Intratumoral (IT) STING activation results in tumor regression in preclinical models, yet factors dictating the balance between innate and adaptive anti-tumor immunity are unclear. Here, clinical candidate STING agonist ADU-S100 (S100) is used in an IT dosing regimen optimized for adaptive immunity to uncover requirements for a T cell-driven response compatible with checkpoint inhibitors (CPIs). In contrast to highdose tumor ablative regimens that result in systemic S100 distribution, low-dose immunogenic regimens induce local activation of tumor-specific CD8 + effector T cells that are responsible for durable anti-tumor immunity and can be enhanced with CPIs. Both hematopoietic cell STING expression and signaling through IFNAR are required for tumor-specific T cell activation, and in the context of optimized T cell responses, TNFa is dispensable for tumor control. In a poorly immunogenic model, S100 combined with CPIs generates a survival benefit and durable protection. These results provide fundamental mechanistic insights into STING-induced anti-tumor immunity.

In the originally published version of this article, the 4T1 tumor cell line described in Figures 1, 2, and 5 and Supplemental Figures S1, S2, and S5 was mis-identified. This cell line has since been identified via short tandem repeat analysis as the murine CT26 tumor cell line, which is an undifferentiated colon carcinoma cell line. Furthermore, the line that was used had been engineered to express the human mesothelin protein. The authors believe that the substance and interpretation of the experiments put forth in the article remain the same. The online article, Figures 2 and S1, and the Supplemental Information have been updated to reflect the correction.

The LINC complex is found in a wide variety of organisms and is formed by the transluminal interaction between outer- and inner-nuclear-membrane KASH and SUN proteins, respectively. Most extensively studied are SUN1 and SUN2 proteins, which are widely expressed in mammals. Although SUN1 and SUN2 play functionally redundant roles in several cellular processes, more recent studies have revealed diverse and distinct functions for SUN1. While several recent in vitro structural studies have revealed the molecular details of various fragments of SUN2, no such structural information is available for SUN1. Herein, we conduct a systematic analysis of the molecular relationships between SUN1 and SUN2, highlighting key similarities and differences that could lead to clues into their distinct functions. We use a wide range of computational tools, including multiple sequence alignments, homology modeling, molecular docking, and molecular dynamic simulations, to predict structural differences between SUN1 and SUN2, with the goal of understanding the molecular mechanisms underlying SUN1 oligomerization in the nuclear envelope. Our simulations suggest that the structural model of SUN1 is stable in a trimeric state and that SUN1 trimers can associate through their SUN domains to form lateral complexes. We also ask whether SUN1 could adopt an inactive monomeric conformation as seen in SUN2. Our results imply that the KASH binding domain of SUN1 is also inhibited in monomeric SUN1 but through weaker interactions than in monomeric SUN2.

Aim To determine the efficacy of fenfluramine on seizure frequency in patients with Sunflower syndrome. Secondary endpoints were changes in electroencephalogram (EEG) characteristics, cognitive functioning, executive functioning, and quality of life. Method In this open‐label study, patients underwent a 4‐week baseline period, followed by 3 months of treatment. An oral solution of fenfluramine was administered twice daily for 3 months. The dose was titrated up to a maximum dose of 0.7mg/kg/day or 26mg/day. Cardiac safety was monitored by transthoracic echocardiogram and electrocardiogram. EEGs, abbreviated neuropsychological testing, and questionnaires were administered before starting the study medication and again at the end of the treatment period. Results Ten patients (eight females, two males; mean age 13y 4mo [SD 4y 11mo], range 7–24y) were enrolled in the study. Nine of the 10 patients completed the core study, eight of whom met the primary endpoint. There were no observations of cardiac valvulopathy or pulmonary hypertension during the study. Interpretation Treatment with low‐dose fenfluramine resulted in a clinically significant reduction in seizure frequency, including hand‐waving episodes. Fenfluramine may be an effective treatment option for patients with Sunflower syndrome. Nine patients with Sunflower syndrome were treated with fenfluramine. Eight patients were responders, displaying a ≥30% reduction in seizure activity. Six patients experienced a ≥70% reduction in hand‐waving episodes. Improvements on electroencephalogram were observed after treatment with fenfluramine. None of the patients developed evidence of cardiac valvulopathy or pulmonary hypertension.

Linkers of the nucleoskeleton and cytoskeleton are key molecular complexes that span the nuclear envelope (NE) and provide a direct linkage between the nucleoskeleton and cytoskeleton. Two major components of these complexes are members of the SUN and KASH protein families that interact in the perinuclear space to allow the transmission of mechanochemical signals across the NE. Structural details of the mammalian SUN domain protein SUN2 have established that SUN2 must form a trimer to bind to KASH, and that this trimerization is mediated through two predicted coiled-coil regions of the protein, CC1 and CC2, which precede the SUN domain. Recent crystallographic data suggest that CC2-SUN formed an unexpected autoinhibited monomer unable to bind to KASH. These structural insights raise the question of how full-length SUN2 transitions from a monomer to a trimer inside the NE. In this study we used a computational approach to model a fragment of SUN2 containing CC1, CC2, and the SUN domain. We observed the dynamics of these modeled structures using ∼1 μs molecular dynamics simulations and showed that the interplay between CC1 and CC2 may be sufficient for the release of CC2-SUN2 from its autoinhibited state. Additionally, using our models and gel filtration analysis, we show the involvement of an E452 residue on CC1 in the monomer–­trimer transition of SUN2. Intriguingly, mutations in this residue have been seen in muscular dystrophy–associated SUN2 variants. Finally, we propose a Ca2+-dependent monomer–trimer transition of SUN2.