Vijay K. Kuchroo

Oncolytic virotherapy represents a promising yet under-explored approach for precision cancer treatment, particularly when tailored to tumor-specific molecular profiles. Patients with high-grade isocitrate dehydrogenase (IDH) mutant astrocytomas have limited treatment options and poor prognoses. Here, we investigate the therapeutic efficacy of rQNestin34.5 v.2 (CAN-3110), an engineered oncolytic herpes simplex virus 1 (oHSV-1), in IDH1-R132H-mutant diffuse gliomas. We demonstrate that the IDH1-R132H mutation enhances glioma susceptibility to viral infection through upregulation of Nectin-1, the main HSV-1 entry receptor. Concurrently, IDH1-R132H-driven DNA hypermethylation suppresses interferon (IFN) signaling, creating a permissive microenvironment that facilitates viral replication and tumor cell apoptosis. In immunocompetent murine glioma models, intratumoral administration of rQNestin34.5 v.2 induces robust antitumor immune activation, including increased immune infiltration and systemic IFN-γ release. However, elevated expression of poliovirus receptor (PVR) and the immune checkpoint T-cell immunoreceptor with immunoglobulin and ITIM domain (TIGIT) on tumor-infiltrating leukocytes suggests a potential resistance mechanism to virotherapy. Combining rQNestin34.5 v.2 with TIGIT blockade enhances therapeutic efficacy compared to monotherapy, identifying IDH1-R132H as a potential predictive biomarker for oncolytic virotherapy response.

T helper 17 (T _H 17) cells are thought to play an important role in the pathogenesis of many autoimmune disorders, including multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE). However, recent studies have suggested that interleukin-17 (IL-17) may be dispensable for the induction of EAE. Here, we use an adoptive transfer model of EAE to demonstrate that an adaptive cellular source of IL-17 is absolutely required for the induction of EAE disease. We further show that B cells can regulate the transfer of EAE disease in this context. Transcriptional profiling of T _H 17 cells in our model suggests that loss of IL-17A/F in T cells results in a lack of an IL-23 receptor (IL-23R)–driven signaling signature. Our data demonstrate the critical importance of an adaptive immune cellular source of IL-17A and IL-17F to mediate EAE and that IL-17 signaling is required for IL-23–mediated T _H 17 cell pathogenicity.

Inhibitory receptors (IRs) such as CTLA-4, PD-1, LAG3, TIM-3, and TIGIT are critical regulators of immune homeostasis, functioning to restrain excessive immune activation and prevent autoimmunity. While the blockade of IRs has transformed cancer immunotherapy by reinvigorating antitumor T cell responses, emerging strategies aim to harness the immunosuppressive potential of these receptors for treating autoimmune and inflammatory diseases. Agonistic antibodies that activate IR signaling have demonstrated promising results in preclinical models by promoting immune tolerance and suppressing pathological effector T cell functions. This review highlights recent progress in the development of agonistic IR-targeted therapies, examining their mechanisms of action, therapeutic efficacy, and the translational challenges that must be addressed to bring these innovative approaches into clinical practice for the management of autoimmunity and inflammatory disorders.

The gut experiences daily fluctuations in microbes and nutrients aligned with circadian rhythms that regulate nutrient absorption and immune function. Group 3 innate lymphoid cells (ILC3s) support gut homeostasis through interleukin-22 (IL-22) but can convert into interferon-γ-producing ILC1s. How circadian proteins control this plasticity remains unclear. Here we showed that the circadian proteins REV-ERBα and REV-ERBβ maintain ILC3 identity. Their combined deletion promoted ILC3-to-ILC1 conversion, reduced energy metabolism and IL-22 production, increased interferon-γ production, and heightened susceptibility to Citrobacter rodentium infection. Single-cell multiomics and gene editing revealed that REV-ERBα/REV-ERBβ deficiency upregulated the transcription factor NFIL3, which repressed the expression of RORγt via a -2-kb cis-regulatory element in the Rorc gene, shifting cells toward a T-bet-driven state. Chromatin and metabolic analyses indicated that REV-ERBα/REV-ERBβ loss reprogrammed regulatory and metabolic circuits. Thus, REV-ERBα/REV-ERBβ safeguard gut integrity by regulating clock genes that control RORγt expression and preserve ILC3 identity and resistance to intestinal inflammation.

Enteric nervous system (ENS)–derived neuropeptides modulate immune cell function, yet our understanding of how inflammatory cues directly influence enteric neuron responses during infection is considerably lacking. Here, we characterized a primary enteric sensory neuron (PSN) subset producing the neuropeptides neuromedin U (NMU) and calcitonin gene-related peptide β (CGRPβ) and coexpressing receptors for the type 2 cytokines interleukin-4 (IL-4) and IL-13. Type 2 cytokines amplified NMU and CGRPβ expression in PSNs, in vitro and in vivo, which was abrogated by PSN-specific Il13ra1 deletion. Deletion of Il13ra1 in PSNs impaired host defense to the gastrointestinal helminth Heligmosomoides polygyrus and blunted muscularis immune responses. Co-administration of NMU23 and CGRPβ rescued helminth clearance deficits and restored anti-helminth immunity, highlighting the essential bi-directional neuro-immune crosstalk regulating intestinal type 2 inflammation.

Microglia are the resident immune cells in the brain and have pivotal roles in neurodevelopment and neuroinflammation^1,2. This study investigates the function of the immune-checkpoint molecule TIM-3 (encoded by HAVCR2) in microglia. TIM-3 was recently identified as a genetic risk factor for late-onset Alzheimer’s disease³, and it can induce T cell exhaustion⁴. However, its specific function in brain microglia remains unclear. We demonstrate in mouse models that TGFβ signalling induces TIM-3 expression in microglia. In turn, TIM-3 interacts with SMAD2 and TGFBR2 through its carboxy-terminal tail, which enhances TGFβ signalling by promoting TGFBR-mediated SMAD2 phosphorylation, and this process maintains microglial homeostasis. Genetic deletion of Havcr2 in microglia leads to increased phagocytic activity and a gene-expression profile consistent with the neurodegenerative microglial phenotype (MGnD), also referred to as disease-associated microglia (DAM). Furthermore, microglia-targeted deletion of Havcr2 ameliorates cognitive impairment and reduces amyloid-β pathology in 5×FAD mice (a transgenic model of Alzheimer’s disease). Single-nucleus RNA sequencing revealed a subpopulation of MGnD microglia in Havcr2-deficient 5×FAD mice characterized by increased pro-phagocytic and anti-inflammatory gene expression alongside reduced pro-inflammatory gene expression. These transcriptomic changes were corroborated by single-cell RNA sequencing data across most microglial clusters in Havcr2-deficient 5×FAD mice. Our findings reveal that TIM-3 mediates microglia homeostasis through TGFβ signalling and highlight the therapeutic potential of targeting microglial TIM-3 in Alzheimer’s disease.