Project description:The intestinal tract generates significant reactive oxygen species (ROS), but the role of T cell antioxidant mechanisms in maintaining intestinal homeostasis is poorly understood. We used T cell-specific ablation of the catalytic subunit of glutamate cysteine ligase (Gclc), which impaired glutathione (GSH) production, crucially reducing IL-22 production by Th17 cells in the lamina propria, which is critical for gut protection. Under steady-state conditions, Gclc deficiency did not alter cytokine secretion; however, C. rodentium infection induced increased ROS and disrupted mitochondrial function and TFAM-driven mitochondrial gene expression, resulting in decreased cellular ATP. These changes impaired the PI3K/AKT/mTOR pathway, reducing phosphorylation of 4E-BP1 and consequently limiting IL-22 translation. The resultant low IL-22 levels led to poor bacterial clearance, severe intestinal damage, and high mortality. Our findings highlight a previously unrecognized, essential role of Th17 cell-intrinsic GSH in promoting mitochondrial function and cellular signaling for IL-22 protein synthesis, which is critical for intestinal integrity and defense against gastrointestinal infections.
Project description:CD4+ and CD8+ T cells can reciprocally differentiate into Th/Tc1, Th/Tc17 and Th/Tc22. Although alloreactive Th/Tc1 cells play a critical role in initiating pathogenesis of gut acute graft-versus-host disease (Gut-aGVHD), the pathogenic T cells in steroid-resistant Gut-aGVHD (SR-Gut-aGVHD) remains unclear. Here, we show that in murine models of SR-Gut-aGVHD, the pathogenesis is associated with reduction of IFN-g+ Th/Tc1 and IL-17A+IL-22- Th/Tc17 cells but expansion of IL-17-IL-22+ Th/Tc22, particularly Tc22 cells. The IL-22 from Th/Tc22 cells causes dysbiosis.
Project description:CD4+ and CD8+ T cells can reciprocally differentiate into Th/Tc1, Th/Tc17 and Th/Tc22. Although alloreactive Th/Tc1 cells play a critical role in initiating pathogenesis of gut acute graft-versus-host disease (Gut-aGVHD), the pathogenic T cells in steroid-resistant Gut-aGVHD (SR-Gut-aGVHD) remains unclear. Here, we show that in murine models of SR-Gut-aGVHD, the pathogenesis is associated with reduction of IFN-g+ Th/Tc1 and IL-17A+IL-22- Th/Tc17 but expansion of IL-17-IL-22+ Th/Tc22, particularly Tc22 cells. IL-22 from Th/Tc22 cells causes dysbiosis. Using a Gut-aGVHD model induced by alloreactive IFN-g-/- CD8+ T cells, we show that the Gut-aGVHD pathogenesis requires both dysbiosis and depletion of CX3CR1hi mononuclear phagocytes (MNP) that regulate intestinal bacterial translocation. Absence of IFN-g leads to preferential expansion of Tc22 that induce dysbiosis by augmenting RegIIIg production, and depletion of CX3CR1hi MNP via its PD-1 interaction with tissue PD-L1. Interestingly, SR-Gut-aGVHD is also associated with depletion of CX3CR1hi MNP that reduces expansion of Tc22 under steroid treatment. Our studies indicate that expansion of Th/Tc22, dysbiosis, and depletion of CX3CR1hi MNP cells play critical roles in SR-Gut-aGVHD pathogenesis. These results provide new avenue towards studies in patients and call for caution in clinical testing of IL-22 agonists or IFN-g antagonist in patients.
Project description:Necrotizing enterocolitis (NEC) is a devastating intestinal inflammatory disorder that primarily affects premature infants. Despite decades of research, this disease remains a significant cause of death in the absence of efficient therapeutics. Interleukin (IL)-22 has been shown to play a critical role in maintaining the gut barrier, promoting epithelial regeneration, and controlling intestinal inflammation in adult animal models with an established microbiome. However, the importance of IL-22 signaling in the regulation of gut homeostasis and protection in neonates that lack an established microbiome remains unknown. Therefore, the aim of the current study is to investigate the role of IL-22 in the neonatal intestinal epithelium under homeostatic and inflammatory conditions by using a mouse model of NEC. Our data reveal that Il22 expression in neonatal murine intestine is negligible until weaning. In addition, both human and murine neonates lack IL-22 production during NEC. Mice deficient in IL-22 or mice lacking the expression of IL-22 receptor in intestinal epithelial cells, display a similar susceptibility of neonates to NEC consistent with the lack of endogenous IL-22 at this critical stage of intestinal development. Conversely, treatment with recombinant IL-22 during NEC substantially reduces disease severity. This IL-22-mediated protection is associated with enhanced epithelial regeneration and increased expression of several antimicrobial genes. Strikingly, despite an IL-22-mediated induction of an antimicrobial transcriptional program, the composition of the intestinal microbial communities remains unchanged. Taken together, this study demonstrates that an IL-22 signaling axis promotes protection against neonatal NEC through the induction of epithelial cell regeneration.
Project description:Homeostasis of the gut microbiota is pivotal to the survival of the host. Intestinal T cells and Innate Lymphoid cells (ILCs) control the composition of the microbiota and respond to its perturbations. Interleukin 22 (IL-22) plays a pivotal role in the immune control of gut commensal and pathogenic bacteria and is secreted by a heterogeneous population of intestinal T cells, NCR- ILC3 and NCR+ILC3. Expression of NCR by ILC3 is believed to define an irreversible effector ILC3 end-state fate in which these cells are key to control of bacterial infection via their production of IL-22. Here we identify the core transcriptional signature that drives the differentiation of NCR- ILC3 into NCR+ ILC3 and reveal that NCR+ILC3 exhibit more plasticity than originally thought, as NCR+ ILC3 can revert to NCR- ILC3. Contrary to the prevailing understanding of NCR+ ILC3 genesis and function, in vivo analyses of mice conditionally deleted of the key ILC3 genes Stat3, Il22, Tbet and Mcl1 demonstrated that NCR+ ILC3 were not essential for the control of colonic infections in the presence of T cells. However, NCR+ ILC3 were mandatory for homeostasis of the caecum. Our data identify that the interplay of intestinal T cells and ILC3 results in robust complementary fail-safe mechanisms that ensure gut homeostasis.
Project description:Preclinical cancer drug discovery efforts have employed two-dimensional (2D)-cell-based assay models, which fail to forecast in vivo efficacy and contribute to a lower success rates of clinical approval. Three-dimensional (3D) cell culture models are recently expected to bridge the gap between 2D and in vivo models. We have developed novel 3D culture method that improves the growth of spheroid-forming cancer cells under anchorage-independent condition by leveraging a feature of FP001. Gene microarrays were used to observe the global gene expression in A549 cells cultured with normal adhesion plate (2D, control) or with low adhesion plate (+FP001) and identified distinct classes of up or down-regulated genes. A549 cells were cultured for 5 days in three different conditions as follows. (1) Normal attachment plates with normal medium (as control), (2) low-attachment plates with normal medium, (3) low-attachment plates with FP001 containing medium. Each sample was collected three times.
Project description:Analysis of 2D (transwell) and 3D (collagen type I) cultured MDCK cells and HGF (a MAPK activator). Traditional 2D cultures are fast and inexpensive but do no mimic natural niche/cell environment as well as the more laborious and costly 3D-cultures. 3D cultures, arguably, are better models for the study of developmental processes, such as tubulogenesis. Epithelial organs (such as kidney) develop via tubulogenesis, a process, at least in part, regulated by MAPK signaling. Therefore, 2D and 3D cells also treated with HGF plus MAPK inhibitors. Results provide insights into differential response to HGF-induced tubulogenesis depending on cell culture conditions (2D vs. 3D). 29 samples total: 2D and 3D control (untreated) in quadruplicate, respectively; 2D and 3D + HGF in quadruplicate, respectively; 2D + HGF + PD-98059 in quadruplicate; 3D + HGF + PD-98059 in triplicate; 2D + HGF + U0126 in triplicate; and 3D + HGF + U0126 in triplicate.