Cell Expansion Research Articles

Origin and evolution of auxin-mediated acid growth

The classical acid growth theory suggests that auxin stimulates cell expansion by triggering apoplast acidification via plasma membrane (PM)-localized H+-ATPase. Here, we reconstructed the origin and evolutionary history of auxin-mediated acid growth. Comparative phylogenomic analysis showed that most core components of acid growth originated in Charophyta and then underwent subclass expansion and functional innovation during plant terrestrialization. In Charophyceae algae Chara braunii, we found that PM H+-ATPase has formed a core regulatory module with TMK and PP2C.D, which can be activated by photosynthesis-dependent phosphorylation through light rather than auxin. Despite the lack of canonical auxin receptor TRANSPORT INHIBITOR RESPONSE 1/AUXIN SIGNALING F-BOX (TIR1/AFB), auxin elicits significant internodal elongation and transcriptional reprogramming in C. braunii, implying the existence of an ancient auxin-mediated growth mechanism. We propose that the evolution of acid growth represents a neofunctional adaptation to terrestrial environments, in which PM H+-ATPase in carbon concentrating for photosynthesis was utilized to acidify apoplast for cell expansion, and the core components responsible for acid growth eventually established a regulatory network in land plants by connecting with the TIR1/AFB pathway.

An erythroid-specific lentiviral vector improves anemia and iron metabolism in a new model of XLSA.

X-linked sideroblastic anemia (XLSA) is a congenital anemia caused by mutations in ALAS2, a gene responsible for heme synthesis. Treatments are limited to pyridoxine supplements and blood transfusions, offering no definitive cure except for allogeneic hematopoietic stem cell transplantation, only accessible to a subset of patients. The absence of a suitable animal model has hindered the development of gene therapy research for this disease. We engineered a conditional Alas2-KO mouse model using tamoxifen administration or treatment with lipid nanoparticles (LNP) carrying Cre-mRNA and conjugated to an anti-CD117 antibody. Alas2-KOBM animals displayed a severe anemic phenotype characterized by ineffective erythropoiesis (IE), leading to low numbers of red blood cells (RBC), hemoglobin (Hb), and hematocrit (HCT). In particular, erythropoiesis in these animals showed expansion of polychromatic erythroid cells, characterized by reduced oxidative phosphorylation, mitochondria's function, and activity of key Tricarboxylic Acid (TCA) cycle enzymes. In contrast, glycolysis was increased in the unsuccessful attempt to extend cell survival despite mitochondrial dysfunction. The IE was associated with marked splenomegaly and low hepcidin levels, leading to iron accumulation in the liver, spleen, and bone marrow and the formation of ring sideroblasts. To investigate the potential of a gene therapy approach for XLSA, we developed a lentiviral vector (X-ALAS2-LV) to direct ALAS2 expression in erythroid cells. Infusion of BM cells with 0.6-1.4 copies of the X-ALAS2-LV in Alas2-KOBM mice improved CBC levels, tissue iron accumulation, and survival rates. These findings suggest our vector could be curative in XLSA patients.

Clonal hematopoiesis-related mutant ASXL1 promotes atherosclerosis in mice via dysregulated innate immunity.

Certain somatic mutations provide a fitness advantage to hematopoietic stem cells and lead to clonal expansion of mutant blood cells, known as clonal hematopoiesis (CH). Among the most common CH mutations, ASXL1 mutations pose the highest risk for cardiovascular diseases (CVDs), yet the mechanisms by which they contribute to CVDs are unclear. Here we show that hematopoietic cells harboring C-terminally truncated ASXL1 mutant (ASXL1-MT) accelerate the development of atherosclerosis in Ldlr-/- mice. Transcriptome analyses of plaque cells showed that monocytes and macrophages expressing ASXL1-MT exhibit inflammatory signatures. Mechanistically, we demonstrate that wild-type ASXL1 has an unexpected non-epigenetic role by suppressing innate immune signaling through the inhibition of IRAK1-TAK1 interaction in the cytoplasm. This regulatory function is lost in ASXL1-MT, resulting in NF-κB activation. Inhibition of IRAK1/4 alleviated atherosclerosis driven by ASXL1-MT and decreased inflammatory monocytes. The present work provides a mechanistic and cellular explanation linking ASXL1 mutations, CH and CVDs.

The epigenetic role of EZH2 in acute myeloid leukemia.

Acute myeloid leukemia (AML), a malignant disease of the bone marrow, is characterized by the clonal expansion of myeloid progenitor cells and a block in differentiation. The high heterogeneity of AML significantly impedes the development of effective treatment strategies. Enhancer of zeste homolog 2 (EZH2), the catalytic subunit of the polycomb repressive complex 2 (PRC2), regulates the expression of downstream target genes through the trimethylation of lysine 27 on histone 3 (H3K27me3). Increasing evidence suggests that the dysregulation of EZH2 expression in various cancers is closely associated with tumorigenesis. In the review, we examine the role of EZH2 in AML, highlighting its crucial involvement in regulating stemness, proliferation, differentiation, immune response, drug resistance and recurrence. Furthermore, we summarize the application of EZH2 inhibitors in AML treatment and discuss their potential in combination with other therapeutic modalities. Therefore, targeting EZH2 may represent a novel and promising strategy for the treatment of AML.

Clonal hematopoiesis of indeterminate potential (CHIP) and its association with treatment outcomes and adverse events in patients with solid tumours.

Clonal hematopoiesis of indeterminate potential (CHIP) is the clonal expansion of hematopoietic stem cells from somatic mutations. It is a common incidental finding in cell-free DNA (cfDNA). We investigated the incidence of CHIP in cfDNA from patients with solid tumours and explored its association with treatment outcomes and adverse events. We reviewed cfDNA results from a local prospective solid tumour cohort (PREDiCT-l) and two randomized trials: CCTG CO.26 (durvalumab + tremelimumab [D+T] or best supportive care in metastatic colorectal cancer) and CCTG PA.7 (gemcitabine and nab-paclitaxel +/- D+T in metastatic pancreatic adenocarcinoma). CHIP+ was defined as any mutation in DNMT3A, TET2 or ASXL1 with a variant allele frequency (VAF) ≥2% Presumed germline variants (VAF>40%) were removed. The first line of treatment after cfDNA was reviewed for grade 3 and dose-limiting toxicities. The prevalence of CHIP in the 465 included patients was 10-30% and it was more common as age increased (p=0.003). DNMT3A was the gene most frequently mutated in all cohorts. Patients with CHIP in PA.7 treated with immunotherapy showed an improved progression-free survival (PFS) versus CHIP- (HR 0.55 [0.28-1.07], p=0.079, p-interaction=0.098 [multivariable]). However, patients with CHIP treated with chemotherapy in PREDiCT-l showed a trend towards worse PFS (HR 1.82 [0.98-3.38], p=0.059). There was no difference in adverse event rates between CHIP+/- groups for those treated with chemotherapy or immunotherapy. CHIP is common in patients with solid tumours. Although not appearing to impact rates of adverse events, CHIP may impact outcomes from immunotherapy or chemotherapy.

DMT1 Maintains Iron Homeostasis to Regulate Mitochondrial Function in Porcine Oocytes.

Iron plays critical roles in many cellular functions, including energy production, metabolism, and cell proliferation. However, the role of iron in maintaining oocyte quality remains unclear. In this study, DMT1 was identified as a key iron transporter during porcine oocyte maturation. The results demonstrated that iron deficiency in porcine oocyte led to aberrant meiotic progression, accompanied by increased gene expression of DMT1. Inhibition of DMT1 resulted in the failure of cumulus cell expansion and oocyte maturation, along by the abnormal actin and microtubule assembly. Furthermore, loss of DMT1 function caused disruption in mitochondrial function and dynamics, resulting in oxidative stress and Ca2+ dyshomeostasis. Additionally, the absence of DMT1 function activated PINK1/Parkin-dependent mitophagy in porcine oocyte. These findings suggested that DMT1 played a crucial role in safeguarding oocyte quality by protecting against iron-deficiency-induced mitochondrial dysfunction and autophagy. This study provided compelling evidence that DMT1 and iron homeostasis were crucial for maintaining the capacity of porcine oocyte maturation. Moreover, the results hinted at the potential of DMT1 as a novel therapeutic target for treating iron deficiency-related female reproductive disorders.

Microwave Ablation Combined with Flt3L Provokes Tumor-Specific Memory CD8+ T Cells-Mediated Antitumor Immunity in Response to PD-1 Blockade.

For medically inoperable non-small cell lung cancer, microwave ablation (MWA) represents a superminimally invasive alternative treatment. However, tumor recurrence remains a concern. Here, it is demonstrated that the combination of MWA with Flt3L significantly inhibits tumor recurrence by CD8+ central memory T (TCM)-like cell-dependent antitumor immune responses within the tumor-draining lymph nodes (TdLN). TdLN-TCM-like cells encompassedboth tumor-specific memory T (TTSM) and progenitor-exhausted T (TPEX) cells. The expansion of these cells markedly altered the differentiation of exhausted T cells within the tumor microenvironment (TME). TPEX predominantly differentiated into transitory effector-like exhausted T cells (TEX-int). The expansion of TTSM cells elicited by the combined therapy was reliant on conventional dendritic cells (cDCs) and was likely specifically dependent on the migratory cDC1s (Mig cDC1s) within the TdLN. The upregulation of ICOSL on migratory cDC1s was pivotal in initiating TTSM-like cell-mediated antitumor responses. Slc38a2 may be a critical gene responsible for the upregulation of ICOSL in Mig cDC1s following combined treatment. Finally, the combined treatment significantly enhanced the antitumor efficacy of immunotherapy based on PD-1 blockade. The research thereby afforded a novel strategic approach to forestall tumor recurrence after MWA therapy, while also providing the foundational proof-of-concept for impending clinical investigations.

Chromosome 1 Alterations in Multiple Myeloma: Considerations for Precision Therapy.

Multiple myeloma (MM) is an incurable blood malignancy characterized by the clonal expansion of plasma cells and the secretion of monoclonal immunoglobulins. High-risk MM, defined by specific cytogenetic abnormalities, poses significant therapeutic challenges and is associated with inferior survival outcomes compared to standard-risk disease. Although molecularly targeted therapies have shown efficacy in other hematologic malignancies, currently venetoclax is the only targeted therapy approved for MM (t(11;14)). However, chromosome 1q gains, amplifications, and 1p deletions are frequently observed in MM, and have been linked to drug resistance and poor patient prognosis. Accordingly, this review focuses on emerging MM precision therapies capable of targeting dysregulated genes within these regions. It addresses gene therapies, small molecule inhibitors and monoclonal antibodies currently under investigation to antagonize oncogenic drivers including MCL-1, BCL9, F11R, and CKS1B, all of which are implicated in cell survival, proliferation or drug resistance. In conclusion, the link between chromosome 1 abnormalities and high-risk disease in MM patients offers a compelling rationale to identify and explore therapeutic targeting of chromosome 1 gene products as a novel precision medicine approach for a poorly served patient population.

Concomitant loss of TET2 and TET3 results in T cell expansion and genomic instability in mice

Ten eleven translocation (TET) proteins are tumor suppressors that through their catalytic activity oxidize 5-methylcytosine to 5-hydroxymethylcytosine, to promote DNA demethylation and to regulate gene expression. Notably, TET2 is one of the most frequently mutated genes in hematological malignancies, including T cell lymphomas. However, murine models with deletion of TET2 do not exhibit T cell expansion, presumably due to redundancy with other members of the TET family of proteins. In order to gain insight on the TET mediated molecular events that safeguard T cells from aberrant proliferation we performed serial adoptive transfers of murine CD4 T cells that lack concomitantly TET2 and TET3 to fully immunocompetent congenic mice. Here we show a progressive acquisition of malignant traits upon loss of TET2 and TET3 that is characterized by loss of genomic integrity, acquisition of aneuploidy and upregulation of the protooncogene Myc.

Concurrent intratumoural Treg cell depletion and CD8+ T cell expansion via a cleavable anti-4-1BB-interleukin-15 fusion protein.

Potent agonists of the inducible co-stimulatory receptor 4-1BB are too toxic for patients with advanced cancer. Here, on the basis of observations of a weak agonist of 4-1BB depleting regulatory T (Treg) cells within the tumour microenvironment without leading to substantial restoration of dysfunctional cytotoxic T cells (CTLs), we show that effective tumour control can be achieved via concurrent Treg cell depletion and CTL expansion through an anti-4-1BB antibody fused to interleukin-15 (IL-15) via a peptide sensitive to tumour proteases. In mouse models of advanced cancers, intraperitoneal injection of the bifunctional protein attenuated the activity of the interleukin mostly in the periphery of the primary tumour while allowing for the expansion of CTLs within the tumour microenvironment, led to more effective tumour inhibition and to lower systemic toxicity than treating the cancers with combinatorial treatment with unlinked anti-4-1BB antibody and IL-15, and reduced the resistance of tumours to checkpoint blockade. Concurrent eradication of Treg cells and activation of tumour-infiltrating lymphocytes may represent a general strategy for the effective control of advanced metastatic tumours.

The Spectrum of B-cell and Plasma Cell Proliferations in Nodal T Follicular Helper Cell Lymphomas.

B-cell and plasma cell proliferations are frequently observed in nodal T follicular helper (nTfh) cell lymphomas and can present a diagnostic challenge. These proliferations can be monotypic or monoclonal and morphologically resemble lymphoma or plasmacytoma, but their clinical behavior is poorly defined. In this study, we reviewed 414 cases of nTfh lymphoma seen over the past decade at our institution. We identified 78 (19%) cases that exhibited B-cell or plasma cell proliferation detected by morphology, flow cytometry, immunohistochemistry, and/or molecular techniques. The B-cell/plasma cell proliferations occurred before (22%), concurrently with (50%), or after (28%) the diagnosis of nTfh lymphoma. We divided them into 3 categories: (1) focal or scattered B-immunoblastic proliferations recognized morphologically without a monotypic/monoclonal B-cell population (17%), (2) monotypic/monoclonal B-cell/plasma cells identified solely by flow cytometry or molecular clonality studies without morphologic confirmation (11%), and (3) unequivocal B-cell/plasma cell expansions recognized by morphologic assessment (72%). We further subdivided group 3 into proliferations associated with and possibly dependent on neoplastic Tfh cells versus those proliferations occurring in the absence of neoplastic Tfh cells and likely bona fide lymphomas. Follow-up biopsy specimens showed persistence of B-cell/plasma cell proliferations in various patient subcategories, with transformation to higher-grade B-cell proliferation or persistence without Tfh cells in some cases. In conclusion, our data support the notion that most B-cell and plasma cell proliferations associated with neoplastic Tfh clones have little impact on the clinical course of patients with nTfh lymphoma and likely do not constitute an independent B-cell lymphoma, especially those of small B cells of plasma cells. However, B-cell expansions exhibiting aggressive morphologic features may represent an independent B-cell lymphoma.

Foliar Spraying of Potassium Sulfate during Fruit Development Comprehensively Improves the Quality of Citrus Fruits

Sugar accumulation is influenced by various fertilizer treatments, of which potassium spraying is the most effective. However, the effect of different potassium sources as a foliar application at different fruit development stages on citrus fruits is still unclear. In this study, three different potassium fertilizers and one water (F1: 0.65% KNO3, F2: 0.88% KH2PO4, F3: 0.56% K2SO4, and F4: water) were sprayed on Citrus reticulata cv. Nanfeng at cell division, cell expansion, fruit ripening, and throughout fruit developmental stages, respectively. Results showed that the six-time K2SO4 application had the best function in enhancing fruit physiological attributes such as fruit weight and the total carotenoids; also, this treatment significantly decreased TA (titratable acid), increased fruit TSS (total soluble solids), soluble sugar content, and TSS:TA ratio. Furthermore, K2SO4 spraying obviously increased the expression of CsCWINV-2/6 in the segment membrane, and CsSUT-1/2 and CsVPP-1/2 in fruit juices. Taken together, six-time application of K2SO4 throughout fruit developmental stages produced better fruit quality, at least through enhancing sink strength and promoting sugar transportation in citrus fruits. This study might effectively contribute to maximizing fruit quality and its marketability.

Interferon gamma-mediated prevention of tumor progression in a mouse model of multiple myeloma.

Malignant plasma cells in multiple myeloma patients reside in the bone marrow and continuously interact with local immune cells. Progression and therapy response are influenced by this immune environment, highlighting the need for a detailed understanding of endogenous immune responses to malignant plasma cells. Here we used the 5TGM1 murine transfer model of multiple myeloma to dissect early immune responses to myeloma cells. We modeled stable and progressive disease by transferring 5TGM1 murine myeloma cells into C57Bl/6 mice and KaLwRij mice, respectively. We used flow cytometry and single-cell and bulk transcriptomic analyses to characterize differential immune responses in stable and progressive disease. Transfer of 5TGM1 cells in C57Bl/6 mice led to stable disease with low tumor burden in a subset of animals. Stable disease was associated with sustained activation and expansion of NK cells, ILC1, and CD8+ T cells, a response that was lost upon disease progression. Single-cell RNA-sequencing of immune cells and bulk RNA sequencing of immune and mesenchymal stromal cells implicated the activation of interferon responses as a central immune pathway during stable disease. Experimentally, neutralization of IFNγ significantly increased myeloma development and progression in C57Bl/6 mice, testifying to the importance of this pathway in early disease control. In conclusion, we provide a framework for studying immune responses to multiple myeloma progression in immunocompetent and genetically modifiable mice and highlight the importance of bone marrow immunity in tumor control.

Long-term in vitro expansion of a human fetal pancreas stem cell that generates all three pancreatic cell lineages

The mammalian pancreas consists of three epithelial compartments: the acini and ducts of the exocrine pancreas and the endocrine islets of Langerhans. Murine studies indicate that these three compartments derive from a transient, common pancreatic progenitor. Here, we report derivation of 18 human fetal pancreas organoid (hfPO) lines from gestational weeks 8-17 (8-17 GWs) fetal pancreas samples. Four of these lines, derived from 15 to 16 GWs samples, generate acinar-, ductal-, and endocrine-lineage cells while expanding exponentially for >2 years under optimized culture conditions. Single-cell RNA sequencing identifies rare LGR5+ cells in fetal pancreas and in hfPOs as the root of the developmental hierarchy. These LGR5+ cells share multiple markers with adult gastrointestinal tract stem cells. Organoids derived from single LGR5+ organoid-derived cells recapitulate this tripotency invitro. We describe a human fetal tripotent stem/progenitor cell capable of long-term expansion invitro and of generating all three pancreatic cell lineages.

Irreversible oxygen uptake and thermal expansion in the solid electrolyte oxygen-deficient perovskite Ca(Ti0.8Fe0.2)O3−δ

The efficient operation of solid oxide fuel cells for renewable energy generation requires solid electrolytes with high ionic conductivity, thermal stability, and chemical durability. Metal oxide perovskites of the form ABO3 are promising candidates, especially when doped with cations that incorporate interstitial oxygen or oxygen vacancies to enhance ionic conductivity. However, doping can lead to complex and poorly understood crystallographic structures. In this study, we investigate the effects of Fe3+ doping on the orthorhombic Pbnm CaTiO3 perovskite, forming Ca(Ti0.8Fe0.2)O3−δ, and demonstrate the complexity of its phase transitions at operational temperatures. Using synchrotron X-ray diffraction and thermogravimetric analysis, we show that this material undergoes significant oxygen uptake at elevated temperatures, leading to an irreversible expansion of the unit cell and changes in polyhedral coordination upon cooling. These structural modifications are attributed to the partial oxidation of Fe3+ to Fe4+, providing insight into the inconsistencies observed in previous studies of oxygen-deficient perovskites. Our findings highlight the critical role of thermal history and oxygen availability in determining the structural stability and long-term performance of perovskite-based solid electrolytes in solid oxide fuel cells.

Combinatorial immunotherapy of anti-MCAM chimeric antigen receptor modified expanded natural killer cells and NKTR-255 against neuroblastoma

Pediatric patients with recurrent metastatic neuroblastoma (NB) have a dismal 5-year survival. Novel therapeutic approaches are urgently needed. The melanoma cell adhesion molecule (MCAM/CD146/MUC18) is expressed in a variety of pediatric solid tumors, including NB, and constitutes anovel target for immunotherapy. Here, we developed a chimeric antigen receptor (CAR) expressing natural killer (NK) cell-targeting MCAM by non-viral electroporation of CAR mRNA into exvivo expanded NK cells. Expression of anti-MCAM CAR significantly enhanced NK cell cytotoxic activity compared to mock NK cells against MCAMhigh but not MCAMlow/knockout NB cells invitro. Anti-MCAM-CAR-NK cell treatment significantly decreased tumor growth and prolonged animal survival in an NB xenograft mouse model. NKTR-255, a polymer-conjugated recombinant human interleukin-15 agonist, significantly stimulated NK cell proliferation and expansion and further enhanced the in vitro cytotoxic activity and invivo anti-tumor efficacyofanti-MCAM-CAR-NK cells against NB. Our preclinical studies demonstrate that exvivo expanded andmodified anti-MCAM-CAR-NK cells alone and/or incombination with NKTR-255 are promising novel alternative therapeutic approaches to targeting MCAMhigh malignant NB.

IPSC-derived mesenchymal stromal cells stimulate neovascularization less than their primary counterparts.

Mesenchymal stromal cells (MSCs) are being tested and accepted as a source for cell therapy worldwide. However, the advanced age of the patients, together with the difficulties in achieving the required cell amounts, impede autologous treatments. Reprogramming of MSCs into induced pluripotent stem cells (iPSCs), followed by re-differentiation to MSCs has emerged as a promising and safe method to facilitate the cell expansion and the removal of aging-associated characteristics. However, the effect of reprogramming on the MSC's pro-angiogenicity is poorly understood. In this study, we use a microfluidic organ-on-a-chip platform designed for vascularization assays to study and compare the effects of bone marrow MSCs (BM-MSCs) and iPSC-derived MSCs (iMSCs) in stimulating the formation of vessels by endothelial cells. Cells were loaded in fibrin hydrogels, injected into the microfluidic channel, and grown for ten days. Fluorescence microscopy revealed that BM-MSCs promote the formation of long and interconnected endothelial vessels, while iMSCs barely stimulate neoangiogenesis. This was further confirmed and explained by bulk RNA sequencing, showing a decrease of pro-angiogenic agents in both of the iMSCs co-cultures. Furthermore, transmission electron microscopy revealed that BM-MSCs closely associate with the new vessels as perivascular cells, while iMSCs just remain in proximity. These results highlight iMSCs as a promising substitute for BM-MSCs in the treatment of diseases with pernicious vascularization, such as osteoarthritis, ocular degeneration, and cancer.

Nano‐Biosensors for mRNA‐Based Cell Sorting Using Intracellular Markers at the Early Stage of Cell Reprogramming

AbstractCell reprogramming and manufacturing have broad applications in tissue regeneration and disease treatment. However, many derived cell types lack unique cell surface markers for protein‐based cell sorting, making it difficult to isolate these cells from mixed populations. Additionally, there is a need to identify and isolate cells of interest at the early stages of cell expansion. To address this challenge, a nucleic acid‐based gold nanorod (NAGNR) fluorescent biosensor was engineered to detect the mRNA expression of intracellular markers for cell sorting. Its application is demonstrated in isolating induced neuronal (iN) cells from dermal fibroblast populations during the early stages of cell reprogramming. Cell sorting based on the mRNA of the neuronal transcriptional factor Ascl1 resulted in an enrichment of iN cells from 3% to 72%, and additional sorting with the transcriptional factor Scn2 further increased iN enrichment. Moreover, NAGNR biosensors can be used in conjunction with protein marker‐based cell sorting. NAGNR‐sorted iN cells show a functional response to electrical stimulation in a co‐culture of iN cells and muscle cells. These findings demonstrate that NAGNR‐based cell sorting offers great potential for cell identification and isolation at an early stage of cell reprogramming and manufacturing.

Antimalarial Drug Artemotil Promotes Induction of Type 1 Regulatory T Cells.

Artemisinin and its derivatives, used as front-line anti-malarial drugs, exhibit anti-inflammatory properties. They were found to suppress the generation and function of Th1 and Th17 cells while promoting the generation of Foxp3 + regulatory T cells (Tregs). However, the specific role of Artemotil (β-arteether) in modulating the generation and functions of CD4 + T cells, particularly Type 1 regulatory T cells (Tr1), remains to be explored. Tr1 cells are one of the key cell types that are essential for regulating inflammatory response through IL-10. In this study, we report that Artemotil selectively promotes generation of Tr1 cells induced by IL-27 by upregulating signature genes of Tr1 cells, such as c-Maf, AhR, prdm1, IRF-1, and Batf, while inhibiting the Th1, Th2, and Th17 cells generation. We found that co-administration of Artemotil with anti-CD3 antibody increases the induction of IL-10 and frequency of Tr1 cells while suppressing Th1 and Th17 cells in vivo. Artemotil suppresses T-cell-induced enteropathy and alleviates the signs of colitis associated with the increased frequencies of Tr1 cells. Taken together, our data suggest that Artemotil provides protection in T-cell-mediated colitis by increasing the expansion of Tr1 cells and inhibiting the generation of Th1 and Th17 cells.

STING deficiency ameliorates mouse models of lupus and atherosclerosis.

Systemic lupus erythematosus (SLE) is a systemic autoimmune syndrome characterized by autoreactive responses to nucleic acids, dysregulation of the type I Interferon (IFN-I) pathway, and accelerated atherosclerosis. The stimulator of interferon genes (STING), a cytosolic DNA-sensor, has pathogenic implications in various inflammatory diseases. However, its specific role in SLE pathogenesis, particularly in tissue damage, remains unclear. This study aimed to elucidate the role of STING in murine models of TLR7-driven lupus and atherosclerosis. A TLR7-driven lupus model was induced using imiquimod (IMQ) in wild type (WT) and STING knockout (Sting1-/-) mice on a B6 background. Mice were assessed for organ involvement, serum autoantibodies, and innate and adaptive immune responses. Additionally, Sting1-/- mice were backcrossed to Apolipoprotein E knockout (Apoe-/-) mice, and both Apoe-/- and Apoe-/-Sting1-/- mice were fed a high-fat chow (HFC) diet to induce atherosclerosis. Phenotypic assessments were conducted. Compared to IMQ-treated WT mice, Sting1-/- mice exhibited reduced disease severity in the lupus-like phenotype, characterized by decreased splenomegaly, lower renal immune complex deposition and renal damage, diminished expansion of myeloid cells, and reduced activation of T and B lymphocytes. IMQ-induced DNA release associated with IFN-β production and subsequent IFN-induced responses were attenuated in Sting1-/- mice. DNase I treatment mitigated IMQ-induced pro-inflammatory responses in WT mice but had no effect in Sting1-/- mice. Furthermore, STING deficiency conferred protection against vascular damage and reduced atherosclerosis burden, accompanied by decreased IFN-I production. Human monocyte-derived macrophages treated with IFN-I significantly internalized more acetylated LDL when compared to untreated cells, while an association between oxidized nucleic acids and disease activity and vascular damage was found in human SLE. These findings highlight a pathogenic role of STING and downstream IFN responses in TLR7-driven autoimmunity, vascular damage and atherosclerosis, supporting a therapeutic potential for STING inhibition in SLE treatment. Further research is warranted to elucidate the mechanisms underlying STING's involvement in these processes and to explore the feasibility of targeting STING as a therapeutic strategy in SLE and related autoimmune disorders.