Glioblastoma (GBM), the most aggressive type of primary brain tumor, continues to defy therapeutic advances with its metabolic adaptability and resistance to treatment. In this issue of the JCI, Zeng et al. delve into a pivotal mechanism underpinning this adaptability. They identified an important role for TNF receptor–associated factor 3 (TRAF3) in regulating lipid metabolism through its interaction with enoyl-CoA hydratase 1 (ECH1). These findings elucidate a unique signaling axis that shields GBM cells from lipid peroxidation and antitumor immunity, advancing therapeutic strategies for GBM that may also carry over to other cancers with similar metabolic vulnerabilities.
Tzu-Yi Chia, Nishanth S. Sadagopan, Jason Miska
Metabolic reprogramming in pancreatic ductal adenocarcinoma (PDAC) fosters an immunosuppressive tumor microenvironment (TME) characterized by elevated lactate levels, which contribute to immune evasion and therapeutic resistance. In this issue of the JCI, Sun, Zhang, and colleagues identified nonhistone ENSA-K63 lactylation as a critical regulator that inactivates PP2A, activates STAT3/CCL2 signaling, recruits tumor-associated macrophages (TAMs), and suppresses cytotoxic T cell activity. Targeting ENSA-K63 lactylation or CCL2/CCR2 signaling reprograms the TME and enhances the efficacy of immune checkpoint blockade (ICB) in PDAC preclinical models. This work provides critical insights into the metabolic-immune crosstalk in PDAC and highlights promising therapeutic strategies for overcoming immune resistance and improving patient outcomes.
Qun Chen, Hao Yuan, Michael S. Bronze, Min Li
Immune correlates of protection against infection with Mycobacterium tuberculosis (Mtb) remain elusive. In this issue of the JCI, Dallmann-Sauer and authors demonstrate that lack of tuberculin skin test (TST) and interferon γ release assay (IGRA) conversion among people with HIV despite years-long Mtb exposure is associated with alveolar lymphocytosis, including specific poly-cytotoxic T cells, and M1-type alveolar macrophages with a stronger ex vivo response to the pathogen. Studies in these rare individuals, termed “TB resisters” and in tuberculosis household contacts who are repeatedly IGRA negative in the months after a specific exposure event (known as “early clearers”) help elucidate manipulatable mechanisms to boost protection against Mtb infection.
Todia P. Setiabudiawan, Philip C. Hill, Andrew R. DiNardo, Reinout van Crevel
Non–small cell lung cancer (NSCLC), the most common type of lung cancer, remains a leading cause of cancer-related mortality worldwide. Immune checkpoint inhibitors (ICIs) have emerged as a promising therapy for NSCLC but only benefit a subset of patients. In this issue of the JCI, Jiao et al. revealed that acetyl-CoA acetyltransferase 1 (ACAT1) limited the efficacy of ICIs in NSCLC by impeding tertiary lymphoid structures (TLS) in the tumor microenvironment (TME). Targeting ACAT1 in tumor cells reduced mitochondrial hypersuccinylation and oxidative stress, enhancing TLS abundance and improving the efficacy of ICIs in preclinical murine models of NSCLC.
Sophie O’Keefe, Qiwei Wang
Nucleoporin 98 (NUP98) fusion oncogenes are known to promote aggressive pediatric leukemia by disrupting chromatin structure and modulating the expression of homeobox (HOX) genes, yet the precise molecular events are unclear. In this issue of the JCI, K. Hamamoto et al. explore the mechanistic underpinnings of NUP98 fusion–driven pediatric leukemia, with a focus on aberrant activation of the Hoxb-associated long, noncoding RNA (lncRNA) HoxBlinc. The authors provide compelling evidence that HoxBlinc plays a central role in the oncogenic transformation associated with NUP98 fusion protein. The study underscores a CTCF-independent role of HoxBlinc in the regulation of topologically associated domains (TADs) and chromatin accessibility, which has not been fully appreciated in previous research on the NUP98 fusion oncogenes. The discovery of HoxBlinc lncRNA as a downstream regulator of NUP98 fusion oncoproteins offers a potential target for therapeutic intervention in pediatric leukemia.
Jian Xu, Wei Du
Inherited bone marrow failure syndromes (IBMFSs) encompass a diverse group of hematological disorders characterized by a progressive single-lineage cytopenia or pancytopenia. Despite their heterogeneity, these syndromes often result from genetic errors affecting key biological mechanisms, including telomere maintenance, DNA repair and chromosomal stability, and ribosome assembly, generally leading to accelerated apoptosis of hematopoietic cells. Nevertheless, a genetic diagnosis remains elusive in more than half of the cases. The increased risk of myelodysplastic syndrome (MDS), acute leukemia, and solid tumors associated with IBMFS frequently prompts early hematopoietic stem cell transplantation (HSCT). In this issue of the JCI, Garrigue, Kermasson, and colleagues identified a homozygous variant in Oncostatin M (OSM) in 3 children from a consanguineous family presenting with IBMFS characterized by profound anemia, thrombocytopenia, and neutropenia. The findings suggest that the loss-of-function OSM variant affected hematopoietic stem cell function through changes to the bone marrow microenvironment (BMM).
Selket Delafontaine, Isabelle Meyts
Pulmonary hypertension (PH) encompasses a heterogenous group of disorders with the common feature of increased pulmonary arterial pressures. Patients with PH associated with lung disease and/or hypoxia undergo immune-mediated vascular remodeling that includes thickening of the muscular layer surrounding arteries and arterioles. In this issue of the JCI, Kumar and colleagues examined the role of interstitial macrophages in a model of high-altitude PH. Resident interstitial macrophages increased, proliferated, and expressed CCL2, a monocyte chemoattractant ligand. There was also a rise in CCR2+ macrophages expressing thrombospondin-1, which is known to activate vascular remodeling through TGF-β. Blocking monocyte recruitment partially reduced hypoxic PH, and corticosteroid treatment effectively reduced CCL2 expression and CCR2+ monocyte recruitment. Further, plasma samples collected from individuals ascending from low to high altitudes showed increased thrombospondin-1 and TGF-β levels, which were reduced with dexamethasone. These findings reveal interstitial macrophage populations as potential therapeutic targets in hypoxic PH.
Edda Spiekerkoetter
Approximately one-quarter of the global population is estimated to be infected with Mycobacterium tuberculosis. New developments in vaccine design and therapeutics are urgently needed, particularly in the face of multidrug-resistant tuberculosis (TB). In this issue of the JCI, Sakai and colleagues used a multidisciplinary approach to determine that trehalose-6-monomycolate (TMM), a mycobacterial cell wall lipid, serves as a T cell antigen presented by CD1b. CD1b-TMM–specific T cells were characterized by conserved T cell receptor features and were present at elevated frequencies in individuals with active TB disease. These findings highlight the dual role of TMM in stimulating both innate and adaptive immunity and broaden our understanding of CD1-mediated lipid recognition by unconventional T cells.
Catarina F. Almeida, Jennifer A. Juno
N-methyl-d-aspartate (NMDA) receptor–mediated autoimmune encephalitis (NMDAR-AE) is the most common cause of autoimmune encephalitis, especially in children and young adults. The disorder is caused by antibodies directed against the GluN1 protein, an obligatory constituent of NMDA receptors, which are key signaling molecules in brain development, learning and memory, and executive function. The manuscript by Zhou et al. offers key insights into aberrant development of cortical pathways that may underly persistent sensorimotor deficits associated with this encephalitis in a newly generated mouse model. This study convincingly links transient exposure to a patient-derived anti-GluN1 mAb during a critical developmental period to lasting disruptions in interhemispheric connectivity through callosal projections. These findings provide insight into the impact of a prevalent autoimmune disorder on fundamental aspects of brain development and establish a model system that could be further employed to probe other aspects of NMDAR-AE pathogenesis.
Puneet Opal, Geoffrey T. Swanson
Cellular senescence is a cell state induced by irreparable cellular damage. The hallmark of senescence is cell cycle exit, yet neurons, which are postmitotic from birth, have also been found to undergo senescence. Neuronal senescence is prevalent in aging as well as in neurodegenerative disease. However, a role for senescence in epilepsy is virtually unexplored. In this issue of the JCI, Ge and authors used resected brain tissue from individuals with drug-resistant epilepsy, a genetic knockout mouse model, and a chemoconvulsant mouse model, to demonstrate a subset of cortical pyramidal senescent neurons that likely contribute to the pathophysiology of epilepsy. These findings highlight senescence as a possible target in precision-therapy approaches for epilepsy and warrant further investigation.
Gemma L Carvill
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