👤 Richard Riedel

Neurodevelopmental disorders have been increasingly associated with maternal immune activation (MIA) during pregnancy, particularly in response to viral infections. However, the impact of human respiratory syncytial virus (hRSV) infection during gestation on offspring neurodevelopment remains poorly understood. This study aimed to characterize hRSV-induced MIA and evaluate its effects on fetal brain development and offspring behavior using a murine model. Pregnant mice were infected with hRSV at gestational day 14, and tissues were analyzed at day 19. Infection induced pulmonary inflammation, evidenced by increased neutrophil infiltration, and viral replication was detected in maternal lungs and placental tissue, but not in fetal organs. Placental infection was associated with increased decidual immune cells and a shift toward a pro-inflammatory cytokine profile, including elevated IL-6, TNF-α, IFN-γ, and IL-1β, along with decreased IL-10 and IFN-λ. Increased levels of IL-6, TNF-α, and IL-4 were also detected in maternal serum and fetal brains, suggesting vertical transfer of cytokines. Additionally, reduced brain-derived neurotrophic factor levels and altered expression of tight junction-related genes were observed in fetal brains. Behavioral analyses revealed that offspring of infected dams exhibited impaired short-term memory and altered anxiety-like and repetitive behaviors, which persisted or intensified with age. These findings demonstrate that maternal hRSV infection induces MIA, disrupts the fetal neuroimmune environment, and leads to long-term behavioral alterations in offspring, highlighting hRSV as a potential risk factor for neurodevelopmental disorders. Show less

Inhibitors of the menin-KMT2A interaction are promising agents for the treatment of KMT2A-rearranged leukemias. We evaluated menin inhibition in patient-derived xenografts of KMT2A-rearranged leukemias with high-risk features. Three acute myeloid leukemias with high-risk fusion partners (mixed-lineage leukemia-10 [MLLT10] and mixed-lineage leukemia-4 [MLLT4]) and two infant acute lymphocytic leukemia (ALL) samples were sensitive to menin inhibition. We also evaluated serial samples from two patients with multiply relapsed ALL. We found that highly pretreated KMT2A::AFF1 ALL samples were much less sensitive compared with cells obtained earlier in the same patients' disease course. Because none of the patients had been treated with a menin inhibitor, resistance in these highly pretreated samples was acquired in the absence of menin-inhibitor exposure. Transcriptomic analysis documented sustained on-target efficacy toward the canonical targets of the menin inhibitor in resistant cells. Targeted genomic analysis documented the emergence of multiple comutations, including RAS pathway and TP53 mutations, although neither was sufficient to induce menin-inhibitor resistance in vitro. Downregulation of KMT3D may account for resistance in one patient; inactivation of KMT2C/D has been reported to result in menin-inhibitor resistance, and KMT2C-edited cells from this patient were selected for in menin-inhibitor-containing growth conditions. Future studies will need to clarify more broadly which genomic/epigenomic alterations drive upfront resistance. Regardless of mechanism, our data support using menin inhibitors upfront or in early lines of therapy before substantial genomic or epigenomic evolution has occurred. Show less

ROS1 fusions are well treatable aberrations in NSCLC. Besides solvent-front mutations (SFM) in resistance to targeted therapy, small-scale ROS1 mutations are largely unknown. We exploratively analyzed the clinical and molecular characteristics of small-scale ROS1 mutations in NSCLC patients without activating ROS1 fusions or SFMs. Next-generation sequencing was performed on tissue samples from NSCLC patients within the Network Genomic Medicine. Patients with ROS1 fusions and SFMs were excluded. We analyzed clinical characteristics of patients harboring small-scale ROS1-mutations, ROS1- and co-occurring mutations, and their response to systemic therapy. Of 10,396 patients analyzed, 101 (1.0%) patients harbored small-scale ROS1 mutations. Most patients were male (73.3%) and smokers (96.6%). Nearly half of the patients presented with squamous-cell carcinoma (SqCC, 40.4%). Most mutations were transversions (50.5%), and 66% were in the kinase domain. Besides TP53 mutations (65.3%), KRAS (22.8%), EGFR (5.9%), PIK3CA (9.9%) and FGFR1-4 mutations (8.9%) co-occurred. In 10 (9.9%) patients, ROS1 mutation was the only aberration detected. Median overall survival (mOS) differed significantly in patients with or without KRAS co-mutations (9.7 vs 21.5 months, p = 0.02) and in patients treated with or without immune-checkpoint blockade (ICB) during treatment (21.5 vs 4.4 months, p = 0.003). The cohort's clinical characteristics contrasted ROS1-fused cohorts. Co-occurrence of KRAS mutations led to shortened survival and patients benefited from ICB. Our data does not support the idea of ROS1 small-scale mutations as strong oncogenic drivers in NSCLC, but rather as relevant bystanders altering the efficacy of treatment approaches. Show less