Project description:The importance of unanchored Ub in innate immunity has been shown only for a limited number of unanchored Ub-interactors. We investigated what additional cellular factors interact with unanchored Ub and whether unanchored Ub plays a broader role in innate immunity. To identify unanchored Ub-interacting factors from murine lungs, we used His-tagged recombinant poly-Ub chains as bait. These chains were mixed with lung tissue lysates and protein complexes were isolated with Ni-NTA beads. Sample elutions were subjected to mass spectrometry (LC-MSMS) analysis.
Project description:The nature of gut intraepithelial lymphocytes lacking antigen receptors remains controversial. Herein we showed that, in humans and in mice, innate intestinal intraepithelial lymphocytes expressing intracellular CD3 (iCD3+ innate IELs) differentiate along an Id2 transcription factor (TF)-independent pathway in response to TF NOTCH1, interleukin 15 (IL-15) and Granzyme B signals. In NOTCH1-activated human hematopoietic precursors, IL-15 induced Granzyme B, which cleaved NOTCH1 into a peptide lacking transcriptional activity. As a result, NOTCH1 target genes indispensable for T cell differentiation were silenced and precursors were reprogrammed into innate cells with T cell marks including intracellular CD3 and T cell rearrangements. This pathway was operational in vivo in the mouse gut and led to the local differentiation of iCD3+ innate IELs from a bone marrow-derived precursor. In a subset of celiac patients, iCD3+ innate IELs with gain-of-function mutations in Janus kinase 1 or Signal transducer and activator of transcription 3 displayed enhanced response to IL-15 and acquired a selective advantage that favored clonal expansion and transformation into lymphoma. Overall we characterized gut T cell-like innate IELs, deciphered their pathway of differentiation, and showed their malignant transformation in celiac disease.
Project description:The intestinal mucosa harbors the largest accumulation of T lymphocytes in the body. While these T cells play an important role in immune homeostasis, they are also implicated in triggering and maintaining pathological intestinal inflammation. In humans they are poorly characterised, and even mouse transcriptomes have been reported for only a few individual cell types, many of which lack direct human equivalents. Using expression microarrays on T cells isolated from ileal biopsies and in silico analysis, we present here an unbiased, transcriptome-wide view of function in T cell subpopulations of the healthy human intestine and delineate signalling pathways that are distinct from those seen in peripheral blood T cells. Paired blood and intestinal biopsies from 6 age/sex matched healthy human subjects. Intestinal biopsies processed to release intraepithelial lymphocytes (IEL) and lamina propria lymphocytes (LPL). All samples then used to generate T effector memory (Tem) cells of CD4+ and CD8+ subsets by flow sorting. 6 individuals; 3 cell sources per individual (blood, LPL, IEL); 2 Tem subsets per cell source (CD4+ and CD8+). 36 arrays in total
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.