Explore the vast range of titles available.

Programmed cell death protein 1 (PD-1), expressed on tumor-infiltrating T cells, is a T cell exhaustion marker. The mechanisms underlying PD-1 upregulation in CD4 T cells remain unknown. Here we develop nutrient-deprived media and a conditional knockout female mouse model to study the mechanism underlying PD-1 upregulation. Reduced methionine increases PD-1 expression on CD4 T cells. The genetic ablation of SLC43A2 in cancer cells restores methionine metabolism in CD4 T cells, increasing the intracellular levels of S-adenosylmethionine and yielding H3K79me2. Reduced H3K79me2 due to methionine deprivation downregulates AMPK, upregulates PD-1 expression and impairs antitumor immunity in CD4 T cells. Methionine supplementation restores H3K79 methylation and AMPK expression, lowering PD-1 levels. AMPK-deficient CD4 T cells exhibit increased endoplasmic reticulum stress and Xbp1s transcript levels. Our results demonstrate that AMPK is a methionine-dependent regulator of the epigenetic control of PD-1 expression in CD4 T cells, a metabolic checkpoint for CD4 T cell exhaustion. The deprivation of amino acids in the tumor microenvironment affects T cell survival and activation. Here the authors show that reduced levels of methionine are associated with PD1 upregulation in CD4+ T cells and that methionine supplementation promotes CD4+ T cell dependent anti-tumor immune responses.

Background AMP-activated protein kinase (AMPK) is a metabolic sensor that maintains energy homeostasis. AMPK functions as a tumor suppressor in different cancers; however, its role in regulating antitumor immunity, particularly the function of regulatory T cells (Tregs), is poorly defined. Methods AMPKα1 fl/fl Foxp3 YFP-Cre , Foxp3 YFP-Cre , Rag1 −/− , and C57BL/6 J mice were used for our research. Flow cytometry and cell sorting, western blotting, immuno-precipitation, immuno-fluorescence, glycolysis assay, and qRT-PCR were used to investigate the role of AMPK in suppressing programmed cell death 1 (PD-1) expression and for mechanistic investigation. Results The deletion of the AMPKα1 subunit in Tregs accelerates tumor growth by increasing the expression of PD-1. Metabolically, loss of AMPK in Tregs promotes glycolysis and the expression of 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), a key enzyme of the mevalonate pathway. Mechanistically, AMPK activates the p38 mitogen-activated protein kinase (MAPK) that phosphorylates glycogen synthase kinase-3β (GSK-3β), inhibiting the expression of PD-1 in Tregs. Conclusion Our study identified an AMPK regulatory mechanism of PD-1 expression via the HMGCR/p38 MAPK/GSK3β signaling pathway. We propose that the AMPK activator can display synergic antitumor effect in murine tumor models, supporting their potential clinical use when combined with anti-PD-1 antibody, anti-CTLA-4 antibody, or a HMGCR inhibitor.

Targeting the programmed cell death protein 1 (PD-1)/programmed death ligand 1 (PD-L1) pathway is promising in treating cancer in humans and offers potential for veterinary applications. However, no PD-L1 antibodies have been approved specifically for treating canine cancer. We aimed to develop PD-L1-specific antibodies using phage display technology for treating canine cancer. A synthetic antibody library was screened, and 18 high-affinity single-chain variable fragment clones were subsequently converted to the IgG format for enhancing binding affinity and functional stability. The clone #15 exhibited the highest binding affinity and most pronounced antitumor effects. The PD-1/PD-L1 interaction was inhibited by antibody #15. The binding and thermal stabilities of the antibodies were validated by flow cytometry and thermal stability assays, respectively. In NOG mice xenografted with canine osteosarcoma cells and treated with canine peripheral blood mononuclear cells and antibody #15, the tumor size and weight were reduced. Antibody #15 significantly increased apoptosis of tumor cells and lymphocyte populations. Therefore, anti-PD-L1 antibodies, particularly antibody #15, have substantial potential as novel immunotherapeutic agents against canine osteosarcoma. This study represents a significant advancement in veterinary oncology, with the potential of improving treatment outcomes for canine cancers and providing insights into similar strategies in human cancer therapy.

Coxsackievirus B3 (CVB3) is an important human pathogen associated with the development of acute pancreatitis, myocarditis, and type 1 diabetes. Currently, no vaccines or antiviral therapeutics are approved for the prevention and treatment of CVB3 infection. We found that Saururus chinensis Baill extract showed critical antiviral activity against CVB3 infection in vitro . Further, manassantin B inhibited replication of CVB3 and suppressed CVB3 VP1 protein expression in vitro . Additionally, oral administration of manassantin B in mice attenuated CVB3 infection-associated symptoms by reducing systemic production of inflammatory cytokines and chemokines including TNF-α, IL-6, IFN-γ, CCL2, and CXCL-1. We found that the antiviral activity of manassantin B is associated with increased levels of mitochondrial ROS (mROS). Inhibition of mROS generation attenuated the antiviral activity of manassantin B in vitro . Interestingly, we found that manassantin B also induced cytosolic release of mitochondrial DNA based on cytochrome C oxidase DNA levels. We further confirmed that STING and IRF-3 expression and STING and TBK-1 phosphorylation were increased by manassantin B treatment in CVB3-infected cells. Collectively, these results suggest that manassantin B exerts antiviral activity against CVB3 through activation of the STING/TKB-1/IRF3 antiviral pathway and increased production of mROS.

•Oral administration of NCHBL-004 improves obesity in HFD-fed mice.•NCHBL-004 induces the production of serum GLP-1 and increases SCFAs levels in feces.•Administration of NCHBL-004 increases the proportion of SCFA-producing microbes. This study investigated the therapeutic potential of Lactobacillus plantarum NCHBL-004 (NCHBL-004) in the treatment of obesity and associated metabolic disorders. Mice were fed either a normal diet (ND) or a high-fat diet (HFD) with oral administration of NCHBL-004. After euthanasia, blood, liver and adipose tissue were collected. Furthermore, the microbiome and short-chain fatty acids (SCFAs) were analyzed from feces. Oral administration of live NCHBL-004 to mice fed a HFD resulted in notable reductions in weight gain, improvements in glucose metabolism, and maintenance of balanced lipid levels. A comparative analysis with other Lactobacillus strains highlighted the superior efficacy of NCHBL-004. Moreover, heat-killed NCHBL-004 demonstrated beneficial effects similar to those of live NCHBL-004. Additionally, administration of live NCHBL-004 induced glucagon-like peptide 1 (GLP-1) production and increased the levels of short-chain fatty acids (SCFAs), including acetate and propionate, in feces, positively influencing liver lipid metabolism and mitigating inflammation. Consistent with this, analysis of the gut microbiome following NCHBL-004 administration showed increases in SCFA-producing microbes with increased proportions of Lactobacillus spp. and a significant increase in the proportion of microbes capable of promoting GLP-1 secretion. These findings underscore the potential of both live and inactivated NCHBL-004 as potential therapeutic approaches to managing obesity and metabolic disorders, suggesting avenues for further investigation and clinical applications.

Endoplasmic reticulum stress is closely associated with the onset and progression of inflammatory bowel disease. ERdj5 is an endoplasmic reticulum-resident protein disulfide reductase that mediates the cleavage and degradation of misfolded proteins. Although ERdj5 expression is significantly higher in the colonic tissues of patients with inflammatory bowel disease than in healthy controls, its role in inflammatory bowel disease has not yet been reported. In the current study, we used ERdj5 -knockout mice to investigate the potential roles of ERdj5 in inflammatory bowel disease. ERdj5 deficiency causes severe inflammation in mouse colitis models and weakens gut barrier function by increasing NF-κB-mediated inflammation. ERdj5 may not be indispensable for goblet cell function under steady-state conditions, but its deficiency induces goblet cell apoptosis under inflammatory conditions. Treatment of ERdj5 -knockout mice with the chemical chaperone ursodeoxycholic acid ameliorated severe colitis by reducing endoplasmic reticulum stress. These findings highlight the important role of ERdj5 in preserving goblet cell viability and function by resolving endoplasmic reticulum stress. Inflammatory bowel disease: A protective enzyme in intestinal goblet cells Studies of inflammatory bowel disease (IBD) in mice reveal the role of an enzyme that assists the degradation of mis-folded proteins in the ‘goblet’ cells involved in producing the mucus barrier that lines and protects the interior of the gut. The most common forms of IBD are ulcerative colitis and Crohn’s disease. Researchers in South Korea led by Hyun-Jeong Ko at Kangwon National University, Chuncheon, and Sun-Young Chang at Ajou University, Suwon, compared goblet cell biology in normal mice with mice in which the gene encoding the protein-degrading enzyme ERdj5 had been disabled. This showed that ERdj5 protects goblet cells from a form of stress-mediated cell death that occurs during gut inflammation. The results suggest that drugs modifying the molecular mechanisms underlying ERdj5’s actions could open new avenues towards preventing and treating IBD.

Background Cancer is a leading cause of mortality worldwide, necessitating the development of novel therapeutic targets and strategies to prevent recurrence and metastasis. In this study, we aimed to evaluate whether a recombinant attenuated Salmonella vaccine (RASV) can stimulate antitumor immunity and prevent cancer progression in vivo. Methods We established a mouse model by transplanting cancer cells subcutaneously 4 weeks after oral RASV inoculation and analyzed bone marrow (BM) cells and tumor-infiltrated immune cells by flow cytometry. Further, we established a 4 T-1-induced metastatic cancer model to evaluate the RASV-mediated prevention of tumor metastasis. Results Adjuvant RASV significantly reduced tumor growth by enhancing CD8 + T cell activity and inducing changes in BM progenitor cells, which contributed combinatorically to the antitumor effects of RASV by increasing the number of common lymphoid progenitor cells. The antitumor effects mediated by RASV were inhibited upon interleukin (IL)-7 receptor blockage. Moreover, interferon-γ-stimulated genes, including Irf1 , were upregulated in the BM of RASV-treated mice, thus mediating IL-7 expression. Furthermore, RASV inoculation prevented lung metastasis in mice with breast cancer. Conclusions RASV inoculation can promote marked alterations in the BM microenvironment, thus reshaping the anticancer immune response in vivo. This strategy holds therapeutic potential for preventing cancer recurrence and metastasis. Graphical abstract

Early secretory antigenic target-6 (ESAT6) is a potent immunogenic antigen expressed in as well as in some non-tuberculous mycobacteria (NTM), such as . is one of the most clinically relevant species of NTM that causes mycobacterial lung disease, which is clinically indistinguishable from tuberculosis. In the current study, we designed a novel cell-based vaccine using B cells that were transduced with vaccinia virus expressing ESAT6 (vacESAT6), and presenting α-galactosylceramide (αGC), a ligand of invariant NKT cells. We found that B cells loaded with αGC had increased levels of CD80 and CD86 after stimulation with NKT cells. Immunization of mice with B/αGC/vacESAT6 induced CD4 T cells producing TNF-α and IFN-γ in response to heat-killed . Immunization of mice with B/αGC/vacESAT6 ameliorated severe lung inflammation caused by infection. We also confirmed that immunization with B/αGC/vacESAT6 reduced bacterial burden in the lungs. In addition, therapeutic administration of B/αGC/vacESAT6 increased IFN-γ CD4 T cells and inhibited the progression of lung pathology caused by infection. Thus, B/αGC/vacESAT6 could be a potent vaccine candidate for the prevention and treatment of ESAT6-expressing mycobacterial infection caused by .

Inhibitor of kappa B (IκB)-ζ transcription is rapidly induced by stimulation with TLR ligands and IL-1. Despite high IκBζ expression in inflammation sites, the association of IκBζ with host defence via systemic immune responses against bacterial infection remains unclear. Oral immunisation with a recombinant attenuated Salmonella vaccine (RASV) strain did not protect IκBζ-deficient mice against a lethal Salmonella challenge. IκBζ-deficient mice failed to produce Salmonella LPS-specific IgG, especially IgG2a, although inflammatory cytokine production and immune cell infiltration into the liver increased after oral RASV administration. Moreover, IκBζ-deficient mice exhibited enhanced splenic germinal centre reactions followed by increased total IgG production, despite IκBζ-deficient B cells having an intrinsic antibody class switching defect. IκBζ-deficient CD4 + T cells poorly differentiated into Th1 cells. IFN-γ production by CD4 + T cells from IκBζ-deficient mice immunised with RASV significantly decreased after restimulation with heat-killed RASV in vitro , suggesting that IκBζ-deficient mice failed to mount protective immune responses against Salmonella infection because of insufficient Th1 and IgG production. Therefore, IκBζ is crucial in protecting against Salmonella infection by inducing Th1 differentiation followed by IgG production.

Anti-cluster of differentiation (CD) 3 × α programmed death-ligand 1 (PD-L1) bispecific T-cell engager (BsTE)-bound T-cells (BsTE:T) are a promising new cancer treatment agent. However, the mechanisms of action of bispecific antibody-armed activated T-cells are poorly understood. Therefore, this study aimed to investigate the anti-tumor mechanism and efficacy of BsTE:T. The BsTE:T migration was assessed in vivo and in vitro using syngeneic and xenogeneic tumor models, flow cytometry, immunofluorescence staining, transwell migration assays, microfluidic chips, Exo View R100, western blotting, and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 technology. In murine B16 melanoma, MC38 colon cancer, and human multiple myeloma cells, BsTE:T exhibited superior tumor elimination relative to that of T-cells or BsTE alone. Moreover, BsTE:T migration into tumors was significantly enhanced owing to the presence of PD-L1 in tumor cells and secretion of PD-L1-containing exosomes. Furthermore, increased infiltration of CD44highCD62Llow effector memory CD8+ T-cells into tumors was closely associated with the anti-tumor effect of BsTE:T. Therefore, BsTE:T is an innovative potential anti-tumor therapy, and exosomal PD-L1 plays a crucial role both in vitro and in vivo in the anti-tumor activity of BsTE:T.