Si-Ni-San alleviates intestinal and liver damage in ulcerative colitis mice by regulating cholesterol metabolism.

ETHNOPHARMACOLOGICAL RELEVANCE: Si-Ni-San (SNS), a traditional Chinese medicinal formula derived from Treatise on Febrile Diseases, is considered effective in the treatment of inflammatory bowel diseases based upon thousands of years of clinical practice. However, the bioactive ingredients and underlying mechanisms are still unclear and need further investigation. AIM OF THE STUDY: This study aimed to evaluate the effect, explore the bioactive ingredients and the underlying mechanisms of SNS in ameliorating ulcerative colitis (UC) and associated liver injury in dextran sodium sulphate (DSS)-induced mouse colitis models. MATERIALS AND METHODS: The effect of SNS (1.5, 3, 6 g/kg) on 3% DSS-induced acute murine colitis was evaluated by disease activity index (DAI), colon length, inflammatory cytokines, hematoxylin-eosin (H&E) staining, tight junction proteins expression, ALT, AST, and oxidative stress indicators. HPLC-ESI-IT/TOF MS was used to analyze the chemical components of SNS and the main xenobiotics in the colon of UC mice after oral administration of SNS. Network pharmacological study was then conducted based on the main xenobiotics. Flow cytometry and immunohistochemistry techniques were used to demonstrate the inhibitory effect of SNS on Th17 cells differentiation and the amelioration of Th17/Treg cell imbalance. LC-MS/MS, Real-time quantitative polymerase chain reaction (RT-qPCR), and western blotting techniques were performed to investigate the oxysterol-Liver X receptor (LXRs) signaling activity in colon. Targeted bile acids metabolomics was conducted to reveal the change of the two major pathways of bile acid synthesis in the liver, and the expression of key metabolic enzymes of bile acids synthesis was characterized by RT-qPCR and western blotting techniques. RESULTS: SNS (1.5, 3, 6 g/kg) decreased the DAI scores, protected intestinal mucosa barrier, suppressed the production of pro-inflammatory cytokines, improved hepatic and splenic enlargement and alleviated liver injury in a dose-dependent manner. A total of 22 components were identified in the colon of SNS (6 g/kg) treated colitis mice, and the top 10 components ranked by relative content were regarded as the potential effective chemical components of SNS, and used to conduct network pharmacology research. The efficacy of SNS was mediated by a reduction of Th17 cell differentiation, restoration of Th17/Treg cell homeostasis in the colon and spleen, and the experimental results were consistent with our hypothesis and the biological mechanism predicted by network pharmacology. Mechanistically, SNS regulated the concentration of 25-OHC and 27-OHC by up-regulated CH25H, CYP27A1 protein expression in colon, thus affected the expression and activity of LXR, ultimately impacted Th17 differentiation and Th17/Treg balance. It was also found that SNS repressed the increase of hepatic cholesterol and reversed the shift of BA synthesis to the acidic pathway in UC mice, which decreased the proportion of non-12-OH BAs in total bile acids (TBAs) and further ameliorated colitis and concomitant liver injury. CONCLUSIONS: This study set the stage for considering SNS as a multi-organ benefited anti-colitis prescription based on the significant effect of ameliorating intestinal and liver damage, and revealed that derivatives of cholesterol, namely oxysterols and bile acids, were closely involved in the mechanism of SNS anti-colitis effect.

Tumor microenvironment immunomodulation by nanoformulated TLR 7/8 agonist and PI3k delta inhibitor enhances therapeutic benefits of radiotherapy.

Infiltration of immunosuppressive cells into the breast tumor microenvironment (TME) is associated with suppressed effector T cell (Teff) responses, accelerated tumor growth, and poor clinical outcomes. Previous studies from our group and others identified infiltration of immunosuppressive myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs) as critical contributors to immune dysfunction in the orthotopic claudin-low tumor model, limiting the efficacy of adoptive cellular therapy. However, approaches to target these cells in the TME are currently lacking. To overcome this barrier, polymeric micellular nanoparticles (PMNPs) were used for the co-delivery of small molecule drugs activating Toll-like receptors 7 and 8 (TLR7/8) and inhibiting PI3K delta (PI3Kδ). The immunomodulation of the TME by TLR7/8 agonist and PI3K inhibitor led to type 1 macrophage polarization, decreased MDSC accumulation and selectively decreased tissue-resident Tregs in the TME, while enhancing the T and B cell adaptive immune responses. PMNPs significantly enhanced the anti-tumor activity of local radiation therapy (RT) in mice bearing orthotopic claudin-low tumors compared to RT alone. Taken together, these data demonstrate that RT combined with a nanoformulated immunostimulant diminished the immunosuppressive TME resulting in tumor regression. These findings set the stage for clinical studies of this approach.

Eldecalcitol ameliorates diabetic osteoporosis and glucolipid metabolic disorder by promoting Treg cell differentiation through SOCE.

Active vitamin D, known for its role in promoting osteoporosis, has immunomodulatory effects according to the latest evidence. Eldecalcitol (ED-71) is a representative of the third-generation novel active vitamin D analogs, and its specific immunological mechanisms in ameliorating diabetic osteoporosis remain unclear. We herein evaluated the therapeutic effects of ED-71 in the context of type 2 diabetes mellitus (T2DM), delving into its underlying mechanisms. In a T2DM mouse model, ED-71 attenuated bone loss and marrow adiposity. Simultaneously, it rectified imbalanced glucose homeostasis and dyslipidemia, ameliorated pancreatic ß-cell damage and hepatic glycolipid metabolism disorder. Subsequently, in mice injected with the Treg cell-depleting agent CD25, we observed that the beneficial effects of ED-71 mentioned earlier were partially contingent on the Treg subsets ratio. Mechanistically, ED-71 promoted the differentiation of CD4+ T cells into Treg subsets, facilitating Ca2+ influx and the expression of ORAI1 and STIM1, pivotal proteins in store-operated Ca2+ entry (SOCE). The SOCE inhibitor, 2-APB, partially attenuated the positive effects of ED-71 observed in the above results. Overall, ED-71 regulates SOCE-mediated Treg cell differentiation, accomplishing the dual purpose of simultaneously ameliorating diabetic osteoporosis and glucolipid metabolic disorders, showcasing its potential in osteoimmunity therapy and interventions for diseases involving SOCE.

Interleukin-2 improves insulin sensitivity through hypothalamic sympathetic activation in obese mice.

BACKGROUND: IL-2 regulates T cell differentiation: low-dose IL-2 induces immunoregulatory Treg differentiation, while high-dose IL-2 acts as a potent activator of cytotoxic T cells and NK cells. Therefore, high-dose IL-2 has been studied for use in cancer immunotherapy. We aimed to utilize low-dose IL-2 to treat inflammatory diseases such as obesity and insulin resistance, which involve low-grade chronic inflammation. MAIN BODY: Systemic administration of low-dose IL-2 increased Treg cells and decreased inflammation in gonadal white adipose tissue (gWAT), leading to improved insulin sensitivity in high-fat diet-fed obese mice. Additionally, central administration of IL-2 significantly enhanced insulin sensitivity through the activation of the sympathetic nervous system. The sympathetic signaling induced by central IL-2 administration not only decreased interferon γ (IFNγ) + Th1 cells and the expression of pro-inflammatory cytokines, including Il-1ß, Il-6, and Il-8, but also increased CD4 + CD25 + FoxP3 + Treg cells and Tgfß expression in the gWAT of obese mice. These phenomena were accompanied by hypothalamic microgliosis and activation of pro-opiomelanocortin neurons. Furthermore, sympathetic denervation in gWAT reversed the enhanced insulin sensitivity and immune cell polarization induced by central IL-2 administration. CONCLUSION: Overall, we demonstrated that IL-2 improves insulin sensitivity through two mechanisms: direct action on CD4 + T cells and via the neuro-immune axis triggered by hypothalamic microgliosis.

Effects of Ruxolitinib on Immune Checkpoint Molecule Expression in JAK2 V617F-Positive Cells.

BACKGROUND: This study aimed to explore the clinical significance of ruxolitinib and its effects on the proliferation and apoptosis of human erythroleukemia (HEL) cells and the expression of immune checkpoint molecules programmed death-1 (PD-1), programmed death-ligand 1 (PD-L1), and regulatory T cells (Tregs) in HEL cells and JAK2 V617F-positive patients with myeloproliferative neoplasms (MPNs). METHODS: JAK2 V617F-positive patients with MPNs admitted to the Baoding No. 1 Hospital from January 2016 to September 2023 were recruited, including 30 patients for the newly diagnosed group and 10 for the treatment group. Additionally, 15 healthy volunteers were selected as the control group. JAK2 V617F mutation was detected by using fluorescence quantitative PCR, and the expression levels of phosphorylated JAK2 (p-JAK2), PD-1, and PD-L1 in fresh bone marrow were examined by immunohistochemistry. HEL cells were treated with ruxolitinib at different concentrations (0, 50, 100, 250, 500, and 1,000 nmol/L). Cell viability was detected by CCK-8 assay. The mRNA expression levels of JAK2, PD-1, and PD-L1 were determined by using fluorescence quantitative PCR. The protein expression of p-JAK2 was detected by Western blot and those of PD-1 and PD-L1 were evaluated by flow cytometry. The expression of PD-1, PD-L1, and Tregs after the 48-hour co-culture of primary bone marrow cells and HEL cells were also analyzed by flow cytometry. RESULTS: In the newly diagnosed group, the bone marrow myeloid cells highly expressed p-JAK2, PD-1, and PD-L1. The Tregs expression in their peripheral blood increased and was significantly higher than those in the treatment and control groups (all p < 0.05). Ruxolitinib at different concentrations could inhibit the proliferation of HEL cells and was positively correlated with treatment time and dose. Additionally, ruxolitinib could reduce p-JAK2, PD-1, and PD-L1 expression in HEL cells and Tregs expression. CONCLUSIONS: Ruxolitinib reduces the expression of p-JAK2, PD-1, and PD-L1 in JAK2 V617F-positive cells by specifically inhibiting the JAK2 signaling pathway, thereby suppressing the progression of MPNs.

Discovery of a proteolysis targeting chimera (PROTAC) as a potent regulator of FOXP3.

Regulatory T (Treg) cells play a central role in immune homeostasis. Forkhead box P3 (Foxp3), a hallmark molecule in Treg cells, is a vital transcription factor for their development and function. Studies have shown that degradation of the Foxp3 could provide therapeutic benefits in achieving effective anti-tumor immunity. In this study, we designed three PROTAC molecules, P60-L1-VHL, P60-L2-VHL, and P60-L3-VHL, based on a 15-mer peptide inhibitor of Foxp3 (P60), and explored their potential in regulating Foxp3 expression and function. Our data show that, among these molecules, P60-L3-VHL can inhibit the expression and nuclear localization of Foxp3 in HEK 293 T and HeLa cells, respectively. Meanwhile, use of proteasome inhibitor in P60-L3-VHL treated cells revealed an increased Foxp3 expression, indicating that P60-L3-VHL mediates the inhibition of Foxp3 through its degradation in the proteasome pathway. We further substantiate that P60-L3-VHL reduces the differentiation and Foxp3 expression in the in-vitro activated Treg cells. Overall, our findings suggest that P60-L3-VHL inhibits the differentiation of Treg cells by degrading the Foxp3, which may have potential implications in cancer immunotherapy.

Simvastatin alleviates experimental autoimmune encephalomyelitis through regulating the balance of Th17 and Treg in mice.

The aim of this study was to elucidate the therapeutic effect of simvastatin on experimental autoimmune encephalomyelitis (EAE) by regulating the balance between Th17 and Treg cells in mice. C57BL/6 mice were randomly divided into four groups: normal group, EAE group, simvastatin (2 and 10 mg/kg) group, and AG490 group (with AG490 serving as the positive control). Neurological function scores of mice were assessed daily. The four groups received treatments of normal saline, normal saline, and simvastatin (2 and 10 mg/kg), respectively. In the AG490 group, mice were injected intraperitoneally with AG490 (1 mg) every other day, and treatment was halted after 3 weeks. The spinal cord was stained with hematoxylin and eosin (H&E), and immunohistochemical staining for retinoic acid receptor-related orphan receptor γ(RORγ) and Foxp3 (Foxp3) was performed. Spleen samples were taken for Th17 and Treg analysis using flow cytometry. The levels of interleukin-17 and transforming growth factor-ß (TGF-ß) were detected using enzyme-linked immunosorbent assay (ELISA). In the simvastatin and AG490 groups, recovery from neurological impairment was earlier compared to the EAE group, and the symptoms were notably improved. Both simvastatin and AG490 reduced focal inflammation, decreased RORγ-positive cell infiltration, and significantly increased the number of FOXP3-positive cells. The number of Th17 cells and the level of IL-17 in the spleen were decreased in the simvastatin and AG490 treatment groups, while the number of Treg cells and TGF-ß levels were significantly increased across all treatment groups. Simvastatin exhibits anti-inflammatory and immunomodulatory effects, potentially alleviating symptoms of neurological dysfunction of EAE. Regulating the balance between Th17 and Treg may represent a therapeutic mechanism for simvastatin in treating EAE.

Harnessing immune cells to leverage PARP inhibitors.

Homologous-recombination deficiency in DNA repair characterizes a unique group of cancers that are vulnerable to PARP inhibitors and cytotoxic chemotherapy. In this issue of Cell, Luo et al., demonstrated that this genetic attribute in cancer cells may reprogram tumor immune microenvironment and show promise of targeting effector-Treg cells.

Zinc dampens antitumor immunity by promoting Foxp3+ regulatory T cells.

Introduction: The role of zinc (Zn) in tumor development and immune modulation has always been paradoxical. This study redefines our understanding of the impact of Zn on cancer progression and therapeutic strategies. Methods: We investigated the effects of dietary Zn levels on tumor progression and immune responses. This included examining the impact of both high and deficient dietary Zn, as well as Zn chelation, on tumor growth and immune cell populations. Specifically, we analyzed the frequency of Foxp3+ regulatory T-cells (Tregs) and identified the role of FOXO1 in Zn-mediated effects on Tregs. Additionally, we explored the therapeutic potential of clioquinol (CQ) in enhancing α-PD-1 immunotherapy responses, particularly in melanoma. Results: Our findings show that high dietary Zn promotes tumor progression by fostering a protumorigenic environment mediated by T cells. Increased Zn intake was found to facilitate tumor progression by increasing Foxp3+ Treg frequency. In contrast, deficiency in dietary Zn and chelation of tissue Zn emerged as potent drivers of antitumor immunity. We pinpointed FOXO1 as the master regulator governing the influence of Zn on Tregs. Discussion: These results reveal a novel mechanistic insight into how Zn influences tumor progression and immune regulation. The identification of FOXO1 as a key regulator opens new avenues for understanding the role of Zn in cancer biology. Furthermore, we introduce a promising therapeutic approach by showing that administering clioquinol (CQ) significantly enhances α-PD-1 immunotherapy response, particularly in melanoma. These revelations transform our comprehension of the multifaceted role of Zn in tumorigenesis and immune regulation, highlighting innovative possibilities for cancer therapy.

Epigenetic modification of CD4+ T cells into Tregs by 5-azacytidine as cellular therapeutic for atherosclerosis treatment.

Recent research has explored the potential of the demethylating drug 5-azacytidine (Aza) as therapy for a range of diseases. However, the therapeutic efficacy of Aza for patients of atherosclerosis remains unclear. This study investigates the therapeutic application of Aza to atherosclerosis in order to elucidate the underlying mechanisms. We generated induced Tregs (iTregs) from CD4+ T cells by using Aza in vitro, and this was followed by the intravenous infusion of iTregs for the treatment of atherosclerosis. The adoptive transfer of Aza-iTreg significantly increased peripheral blood Treg cells, suppressed inflammation, and attenuated atherosclerosis in ApoE-/- mice. Furthermore, we observed a notable demethylation of the Forkhead box P3 (Foxp3)-regulatory T cell-specific demethylated region (TSDR) and an upregulation of Foxp3 expression in the CD4+ T cells in the spleen of the ApoE-/- mice following the transfer of Aza- iTregs. We also demonstrated that Aza converted naive CD4+ T cells into Tregs by DNA methyltransferase 1 (Dnmt1)-mediated Foxp3-TSDR demethylation and the upregulation of Foxp3 expression. Conversely, the overexpression of Dnmt1 in the CD4+ T cells attenuated the Aza-induced Foxp3-TSDR demethylation and upregulation of Foxp3 expression. Our results reveal that Aza converts naive CD4+ T cells into functional Tregs by inhibiting Dnmt1, and the transfer of Aza-iTregs suppresses atherosclerosis in mice.

Tryptophan-rich diet and its effects on Htr7+ Tregs in alleviating neuroinflammation and cognitive impairment induced by lipopolysaccharide.

BACKGROUND: Neuroinflammation is a vital pathogenic mechanism for neurodegenerative diseases such as Alzheimer's, schizophrenia, and age-related cognitive decline. Regulatory T cells (Tregs) exhibit potent anti-inflammatory properties and can modulate neurodegenerative diseases arising from central nervous system inflammatory responses. However, the role of Tregs in neuroinflammation-related cognitive dysfunction remains unclear. It is highly plausible that Htr7+ Tregs expressing unique genes associated with the nervous system, including the Htr7 gene encoding the serotonin receptor 5-HT7, play a pivotal role. METHODS: Mice were given a tryptophan-rich diet (with a tryptophan content of 0.6%) or a normal diet (with a tryptophan content of 0.16%). The neuroinflammation-mediated cognitive dysfunction model was established by intracerebroventricular injection of lipopolysaccharide (LPS) in 8-week-old C57BL/6J mice. The activation and infiltration of Tregs were measured using flow cytometry. Primary Tregs were cocultured separately with primary CD8+ T cells and primary microglia for in vitro validation of the impact of 5-HT and 5-HT7 receptor on Tregs. Prior to their transfer into recombination activating gene 1 (Rag1-/-) mice, Tregs were ex vivo transfected with lentivirus to knock down the expression of Htr7. RESULTS: In this study, the tryptophan-rich diet was found to reverse LPS-induced cognitive impairment and reduce the levels of 5-HT in peripheral blood. The tryptophan-rich diet led to increased levels of 5-HT in peripheral blood, which in turn promoted the proliferation and activation of Htr7+ Tregs. Additionally, the tryptophan-rich diet was also shown to attenuate LPS-mediated neuroinflammation by activating Htr7+ Tregs. Furthermore, 5-HT and 5-HT7 receptor were found to enhance the immunosuppressive effect of Tregs on CD8+ T cells and microglia. In Rag1-/- mice, Htr7+ Tregs were shown to alleviate LPS-induced neuroinflammation and cognitive impairment. CONCLUSIONS: Our research revealed the ability of Htr7+ Tregs to mitigate neuroinflammation and prevent neuronal damage by suppressing the infiltration of CD8+ T cells into the brain and excessive activation of microglia, thereby ameliorating LPS-induced cognitive impairment. These insights may offer novel therapeutic targets involving Tregs for neuroinflammation and cognitive impairment.

IDO1 inhibitors are synergistic with CXCL10 agonists in inhibiting colon cancer growth.

Indoleamine 2,3-dioxygenase 1 (IDO1) is an immune checkpoint that degrades L-tryptophan to kynurenine (Kyn) and enhance immunosuppression, which can be an attractive target for treating colon cancer. IDO1 inhibitors have limited efficacy when used as monotherapies, and their combination approach has been shown to provide synergistic benefits. Many studies have shown that targeting chemokines can promote the efficacy of immune checkpoint inhibitors. Therefore, this study explored the use of IDO1 inhibitors with multiple chemokines to develop a new combination regimen for IDO1 inhibitors. We found that IDO1 inhibitors reduce the secretion of C-X-C motif ligand 10(CXCL10) in cancer cells, and CXCL10 supplementation significantly improved the anticancer effect of IDO1 inhibitors. The combination of the IDO1 inhibitor with CXCL10 or its agonist axitinib had a synergistic inhibitory effect on the growth of colon cancer cells and transplanted CT26 tumors. This synergistic effect may be achieved by inhibiting cancer cell proliferation, promoting cancer cell apoptosis, promoting CD8+T cell differentiation and decreasing Tregs. Two downstream pathways of IDO1 affect CXCL10 secretion. One being the Kyn-aryl hydrocarbon receptor (AHR) pathway, the other is the general control nonderepressible 2(GCN2). Our study provides a new reference for combination regimens of IDO1 inhibitors.

Pirfenidone inhibits CCL2-mediated Treg chemotaxis induced by palbociclib and fulvestrant in HR+/HER2- breast cancer.

In human epidermal growth factor receptor 2-negative (HR+/HER2-) breast cancer, the most prevalent subtype, the pathological complete response (pCR) rate after neoadjuvant chemotherapy is less than 18 %, and the survival of patients with advanced-stage disease is approximately 34 %, highlighting the critical demand for more potent therapies. Recent research has underscored the substantial therapeutic benefits of the combination of CDK4/6 inhibitors and fulvestrant (Ful) in managing HR+/HER2- breast cancer. These therapeutics not only curtail tumor proliferation but also alter the tumor immune microenvironment, suggesting novel avenues for immunotherapy for this breast cancer subtype. Flow cytometry, PCR, WB, and RNA-seq experiments revealed that the combination of the CDK4/6 inhibitor palbociclib (Pal) with Ful upregulated CCL2 in tumor cells by inducing the SASP and activating the MAPK signaling pathway. CCL2 attracts Tregs to the tumor microenvironment, where it exerts an immunosuppressive effect. By administering the CCL2 inhibitor pirfenidone, we inhibited these effects and enhanced the antitumor efficacy of Pal + Ful. Our research revealed an immunosuppressive effect of CDK4/6 inhibitors and fulvestrant and suggested that CCL2 inhibitors may be a viable approach for treating patients with advanced HR+/HER2- breast cancer.

Percutaneous Delivery of Hederacoside C-Loaded Nanoliposome Gel Alleviates Psoriasiform Skin Inflammation through the CCL17/Treg Axis.

Psoriasis is a chronic, recurrent, and inflammatory skin disease. Topical agents, which can avoid the adverse effects of systemic treatment, are the first-choice therapy for patients with mild-to-moderate psoriasis. Hederacoside C (HSC) with anti-inflammatory properties has been used to treat some inflammatory diseases. We speculated that HSC might also be effective for psoriasis treatment. However, topical application of HSC for psoriasis treatment is challenging because of its low water solubility and poor skin permeability. Therefore, it is important to effectively deliver HSC percutaneously using certain biomaterials. Here we constructed a hydroxypropyl-ß-cyclodextrin-coated liposome gel formulation for the loading and percutaneously delivering of HSC, referred to as HSC-Lipo@gel. The characterization, stability, release properties, and mechanical or transdermal features of the HSC-Lipo@gel were evaluated. Its therapeutic potential was also demonstrated using mouse models of IMQ-induced psoriasis. We found that HSC-Lipo@gel effectively improved the skin permeability of HSC with the property of good stability and sustained release. Importantly, HSC-Lipo@gel showed higher efficacy than HSC@gel without liposomes in alleviating psoriatic skin lesions. It attenuated epidermal hyperplasia and suppressed expression of IL-17A, TNF-α, IL-6, and IL-23 in lesional skin. Interestingly, HSC-Lipo@gel reduced the expression of CC chemokine ligand 17 (CCL17), but not CCL22, in the skin. Especially, HSC-Lipo@gel inhibited CCL17 expression by skin dendritic cells while increasing regulatory T cells (Tregs) in both skin and draining lymph nodes of psoriatic mice. Administration of CCL17 resulted in severe skin lesions and reduced CD4+FoxP3+ Tregs in psoriatic mice previously treated with HSC-Lipo@gel. Finally, HSC or HSC-Lipo also suppressed the CCL17 production by dendritic cells in vitro. Therefore, HSC-Lipo@gel alleviated psoriasiform skin inflammation by increasing cutaneous Tregs via downregulation of the expression of CCL17, but not CCL22. Thus, HSC-Lipo@gel may be a stable, highly permeable, and effective system for topical treatment of psoriasis.

Nanoreactors with Cascade Catalytic Activity Reprogram the Tumor Microenvironment for Enhanced Immunotherapy by Synchronously Regulating Treg and Macrophage Cells.

Immunotherapy has been extensively utilized and studied as a prominent therapeutic strategy for tumors. However, the presence of a hypoxic immunosuppressive tumor microenvironment significantly reduces the efficacy of the treatment, thus impeding its application. In addition, the hypoxic microenvironment can also lead to the enrichment of immunosuppressive cells and reduce the effectiveness of tumor immunotherapy; nanoparticles with biocatalytic activity have the ability to relieve hypoxia in tumor tissues and deliver drugs to target cells and have been widely concerned and applied in the field of tumor therapy. The present study involved the development of a dual nanodelivery system that effectively targets the immune system to modify the tumor microenvironment (TME). The nanodelivery system was developed by incorporating R848 and Imatinib (IMT) into Pt nanozyme loaded hollow polydopamine (P@HP) nanocarriers. Subsequently, their surface was modified with specifically targeted peptides that bind to M2-like macrophages and regulatory T (Treg) cells, thereby facilitating the precise targeting of these cells. When introduced into the tumor model, the nanocarriers were able to selectively target immune cells in tumor tissue, causing M2-type macrophages to change into the M1 phenotype and reducing Treg activation within the tumor microenvironment. In addition, the carriers demonstrated exceptional biocatalytic activity, effectively converting H2O2 into oxygen and water at the tumor site while the drug was active, thereby alleviating the hypoxic inhibitory conditions present in the tumor microenvironment. Additionally, this further enhanced the infiltration of M1-type macrophages and cytotoxic T lymphocytes. Moreover, when used in conjunction with immune checkpoint therapy, the proposed approach demonstrated enhanced antitumor immunotherapeutic effects. The bimodal targeted immunotherapeutic strategy developed in the present study overcomes the drawbacks of traditional immunotherapy approaches while offering novel avenues for the treatment of cancer.

[Immune mechanism of Daphnes Cortex and its processed products on CIA rats based on B7/CD28/CTLA-4 pathway].

This study investigates the effects of Daphnes Cortex and its processed products on the differentiation of Th17/Treg cells in SD rats with type Ⅱ collagen-induced arthritis(CIA).Sixty-four SD rats were randomly divided into the normal group(normal),model group(model),fried Daphne giraldii Nitsche low-dose and high-dose groups(FDGN-L group, FDGN-H group),raw D. giraldii Nitsche low-dose and high-dose groups(RDGN-L group, RDGN-H group),daphnetin group(DAPH group),and tripterygium glycosides group(GTW group).Except for the normal group, the CIA model was immunized on the seventh day after the first immunization, and was gavaged for 28 days after the second immunization.After sampling, the inflammation of articular synovial membrane in CIA rats was observed by hematoxylin-eosin(HE)staining; the levels of transforming growth factor-ß(TGF-ß),interferon-γ(IFN-γ),interleukin(IL)-2,IL-4,and IL-10 in serum were detected by enzyme-linked immunosorbent assay(ELISA); real-time reverse transcription-PCR(qRT-PCR)and Western blot were used to detect the mRNA and protein expressions of cluster of differentiation(CD) 80(B7-1),CD 86(B7-2),CD28,and cytotoxic T lymphocyte-associated antigen 4(CTLA-4)in the synovial membrane of rats; flow cytometry was used to detect the proportion of Th17 and Treg cells in the synovial membrane of rats.The results showed that compared with the normal group, the joint synovial inflammation of rats in the model group was significantly aggravated, the arthritis index was significantly increased, and the immune organ index was increased(P<0.01).Compared with the model group, each drug administration group could improve the joint inflammation of rats to varying degrees, reduce the arthritis index, inhibit synovial hyperplasia, and reduce the immune organ index; compared with the model group, the serum levels of IL-2 and IFN-γ in each drug administration group were significantly decreased(P<0.01),TGF-ß,IL-4,and IL-10 were significantly increased(P<0.01),the mRNA and protein expressions of B7-1 and CTLA-4 in the synovial membrane were significantly increased(P<0.01),and the proportion of Th17 cells and Treg cells in the joint tissue was significantly decreased(P<0.01).In conclusion, Daphnes Cortex inhibits the expression of Th17 cells in CIA rats and promotes the expression of Treg cells by regulating the B7/CD28/CTLA-4 pathway and the balance of Th17/Treg, thereby treating rheumatoid arthritis.

Pharmacologic LDH inhibition redirects intratumoral glucose uptake and improves antitumor immunity in solid tumor models.

Tumor reliance on glycolysis is a hallmark of cancer. Immunotherapy is more effective in controlling glycolysis-low tumors lacking lactate dehydrogenase (LDH) due to reduced tumor lactate efflux and enhanced glucose availability within the tumor microenvironment (TME). LDH inhibitors (LDHi) reduce glucose uptake and tumor growth in preclinical models, but their impact on tumor-infiltrating T cells is not fully elucidated. Tumor cells have higher basal LDH expression and glycolysis levels compared with infiltrating T cells, creating a therapeutic opportunity for tumor-specific targeting of glycolysis. We demonstrate that LDHi treatment (a) decreases tumor cell glucose uptake, expression of the glucose transporter GLUT1, and tumor cell proliferation while (b) increasing glucose uptake, GLUT1 expression, and proliferation of tumor-infiltrating T cells. Accordingly, increasing glucose availability in the microenvironment via LDH inhibition leads to improved tumor-killing T cell function and impaired Treg immunosuppressive activity in vitro. Moreover, combining LDH inhibition with immune checkpoint blockade therapy effectively controls murine melanoma and colon cancer progression by promoting effector T cell infiltration and activation while destabilizing Tregs. Our results establish LDH inhibition as an effective strategy for rebalancing glucose availability for T cells within the TME, which can enhance T cell function and antitumor immunity.

Regulatory T Cells Nanoextinguisher to Manipulate Multiple Immune Evasion for Immunotherapy.

Regulatory T cells (Treg) play key roles in inhibiting effective antitumor immunity. However, therapeutic Treg depletion fails to consistently enhance immune responses due to the emergence of a wave of peripherally converted Treg cells postdepletion, along with undesired off-target side effects. Here, we report a nanoextinguisher decorated with functional peptides via tumor microenvironment responsive linkers to selectively block Treg function and maintain Treg levels rather than deplete them. The nanoextinguisher specifically neutralizes TGF-ß to inhibit the recruitment of Treg cells and the conversion of naive T cells into Treg cells, thus promoting antitumor immunity. Moreover, the nanoextinguisher can alleviate tumor resistance to immunogenic photodynamic therapy, vaccination therapy, and checkpoint inhibition. The nanoextinguisher showed 30-fold potentiation in antitumor effect compared to standalone photodynamic therapy or vaccination therapy. Overall, utilizing a nanoextinguisher to inhibit Treg function without triggering reconversion represents a generalizable method to reverse immune evasion, yielding antitumor efficacy.

SPH7854, a gut-limited RORγt antagonist, ameliorates TNBS-induced experimental colitis in rat.

Multiple lines of evidence suggest that Retinoic Acid Related Orphan Nuclear Receptor gamma t (RORγt) is a potent therapeutic target for inflammatory bowel disease (IBD). However, systemic blockade of RORγt easily leads to thymic lymphoma and aberrant liver function. Therefore, the development of gut-limited RORγt antagonists may lead to the development of innovative IBD therapeutics that improve safety and retain effectiveness. We discovered SPH7854, a potent and selective RORγt antagonist. The effect of SPH7854 on the differentiation of T helper 1 (Th1)/Th17/regulatory T (Treg) cells was evaluated in mouse and human primary cells. SPH7854 (2-(4-(ethylsulfonyl)phenyl)-N- (6-(2-methyl-2-(pyridin-2-yl) propanoyl)pyridin-3-yl)acetamide) dose-dependently inhibited interleukin-17A (IL-17A) secretion from mouse CD4 + T cells and human peripheral blood mononuclear cells (PBMC). Additionally, SPH7854 strongly suppressed Th17 cell differentiation and considerably promoted Treg cell differentiation while slightly affected Th1 cell differentiation from mouse CD4 + T cells. The pharmacokinetic (PK) studies indicated that SPH7854 was restricted to the gut: the bioavailability and maximal plasma concentration of SPH7854 after oral administration (6 mg/kg) were 1.24 ± 0.33 % and 4.92 ± 11.81 nM, respectively, in rats. Strikingly, oral administration of SPH7854 (5 mg/kg and 15 mg/kg) twice daily significantly alleviated 2, 4, 6-trinitrobenzensulfonic acid (TNBS)-induced colitis in rats. SPH7854, especially at 15 mg/kg, significantly alleviated symptoms and improved macroscopic signs and microscopic structure in rat colitis, with decreased colonic mucosal levels of IL-17A, IL-6, tumor necrosis factor α (TNFα), monocyte chemoattractant protein-1 (MCP-1) and myeloperoxidase (MPO). These evidences indicated that blockade of RORγt activity via a gut-limited antagonist may be an effective and safe therapeutic strategy for IBD treatment.