Cellular spermine targets JAK signaling to restrain cytokine-mediated autoimmunity.

Prolonged activation of the type I interferon (IFN-I) pathway leads to autoimmune diseases such as systemic lupus erythematosus (SLE). Metabolic regulation of cytokine signaling is critical for cellular homeostasis. Through metabolomics analyses of IFN-ß-activated macrophages and an IFN-stimulated-response-element reporter screening, we identified spermine as a metabolite brake for Janus kinase (JAK) signaling. Spermine directly bound to the FERM and SH2 domains of JAK1 to impair JAK1-cytokine receptor interaction, thus broadly suppressing JAK1 phosphorylation triggered by cytokines IFN-I, IFN-II, interleukin (IL)-2, and IL-6. Peripheral blood mononuclear cells (PBMCs) from individuals with SLE showing decreased spermine concentrations exhibited enhanced IFN-I and lupus gene signatures. Spermine treatment attenuated autoimmune pathogenesis in SLE and psoriasis mice and reduced IFN-I signaling in monocytes from individuals with SLE. We synthesized a spermine derivative (spermine derivative 1 [SD1]) and showed that it had a potent immunosuppressive function. Our findings reveal spermine as a metabolic checkpoint for cellular homeostasis and a potential immunosuppressive molecule for controlling autoimmune disease.

The tumor niche can reprogram long-lived protumorigenic neutrophils.

The heterogeneity and plasticity of neutrophils in tumor-host interactions and how tumor signals induce reprogramming of neutrophil subpopulations need further investigation. Ng et al. recently reported that a hypoxic-glycolytic niche in mouse tumors could reprogram mature and immature neutrophils into a long-lived and terminally-differentiated subset, which promoted angiogenesis and tumor growth.

Methyltransferase Setd2 prevents T cell-mediated autoimmune diseases via phospholipid remodeling.

Coordinated metabolic reprogramming and epigenetic remodeling are critical for modulating T cell function and differentiation. However, how the epigenetic modification controls Th17/Treg cell balance via metabolic reprogramming remains obscure. Here, we find that Setd2, a histone H3K36 trimethyltransferase, suppresses Th17 development but promotes iTreg cell polarization via phospholipid remodeling. Mechanistically, Setd2 up-regulates transcriptional expression of lysophosphatidylcholine acyltransferase 4 (Lpcat4) via directly catalyzing H3K36me3 of Lpcat4 gene promoter in T cells. Lpcat4-mediated phosphatidylcholine PC(16:0,18:2) generation in turn limits endoplasmic reticulum stress and oxidative stress. These changes decrease HIF-1α transcriptional activity and thus suppress Th17 but enhance Treg development. Consistent with this regulatory paradigm, T cell deficiency of Setd2 aggravates neuroinflammation and demyelination in experimental autoimmune encephalomyelitis due to imbalanced Th17/Treg cell differentiation. Overall, our data reveal that Setd2 acts as an epigenetic brake for T cell-mediated autoimmunity through phospholipid remodeling, suggesting potential targets for treating neuroinflammatory diseases.

E3 Ubiquitin Ligase RNF13 Suppresses TLR Lysosomal Degradation by Promoting LAMP-1 Proteasomal Degradation.

As a highly organized system, endo-lysosomes play a crucial role in maintaining immune homeostasis. However, the mechanisms involved in regulating endo-lysosome progression and subsequent inflammatory responses are not fully understood. By screening 103 E3 ubiquitin ligases in regulating endo-lysosomal acidification, it is discovered that lysosomal RNF13 inhibits lysosome maturation and promotes inflammatory responses mediated by endosomal Toll-like receptors (TLRs) in macrophages. Mechanistically, RNF13 mediates K48-linked polyubiquitination of LAMP-1 at residue K128 for proteasomal degradation. Upon TLRs activation, LAMP-1 promotes lysosomes maturation, which accelerates lysosomal degradation of TLRs and reduces TLR signaling in macrophages. Furthermore, peripheral blood mononuclear cells (PBMCs) from patients with rheumatoid arthritis (RA) show increased RNF13 levels and decreased LAMP-1 expression. Accordingly, the immunosuppressive agent hydroxychloroquine (HCQ) can increase the polyubiquitination of RNF13. Taken together, the study establishes a linkage between proteasomal and lysosomal degradation mechanisms for the induction of appropriate innate immune response, and offers a promising approach for the treatment of inflammatory diseases by targeting intracellular TLRs.

Eosinophils promote CD8+ T cell memory generation to potentiate anti-bacterial immunity.

Memory CD8+ T cell generation is crucial for pathogen elimination and effective vaccination against infection. The cellular and molecular circuitry that underlies the generation of memory CD8+ T cells remains elusive. Eosinophils can modulate inflammatory allergic responses and interact with lymphocytes to regulate their functions in immune defense. Here we report that eosinophils are required for the generation of memory CD8+ T cells by inhibiting CD8+ T cell apoptosis. Eosinophil-deficient mice display significantly impaired memory CD8+ T cell response and weakened resistance against Listeria monocytogenes (L.m.) infection. Mechanistically, eosinophils secrete interleukin-4 (IL-4) to inhibit JNK/Caspase-3 dependent apoptosis of CD8+ T cells upon L.m. infection in vitro. Furthermore, active eosinophils are recruited into the spleen and secrete more IL-4 to suppress CD8+ T cell apoptosis during early stage of L.m. infection in vivo. Adoptive transfer of wild-type (WT) eosinophils but not IL-4-deficient eosinophils into eosinophil-deficient mice could rescue the impaired CD8+ T cell memory responses. Together, our findings suggest that eosinophil-derived IL-4 promotes the generation of CD8+ T cell memory and enhances immune defense against L.m. infection. Our study reveals a new adjuvant role of eosinophils in memory T cell generation and provides clues for enhancing the vaccine potency via targeting eosinophils and related cytokines.

The RNA m6A demethylase ALKBH5 drives emergency granulopoiesis and neutrophil mobilization by upregulating G-CSFR expression.

Emergency granulopoiesis and neutrophil mobilization that can be triggered by granulocyte colony-stimulating factor (G-CSF) through its receptor G-CSFR are essential for antibacterial innate defense. However, the epigenetic modifiers crucial for intrinsically regulating G-CSFR expression and the antibacterial response of neutrophils remain largely unclear. N6-methyladenosine (m6A) RNA modification and the related demethylase alkB homolog 5 (ALKBH5) are key epigenetic regulators of immunity and inflammation, but their roles in neutrophil production and mobilization are still unknown. We used cecal ligation and puncture (CLP)-induced polymicrobial sepsis to model systemic bacterial infection, and we report that ALKBH5 is required for emergency granulopoiesis and neutrophil mobilization. ALKBH5 depletion significantly impaired the production of immature neutrophils in the bone marrow of septic mice. In addition, Alkbh5-deficient septic mice exhibited higher retention of mature neutrophils in the bone marrow and defective neutrophil release into the circulation, which led to fewer neutrophils at the infection site than in their wild-type littermates. During bacterial infection, ALKBH5 imprinted production- and mobilization-promoting transcriptome signatures in both mouse and human neutrophils. Mechanistically, ALKBH5 erased m6A methylation on the CSF3R mRNA to increase the mRNA stability and protein expression of G-CSFR, consequently upregulating cell surface G-CSFR expression and downstream STAT3 signaling in neutrophils. The RIP-qPCR results confirmed the direct binding of ALKBH5 to the CSF3R mRNA, and the binding strength declined upon bacterial infection, accounting for the decrease in G-CSFR expression on bacteria-infected neutrophils. Considering these results collectively, we define a new role of ALKBH5 in intrinsically driving neutrophil production and mobilization through m6A demethylation-dependent posttranscriptional regulation, indicating that m6A RNA modification in neutrophils is a potential target for treating bacterial infections and neutropenia.

The deubiquitinase BAP1 and E3 ligase UBE3C sequentially target IRF3 to activate and resolve the antiviral innate immune response.

Ubiquitination is essential for the proteasomal turnover of IRF3, the central factor mediating the antiviral innate immune response. However, the spatiotemporal regulation of IRF3 ubiquitination for the precise activation and timely resolution of innate immunity remains unclear. Here, we identified BRCA1-associated protein-1 (BAP1) and ubiquitin-protein ligase E3C (UBE3C) as the key deubiquitinase and ubiquitinase for temporal control of IRF3 stability during viral infection. In the early stage, BAP1 dominates and removes K48-linked ubiquitination of IRF3 in the nucleus, preventing its proteasomal degradation and facilitating efficient interferon (IFN)-ß production. In the late stage, E3 ligase UBE3C, induced by IFN-ß, specifically mediates IRF3 ubiquitination and promotes its proteasomal degradation. Overall, the sequential interactions with BAP1 and UBE3C govern IRF3 stability during innate response, ensuring effective viral clearance and inflammation resolution. Our findings provide insights into the temporal control of innate signaling and suggest potential interventions in viral infection.

Hydrogen therapy promotes macrophage polarization to the M2 subtype in radiation lung injury by inhibiting the NF-κB signalling pathway.

Background: Radiotherapy has become a standard treatment for chest tumors, but a common complication of radiotherapy is radiation lung injury. Currently, there is still a lack of effective treatment for radiation lung injury. Methods: A mouse model of radioactive lung injury (RILI) was constructed and then treated with different cycles of hydrogen inhalation. Lung function tests were performed to detect changes in lung function.HE staining was used to detect pathological changes in lung tissue. Immunofluorescence staining was used to detect the polarization of macrophages in lung tissue. Immunohistochemistry was used to detect changes in cytokine expression in lung tissues. Western Blot was used to detect the expression of proteins related to the NF-κB signalling pathway. Results: Lung function test results showed that lung function decreased in the model group and improved in the treatment group.HE staining showed that inflammatory response was evident in the model group and decreased in the treatment group. Immunohistochemistry results showed that the expression of pro-inflammatory factors was significantly higher in the model group, and the expression of pro-inflammatory factors was significantly higher in the treatment group. The expression of pro-inflammatory factors in the treatment group was significantly lower than that in the model group, and the expression of anti-inflammatory factors in the treatment group was higher than that in the model group. Immunofluorescence showed that the expression of M1 subtype macrophages was up-regulated in the model group and down-regulated in the treatment group. The expression of M2 subtype macrophages was up-regulated in the treatment group relative to the model group. Western Blot showed that P-NF-κB p65/NF-κB p65 was significantly increased in the model group, and P-NF-κB p65/NF-κB p65 was decreased in the treatment group. Conclusion: Hydrogen therapy promotes macrophage polarization from M1 to M2 subtypes by inhibiting the NF-κB signalling pathway, thereby attenuating the inflammatory response to radiation lung injury.

EFHD2 suppresses intestinal inflammation by blocking intestinal epithelial cell TNFR1 internalization and cell death.

TNF acts as one pathogenic driver for inducing intestinal epithelial cell (IEC) death and substantial intestinal inflammation. How the IEC death is regulated to physiologically prevent intestinal inflammation needs further investigation. Here, we report that EF-hand domain-containing protein D2 (EFHD2), highly expressed in normal intestine tissues but decreased in intestinal biopsy samples of ulcerative colitis patients, protects intestinal epithelium from TNF-induced IEC apoptosis. EFHD2 inhibits TNF-induced apoptosis in primary IECs and intestinal organoids (enteroids). Mice deficient of Efhd2 in IECs exhibit excessive IEC death and exacerbated experimental colitis. Mechanistically, EFHD2 interacts with Cofilin and suppresses Cofilin phosphorylation, thus blocking TNF receptor I (TNFR1) internalization to inhibit IEC apoptosis and consequently protecting intestine from inflammation. Our findings deepen the understanding of EFHD2 as the key regulator of membrane receptor trafficking, providing insight into death receptor signals and autoinflammatory diseases.

Nuclear RPSA senses viral nucleic acids to promote the innate inflammatory response.

Innate sensors initiate the production of type I interferons (IFN-I) and proinflammatory cytokines to protect host from viral infection. Several innate nuclear sensors that mainly induce IFN-I production have been identified. Whether there exist innate nuclear sensors that mainly induce proinflammatory cytokine production remains to be determined. By functional screening, we identify 40 S ribosomal protein SA (RPSA) as a nuclear protein that recognizes viral nucleic acids and predominantly promotes proinflammatory cytokine gene expression in antiviral innate immunity. Myeloid-specific Rpsa-deficient mice exhibit less innate inflammatory response against infection with Herpes simplex virus-1 (HSV-1) and Influenza A virus (IAV), the viruses replicating in nucleus. Mechanistically, nucleus-localized RPSA is phosphorylated at Tyr204 upon infection, then recruits ISWI complex catalytic subunit SMARCA5 to increase chromatin accessibility of NF-κB to target gene promotors without affecting innate signaling. Our results add mechanistic insights to an intra-nuclear way of initiating proinflammatory cytokine expression in antiviral innate defense.

RNA-binding protein and tumor biotherapy: new opportunities and strategies / 中国肿瘤生物治疗杂志

@#RNA结合蛋白（RBP）由于其独特的生物学功能，目前已经成为肿瘤生物治疗相关靶点筛选的宠儿，很可能为肿瘤生物治疗带来新的机遇。RBP能调控肿瘤细胞及肿瘤微环境免疫细胞和间质细胞的DNA-RNA-蛋白质相互作用网络，进而广泛影响肿瘤发生发展、抗肿瘤免疫应答及肿瘤免疫逃逸过程，目前RBP相关肿瘤生物治疗的研发，主要聚焦在治疗性疫苗、免疫细胞治疗、表观调控治疗等方面，部分研发成果已处于临床试验阶段。随着新理论、新技术的发展以及研究模式的创新，靶向RBP的治疗逐渐摆脱了既往靶向难、疗效欠佳的困局，迎来了新的机遇，通过改良精准靶向和优化组合用药等新策略，为肿瘤生物治疗注入了新的活力，对精准个体化医疗的发展具有重要意义。

Personalized neoantigen vaccines for tumor immunotherapy: a long hard journey to promising land / 中国肿瘤生物治疗杂志

@#[摘 要] 个性化新抗原肿瘤疫苗逐渐崭露头角，在恶性黑色素瘤、肺癌、脑胶质瘤等肿瘤治疗领域取得了突破，展现了良好的应用前景。随着测序成本的降低、人工智能技术的不断突破和对肿瘤免疫理解的不断深入，对一个肿瘤患者进行全过程动态跟踪和捕捉其肿瘤相关体细胞突变的克隆多样性已成为可能，随之研发的新抗原肿瘤疫苗则成为肿瘤治疗的前沿热点，未来可期。本文从新抗原的筛选鉴定、新抗原相关的肿瘤疫苗及其临床应用现状、个性化新抗原肿瘤疫苗面临的挑战和未来发展趋势等五个方面，系统地总结了个性化新抗原肿瘤疫苗这一新兴的精准免疫治疗方法的研究脉络及进展，并对未来重点走向进行了展望。

Tumor immunity and immunotherapy: opportunities and challenges / 中国肿瘤生物治疗杂志

@# With the development of new technology and the innovation of research mode, tumor immunological research has achieved rapid development, and tumor immunotherapy has also shown remarkable clinical efficacy, jointly promoting the improvement of tumor immunology from mechanism research to clinical transformation and from single discipline to multi-disciplinary integration. However, multiple challenges still exist in tumor immunological research, such as the animal model replication for clinical tumor study, the complexity of tumor intrinsic regulation and its relationship with host microenvironment, and the screening of immunotherapy targets and the prediction of treatment effect. These problems limit the further development and application of tumor immunology, but also bring research opportunities to basic and clinical immunology researchers. Therefore, this review summarizes the research status and challenges as well as looks into the future of tumor immunity and immunotherapy in five aspects: the change of research model,the innovation of mechanism, the exploration of research objects, the screening and evaluation of therapeutic targets, as well as the application and innovation of new technologies.

Roles and mechanisms of Wnt/β -catenin signaling related lncRNA in tumor progression / 中国肿瘤生物治疗杂志

@# 长链非编码RNA（lncRNA）是一类长度大于200 nt、且不编码的RNA。lncRNA已被证明与人类疾病紧密相关，尤其 是肿瘤发生发展。研究表明，肿瘤中一些异常表达的lncRNA可以通过不同的信号通路， 如Wnt/β-catenin信号通路，促进肿瘤进 展过程。在不同肿瘤组织中具有特异性表达特征的lncRNA与Wnt/β-catenin信号通路之间的相互作用显示出其作为新的生物标 志物和治疗靶点的潜能。本文就Wnt/β-catenin信号通路相关lncRNA通过调控Wnt/β-catenin信号转导，影响不同肿瘤类型发生 发展的作用进行综述。本文结果或可为临床肿瘤诊断和治疗提供新的思路。

Expression of ECT2 gene in human pancreatic ductal adenocarcinoma and its effect on tumor biological characteristics / 中国肿瘤生物治疗杂志

@# Objective: To investigate the expression of ECT2 (epithelial Transforming sequence 2) gene in human pancreatic ductal adenocarcinoma (PDAC) and its effect on the proliferation and apoptosis of pancreatic cancer cells. Methods: Carcinoma tissues and corresponding para-carcinoma tissues from 35 PDAC patients at Changhai Hospital Affiliated to Naval Medical University from July 2018 to March 2019 were collected for this study. The differentially expressed genes in pancreatic cancer were screened out by using Gene Expression Omnibus (GEO) Database. Then, the related gene expression in PDAC and its relation with patients’survival were analyzed by The Cancer Genome Atlas (TCGA) database. QPCR and immunohistochemistry were used to verify the mRNAand protein expressions of ECT2 in human PDAC samples. To explore the effect of ECT2 on the biological behaviors of pancreatic cancer cells, si-RNA was used to silence the ECT2 gene in pancreatic cancer PANC-1 cells, and CCK-8 proliferation assay and Flow cytometry were used to detect the proliferation and apoptosis rate of PANC-1 cells after ECT2 silence. Finally, the expressions of apoptosis-related proteins were detected by WB. Results: The differentially expressed gene-ECT2, was screened out by analyzing the gene expression profiles of human pancreatic cancer in GEO database. TCGA database analysis showed that ECT2 was highly expressed in pancreatic cancer tissues (t=4.005, P<0.05) and significantly correlated with patients’survival (P< 0.01). Moreover, it is also verified that ECT2 was highly expressed in PDAC tissues at mRNA (1.01±0.06 vs 4.25±0.12; t=24.09， P<0.01) and protein level. After ECT2 silence in PANC-1 cells, the proliferation rate was decreased (P<0.01), while the Tamoxifeninduced apoptosis rate was increased (P<0.01), and the expressions of apoptosis-related proteins (BAX and Bcl-2) were also affected. Conclusion: ECT2 is highly expressed in human pancreatic ductal adenocarcinoma and is related with patients’survival. ECT2 promotes the proliferation and apoptosis resistance of pancreatic cancer cells, providing the basis for exploring ECT2 as a new target for the prognostic judgment and treatment of pancreatic cancer.