Project description:Inducible co-stimulator (ICOS) interaction with its ligand (ICOSL) is involved in several T cell effector functions. While blockade of ICOS:ICOSL interaction in chronic graft versus host disease (GVHD) seems benefi cial, results for acute GVHD remain controversial. To further elucidate its role in acute GVHD, C57BL / 6 mice were lethally irradiated and reconstituted with allogeneic spleen cells in the absence or presence of ICOSL-blocking mAb. Mice reconstituted with allogeneic spleen cells experienced severe GVHD and died untreated within 6 – 9 days after transplantation. Mice treated with an anti-ICOSL mAb starting from day 3 after transplantation gained weight again and survived for at least additional 12 days, although the treatment was already stopped at day 11 after transplantation. In contrast, the anti-ICOSL treatment starting from day 0 did not prevent GVHD. The diff erence between therapeutic (day 3) and prophylactic (day 0) anti-ICOSL treatment was independent of CD25 + CD4 + regulatory T cells since their depletion did not abrogate the therapeutic eff ect of ICOSL blockade. Microarray analysis revealed IFN- γ and chemokine up-regulation in spleen cells of prophylactically treated mice, emphasizing kinetic dependence of acute GVHD modulation via blockade of ICOS:ICOSL interaction.
Project description:Inducible co-stimulator (ICOS) interaction with its ligand (ICOSL) is involved in several T cell effector functions. While blockade of ICOS:ICOSL interaction in chronic graft versus host disease (GVHD) seems benefi cial, results for acute GVHD remain controversial. To further elucidate its role in acute GVHD, C57BL / 6 mice were lethally irradiated and reconstituted with allogeneic spleen cells in the absence or presence of ICOSL-blocking mAb. Mice reconstituted with allogeneic spleen cells experienced severe GVHD and died untreated within 6 M-bM-^@M-^S 9 days after transplantation. Mice treated with an anti-ICOSL mAb starting from day 3 after transplantation gained weight again and survived for at least additional 12 days, although the treatment was already stopped at day 11 after transplantation. In contrast, the anti-ICOSL treatment starting from day 0 did not prevent GVHD. The diff erence between therapeutic (day 3) and prophylactic (day 0) anti-ICOSL treatment was independent of CD25 + CD4 + regulatory T cells since their depletion did not abrogate the therapeutic eff ect of ICOSL blockade. Microarray analysis revealed IFN- M-NM-3 and chemokine up-regulation in spleen cells of prophylactically treated mice, emphasizing kinetic dependence of acute GVHD modulation via blockade of ICOS:ICOSL interaction. B6 recipients were irradiated with 10.0 Gray, administered from a 137 Cs source. Splenocytes from C3H mice were prepared as single cell suspensions in PBS, depleted of red blood cells and counted. 2 M-bM-^@M-^S 3 M-CM-^W 10^7 C3H splenocytes in a volume of 200 M-NM-<l were transplanted into B6 recipients via tail vein injection (4 mice per group per experiment) 4 M-bM-^@M-^S 6 h after irradiation. Mice in the treatment group with anti-ICOSL mAb and their respective controls, received 500 M-NM-<g mAb i. p starting at day 0 or day 3, followed by subsequent injections of 200 M-NM-<g of mAb every other day. At day 4 after transplantation RNA of spleen cells was prepared and subjected to microarray analysis. Combined RNA from allogeneic transplanted mice was hybridized onto 2 independent arrays.
Project description:T follicular helper (Tfh) cells constitute an essential cell type in the induction of antibodies. We report that CD4 T cells lacking Foxo1 almost uniformly became CXCR5int Tfh cells following immunization. Moreover, a Foxo1 loss-of-function complemented an Icos mutation allowing the appearance of Tfh cells along with follicular, class-switched B cells and IgG isotype anti-DNA antibodies. Similarly, FOXO1 deficient Tfh differentiation displayed a substantially reduced dependence on ICOSL. Functional and molecular analyses show that FOXO1 regulates Tfh differentiation through a broad program of gene expression exemplified by positive regulation of Icos and negative regulation of Bcl6. These results demonstrate that a key step in Tfh differentiation is the ICOS-initiated activation of the PI3K-AKT pathway resulting in the inactivation of FOXO1. Performed ChIP-seq analysis to examine the role of foxo1 in the development of Tfh cells
Project description:Acetaminophen is a widely used antipyretic and analgesic drug, and its overdose is the leading cause of drug-induced acute liver failure. This study aimed to investigate the effect and mechanism of Lacticaseibacillus casei Shirota (LcS), an extensively used and highly studied probiotic, on acetaminophen-induced acute liver injury. C57BL/6 mice were gavaged with LcS suspension or saline once daily for 7 days before the acute liver injury was induced via intraperitoneal injection of 300 mg/kg acetaminophen. The results showed that LcS significantly decreased acetaminophen-induced liver and ileum injury, as demonstrated by reductions in the increases in aspartate aminotransferase, total bile acids, total bilirubin, indirect bilirubin and hepatic cell necrosis. Moreover, LcS alleviated the acetaminophen-induced intestinal mucosal permeability, elevation in serum IL-1α and lipopolysaccharide, and decreased levels of serum eosinophil chemokine (eotaxin) and hepatic glutathione levels. Furthermore, analysis of the gut microbiota and metabolome showed that LcS reduced the acetaminophen-enriched levels of Cyanobacteria, Oxyphotobacteria, long-chain fatty acids, cholesterol and sugars in the gut. Additionally, the transcriptome and proteomics showed that LcS mitigated the downregulation of metabolism and immune pathways as well as glutathione formation during acetaminophen-induced acute liver injury. This is the first study showing that pretreatment with LcS alleviates acetaminophen-enriched acute liver injury, and it provides a reference for the application of LcS.