literature review was conducted in PubMed in September 2023, focusing on ITCs involving CAR-T therapies for DLBCL. The search was based on keywords categorized into three groups: techniques (ITCs and related terms), drugs (CAR-T therapies), and indication (DLBCL). Results: The rapid literature review identified 21 articles, of which 11 were selected for analysis. Exclusions were made for articles that did not identify confounders, were letters to editors, or addressed conditions other than DLBCL. Among the 11 selected publications, 10 did not clearly specify the methodology used to identify adjustment variables. A total of 25 potential confounders were identified across the studies, with substantial variability in the set of variables used, reflecting a lack of standardization in confounder selection. Commonly identified confounders included the number of prior treatment lines and Eastern Cooperative Oncology Group Performance Status (ECOG PS), although their inclusion as adjustment variables in ITCs was inconsistent, often due to missing data. Conclusions: While the identified confounders are clinically relevant, the methodologies for selecting them remain unclear, resulting in significant variability across studies. Additionally, key variables commonly considered in health technology assessments (HTAs), such as age, sex, and disease severity, were inconsistently incorporated into ITCs. To improve the reliability and consistency of ITC outcomes, there is a pressing need for standardized methodologies for identifying and adjusting for confounders.

Infection with SARS-CoV-2 results in mild to severe COVID-19 disease courses. Several studies showed the association of impaired T-cell responses and certain HLA haplotypes with disease severity. However, it remained unclear if T-cell activation was compromised due to a general reduction of presented epitopes or other intrinsic factors within APCs or T cells. Furthermore, a potential reduction of presented epitopes would suggest if an upcoming SARS-CoV-2 variant could escape T-cell immunity. Hence, knowledge about the T-cell epitope landscape of SARS-CoV-2 would allow to better understand mechanisms leading to severe disease and to estimate the potential stability of the T-cell response in light of virus evolution, which might provide insights for future vaccine designs. Hence, in the present study, the T-cell epitope landscape of SARS-CoV-2 was determined via in vitro T-cell stimulation plus in silico prediction. HLAs associated with mild and severe disease courses showed almost the same potential in epitope presentation, suggesting intrinsic factors of APCs or T cells as contributors to the more severe disease courses. As T-cell epitopes did also not originate from regions of SARS-CoV-2 having shown high mutation rates in the past, a relatively stable T-cell response can be expected regarding new SARS-CoV-2 strains in the future. Analysis of the T-cell epitope landscape of SARS-CoV-2 suggests T-cell intrinsic factors as likely modulators of disease severity and that the capacity of MHC-peptide presentation remains stable among circulating SARS-CoV-2 viral strains.

Subgroup definitions for possible deescalation of neoadjuvant cancer treatment are urgently needed in clinical practice. To investigate the effect of BRCA1 and/or BRCA2 tumor pathogenic variants (tPVs) by comparing 2 deescalated neoadjuvant regimens (nab-paclitaxel plus either carboplatin or gemcitabine) on pathologic complete response (pCR), invasive disease-free survival (IDFS), and overall survival (OS) of patients with early-stage triple-negative breast cancer (TNBC). This was a preplanned secondary analysis of a phase 2 prospective randomized clinical trial (ADAPT-TN) conducted by the West German Study Group (WSG) at 45 sites in Germany between June 2013 and February 2015. The trial enrolled patients with noninflammatory early-stage TNBC (clinical tumor size ≥1 cm; estrogen receptor and progesterone receptor expression <1%; and ERBB2 negative). DNA samples from pretreatment biopsies were obtained. Genetic analysis was performed between January 2018 and March 2020. Final data analyses took place in September 2023. Patients were randomized to 12 weeks of treatment with nab-paclitaxel plus either carboplatin or gemcitabine; omission of otherwise mandatory anthracycline-containing chemotherapy was allowed in the case of pCR. tPVs in 20 cancer-associated genes, including BRCA1 and BRCA2, were analyzed using a customized gene panel. The prevalence of BRCA1 and/or BRCA2 tPVs and their effect on pCR rate, IDFS, and OS were evaluated using logistic and Cox proportional hazards regression. Of the 307 patients with DNA samples from pretreatment biopsies available, tumor next-generation sequencing analyses were successful for 266 patients. The 266 patients included in this analysis were female, with a median age of 51 years (range, 26-76 years). A total of 162 patients (60.9%) had a clinical tumor size of 2 cm or greater, and 70 (26.3%) had clinical node-positive disease. BRCA1 and/or BRCA2 tPVs were detected in 42 patients (15.8%). The highest pCR rate among patients with BRCA1 and/or BRCA2 tPVs was seen in the nab-paclitaxel plus carboplatin group (9 of 14 patients [64.3%]) compared with the nab-paclitaxel plus gemcitabine group (10 of 28 [35.7%]) (odds ratio, 3.24 [95% CI, 0.85-12.36]; P = .08); the highest numeric 5-year IDFS and OS rates (84.4% and 92.9%, respectively) were seen in the nab-paclitaxel plus carboplatin group. In this secondary analysis of the WSG-ADAPT-TN randomized clinical trial on tPVs, deescalated nab-paclitaxel plus carboplatin was superior to nab-paclitaxel plus gemcitabine, particularly in patients with BRCA1 and/or BRCA2 tPVs. These findings suggest that BRCA1 and/or BRCA2 tPV status could be a candidate marker for a deescalation strategy in early-stage TNBC; however, prospective validation of survival outcomes in larger cohorts with differentiation between germline and somatic pathogenic variants is necessary. ClinicalTrials.gov Identifier: NCT01815242.