Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor, characterized by a high degree of intertumoral heterogeneity. However, a common feature of the GBM microenvironment is hypoxia, which can promote radio- and chemotherapy resistance, immunosuppression, angiogenesis, and stemness. We experimentally defined common GBM adaptations to physiologically relevant oxygen gradients, and we assessed their modulation by the metabolic drug metformin. We directly exposed human GBM cell lines to hypoxia (1% O₂) and to physioxia (5% O₂). We then performed transcriptional profiling and compared our in vitro findings to predicted hypoxic areas in vivo using in silico analyses. We observed a heterogenous hypoxia response, but also a common gene signature that was induced by a physiologically relevant change in oxygenation from 5% O₂ to 1% O₂. In silico analyses showed that this hypoxia signature was highly correlated with a perinecrotic localization in GBM tumors, expression of certain glycolytic and immune-related genes, and poor prognosis of GBM patients. Metformin treatment of GBM cell lines under hypoxia and physioxia reduced viable cell number, oxygen consumption rate, and partially reversed the hypoxia gene signature, supporting further exploration of targeting tumor metabolism as a treatment component for hypoxic GBM.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a worldwide pandemic with at least 3.8 million deaths to date. For that reason, finding an efficient vaccine for this virus quickly became a global priority. The majority of vaccines now marketed are based on the SARS-CoV-2 spike protein that has been described as the keystone for optimal immunization. In order to monitor SARS-CoV-2 spike-specific humoral responses generated by immunization or infection, we have developed a robust and reproducible enzyme-linked immunosorbent assay (ELISA) protocol. This protocol describes a method for quantitative detection of IgG antibodies against the SARS-CoV-2 spike protein using antigen-coated microtiter plates. Results showed that antibodies could be quantified between the range of 1.953 ng/mL to 500 ng/mL with limited inter- and intra-assay variability.

Over two decades, most cancer vaccines failed clinical development. Key factors may be the lack of efficient priming with tumor-specific antigens and strong immunostimulatory signals. MVX-ONCO-1, a personalized cell-based cancer immunotherapy, addresses these critical steps utilizing clinical-grade material to replicate a successful combination seen in experimental models: inactivated patient’s own tumor cells, providing the widest cancer-specific antigen repertoire and a standardized, sustained, local delivery over days of a potent adjuvant achieved by encapsulated cell technology. We conducted an open-label, single-arm, first-in-human phase I study with MVX-ONCO-1 in patients with advanced refractory solid cancer. MVX-ONCO-1 comprises irradiated autologous tumor cells coimplanted with two macrocapsules containing genetically engineered cells producing granulocyte–macrophage colony-stimulating factor. Patients received six immunizations over 9 weeks without maintenance therapy. Primary objectives were safety, tolerability, and feasibility, whereas secondary objectives focused on efficacy and immune monitoring. Data from 34 patients demonstrated safety and feasibility with minor issues. Adverse events included one serious adverse event possibly related to investigational medicinal product and two moderate-related adverse events. More than 50% of the patients with advanced and mainly nonimmunogenic tumors showed clinical benefits, including partial responses, stable diseases, and prolonged survival. In recurrent/metastatic head and neck squamous cell carcinoma, one patient achieved a partial response, whereas another survived for more than 7 years without anticancer therapy for over 5 years. MVX-ONCO-1 is safe, well tolerated, and beneficial across several tumor types. Ongoing phase IIa trials target patients with advanced recurrent/metastatic head and neck squamous cell carcinoma after initial systemic therapy. Significance: This first-in-human phase I study introduces a groundbreaking approach to personalized cancer immunotherapy, addressing limitations of traditional strategies. By combining autologous irradiated tumor cells as a source of patient-specific antigens and utilizing encapsulated cell technology for localized, sustained delivery of granulocyte–macrophage colony-stimulating factor as an adjuvant, the study shows a very good safety and feasibility profile. This innovative approach holds the promise of addressing tumor heterogeneity by taking advantage of each patient's antigenic repertoire.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a worldwide pandemic with recurrences. Therefore, finding a vaccine for this virus became a priority for the scientific community. The SARS-CoV-2 spike protein has been described as the keystone for viral entry into cells and effective immune protection against SARS-CoV-2 is elicited by this protein. Consequently, many commercialized vaccines focus on the spike protein and require the use of an optimal adjuvant during vaccination. Granulocyte-macrophage colony-stimulating factor (GM-CSF) has demonstrated a powerful enhancement of acquired immunity against many pathogens when delivered in a sustained and local manner. In this context, we developed an encapsulated cell-based technology consisting of a biocompatible, semipermeable capsule for secretion of GM-CSF. In this study, we investigated whether murine GM-CSF (muGM-CSF) represents a suitable adjuvant for SARS-CoV-2 immunization, and which delivery strategy for muGM-CSF could be most beneficial. To test this, different groups of mice were immunized with intra-dermal (i.d.) electroporated spike DNA in the absence or presence of recombinant or secreted muGM-CSF. Results demonstrated that adjuvanting a spike DNA vaccine with secreted muGM-CSF resulted in enhancement of specific cellular and humoral immune responses against SARS-CoV-2. Our data also highlighted the importance of delivery strategies to the induction of cellular and humoral-mediated responses.

The impact of adiposity on the immune system remains largely unexplored. While obesity has been suggested to be a predisposing or adverse prognostic factor in certain neoplastic diseases it is not yet clear to what extent this may involve the innate or adaptative immune systems. Adipose tissue produces a large number of secreted molecules, or adipocytokines, which may have immunomodulatory functions. This project aimed to determine whether phenotypical and/or functional properties of circulating natural killer (NK) cells were influenced by body mass index (BMI). In a preliminary study, 47 patients with no history of hematological malignancy were included, including 14 healthy volunteers with a normal BMI (18.5-25), 10 patients considered to be overweight (25 < BMI < 30), 11 patients considered as obese (BMI > 30) and 12 patients who were previously obese and had lost weight. Peripheral blood was analyzed by flow cytometry for the following markers: activating receptors (CD16, C161, DNAM-1, 2B4, NKG2C, NKG2D, NKp46, NKp30), inhibitor receptors (NKG2A, KIR2DL1, KIR2DL2, KIR3DL1), activation markers (CD69, granzyme B, NKG2C), maturation markers (CD56, CD57, CD94, CX3CR1) and cytotoxicity markers (perforin, NKG7). Moreover the capacity of NK cells to degranulate and to produce several cytokines (TNF, IFN-g) or chemokines (MIP1-b) in response to stimulation by K562 cells or Rituximab coated -tumor B cells was evaluated. Results showed a positive correlation between BMI and total number of circulating NK cells, with a significant difference between lean patients and obese patients. Immunophenotypic analyses showed that NKp46 and CD94 expression (measured by Mean Fluorescence Intensity) were both significantly reduced with increased BMI. NK cells from obese patients also show signs of activation, characterized by an elevation of the expression of CD69 and granzyme B and a reduction of the expression of CD16. The ability of NK cells to be activated in the presence of cell lines was also reduced in obese patients: NK cell secretion of IFN-g and MIP-1b in the presence of Granta cells or MIP-1b in the presence of K562 decreased linearly with increasing BMI. NK cell degranulation upon co-culture with K562 cells was also negatively correlated with BMI. In these different assays pre-obese and ex-obese patients scored intermediate between lean and obese patients. Overall these results suggest in vivo activation and exhaustion of NK cells in obese patients. These cells are thus potentially less likely to participate as effector cells in immunotherapeutic regimens. Disclosures: No relevant conflicts of interest to declare.