Intestinal CD4 Research Articles

Immune-Modifying Microparticles for Treatment of Acute Graft-Versus-Host-Disease

Abstract Background: Acute Graft versus host disease (aGVHD) is one of the most common complication of allogeneic hematopoietic stem cell transplant. We have previously shown that infused immune-modifying particles (IMPs) can reduce clinical symptoms and improve survival in inflammatory conditions. IMPs are taken up by inflammatory monocytes (θIM) via the macrophage receptor with collagenous structure (MARCO) and then undergo splenic sequestration. Given these findings, IMPs may be an effective method of reducing inflammation in aGVHD. Methods: We tested the efficacy of IMP in an established aGVHD murine model. We also explored the changes in immune cell subsets and serum cytokines. To assess impact of IMP on graft-versus-tumor (GVT), we infused host mice with A20 lymphoma cells. Results: We demonstrated that treatment with IMPs effectively rescues mice in a lethal aGVHD model. Treatment with IMPs also significantly improved clinical and target organ histopathological scores. IMP treatment resulted in increased splenic and intestinal CD4 +CD25 +Foxp3 +Tregs. IMP treated mice had lower numbers of colonic CD11b +Ly6c hiθIM and a lower peak of serum inflammatory cytokines. Maintenance of GVT effect was demonstrated by comparable survival rates in host mice with co-infusion of A20 lymphoma cells. Conclusion: Systemic IMP was effective at rescuing mice in this lethal aGVHD model. This demonstrates that targeting θIMs with IMPs could be an effective strategy to treat aGVHD. Further investigation of the mechanisms by which IMPs ameliorate aGVHD is warranted, as is investigation of the use of IMPs to treat aGVHD in the clinical setting. Supported by Nanoparticle Tolerance Research Fund

Small intestine and colon tissue-resident memory CD8 +T cells exhibit molecular heterogeneity and differential dependence on Eomesodermin

Abstract Tissue-resident memory CD8 +T (T RM) cells are a subset of memory T cells positioned at barrier sites, critical for host defense against infection. Recent studies have begun to reveal substantial heterogeneity in CD8 +T RMpopulations across different tissues. The gut consists of four anatomically distinct compartments, the epithelia and lamina propria in the small intestine (siIEL, siLPL) and colon (cIEL, cLPL). While CD8 +T RMin the small intestine epithelia are well-described, findings are often generalized to the whole gut, thus obscuring potential differences in CD8 +T RMin the much-less studied small intestine lamina propria and colon compartments. We thereby characterized CD8 +T RMin the four intestinal layers using single cell RNA-sequencing and flow cytometry. We show that CD8 +T RMacross the intestinal compartments exhibit differences in the expression of surface molecules, cytokines, granzymes, and transcription factors. For example, small intestine intraepithelial CD8 +T RMproduce the highest levels of granzymes, whereas colon intraepithelial CD8 +T RMhave the greatest capacity for cytokine production. We also uncover an unexpected, tissue-specific role for the T-box transcription factor Eomesodermin (Eomes), known to suppress T RMformation in the skin, liver, and kidney. Our data demonstrate that Eomes is dispensable for CD8 +T RMformation in both the small intestine and colon. By contrast, following CD8 +T RMformation, Eomes plays a critical role in promoting the maintenance of established CD8 +T RMin the small intestine, but not in the colon. Together, our study provides new insights into intestinal CD8 +T RMheterogeneity and differential transcriptional regulation of intestinal T RMformation vs. maintenance. Presenting author Y.H.L. is supported by the Canadian Institutes of Health Research (CIHR) Doctoral Foreign Study Award. This study is supported by grants from NIH (P01 AI132122).

Single Cell Sequencing Suggests Mucosal Origins of T Cells in HLA-B27-associated Inflammation

Abstract HLA-B27 was one of the first Major Histocompatibility Complex alleles associated with an autoimmune disease, i.e., Ankylosing Spondylitis (AS) and acute anterior uveitis (B27AU), which cause joint and eye inflammation, respectively. As HLA-B27 presents antigens to CD8 T cells, an antigen-specific CD8 T cell response may be central to disease pathogenesis. Consistent with this hypothesis, our recent work identified clonal expansion of public T cell receptors (TCRs) shared across patients with AS and B27AU and enriched in the joint or eye over the blood. These TCRs recognized both bacterial and self-peptides, suggesting a role for molecular mimicry in multiple organs afflicted by HLA-B27-associated inflammation. The main bacterial peptide recognized by these public TCRs is derived from yeiH, a gene present in multiple enteric microbiota. It remains unclear, however, whether these T cells have had a prior antigenic encounter within the gastrointestinal tract. We therefore performed single-cell RNA sequencing (scRNAseq) and T cell receptor sequencing (scTCRseq) on immune cells from the eye and blood during B27AU (n=5) and non-B27AU (n=14). In this analysis, we found that the expanded TCRs in B27AU were associated with CD161 expression and enriched for a transcriptional program from intestinal CD8 T cells. Moreover, we were able to identify an additional expanded TCR sequence that also recognized YEIH. Finally, expanded T cell clones contained higher expression of TNFand IFNG, suggestive of a pro-inflammatory transcriptional program. Collectively, our data suggest that, in HLA-B27-associated inflammation, the early antigen exposure and differentiation of putative pathogenic CD8 T cells may have occurred in enteric organs. This study received support from NIH 5R01AI103867 (KCG), U19AI057229 (KCG), the Howard Hughes Medical Institute (KCG), the Rheumatology Research Foundation (MAP), Arthritis National Research Foundation (MAP), the Rheumatic Diseases Research Resource-based Center at Washington University (NIH P30-AR073752, MAP, WMY), the Bursky Center for Human Immunology and Immunotherapy Programs (WMY), and the Barnes-Jewish Hospital Foundation (WMY).

Intestinal epithelial expression of neutral ceramidase determines severity of chemical colitis in mice

Abstract Sphingolipids are important eukaryotic signaling molecules and regulate inflammation and immunity. Elevated levels of sphingolipid metabolites, e.g. S1p, are found in many chronic inflammatory disorders, including inflammatory bowel disease (IBD). Neutral ceramidase (NcDase) is a key regulator of ceramide, the central intermediate in the sphingolipid metabolism. The contribution of intestinal epithelial cells (IEC) NcDase to IBD is not well understood. Here we demonstrate that mice with IEC-specific loss of NcDase (NcDase ΔIEC) developed less severe DSS-induced colitis than control mice. Deletion of IEC NcDase leads to increase of antimicrobial peptides, anti-inflammatory cytokines and regulatory T (Treg) cells; and reduction of dysbiosis and gut inflammation. Mechanistically, IEC NcDase is required for the generation of ganglioside GD3, which controls the enteric immune response by activating Treg cells and preventing activation of T-helper (Th)17 cells. Administration of dietary GD3 reduces mucosal inflammation. Thus, GD3 is a key epithelial-derived glycosphingolipid that regulates distinct subsets of intestinal CD4 +T cells during inflammatory conditions, a finding with potential implications for treatment of chronic inflammatory disorders. Supported by grants from NIH R21AI159194, R01 DK115406, and R01DK131442 (Z.D.).

Evaluation of CD4 Count, Haemoglobin, and Intestinal Parasites Status of Cancer Patients Receiving Oncology Therapy in Calabar, Nigeria

Cancer is a human cellular error with a high mortality rate, especially in developing regions. Resolving this error with therapy may render patients immunologically depressed and susceptible to opportunistic infections including parasitic. The gut parasites, Cluster of Differentiation four (CD4) cells and haemoglobin (Hb) levels of cancer patients on oncology therapy in Calabar, Nigeria were studied. Stool and blood samples were collected from 317 (186 cancer and 131 apparently healthy) subjects. Parasites were identified using direct smear and formol ether concentration techniques while CD4 and Hb estimation were done using BD-fascount and fluorescent flow cytometric techniques, respectively. Data were analysed using chi-square and independent sample t-test. Overall parasitosis prevalence in this study was (27.44%) with cancer showing an association with intestinal parasitosis (P=0.001) and CD4 level (P=0.002), respectively but none with Hb level. Parasiteinfected cancer subjects had significantly lower mean haemoglobin concentration than their non-infected counterpart (t = - 4.869, P<0.001). Generally, cancer subjects on cancer treatment had an insignificantly lower parasite and significantly lower CD4 levels compared to their non-treated counterpart (P = 0.829) and (P<0.001), respectively but their mean haemoglobin levels were similar (P=0.701). Cancer subjects on chemotherapy alone had significantly higher parasite prevalence, 50.00% compared to 28.95% for those on combined (surgery and chemotherapy) treatment (P=0.014), whereas the type of treatment showed no significant effect on CD4 and Hb levels. Parasite occurrence was only pronounced (71.43%) among subjects with >12 months of treatment duration (P=0.1038). There was a correlation between duration of treatment and CD4 levels (r = - 0.231, P<0.05) but none with haemoglobin levels (r = 0.024, P>0.05) of cancer subjects. In conclusion, although this study has shown that cancer as a condition increases parasite prevalence and reduces mean CD4 counts in subjects, their haemoglobin levels were not significantly affected, except for subjects with intestinal parasite infections. Treatment with cancer therapy did not also affect the haemoglobin concentration, but significantly reduced the CD4 cell number of subjects. Subjects who had majorly, chemotherapy were mostly infected with the parasite but with no noticeable effect on their CD4 and haemoglobin levels. A prolonged duration of treatment increased parasitosis and reduced the CD4 level of subjects but did not affect haemoglobin levels. Apart from the oncological treatments given to cancer subjects, management of cancer subjects should include parasitological examination and treatment, periodic monitoring of their hematologic profile and regular immune revitalization procedures, especially for those placed on prolonged therapy.

Bcl11b sustains multipotency and restricts effector programs of intestinal-resident memory CD8+ T cells.

The networks of transcription factors (TFs) that control intestinal-resident memory CD8+ T (TRM) cells, including multipotency and effector programs, are poorly understood. In this work, we investigated the role of the TF Bcl11b in TRM cells during infection with Listeria monocytogenes using mice with post-activation, conditional deletion of Bcl11b in CD8+ T cells. Conditional deletion of Bcl11b resulted in increased numbers of intestinal TRM cells and their precursors as well as decreased splenic effector and circulating memory cells and precursors. Loss of circulating memory cells was in part due to increased intestinal homing of Bcl11b-/- circulating precursors, with no major alterations in their programs. Bcl11b-/- TRM cells had altered transcriptional programs, with diminished expression of multipotent/multifunctional (MP/MF) program genes, including Tcf7, and up-regulation of the effector program genes, including Prdm1. Bcl11b also limits the expression of Ahr, another TF with a role in intestinal CD8+ TRM cell differentiation. Deregulation of TRM programs translated into a poor recall response despite TRM cell accumulation in the intestine. Reduced expression of MP/MF program genes in Bcl11b-/- TRM cells was linked to decreased chromatin accessibility and a reduction in activating histone marks at these loci. In contrast, the effector program genes displayed increased activating epigenetic status. These findings demonstrate that Bcl11b is a frontrunner in the tissue residency program of intestinal memory cells upstream of Tcf1 and Blimp1, promoting multipotency and restricting the effector program.

IgA2 immune complexes selectively promote inflammation by human CD103+ dendritic cells.

While immunoglobulin A (IgA) is well known for its neutralizing and anti-inflammatory function, it is becoming increasingly clear that IgA can also induce human inflammatory responses by various different immune cells. Yet, little is known about the relative role of induction of inflammation by the two IgA subclasses i.e. IgA1, most prominent subclass in circulation, and IgA2, most prominent subclass in the lower intestine. Here, we set out to study the inflammatory function of IgA subclasses on different human myeloid immune cell subsets, including monocytes, and in vitro differentiated macrophages and intestinal CD103+ dendritic cells (DCs). While individual stimulation with IgA immune complexes only induced limited inflammatory responses by human immune cells, both IgA subclasses strongly amplified pro-inflammatory cytokine production upon co-stimulation with Toll-like receptor (TLR) ligands such as Pam3CSK4, PGN, and LPS. Strikingly, while IgA1 induced slightly higher or similar levels of pro-inflammatory cytokines by monocytes and macrophages, respectively, IgA2 induced substantially more inflammation than IgA1 by CD103+ DCs. In addition to pro-inflammatory cytokine proteins, IgA2 also induced higher mRNA expression levels, indicating that amplification of pro-inflammatory cytokine production is at least partially regulated at the level of gene transcription. Interestingly, cytokine amplification by IgA1 was almost completely dependent on Fc alpha receptor I (FcαRI), whilst blocking this receptor only partially reduced cytokine induction by IgA2. In addition, IgA2-induced amplification of pro-inflammatory cytokines was less dependent on signaling through the kinases Syk, PI3K, and TBK1/IKKϵ. Combined, these findings indicate that IgA2 immune complexes, which are most abundantly expressed in the lower intestine, particularly promote inflammation by human CD103+ intestinal DCs. This may serve an important physiological function upon infection, by enabling inflammatory responses by this otherwise tolerogenic DC subset. Since various inflammatory disorders are characterized by disturbances in IgA subclass balance, this may also play a role in the induction or exacerbation of chronic intestinal inflammation.

A173 ELUCIDATING THE EFFECTS OF NOD2-MEDIATED SIGNALLING ON INTESTINAL RESIDENT-MEMORY T-CELL FORMATION AND FUNCTION

Abstract Background Aberrant resident memory T-cell (TRM) responses have been associated with increased intestinal inflammation and Crohn’s disease (CD) pathology in humans. Intestinal TRM cells are not only important for maintaining the integrity of the intestinal epithelial barrier, but also for the rapid clearance of pathogens in the intestine during infection. Understanding the signals received by the intestinal immune system to generate TRM responses is paramount to elucidating treatments for CD. Genetic mutations in NOD2 are associated with the highest risk of CD development. As a host intracellular sensor of bacterial peptidoglycan, NOD2 is critical for initiating both innate and adaptive immune responses. Furthermore, work from our lab as well as those of our collaborators suggest that NOD2 deficiency reduces systemic memory B and T-cell responses. However, the role of NOD2 in establishing memory T-cell responses in the intestine remains unclear. This work will therefore establish the role of NOD2 signaling in initiating and maintaining optimal TRM responses to achieve intestinal homeostasis and resilience to intestinal inflammation. Purpose It is the main objective of this project to determine whether NOD2-mediated signalling affects: 1. Antigen-specific T-cell priming in vivo 2. Bona fide intestinal TRM generation 3. Bona fide intestinal TRM function Method To address the effects of NOD2-signalling on intestinal T-cell priming in vivo, wildtype (WT) mice were adoptively transferred 50,000 naïve LCMV-specific (SMARTA) CD4+ T-cells. Mice were subsequently infected with LCMV-Armstrong in the presence or absence of the NOD2 agonist; MDP. 5-days following infection, the numbers and percentage of LCMV-specific T-cells in the mesenteric lymph nodes and spleen were examined. To examine the effects of NOD2 on intestinal TRM generation, littermate WT and NOD2 KO mice were infected with LCMV-Armstrong. Thirty-six-days following infection, the percentage and number of LCMV-specific CD4+ T-cells were profiled in the small and large intestinal lamina-propria by means of gp66-77 class-II MHC-tetramer staining. In another set of experiments, littermate WT and NOD2 KO mice were re-infected with LCMV-C13 30-days following LCMV-Armstrong immunization, and the interferon-response in the small intestine was profiled by quantitative PCR to assess the effect of NOD2-deficiency on antigen recall responses. Result(s) NOD2-stimulation by means of MDP injection increased the percentage and number of adoptively transferred SMARTA CD4+ T-cells in the mesenteric lymph nodes upon LCMV infection. Furthermore, NOD2-deficiency did not alter intestinal LCMV-specific CD4+ TRM seeding in the small and large intestinal lamina propria 36 days after infection. However, in vivo antigen recall experiments showed a decreased intestinal IFN response in NOD2 KO mice. Conclusion(s) Our findings reveal a potential role of NOD2 in the intestinal CD4+ T-cell priming and subsequent Ag-specific memory response. Disclosure of Interest None Declared

Retinoic acid signaling during priming licenses intestinal CD103+ CD8 TRM cell differentiation.

CD8 tissue-resident memory T (TRM) cells provide frontline protection at barrier tissues; however, mechanisms regulating TRM cell development are not completely understood. Priming dictates the migration of effector T cells to the tissue, while factors in the tissue induce in situ TRM cell differentiation. Whether priming also regulates in situ TRM cell differentiation uncoupled from migration is unclear. Here, we demonstrate that T cell priming in the mesenteric lymph nodes (MLN) regulates CD103+ TRM cell differentiation in the intestine. In contrast, T cells primed in the spleen were impaired in the ability to differentiate into CD103+ TRM cells after entry into the intestine. MLN priming initiated a CD103+ TRM cell gene signature and licensed rapid CD103+ TRM cell differentiation in response to factors in the intestine. Licensing was regulated by retinoic acid signaling and primarily driven by factors other than CCR9 expression and CCR9-mediated gut homing. Thus, the MLN is specialized to promote intestinal CD103+ CD8 TRM cell development by licensing in situ differentiation.

Damage-induced NAD release activates intestinal CD4+ and CD8+ T cell via P2X7R signaling

BackgroundPostoperative ileus (POI) is characterized by the activation of inflammation triggered by tissue damage. Damage-associated molecular patterns (DAMPs) reportedly induce local inflammation after injury. However, the impact of DAMPs on intestinal resident lymphocytes during POI remains poorly elucidated. MethodsPOI in mice was induced via intestinal manipulation (IM). The concentration of nicotinamide adenine dinucleotide (NAD) was detected after IM. The gastrointestinal motility of the mice was assessed after IM or NAD injection. Cytokine production and calcium influx in T cells were investigated after NAD stimulation using flow cytometry. ResultsThe concentration of extracellular NAD significantly increased after IM administration, and NAD directly impaired gastrointestinal motility. Intraperitoneal injection of NAD promoted the expression of TNF-α in intestinal CD8+ and CD4+ T cells, but only IFN-γ production by CD8+ T cells was significantly promoted by NAD injection. Granzyme B production in CD8+ and CD4+ T cells decreased after administration. Concordantly, the same results were observed in NAD stimulation of intestinal CD3+ T cells in vitro. Blocking the P2X7R-related membrane enzyme ART2.2 significantly diminished the pro-inflammatory effect of NAD. ConclusionIM includes the release of NAD derived from damaged tissues, consequently promoting pro-inflammatory cytokine production in intestinal CD4+ and CD8+ T lymphocytes. NAD-induced intestinal T cells activation may be associated with POI progression in the mouse.

REPOGRAMING OF THE INTESTINAL IMMUNE CELL COMPARTMENT DEFINES THE RESPONSE TO AUTOLOGOUS STEM CELL TRANSPLANTATION IN CROHNS DISEASE

Abstract INTRODUCTION For the treatment of refractory Crohn’s disease (CD) autologous stem cell transplant (auto-SCT) is unparalleled in its ability to induce clinical and endoscopic remission.(1, 2) Auto-SCT is unique as a cellular therapy aimed to reset immune pathophysiology to a pre-disease state using hematopoietic stem cells. As such, the study of how the immune system responds to auto-SCT will provide unique insight into CD pathogenesis and treatment. To date, no studies in any cohort have defined the mucosal and peripheral immune response to auto-SCT. Here we report initial studies of high dimensional immune phenotyping of patients with CD during auto-SCT. METHODS Patients with CD were enrolled in a Phase IIa study of auto-SCT (NCT03219359). 14 patients were transplanted (2018-2022). Paired blood and intestinal samples were taken prior to transplant and 6 months post-transplant. Fresh leukocytes were isolated and analyzed by mass cytometry (CyTOF). Supervised clustering of immune cell populations using canonical markers was performed in parallel with unsupervised clustering by FlowSOM.(3) RESULTS After 6 months post-transplant,12/13 patients had an endoscopic response (↓SES-CD by 50%) and 10/13 patients were in endoscopic remission (SES-CD<4). Supervised clustering of major immune cell subsets demonstrated distinct site-specific responses to transplant in myeloid and lymphoid cell populations (Fig 1). Naïve CD4+ and CD8+ T cells universally decrease in number at 6 months post-transplant whereas all other B and T cell populations have discordant changes in the blood and intestine, especially naïve and transitional CD27- B cell populations which significantly increase in blood and decrease in the intestine. CD14+ populations are universally increased in number post-transplant with a specific increase in CD14+ CD206+ macrophages in the intestine. Unsupervised clustering of blood and intestinal immune cells resolve 100 cell clusters that correlate with canonical immune cell markers (Fig 2). Unsupervised analysis further highlights a significant increase in multiple intestinal CD14+CD206+ immune cell populations reflecting newly arrived and/or differentiating and mature monocyte derived macrophages. Principal component and hierarchical clustering analyses of immune cell clusters suggest a reprograming of the intestinal immune compartment post-transplant whereas changes in circulating immune cells populations fail to separate the pre and post-transplant states. CONCLUSION We demonstrate for the first time differences in the intestinal and peripheral immune response to auto-SCT. These studies highlight the changes in intestinal immune cell networks that define the transplant response perhaps through CD14+ cells.

Intrinsic STING Switches off Pathogenetic Programs of Th1 Cells to Inhibit Colitis

Background & AimsT helper 1 (Th1) effector cells are implicated in inflammatory bowel disease. The stimulator of interferon genes (STING), an intracellular DNA sensor, has been shown to regulate infection and various cancers. However, whether and how intrinsic STING signaling in Th1 cells regulates colitis is still unknown. MethodsDextran sodium sulfate–induced colitis and wild-type/STING-deficient CD4+T cell adoptive transfer models were used to analyze the role of STING in regulating colitis. The effect of STING on Th1 cells was determined by flow cytometry, RNA sequencing, metabolic assays, and mitochondrial functions. 16S ribosomal RNA sequencing and germ-free mice were used to investigate whether the microbiota were involved. The in vivo effect of STING agonist in murine colitis was determined. The expression and role of STING in human T cells were also determined. ResultsActivation of STING transformed proinflammatory IFNγ+Th1 cells into IL-10+IFNγ+Th1 cells, which were dramatically less pathogenic in inducing colitis. STING promoted Th1 interleukin (IL)-10 production by inducing STAT3 translocation into nuclear and mitochondria, which promoted Blimp1 expression and mitochondrial oxidation, respectively. Blockade of glucose or glutamine-derived oxidation, but not lipid-derived oxidation, suppressed STING induction of IL-10. Gut microbiota were changed in STING–/– mice, but the altered microbiota did not mediate STING effects on intestinal CD4+T cell production of IL-10. Translationally, STING agonists suppressed both acute and chronic colitis. Intestinal STING+ CD4+T cells were increased in inflammatory bowel disease patients, and STING agonists upregulated IL-10 production in human CD4+T cells. ConclusionsThese findings establish a crucial role of T cell–intrinsic STING in switching off the pathogenic programs of Th1 cells in intestinal inflammation.

The aryl hydrocarbon receptor cell intrinsically promotes resident memory CD8+ T cell differentiation and function

The Aryl hydrocarbon receptor (Ahr) regulates the differentiation and function of CD4+ Tcells; however, its cell-intrinsic role in CD8+ Tcells remains elusive. Herein we show that Ahr acts as a promoter of resident memory CD8+ Tcell (TRM) differentiation and function. Genetic ablation of Ahr in mouse CD8+ Tcells leads to increased CD127-KLRG1+ short-lived effector cells and CD44+CD62L+ T central memory cells but reduced granzyme-B-producing CD69+CD103+ TRM cells. Genome-wide analyses reveal that Ahr suppresses the circulating while promoting the resident memory core gene program. A tumor resident polyfunctional CD8+ Tcell population, revealed by single-cell RNA-seq, is diminished upon Ahr deletion, compromising anti-tumor immunity. Human intestinal intraepithelial CD8+ Tcells also highly express AHR that regulates invitro TRM differentiation and granzyme B production. Collectively, these data suggest that Ahr is an important cell-intrinsic factor for CD8+ Tcell immunity.

A randomized, double-blind, placebo-controlled, Phase 1/2a trial protocol to assess the safety and efficacy of TAK-101 administered by microneedles in patients with celiac disease

Introduction: Celiac disease (CD) affects 0.2 to 2.0% of the worldwide population, causing significant enteropathy and systemic symptoms. There is no effective treatment for CD, and patients must follow a strict gluten-free diet lifelong. Recent studies investigated the efficacy of the non-immunosuppressive agent TAK-101 delivered intravenously in reducing immunological response to gluten in CD patients. However, no study has evaluated transdermal delivery, which initiates different immunological pathways. Objective: In a population of CD patients, we aim to assess the safety and pharmacokinetics of TAK-1 delivered by a Hollow Microstructured Transdermal microneedle (MN) (Phase 1) and the efficacy of MN-TAK-101 compared to placebo (Phase 2). Methods: This will be a Phase 1/2a trial lasting 180 days for each phase. Phase 1 will be an open-label, 2-part multicenter study: 1A, a group of patients will be divided into escalating dose cohorts. While, in 1B, another group of patients will be divided into repeated ascending dose cohorts until the maximum tolerated dose is reached. Phase 2 will be a double-blind multicentered randomized (stratified, block) placebo-controlled trial comparing TAK-101 and placebo, using different subjects than those in Phase 1. The primary outcome is the change in Interferon-γ production from baseline after MN-TAK-101 or MN-placebo administration. Secondary outcomes will assess the changes in the ratio of villous height to crypt depth, in the number of intestinal intraepithelial lymphocytes, in CD4, CD8, and γδ cells frequency, in the Celiac symptom index-modified questionnaire and safety measurements. The sample size is between 27-49 patients for phases 1A and 1B; 76 patients in phase 2. For statistical analysis, only descriptive analysis will be done for phase 1, while for Phase 2, the choice of parametric vs. nonparametric tests will be considered according to the normality of the data. This is a first Phase 1/2a placebo control randomized trial to assess the safety and efficacy of TAK-101 applied transdermally for patients with celiac disease. Keywords: Celiac Disease; TAK-101; Microneedle; Gluten intolerance; Gluten desensitization.

CDC1-derived IL-27 regulates small intestinal CD4+ T cell homeostasis in mice.

The small intestinal lamina propria contains large numbers of IFNγ-producing T helper (Th1) cells that play important roles in intestinal homeostasis and host defense, but the mechanisms underlying their development remain poorly understood. Here, we demonstrate that Th1 cells accumulate in the SI-LP after weaning and are maintained there long term. While both Th17 and Th1 cell accumulation in the SI-LP was microbiota dependent, Th1 cell accumulation uniquely required IL-27 and MHCII expression by cDC1. This reflected a requirement for IL-27 signaling in the priming of Th1 cells rather than for their maintenance once in the mucosa. cDC1-derived IL-27 was essential for maintaining the Th1-Th17 balance within the SI-LP, and in its absence, remaining Th1 cells expressed enhanced levels of Th17 signature genes. In conclusion, we identify cDC1-derived IL-27 as a key regulator of SI-LP Th1-Th17 cell homeostasis.

Secondary infections rejuvenate the intestinal CD103+ tissue-resident memory T cell pool.

Resident T lymphocytes (TRM) protect tissues during pathogen reexposure. Although TRM phenotype and restricted migratory pattern are established, we have a limited understanding of their response kinetics, stability, and turnover during reinfections. Such characterizations have been restricted by the absence of in vivo fate-mapping systems. We generated two mouse models, one to stably mark CD103+ T cells (a marker of TRM cells) and the other to specifically deplete CD103- T cells. Using these models, we observed that intestinal CD103+ T cells became activated during viral or bacterial reinfection, remained organ-confined, and retained their original phenotype but failed to reexpand. Instead, the population was largely rejuvenated by CD103+ T cells formed de novo during reinfections. This pattern remained unchanged upon deletion of antigen-specific circulating T cells, indicating that the lack of expansion was not due to competition with circulating subsets. Thus, although intestinal CD103+ resident T cells survived long term without antigen, they lacked the ability of classical memory T cells to reexpand. This indicated that CD103+ T cell populations could not autonomously maintain themselves. Instead, their numbers were sustained during reinfection via de novo formation from CD103- precursors. Moreover, in contrast to CD103- cells, which require antigen plus inflammation for their activation, CD103+ TRM became fully activated follwing exposure to inflammation alone. Together, our data indicate that primary CD103+ resident memory T cells lack secondary expansion potential and require CD103- precursors for their long-term maintenance.

CD103 fate mapping reveals that intestinal CD103- tissue-resident memory T cells are the primary responders to secondary infection.

Tissue-resident memory T (TRM) cells remain poised in the tissue and mediate robust protection from secondary infection. TRM cells within the intestine and other tissues are heterogeneous in their phenotype and function; however, the contributions of these TRM subsets to secondary infection remain poorly defined. To address the plasticity of intestinal TRM subsets and their role in local and systemic immunity, we generated mice to fate map intestinal CD103+ TRM cells and track their location and function during secondary infection with Yersinia pseudotuberculosis. We found that CD103+ TRM cells remained lodged in the tissue and were poorly reactivated during secondary challenge. CD103- TRM cells were the primary responders to secondary infection and expanded within the tissue, with limited contribution from circulating memory T cells. The transcriptional profile of CD103- TRM cells demonstrated maintenance of a gene signature similar to circulating T cells along with increased cytokine production and migratory potential. CD103- TRM cells also expressed genes associated with T cell receptor (TCR) activation and displayed enhanced TCR-mediated reactivation both in vitro and in vivo compared with their CD103+ counterparts. These studies reveal the limited recall potential of CD103+ TRM subsets and the role of CD103- TRM cells as central memory-like T cells within peripheral tissues.

Gutsy memory T cells stand their ground against pathogens.

Elegant fate-mapping models to label intestinal tissue-resident memory CD8+ T (TRM) cells demonstrate retention and lack of expansion of CD103+ TRM cells, whereas intestinal CD103- memory cells expand, forming both new tissue-localized CD103+ and CD103- TRM cells (see related Research Articles by Fung etal. and von Hoesslin etal.).

Hedgehog blockade remodels the gut microbiota and the intestinal effector CD8+ T cells in a mouse model of mammary carcinoma

AbstractGiven the gut microbiome's rise as a potential frontier in cancer pathogenesis and therapy, leveraging microbial analyses in the study of breast tumor progression and treatment could unveil novel interactions between commensal bacteria and disease outcomes. In breast cancer, the Hedgehog (Hh) signaling pathway is a potential target for treatment due to its aberrant activation leading to poorer prognoses and drug resistance. There are limited studies that have investigated the influences of orally administered cancer therapeutics, such as Vismodegib (a pharmacological, clinically used Hh inhibitor) on the gut microbiota. Using a 4T1 mammary carcinoma mouse model and 16 S rRNA sequencing, we longitudinally mapped alterations in immunomodulating gut microbes during mammary tumor development. Next, we identified changes in the abundance of commensal microbiota in response to Vismodegib treatment of 4T1 mammary tumor-bearing mice. In addition to remodeling gut microbiota, Vismodegib treatment elicited an increase in proliferative CD8+ T cells in the colonic immune network, without any remarkable gastrointestinal-associated side effects. To our knowledge, this is the first study to assess longitudinal changes in the gut microbiome during mammary tumor development and progression. Our study also pioneers an investigation of the dynamic effects of an orally delivered Hh inhibitor on the gut microbiome and the gut-associated immune-regulatory adaptive effector CD8+ T cells. These findings inform future comprehensive studies on the consortium of altered microbes that can impact potential systemic immunomodulatory roles of Vismodegib.

Rewiring the altered tryptophan metabolism as a novel therapeutic strategy in inflammatory bowel diseases

ObjectiveThe extent to which tryptophan (Trp) metabolism alterations explain or influence the outcome of inflammatory bowel diseases (IBDs) is still unclear. However, several Trp metabolism end-products are essential to intestinal...