Polyendocrine metabolic ovarian syndrome (PMOS) is traditionally attributed to dysfunction of the hypothalamic-pituitary-gonadal axis, but the contribution of extra-reproductive organs remains unclear. Here, we identify a thymus-ovary pathway linking androgen excess to ovarian inflammation. Androgen receptor signaling in thymic stromal cells induces early thymic involution and impairs thymic output before overt reproductive pathology emerges. Athymic mice and Rag1−/− mice with preserved thymic stroma are comparably resistant to PMOS-like pathology, supporting an essential role for thymus-derived T cells in disease development. Antibody-mediated depletion further reveals CD8+, but not CD4+, T cells are required for disease manifestation. Among CD8+ T-cell subsets, virtual memory CD8+ T (TVM) cells preferentially expand in patients and experimental models and accumulate in reproductive tissues. These cells exacerbate disease severity and prolong pathology after androgen withdrawal. Mechanistically, ovarian TVM cells secrete pro-inflammatory cytokines and CCL5, thereby recruiting myeloid cells to the ovary and amplifying local inflammation. Therapeutically, JAK inhibition restricts TVM-cell differentiation, redirects CD8+ T-cell fate away from a cytotoxic CXCR3high state and ameliorates PMOS-like pathology. These findings identify TVM cells as key effectors linking androgen-induced thymic remodeling to ovarian inflammation and persistent pathology.
Group 2 innate lymphoid cells (ILC2s) play a critical role in initiating the type 2 immune response, particularly in allergic airway diseases. Although the effects of glutamate on the immune system have been reported previously, its role in modulating the function of ILC2s and lung inflammation remains unclear. In this study, we report that the glutamate levels increased in lung tissue following exposure to allergens. Consequently, glutamate was found to restrain ILC2 responses during lung inflammation in mice. Using Rag1−/− mice, we demonstrated that the inhibitory effect of glutamate on type 2 inflammation was independent of T and B cells. Further ILC2 adoptive transfer experiments in Rag−/−Il2rg−/− mice confirmed that glutamate likely exerted its effects by directly targeting ILC2s. In vitro experiments revealed that glutamate suppressed ILC2 function through ionic kainate receptor signaling. Genetic deletion of the kainate receptor subunit GluK2 enhanced ILC2 responses and exacerbated type 2 lung inflammation. Mechanistically, transcriptome and metabolic analyses revealed that glutamate reduced oxidative metabolism in ILC2s, thereby limiting their activation. Consistently, in vivo administration of BPAM344—a positive allosteric modulator that potentiates GluK2 signaling—effectively suppressed allergen-induced type 2 inflammation. Notably, ILC2-specific GluK2 deletion markedly attenuated the anti-inflammatory effects of BPAM344, indicating that its protective effects depend on ILC2-intrinsic GluK2 signaling. These findings demonstrate a novel role for glutamate in restraining ILC2 function, as it plays a protective role in alleviating airway inflammation. We propose that GluK2 activation may offer a promising therapeutic strategy for treating ILC2-driven allergic asthma.
Programmed cell death (PCD) is a major regulatory mechanism that maintains tissue homeostasis and immune balance and strongly influences the initiation, progression and resolution of inflammation. Although apoptosis, pyroptosis, necroptosis and ferroptosis are individual PCD modes that are regulated by different molecular mechanisms, they are not mutually exclusive in inflammatory microenvironments. Instead, these pathways are linked via common signaling mediators and regulatory nodes that enable crosstalk, compensatory activation and context-dependent fine-tuning. It is evident that apoptosis, pyroptosis and necroptosis can be coordinated within defined inflammatory platforms, as exemplified by concepts such as PANoptosis. Pathway-specific modeling is inadequate for inflammatory diseases involving multiple PCD modalities, metabolic and organelle stress, immune-cell interactions and tissue-level changes that molecular models cannot capture. Here, an integrated cell death network (ICDN) paradigm is presented as an organizational schema describing how various types of PCD are coregulated through common regulatory pathways in inflamed tissues. This framework does not identify a new mode of cell death per se but rather integrates pathway compensation following extracellular perturbations, disease-specific inflammatory responses, and susceptibility to therapeutic intervention at common network nodes. This review defines the molecular mechanisms and crosstalk of inflammatory pyroptosis, apoptosis, and necroptosis pathways; links recent advances in death modality applications for specific diseases to the ICDN framework; and highlights important current limitations that require further examination, including the need for stronger evidence of dynamic switching across cell death modalities, spatial architecture during inflammation, and reconfiguration at both the multiprotein complex and network levels, such as inflammasome networks.
Engineering autologous T cells for adoptive therapies has revolutionized cancer treatment, yet limited persistence remains a major barrier to robust clinical responses and durable disease control. Although costimulation with 4-1BB markedly improves CAR-T-cell persistence, no comparably effective approach has been identified to enhance persistence in T-cell therapies that rely on native TCR signaling, including conventional TCR-T cells and synthetic T-cell receptor and antigen receptor (STAR) T cells. To identify intrinsic persistence regulators in a TCR-based context, we performed an in vivo CRISPR activation screen in STAR-T cells and identified the noncanonical NF-κB axis, with RELB as the top hit. Direct RELB overexpression, however, exhibited dose-dependent cytotoxicity, motivating a translational alternative: overexpression of p52, the ncNF-κB transcription partner of RELB. Under prolonged antigen exposure, p52 overexpression sustained proliferation, preserved effector functions, and increased the intratumoral trafficking potential, particularly in CD8⁺ T cells, thereby yielding superior tumor control. Mechanistically, transcriptomic profiling revealed coordinated upregulation of cell cycle programs and chemokine receptors, along with downregulation of apoptosis and exhaustion-associated modules. Moreover, p52 overexpression restored RELB nuclear translocation in the context of PD-1/PD-L1 engagement, indicating partial resistance to checkpoint-mediated suppression and sustained ncNF-κB activity in PD-L1hi immunosuppressive environments. Collectively, our findings identify p52 as an antigen-dependent enhancer of ncNF-κB, conferring durable persistence and checkpoint resilience on TCR-based T cells and providing a feasible strategy to improve therapeutic effects in solid tumors.
Generated by stochastic V(D)J recombination, unique B-cell receptors (BCRs) consist of IgH and IgL chains, recognize antigens, and serve as distinct barcodes to identify each individual B cell. Once a B-cell acquires its BCR, does it maintain its identity, or does a peripheral B-cell ever rearrange its BCR again? Under what circumstances a peripheral B-cell would undergo secondary V(D)J recombination at its Igh locus, termed VH gene replacement (VHR), remains poorly understood. Using hen egg lysozyme (HEL) BCR knock-in mice, we observed that when the BCR cannot bind to any foreign or self-antigen, peripheral B cells upregulate the expression of the VDJ recombinase RAG-1 and undergo VHR to acquire new BCRs and become non-HEL-binding. TRAF3 deficiency increased the frequency of VHR-experienced B cells and predisposed them to abnormal oligoclonal expansion by preventing B cells from dying from RAG-initiated DNA double-stranded breaks in an NF-κB2-dependent manner. Engaging the HEL BCR or inhibiting proximal BCR signaling modulated RAG-1 expression. The frequency of VHR was substantially inhibited by enhanced BCR signaling caused by a gain-of-function mutant allele of Cd79b, a signaling component of the BCR complex. We conclude that BCR signaling strength influences the probability of a given B-cell undergoing VHR. Furthermore, signaling molecules such as TRAF3 can serve as nonclassical checkpoints to maintain B-cell genome stability during VHR. Our studies provide fundamental insights into the mechanisms underlying the dynamic regulation of antigen receptor identity in peripheral B cells, with implications for immune tolerance and B-cell homeostasis. Our studies reveal novel mechanisms of genomic instability in VHR-experienced peripheral B cells and provide fundamental insights into the conditions under which B cells alter their identity via VHR, as well as the regulatory mechanisms governing the VHR process.
