Differential Pathogenic Th17 Profile in Mesenteric Lymph Nodes of Crohn's Disease and Ulcerative Colitis Patients

Are single nucleotide polymorphisms underutilized for guiding treatment of inflammatory bowel disease?

Inflammatory bowel disease (IBD), encompassing Crohn's disease (CD), ulcerative colitis (UC) and IBD unclassified (IBDU), significantly impacts quality of life. Despite significant advances in the management of the conditions, responses to treatments vary greatly, and this is due partly to our natural genetic variation. Here we will review the evidence for whether single nucleotide polymorphisms (SNPs) have the potential to guide treatment decisions for people with IBD. We will first consider SNPs that exhibit strong associations with IBD pathogenesis and their relevance to epithelial barrier integrity, cytokine production, and immune system function. Then, we will cover those SNPs implicated in altering response to our various current IBD therapeutics, including the recently implemented drugs ustekinumab and tofacitinib. Finally, we will explore lesser-known SNPs that exhibit complex relationships with the disease and which may be undervalued as pharmacogenetic tools. Overall, it will be demonstrated that SNPs associated with IBD pathology are largely distinct from those predicting response to treatments and that new discoveries of clinically useful tools can be expected from therapy-focused investigations. Given the growing list of treatments available, we argue that beneficial personalization of treatments based on SNPs is still underutilized.

Shared genetic association between inflammatory bowel disease and acute myeloid leukemia: insights from mendelian randomization and transcriptomic analyses

BACKGROUND

Observational studies suggest that a history of inflammatory bowel disease (IBD) is associated with the onset of acute myeloid leukemia (AML), often attributed to drug use. However, these findings are inconsistent. This study aimed to assess the causal relationship between IBD and AML, identify shared pathogenesis, and discover diagnostic and prognostic markers and potential therapeutic drugs.

METHODS

Two-sample Mendelian randomization (MR) was employed to analyze genetic associations between IBD [ulcerative colitis (UC) and Crohn's disease (CD)] and AML. Transcriptomic data from gene expression omnibus (GEO) identified differentially expressed genes (DEGs) in UC, AML, and controls. Weighted Gene Co-expression Network Analysis (WGCNA) and enrichment analyses [Gene Multiple Association Network Integration Algorithm (GeneMANIA), Kyoto Encyclopedia of Genes and Genomes (KEGG), Ractom pathway] and Gene Ontology (GO) explored shared genetic pathways. Receiver Operating Characteristic (ROC) curve and survival analyses screened diagnostic and prognostic markers. Cibersort and GSVA were employed to analyze the proportion of immune cells in UC and AML datasets, as well as to assess the association of specific genes with immune infiltration. The Drug Signatures Database (DSigDB) and Autodock molecular docking identified potential therapeutic small molecules.

RESULTS

MR analysis revealed a causal association between UC and the onset of AML. Differential expression and WGCNA analyses identified 23 co-driver genes regulated by Signal Transducer and Activator of Transcription 3 (STAT3) and Activating Transcription Factor 4 (AFT4), enriched in immune, inflammatory, and cell proliferation pathways. Tissue Inhibitor of Metalloproteinases 1 (TIMP1) and F2R-Like Trypsin Receptor 1 (F2RL1) were identified as practical diagnostic and prognostic markers for AML, with high TIMP1 and low F2RL1 expression promoting an immunosuppressive and inflammatory tumor microenvironment. Quercetin was identified as a promising candidate for UC-associated AML.

CONCLUSIONS

UC is a risk factor for AML pathogenesis. TIMP1 and F2RL1 are diagnostic and prognostic markers for UC-associated AML, potentially facilitating AML development through sustained inflammation and an immunosuppressive tumor microenvironment. Quercetin, a potential TIMP1 and F2RL1 inhibitor, may mitigate UC-AML transformation, providing insights into UC management, AML monitoring, and preventive therapy development.

Natural products for the treatment of ulcerative colitis: focus on the JAK/STAT pathway

Ulcerative colitis (UC) is an autoimmune disease with an incompletely understood pathogenesis. The Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathway plays a key role in immune response and inflammation. More and more studies demonstrated that JAK/STAT signaling pathway is associated with the pathogenesis of UC. The JAK/STAT pathway affects UC in multiple ways by regulating intestinal inflammatory response, affecting intestinal mucosal barrier, modulating T cell homeostasis, and regulating macrophages. Encouragingly, natural products are promising candidates for the treatment of UC. Natural products have the advantage of being multi-targeted and rich in therapeutic modalities. This review summarized the research progress of JAK/STAT pathway-mediated UC. Furthermore, the latest studies on natural products targeting the JAK/STAT pathway for the treatment of UC were systematically summarized, including active ingredients such as arbutin, aloe polysaccharide, berberine, matrine, curcumin, Ginsenoside Rh2, and so on. The aim of this paper is to provide new ideas for drug development to regulate JAK/STAT signaling for treating UC.

Single-Cell Transcriptomic Profile of Innate Cell Populations in Mesenteric Lymph Nodes of Inflammatory Bowel Disease Patients

BACKGROUND AND AIMS

Innate immune cells, including dendritic cells (DCs), monocytes (Mono), macrophages (Mac), natural killer (NK), and innate lymphoid cells (ILC), contribute to chronic inflammation in lymphoid tissues. Here, we characterized the innate immune cell landscape in inflamed mesenteric lymph nodes (MLNs) of patients with inflammatory bowel diseases (IBD) at the single-cell level.

METHODS

Surgically resected colonic MLNs were obtained from patients with Crohn's disease (CD; n = 3), ulcerative colitis (UC; n = 3), non-inflamed UC (n = 1), and non-IBD (n = 2). CD45+CD3-CD19- non-T/non-B cells were FACS-sorted to capture rare innate immune cells. Cellular Indexing of Transcriptomes and Epitopes by Sequencing (CITE-seq) was performed on the BD Rhapsody platform alongside multiparameter flow cytometry staining.

RESULTS

CITE-seq analysis unveiled the molecular signature of 11 Mono/Mac/DC (MMDC) and 7 NK/ILC enriched clusters in human MLNs. DC clusters included 3 newly characterized DC clusters such as CD1c/CD163/VCAN/CD64-expressing DC3; AXL-expressing DCs; and a CD103+ DC subset, expressing LTB, S100B, and IL22RA2 (encoding IL22BP). Mono/Mac clusters comprised inflammatory monocytes, which accumulated in IBD compared to non-IBD MLNs. Among NK/ILC clusters, we identified a cytotoxic ILC subset (IL7R, KLRD1, GNLY), previously not reported in MLNs, reminiscent of cytotoxic ILC1-like cells found in inflamed gut mucosa.

CONCLUSION

CITE-seq and flow-cytometry analyses of colonic MLNs from patients with active IBD reveal the molecular signature and cell distribution of previously uncharacterized DC and ILC subpopulations in human MLNs. These findings expand our understanding of immune responses during chronic inflammation in IBD.

Combined plasma protein and memory T cell profiling discern IBD-patient-immunotypes related to intestinal disease and treatment outcomes

Inflammatory bowel disease (IBD) chronicity results from memory T helper cell (Tmem) reactivation. Identifying patient-specific immunotypes is crucial for tailored treatment. We conducted a comprehensive study integrating circulating immune proteins and circulating Tmem, with intestinal tissue histology and mRNA analysis, in therapy-naïve pediatric IBD (Crohn's disease, CD: n = 62; ulcerative colitis, UC: n = 20; age-matched controls n = 43), and after 10-12 weeks' induction therapy. At diagnosis, plasma protein profiles unveiled two UC and three CD clusters with distinct disease courses. UC patients displayed unchanged circulating Tmem, while CD exhibited increased frequencies of gut-homing ex-Th17, known for high IFN-γ production. UC#2 had elevated Th17/neutrophil-pathway-related proteins and severe disease, with higher endoscopic and histological damage and Th17/neutrophil infiltration. Although both UC#1 and UC#2 responded to therapy, UC#2 required earlier immunomodulation. CD#3 had lower plasma protein concentrations, especially IFN-γ pathway proteins, fewer gut-homing ex-Th17 and clinically milder disease, confirmed by intestinal gene expression. CD#1 and CD#2 had comparably high Th1-related immune profiles, but CD#1 exhibited higher concentrations of proteins previously associated with poorer prognosis. Both CD clusters responded to induction therapy, with similar one-year outcomes. This study highlights feasibility of discriminating patient-specific immunotypes in IBD, advancing our understanding of immune pathogenesis, needed for tailored treatment strategies.

Qingchang suppository ameliorates mucosal inflammation in ulcerative colitis by inhibiting the differentiation and effector functions of Th1 and Th17 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Qing Chang Suppository (QCS), a traditional Chinese medicine formula, has been shown to effectively alleviate mucosal inflammation in patients with ulcerative colitis (UC). While the mechanism of QCS appears to be related to the regulation of CD4+T cell subset responses, direct evidence demonstrating that QCS inhibits Th1 and Th17 cell activation in UC (particularly based on human data) remains lacking. Additionally, the precise mechanisms through which QCS affects these cells have yet to be fully elucidated.

AIM OF STUDY

This study aimed to investigate the effects of QCS on Th1 and Th17 cell responses in UC and to explore the underlying mechanisms.

MATERIALS AND METHODS

Twenty-eight patients with mild-to-moderate UC were recruited and treated with QCS for 12 weeks. Symptoms were assessed every two weeks, with sigmoidoscopies performed at baseline and at week 12. Intestinal mucosal biopsies and peripheral blood (PB) were collected at these time points. At the end of the trial, patients were categorized into responder and non-responder groups based on a modified Mayo disease activity index score. Healthy controls (HCs) were defined as subjects without IBD or colorectal carcinoma but with colon polyps. The frequencies of IFN-γ+CD4+T cells and IL-17A+CD4+T cells in PB and colonic mucosa were measured using flow cytometry. The expression levels and localization of T-bet, RORγT, IFN-γ, TNF-α, and IL-17A were determined via immunofluorescence, and JNK signaling activation was assessed through immunoblotting and immunohistochemistry. All parameters were compared across the three groups.

RESULTS

At week 12, responders showed a significant reduction in colonic mucosal inflammation compared to baseline, accompanied by decreased frequencies of IFN-γ+CD4+T and IL-17A+CD4+ T cells in both PB and the colonic epithelial layer. Notably, Th1 and Th17 cell activity around intestinal epithelial cells (IECs) was nearly undetectable, as evidenced by the diminished expression of T-bet, RORγT, IFN-γ, TNF-α, and IL-17A. Additionally, JNK phosphorylation in these cells was significantly reduced. In contrast, non-responders exhibited no meaningful improvement; colonic pathology remained unchanged, and elevated levels of IFN-γ+CD4+T and IL-17A+CD 4+T cells persisted in both the PB and colonic epithelial layer. The presence of Th1 and Th17 cells and their associated cytokines around IECs remained substantial, and there was no significant change in JNK activation.

CONCLUSION

QCS attenuates mucosal inflammation in UC patients by inhibiting the differentiation and effector functions of Th1 and Th17 cells, primarily through the regulation of the JNK signaling pathway.

Gut microbiota and blood biomarkers in IBD-Related arthritis: insights from mendelian randomization

With the ongoing rise in the incidence of inflammatory bowel disease (IBD), its extraintestinal manifestations have garnered significant attention. IBD-related arthritis is notable for its insidious onset and unpredictability, presenting considerable challenges for clinical diagnosis and management. Factors such as gut microbiota, plasma proteins, inflammatory proteins, and biomarkers found in blood and urine may be closely associated with IBD-related arthritis. However, the mechanisms by which these factors influence this condition remain poorly understood and require urgent investigation. We employed the method of linkage disequilibrium and the two-sample Mendelian randomization (MR) approach, utilizing single nucleotide polymorphisms (SNPs) identified from large-scale genome-wide association studies as instrumental variables. In this scientifically rigorous manner, we explored the potential causal relationship between gut microbiota, plasma proteins, inflammatory proteins, and blood and urine biomarkers in relation to arthritis resulting from inflammatory bowel disease (IBD). This method aids in elucidating the potential roles of these biomarkers in the development of arthritis following IBD, while minimizing the confounding factors and reverse causality commonly encountered in observational studies. To further verify and strengthen our findings, we conducted subsequent sensitivity analyses. These analyses will evaluate the strength of the association between SNPs and the studied biomarkers, as well as post-IBD arthritis, while accounting for variations in SNP distribution among populations and other potential genetic influencing factors. Through these rigorous analytical steps, our objective is to enhance the robustness and credibility of the research findings and provide more reliable scientific evidence regarding the pathogenesis of post-IBD arthritis. MR analysis provides evidence for the association between genetically predicted gut microbiota, plasma proteins, inflammatory proteins, and blood and urine biomarkers with the risk of IBD-related arthritis. This analysis investigates the characteristics of the associations between specific gut microbiota, plasma proteins, inflammatory proteins, and blood and urine biomarkers in relation to IBD-related arthritis. Among the plasma proteins, pterin-4-alpha-carbinolamine dehydratase, aldo-keto reductase family 1 member C4, cathepsin L2, angiostatin, hepatocyte growth factor-like protein, hepatitis A virus cellular receptor 2, protein O-linked mannose beta-1,4-N-acetylglucosaminyltransferase 2, epididymal-specific alpha-mannosidase, and platelet-derived growth factor receptor-like protein are associated with Crohn's disease-related arthritis. In contrast, agrin, methylenetetrahydrofolate synthetase domain-containing protein, neurotrophin-3 (NT-3) growth factor receptor, and neuropilin-1 are associated with ulcerative colitis-related arthritis. Furthermore, regarding gut bacterial pathway abundance, adenosylcobalamin, N-acetylglucosamine, N-acetylmannosamine, and N-acetylneuraminic acid degradation, as well as glycolysis metabolism and degradation pathways, are associated with Crohn's disease-related arthritis. Meanwhile, gut bacterial pathway abundance (pentose phosphate pathway) and gut microbiota abundance (Bacteroidetes, Bacteroidia, Bacteroidales, Porphyromonadaceae, Faecalibacterium, Eubacterium eligens) are linked to ulcerative colitis-related arthritis. Notably, we did not identify any connections between inflammatory protein factors, blood and urine biomarkers, and IBD-related arthritis. Lastly, in the reverse MR study, the insufficient number of SNPs available for analysis precluded the detection of a reverse causal relationship. This study employs the MR method to elucidate the potential causal relationships among gut microbiota, plasma proteins, inflammatory proteins, and blood and urine biomarkers in relation to the occurrence and progression of IBD-related arthritis. This research offers a novel perspective for a deeper understanding of the pathogenesis of IBD-related arthritis and highlights future directions for the diagnosis and treatment strategies of this condition.

Curcumin Attenuates Dextran Sodium Sulfate Induced Colitis in Obese Mice

SCOPE

Curcumin (Cur), with diverse pharmacological properties, shows anti-obesity, immunomodulatory, and anti-inflammatory effects. Its role in ulcerative colitis complicated by obesity remains unclear.

METHODS AND RESULTS

Here, colitis is induced in obese mice using dextran sulfate sodium (DSS), followed by administration of Cur at a dosage of 100 mg kg-1 for 14 days. Cur effectively alleviates DSS-induced colitis in obese mice, accompanied by an increase in body weight and survival rate, reduction in disease activity index, elongation of the colon, decrease in colonic weight, and improvements in ulcer formation and inflammatory cell infiltration in colonic tissues. Additionally, Cur effectively improves lipid metabolism and the composition of the gut microbiota, and enhances mucosal integrity and boosts anti-oxidative stress capacity in obese mice with colitis. Importantly, Cur is effective in improving the homeostasis of memory T cells in obese mice with colitis. Furthermore, Cur regulates inflammatory cytokines expression and inhibits activation of the JAK2/STAT signaling pathway in colonic tissues of obese mice with colitis.

CONCLUSIONS

Cur alleviates colitis in obese mice through a comprehensive mechanism that improves lipid metabolism, modulates gut microbiota composition, enhances mucosal integrity and anti-oxidative stress, balances memory T cell populations, regulates inflammatory cytokines, and suppresses the JAK2/STAT signaling pathway.

Gut instinct: harnessing the power of probiotics to tame pathogenic signaling pathways in ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) marked by persistent inflammation of the mucosal lining of the large intestine, leading to debilitating symptoms and reduced quality of life. Emerging evidence suggests that an imbalance of the gut microbiota plays a crucial role in UC pathogenesis, and various signaling pathways are implicated in the dysregulated immune response. Probiotics are live microorganisms that confer health benefits to the host, have attracted significant attention for their potential to restore gut microbial balance and ameliorate inflammation in UC. Recent studies have elucidated the mechanisms by which probiotics modulate these signaling pathways, often by producing anti-inflammatory molecules and promoting regulatory immune cell function. For example, probiotics can inhibit the nuclear factor-κB (NF-κB) pathway by stabilizing Inhibitor of kappa B alpha (IκBα), dampening the production of proinflammatory cytokines. Similarly, probiotics can modulate the Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway, suppressing the activation of STAT1 and STAT3 and thus reducing the inflammatory response. A better understanding of the underlying mechanisms of probiotics in modulating pathogenic signaling pathways in UC will pave the way for developing more effective probiotic-based therapies. In this review, we explore the mechanistic role of probiotics in the attenuation of pathogenic signaling pathways, including NF-κB, JAK/STAT, mitogen-activated protein kinases (MAPKs), Wnt/β-catenin, the nucleotide-binding domain (NOD)-, leucine-rich repeat (LRR)- and pyrin domain-containing protein 3 (NLRP3) inflammasome, Toll-like receptors (TLRs), interleukin-23 (IL-23)/IL-17 signaling pathway in UC.

Targeting Inflammatory Lesions Facilitated by Galactosylation Modified Delivery System Eudragit/Gal-PLGA@Honokiol for the treatment of Ulcerative Colitis

Honokiol (HNK) is one of the bioactive ingredients from the well-known Chinese herbal medicine Magnolia officinalis, and its research interests is rising for its extensive pharmacological activities, including novel therapeutic effect on ulcerative colitis (UC). However, further application of HNK is largely limited by its unique physicochemical properties, such as poor water solubility, low bioavailability, as well as unsatisfied targeting efficacy for inflammatory lesions. In this study, we constructed galactosylation modified PLGA nanoparticles delivery system for efficient target delivery of HNK to the colitic lesions, which could lay a research foundation for the deep development of HNK for the treatment of UC. D-galactose was grafted by chemical coupling reactions with PLGA to prepare Gal-PLGA, which was used as a carrier for HNK (Gal-PLGA@HNK nanoparticles (NPs)). To improve the colon targeting efficiency by oral administration of the NPs, Eudragit S100 was used for wrapping on the surface of Gal-PLGA@HNK NPs (E/Gal-PLGA@HNK NPs). Our results showed that the encapsulation efficiency and drug loading capacity of E/Gal-PLGA@HNK NPs were 90.72 ± 0.54% and 8.41 ± 0.02%, respectively. Its average particle size was 242.24 ± 8.42 nm, with a PDI value of 0.135 ± 0.06 and zeta-potential of -16.83 ± 1.89 mV. The release rate of HNK from E/Gal-PLGA@HNK NPs was significantly decreased when compared with that of free HNK in simulated gastric and intestinal fluids, which displayed a slow-releasing property. It was also found that the cellular uptake of E/Gal-PLGA@HNK NPs was significantly increased when compared with that of free HNK in RAW264.7 cells, which was facilitated by D-galactose grafting on the PLGA carrier. Additionally, our results showed that E/Gal-PLGA@HNK NPs significantly improved colonic atrophy, body weight loss, as well as reducing disease activity index (DAI) score and pro-inflammatory cytokine levels in UC mice induced by DSS. Besides, the retention time of E/Gal-PLGA@HNK NPs in the colon was significantly increased when compared with that of other preparations, suggesting that these NPs could prolong the interaction between HNK and the injured colon. Taken together, the efficiency for target delivery of HNK to the inflammatory lesions was significantly improved by galactosylation modification on the PLGA carrier, which provided great benefits for the alleviation of colonic inflammation and injury in mice.

Ustekinumab Decreases Circulating Th17 Cells in Ulcerative Colitis

Objective T helper (Th) cells play a central role in the pathogenesis of ulcerative colitis (UC). The present study analyzed the changes in circulating T cells by administration of ustekinumab (UST), an interleukin-12/23p40 antibody. Methods CD4 T cells were isolated from peripheral blood at 0 and 8 weeks after UST treatment, and we analyzed the proportion of CD4 T cells by flow cytometry. Clinical information and laboratory data were obtained at 0, 8, and 16 weeks. Patients We evaluated 13 patients with UC who received UST for the induction of remission between July 2020 and August 2021. Results The median partial Mayo score improved from 4 (1-7) to 0 (0-6) (p<0.001) with UST. Among serological parameters, albumin concentrations, C-reactive protein concentrations, the sedimentation rate, and leucine-rich alpha 2 glycoprotein concentrations showed significant improvement with UST. A flow cytometric analysis of circulating CD4 T cells showed that the percentage of Th17 cells was significantly decreased by UST treatment in all patients (1.85% to 0.98%, p<0.0001). Th1 cells were significantly increased by UST treatment (9.52% to 10.4%, p<0.05), but Th2 and regulatory T cells were not significantly different. The high-Th17 subgroup had a significantly better partial Mayo score than the low-Th17 subgroup at 16 weeks after UST treatment (0 vs. 1, p=0.028). Conclusion Treatment with UST decreases circulating Th17 cells, suggesting that this change may be related to the anti-inflammatory effect of UC.

Astragalus Polysaccharide Alleviates Ulcerative Colitis by Regulating the Balance of mTh17/mTreg Cells through TIGIT/CD155 Signaling

The balance between memory Th17 cells (mTh17) and memory Treg cells (mTreg) plays a key role in the pathogenesis of ulcerative colitis (UC), and TIGIT signaling is involved in the differentiation of mTh17/mTreg cells. Astragalus polysaccharide (APS) has good immunomodulatory and anti-inflammatory effects. Here, the regulatory effects and potential mechanisms of APS on mTh17/mTreg cells in UC are explored. A UC model was induced with dextran sulfate sodium (DSS) and treated simultaneously with APS (200 mg/kg/day) for 10 days. After APS treatment, the mice showed a significant increase in colonic length and a significant decrease in colonic weight, colonic weight index and colonic weight/colonic length, and more intact mucosa and lighter inflammatory cell infiltration. Notably, APS significantly down-regulated the percentages of Th17 (CD4+CCR6+), cmTh17 (CD4+CCR7+CCR6+) and emTh17 (CD4+CCR7-CCR6+) cells and significantly up-regulated the percentages of cmTreg (CD4+CCR7+Foxp3+) and emTreg (CD4+CCR7-Foxp3+) cells in the mesenteric lymph nodes of the colitis mice. Importantly, APS reversed the expression changes in the TIGIT molecule on mTh17/mTreg cells in the colitis mice with fewer CD4+CCR6+TIGIT+, CD4+CCR7-CCR6+TIGIT+ and CD4+CCR7-CCR6+TIGIT+ cells and more CD4+Foxp3+TIGIT+, CD4+CCR7-Foxp3+TIGIT+ and CD4+CCR7-Foxp3+TIGIT+ cells. Meanwhile, APS significantly inhibited the protein expression of the TIGIT ligands CD155, CD113 and CD112 and downstream proteins PI3K and AKT in the colon tissues of the colitis mice. In conclusion, APS effectively alleviated DSS-induced UC in mice by regulating the balance between mTh17/mTreg cells, which was mainly achieved through regulation of the TIGIT/CD155 signaling pathway.

The chromatin and single-cell transcriptional landscapes of CD4 T cells in inflammatory bowel disease link risk loci with a proinflammatory Th17 cell population

Introduction

The imbalance between Th17 and regulatory T cells in inflammatory bowel diseases (IBD) promotes intestinal epithelial cell damage. In this scenario, T helper cell lineage commitment is accompanied by dynamic changes to the chromatin that facilitate or repress gene expression.

Methods

Here, we characterized the chromatin landscape and heterogeneity of intestinal and peripheral CD4 T cellsfrom IBD patients using in house ATAC-Seq and single cell RNA-Seq libraries.

Results

We show that chromatin accessibility profiles of CD4 T cells from inflamed intestinal biopsies relate to genes associated with a network of inflammatory processes. After integrating the chromatin profiles of tissue-derived CD4 T cells and in-vitro polarized CD4 T cell subpopulations, we found that the chromatin accessibility changes of CD4 T cells were associated with a higher predominance of pathogenic Th17 cells (pTh17 cells) in inflamed biopsies. In addition, IBD risk loci in CD4 T cells were colocalized with accessible chromatin changes near pTh17-related genes, as shown in intronic STAT3 and IL23R regions enriched in areas of active intestinal inflammation. Moreover, single cell RNA-Seq analysis revealed a population of pTh17 cells that co-expresses Th1 and cytotoxic transcriptional programs associated with IBD severity.

Discussion

Altogether, we show that cytotoxic pTh17 cells were specifically associated with IBD genetic variants and linked to intestinal inflammation of IBD patients.

Altered Phenotypes of Colonic and Peripheral Blood Follicular Helper and Follicular Cytotoxic T Cells in Mice with DSS-Induced Colitis

Background

Follicular helper T (Tfh), follicular regulatory T (Tfr), and follicular cytotoxic T (Tfc) cells play important roles in autoimmune diseases. Nevertheless, their changes of functional phenotypes in ulcerative colitis (UC), most importantly, their changes in colon tissue as the target-organ, have not been explored.

Methods

DSS-colitis was induced in Balb/c mice and lymphocytes were collected from spleen, mesenteric lymph nodes, peripheral blood and colon. Tfh, Tfr, and Tfc cells were analyzed using flow cytometry based on their CD4+CXCR5+FOXP3-Tfh, CD4+CXCR5+FOXP3+Tfr and CD8+CXCR5+Tfc expressions. Various functional characterization markers including CD44, CD62L, TIGIT, CD226, PD-1, ICOS, Helios, CTLA-4 and Bcl6 were analyzed in the T cell subsets of the organs.

Results

Tfh and Tfr cells in the colon were significantly increased in DSS-colitis mice. Additionally, the proportions of Tfr and Tfc cells in the peripheral blood were also increased, while Tfc cell proportions in the colon were decreased. The proportion of naïve cells in the Tfh, Tfr and Tfc cells in the colon and peripheral blood decreased, while the proportion of effector memory T cells increased. The TIGIT+CD226-Tfh and Tfc cells were upregulated in the colon of DSS-colitis mice. The PD-1+, ICOS+ and PD-1+ICOS+ Tfh cells were increased in both the colonic and peripheral blood Tfh and Tfc of DSS-colitis mice. The Bcl6+ proportions in the Tfh and Tfr were increased in the colon of DSS-colitis mice.

Conclusion

The colonic and peripheral blood Tfh and Tfc cells of DSS-colitis mice have a significantly activated T cell phenotype, which may play a significant role in the pathogenesis of UC.

The role of Th17 cells in inflammatory bowel disease and the research progress

Th17 cells play an important role in the abnormal immune response in inflammatory bowel disease (IBD) and are involved in the development and progression of inflammation and fibrosis. An increasing amount of data has shown that gut microbes are important parts of intestinal immunity and regulators of Th17 cellular immunity. Th17 cell differentiation is regulated by intestinal bacteria and cytokines, and Th17 cells regulate the intestinal mucosal immune microenvironment by secreting cytokines, such as IL-17, IL-21, and IL-26. Solid evidence showed that, regarding the treatment of IBD by targeting Th17 cells, the therapeutic effect of different biological agents varies greatly. Fecal bacteria transplantation (FMT) in the treatment of IBD has been a popular research topic in recent years and is safe and effective with few side effects. To further understand the role of Th17 cells in the progression of IBD and associated therapeutic prospects, this review will discuss the progress of related research on Th17 cells in IBD by focusing on the interaction and immune regulation between Th17 cells and gut microbiota.

Therapeutic targets and pharmacological mechanisms of Coptidis Rhizoma against ulcerative colitis: Findings of system pharmacology and bioinformatics analysis

Evidence of the advantages of Coptidis Rhizoma (CR) for the treatment of ulcerative colitis (UC) is accumulating. However, research revealing the targets and molecular mechanisms of CR against UC is scarce. In this research, a bioinformatics analysis was performed to carry out the physicochemical properties and biological activities of phytochemicals in CR and analyze the binding activities, targets, biological functions and mechanisms of CR against UC. This research shows that the CR's key phytochemicals, which are named Coptisine, Berberrubine, Berlambine, Berberine, Epiberberine, Obacunone, Worenine, Quercetin, (R)-Canadine, Magnograndiolide, Palmatine and Moupinamide, have ideal physicochemical properties and bioactivity. A total of 1,904 potential phytochemical targets and 17,995 UC-related targets are identified, and we finally acquire 233 intersection targets between key phytochemicals and disease. A protein-protein interaction network of 233 common targets was constructed; and six hub targets were acquired with a degree greater than or equal to median, namely TP53, HSP90AA1, STAT3, ESR1, MYC, and RELA. The enrichment analysis suggested that the core targets may exert an impact on anti-inflammatory, immunoregulatory, anti-oxidant and anti-fibrosis functions mainly through the PI3K/ART signaling pathway, Th17 differentiation signaling pathway, inflammatory bowel disease signaling pathway, etcetera. Also, a molecular docking analysis shows that the key phytochemicals have strong affinity for binding to the core targets. Finally, the interaction network of CR, phytochemicals, targets, GO functions, KEGG pathways and UC is constructed. This study indicates that the key phytochemicals in CR have superior drug likeness and bioactivity, and the molecular mechanism of key phytochemicals against UC may be via the signaling pathway mentioned above. The potential and critical pharmacological mechanisms provide a direction for future research.

The Pathogenicity and Synergistic Action of Th1 and Th17 Cells in Inflammatory Bowel Diseases

Inflammatory bowel diseases (IBDs), including ulcerative colitis and Crohn's disease, are characterized by chronic idiopathic inflammation of gastrointestinal tract. Although the pathogenesis of IBD remains unknown, intestinal immune dysfunction has been considered as the core pathogenesis. In the intestinal immune system, T helper 1 (Th1) and Th17 cells are indispensable for intestine homeostasis via preventing pathogenic bacteria invasion, regulating metabolism and functions of intestinal epithelial cells (IECs), and promoting IEC self-renewal. However, during the development of IBD, Th1 and Th17 cells acquire the pathogenicity and change from the maintainer of intestinal homeostasis to the destroyer of intestinal mucosa. Because of coexpressing interferon-γ and interleukin-17A, Th17 cells with pathogenicity are named as pathogenic Th17 cells. In disease states, Th1 cells impair IEC programs by inducing IEC apoptosis, recruiting immune cells, promoting adhesion molecules expression of IECs, and differentiating to epithelial cell adhesion molecule-specific interferon γ-positive Th1 cells. Pathogenic Th17 cells induce IEC injury by triggering IBD susceptibility genes expression of IECs and specifically killing IECs. In addition, Th1 and pathogenic Th17 cells could cooperate to induce colitis. The evidences from IBD patients and animal models demonstrate that synergistic action of Th1 and pathogenic Th17 cells occurs in the diseases development and aggravates the mucosal inflammation. In this review, we focused on Th1 and Th17 cell programs in homeostasis and intestine inflammation and specifically discussed the impact of Th1 and Th17 cell pathogenicity and their synergistic action on the onset and the development of IBD. We hoped to provide some clues for treating IBD.

Glycerol monolaurate ameliorates DSS-induced acute colitis by inhibiting infiltration of Th17, neutrophils, macrophages and altering the gut microbiota

Background and aims

Inflammatory bowel disease (IBD) places a heavy medical burden on countries and families due to repeated and prolonged attacks, and the incidence and prevalence of IBD are increasing worldwide. Therefore, finding an effective treatment is a matter of great urgency. Glycerol monolaurate (GML), which has a twelve-carbon chain, is a compound naturally found in human breast milk. Some studies have shown that GML has antibacterial and anti-inflammatory effects. However, the specific mechanism of action remains unclear.

Methods

Acute colitis was established in mice using 3% DSS, and glycerol monolaurate (500 mg·kg-¹) was administered for two weeks. QPCR and western blotting were performed to examine the inflammatory status. Mice described were subjected to flow cytometry analysis for immune cell activation.

Results

GML treated alleviated macroscopic symptoms such as shortened colons, increased spleen weight, and caused weight loss in mice with DSS-induced colitis. In addition, GML decreased the expression of pro-inflammatory factors (NF-α, IL-1β and IL-1α) and increased the expression of anti-inflammatory factors (IL-10 and TGF-β). GML inhibited the activation of the MAPK and NF-κB signalling pathways, improved tissue damage, and increased the expression of intestinal tight junction proteins. In addition, LPMCs extracted from intestinal tissue via flow cytometry showed that GML treatment led to a decrease of Th17 cells, Neutrophils and Macrophages. 16S rDNA sequencing showed that GML increased the abundance of commensal bacterium such as Akkermansia and Lactobacillus murinus.

Conclusions

We showed that oral administration of GML ameliorated DSS-induced colitis by inhibiting infiltration of Th17 cells, Neutrophils, and Macrophages, protecting the intestinal mucosal barrier and altered the abundance of commensal bacterium. This study provides new insights into the biological function and therapeutic potential of GML in the treatment of IBD.

Targeting interleukin-17 enhances tumor response to immune checkpoint inhibitors in colorectal cancer

Although immune checkpoint inhibitors (ICIs) have gained much attention in managing cancer, only a minority of patients, especially those with tumors that have been classified as immunologically "cold" such as microsatellite stable (MSS) colorectal cancers (CRC), experience clinical benefit from ICIs. Surprisingly, interleukin-17 (IL-17) and its primary source Th17 are enriched in CRC and inversely associated with patient outcome. Our previous study revealed that IL-17A could upregulate programmed death-ligand 1 (PD-L1) expression and impede the efficacy of immunotherapy. IL-17, therefore, can be a possible target to sensitize tumor cells to ICIs. The detailed clinical results from our trial, which is the first to show the benefits of the combination of anti-PD-1 with anti-IL-17 therapy for MSS CRC, have also been presented. In this review, we highlight the role of IL-17 in ICIs resistance and summarize the current clinical evidence for the use of combination therapy. Directions for future strategies to warm up immunologically "cold" MSS CRCs have also been proposed.

High-dimensional profiling reveals Tc17 cell enrichment in active Crohn's disease and identifies a potentially targetable signature

The immune-pathology in Crohn’s disease is linked to dysregulated CD4+ T cell responses biased towards pathogenic TH17 cells. However, the role of CD8+ T cells able to produce IL-17 (Tc17 cells) remains unclear. Here we characterize the peripheral blood and intestinal tissue of Crohn’s disease patients (n = 61) with flow and mass cytometry and reveal a strong increase of Tc17 cells in active disease, mainly due to induction of conventional T cells. Mass cytometry shows that Tc17 cells express a distinct immune signature (CD6^high, CD39, CD69, PD-1, CD27^low) which was validated in an independent patient cohort. This signature stratifies patients into groups with distinct flare-free survival associated with differential CD6 expression. Targeting of CD6 in vitro reduces IL-17, IFN-γ and TNF production. These results identify a distinct Tc17 cell population in Crohn’s disease with proinflammatory features linked to disease activity. The Tc17 signature informs clinical outcomes and may guide personalized treatment decisions.

The T cell compartment in patients with Crohn's disease is dysregulated. Here the authors use cytometric profiling to reveal an enrichment of distinct Tc17 cells during active Crohn's disease and may suggest CD6 as a potential target for therapeutic studies.

Untangling the oral-gut axis in the pathogenesis of intestinal inflammation

An increasing body of literature reveals that host-microbe networks are well-coordinated and impact human health and disease. Recently, it has become evident that an abnormal alteration in bacterial configuration in the oral cavity, namely oral dysbiosis, caused by periodontal inflammation, is associated with various distant inflammatory diseases, including inflammatory bowel disease. However, the extent to which the relationships between oral and distant disorders are merely an association or are causally triggered by oral microorganisms remains debated. In this mini-review, we highlight mechanisms in inter-related organ system diseases , particularly the one between oral and gut inflammation. Further, we discuss clinical perspectives and propose a novel concept of a multi-hit hypothesis in the pathogenesis of gut inflammation, based on our updated knowledge of shared microbiological and immunological pathways between the oral and gut mucosae.

Secondary Lymphoid Organs in Mesenchymal Stromal Cell Therapy: More Than Just a Filter

Mesenchymal stromal cells (MSCs) have demonstrated therapeutic potential in inflammatory models of human disease. However, clinical translation has fallen short of expectations, with many trials failing to meet primary endpoints. Failure to fully understand their mechanisms of action is a key factor contributing to the lack of successful commercialisation. Indeed, it remains unclear how the long-ranging immunomodulatory effects of MSCs can be attributed to their secretome, when MSCs undergo apoptosis in the lung shortly after intravenous infusion. Their apoptotic fate suggests that efficacy is not based solely on their viable properties, but also on the immune response to dying MSCs. The secondary lymphoid organs (SLOs) orchestrate immune responses and play a key role in immune regulation. In this review, we will discuss how apoptotic cells can modify immune responses and highlight the importance of MSC-immune cell interactions in SLOs for therapeutic outcomes.

Intra-abdominal septic complications after ileocolic resection increases risk for endoscopic and surgical postoperative Crohn's disease recurrence

BACKGROUND

Postoperative recurrence [POR] of Crohn's disease following ileocolonic resection is common. The impact of immediate postoperative intra-abdominal septic complications [IASC] on endoscopic and surgical recurrence has not been elucidated.

AIMS

To evaluate if IASC is associated with an increased risk for endoscopic and surgical POR.

METHODS

This was a retrospective study of adult Crohn's disease patients undergoing ileocolonic resection with primary anastomosis between 2009 and 2020. IASC was defined as anastomotic leak or intra-abdominal abscess within 90 days of the date of surgery. Multivariable logistic and Cox proportional hazard modelling were performed to assess the impact of IASC on endoscopic POR [modified Rutgeerts' score ≥ i2b] at index postoperative ileocolonoscopy and long-term surgical recurrence.

RESULTS

In 535 Crohn's disease patients [median age 35 years, 22.1% active smokers, 35.7% one or more prior resection] had an ileocolonic resection with primary anastomosis. A minority of patients [N = 47; 8.8%] developed postoperative IASC. In total, 422 [78.9%] patients had one or more postoperative ileocolonoscopies, of whom 163 [38.6%] developed endoscopic POR. After adjusting for other risk factors for postoperative recurrence, postoperative IASC was associated with significantly greater odds (adjusted odds ratio [aOR]: 2.45 [1.23-4.97]; p = 0.01) and decreased time (adjusted hazards ratio [aHR]: 1.60 [1.04-2.45]; p = 0.03] to endoscopic POR. Furthermore, IASC was associated with increased risk (aOR: 2.3 [1.04-4.87] p = 0.03) and decreased survival-free time [aHR: 2.53 [1.31-4.87]; p = 0.006] for surgical recurrence.

CONCLUSION

IASC is associated with an increased risk for endoscopic and surgical POR of Crohn's disease. Preoperative optimization to prevent IASC, in addition to postoperative biological prophylaxis, may help reduce the risk for endoscopic and surgical POR.

Periodontal connection with intestinal inflammation: Microbiological and immunological mechanisms

Humans have coevolved with the trillions of resident microbes that populate every nook and cranny of the body. At each site, the resident microbiota creates a unique ecosystem specialized to its environment, benefiting the development and maintenance of human physiology through harmonious symbiotic relationships with the host. However, when the resident microbiota is perturbed, significant complications may arise with disastrous consequences that affect the local and distant ecosystems. In this context, periodontal disease results in inflammation beyond the oral cavity, such as in the gastrointestinal tract. Accumulating evidence indicates that potentially harmful oral resident bacteria (referred to as pathobionts) and pathogenic immune cells in the oral mucosa can migrate to the lower gastrointestinal tract and contribute to intestinal inflammation. We will review the most recent advances concerning the periodontal connection with intestinal inflammation from microbiological and immunological perspectives. Potential therapeutic approaches that target the connection between the mouth and the gut to treat gastrointestinal diseases, such as inflammatory bowel disease, will be examined. Deciphering the complex interplay between microbes and immunity along the mouth-gut axis will provide a better understanding of the pathogenesis of both oral and gut pathologies and present therapeutic opportunities.

mTOR Signaling in the Regulation of CD4+ T Cell Subsets in Periodontal Diseases

Periodontal disease results from the inflammatory infiltration by the microbial community which is marked through tooth mobility and alveolar bone resorption. The inflammation in periodontal disease is mediated by CD4⁺ T cells through cytokine secretion and osteoclastogenetic activity. Historically, the inflammatory model in periodontal disease is described through disruption of the balance between two subsets of T helper cells which are T-helper type 1 (Th1) and T-helper type 2 (Th2). However, more and more studies have found that apart from subsets of helper T cells, regulatory T-cells and Th17 cells are also involved in the pathogenesis of periodontal diseases. Growing evidence proves that helper T cells differentiation, activation, and subset determination are under the strong impact of mTOR signaling. mTOR signaling could promote Th1 and Th17 cell differentiation and inhibit Treg commitment through different mTOR complexes, therefore we anticipate a regulation effect of mTOR signaling on periodontal diseases by regulating CD4⁺ T cell subsets. This review aims to integrate the topical researches about the role of different types of Th cells in the pathogenesis of periodontal diseases, as well as the regulation of mTOR signaling in the specification and selection of Th cell commitment.

The Role of the Lymphatic System in the Pathogenesis and Treatment of Inflammatory Bowel Disease

Although the number of therapeutic options for the treatment of inflammatory bowel disease (IBD) has increased in recent years, patients suffer from decreased quality of life due to non-response or loss of response to the currently available treatments. An increased understanding of the disease’s etiology could provide novel insights for treatment strategies in IBD. Lymphatic system components are generally linked to immune responses and presumably related to inflammatory diseases pathophysiology. This review aims to summarize findings on immune-mediated mechanisms in lymphoid tissues linked with IBD pathogenesis and (potential) novel treatments. Enhanced innate and adaptive immune responses were observed in mesenteric lymph nodes (MLNs) and other lymphoid structures, such as Peyer’s patches, in patients with IBD and in animal models. Furthermore, the phenomenon of lymphatic obstruction in the form of granulomas in MLNs and lymphatic vessels correlates with disease activity. There is also evidence that abnormalities in the lymphatic stromal components and lymph node microbiome are common in IBD and could be exploited therapeutically. Finally, novel agents targeting lymphocyte trafficking have been added to the treatment armamentarium in the field of IBD. Overall, gut-associated lymphoid tissue plays a key role in IBD immunopathogenesis, which could offer novel therapeutic targets.

Interleukin 27 is a novel cytokine with anti-inflammatory effects against spondyloarthritis through the suppression of Th17 responses

Introduction

Spondylarthritis (SpA) development in HLA-B27/human β2-microglobulin transgenic rat (B27-rat) is correlated with altered conventional dendritic cell (cDC) function that promotes an inflammatory pattern of CD4+T cells, including a biased expansion of pro-inflammatory Th₁₇ population and imbalance of regulatory T cells cytokine profile. Transcriptomic analysis revealed that cDCs from B27-rats under express IL-27, an anti-inflammatory cytokine which induces the differentiation of IL-10⁺ regulatory T cells and inhibits Th₁₇ cells.

Methods

Here, we first investigated whether in vitro addition of exogenous IL-27 could reverse the inflammatory pattern observed in CD4⁺ T cells. Next, we performed preclinical assay using IL-27 to investigate whether in vivo treatment could prevent SpA development in B27-rats.

Results

in vitro addition of IL-27 to cocultures of cDCs and CD4⁺ T cell subsets from B27-rats reduced IL-17 and enhanced IL-10 production by T cells. Likewise, IL-27 inhibited the production of IL-17 by CD4⁺ T cells from SpA patients. Interestingly, in vivo treatment with recombinant IL-27 starting before SpA onset, inhibited SpA development in B27-rats through the suppression of IL-17/TNF producing CD4⁺ T cells.

Discussion

Overall, our results reveal a potent inhibitory effect of IL-27 and highlight this cytokine as a promising new therapeutic target in SpA, especially for SpA patients non responders to currently approved biotherapies.

Ustekinumab Improves Active Crohn's Disease by Suppressing the T Helper 17 Pathway

BACKGROUND

Ustekinumab (UST), an antibody targeting the p40 subunit of interleukin (IL)-12 and IL-23, is effective in treating Crohn's disease (CD). To clarify the mechanism of UST, we investigated T-cell differentiation in CD patients treated with UST.

METHODS

Twenty-seven patients with active CD were enrolled in this study. Seventeen patients were treated with UST, and 10 patients were treated with anti-tumor necrosis factor (TNF)-alpha therapy. The changes in the proportions of T-cell subsets after these therapies were analyzed by flow cytometry. Comprehensive gene expression changes in the colonic mucosa were also evaluated.

RESULTS

The frequency of T helper (Th) 17 cells was significantly decreased in the peripheral blood of patients with active CD after UST therapy. Anti-TNF therapy had a minimal effect on Th17 cells but increased the proportion of regulatory T cells. Enrichment analysis showed the expression of genes involved in the Th17 differentiation pathway was downregulated in the colonic mucosa after UST but not anti-TNF therapy. There were no common differentially expressed genes between CD patients treated with UST and anti-TNF therapy, suggesting a clear difference in their mechanism of action.

CONCLUSION

In patients with active CD, UST therapy suppressed Th17 cell differentiation both in the peripheral blood and colonic tissues.

Molecular Immune-Inflammatory Connections between Dietary Fats and Atherosclerotic Cardiovascular Disease: Which Translation into Clinics?

Current guidelines recommend reducing the daily intake of dietary fats for the prevention of ischemic cardiovascular diseases (CVDs). Avoiding saturated fats while increasing the intake of mono- or polyunsaturated fatty acids has been for long time the cornerstone of dietary approaches in cardiovascular prevention, mainly due to the metabolic effects of these molecules. However, recently, this approach has been critically revised. The experimental evidence, in fact, supports the concept that the pro- or anti-inflammatory potential of different dietary fats contributes to atherogenic or anti-atherogenic cellular and molecular processes beyond (or in addition to) their metabolic effects. All these aspects are hardly translatable into clinics when trying to find connections between the pro-/anti-inflammatory potential of dietary lipids and their effects on CVD outcomes. Interventional trials, although providing stronger potential for causal inference, are typically small sample-sized, and they have short follow-up, noncompliance, and high attrition rates. Besides, observational studies are confounded by a number of variables and the quantification of dietary intakes is far from optimal. A better understanding of the anatomic and physiological barriers for the absorption and the players involved in the metabolism of dietary lipids (e.g., gut microbiota) might be an alternative strategy in the attempt to provide a first step towards a personalized dietary approach in CVD prevention.

The role of lymphatics in intestinal inflammation

The lymphatic vasculature returns filtered interstitial arterial fluid and tissue metabolites to the blood circulation. It also plays a major role in lipid absorption and immune cell trafficking. Lymphatic vascular defects have been revealed in inflammatory diseases, Crohn's disease, obesity, cardiovascular disease, hypertension, atherosclerosis, and Alzheimer's disease. In this review, we discuss lymphatic structure and function within the gut, such as dietary lipid absorption, the transport of antigens and immune cells to lymph nodes, peripheral tolerance, and lymphocyte migration from secondary lymphoid tissues to the lymphatics and the immune systems. We also discuss the potential roles of these lymphatics on the pathophysiology of inflammatory bowel disease and as new targets for therapeutic management.

The role of lymphatics in intestinal inflammation

The lymphatic vasculature returns filtered interstitial arterial fluid and tissue metabolites to the blood circulation. It also plays a major role in lipid absorption and immune cell trafficking. Lymphatic vascular defects have been revealed in inflammatory diseases, Crohn's disease, obesity, cardiovascular disease, hypertension, atherosclerosis, and Alzheimer's disease. In this review, we discuss lymphatic structure and function within the gut, such as dietary lipid absorption, the transport of antigens and immune cells to lymph nodes, peripheral tolerance, and lymphocyte migration from secondary lymphoid tissues to the lymphatics and the immune systems. We also discuss the potential roles of these lymphatics on the pathophysiology of inflammatory bowel disease and as new targets for therapeutic management.

The role of lymphatics in intestinal inflammation

The lymphatic vasculature returns filtered interstitial arterial fluid and tissue metabolites to the blood circulation. It also plays a major role in lipid absorption and immune cell trafficking. Lymphatic vascular defects have been revealed in inflammatory diseases, Crohn's disease, obesity, cardiovascular disease, hypertension, atherosclerosis, and Alzheimer's disease. In this review, we discuss lymphatic structure and function within the gut, such as dietary lipid absorption, the transport of antigens and immune cells to lymph nodes, peripheral tolerance, and lymphocyte migration from secondary lymphoid tissues to the lymphatics and the immune systems. We also discuss the potential roles of these lymphatics on the pathophysiology of inflammatory bowel disease and as new targets for therapeutic management.

The role of lymphatics in intestinal inflammation

The lymphatic vasculature returns filtered interstitial arterial fluid and tissue metabolites to the blood circulation. It also plays a major role in lipid absorption and immune cell trafficking. Lymphatic vascular defects have been revealed in inflammatory diseases, Crohn's disease, obesity, cardiovascular disease, hypertension, atherosclerosis, and Alzheimer's disease. In this review, we discuss lymphatic structure and function within the gut, such as dietary lipid absorption, the transport of antigens and immune cells to lymph nodes, peripheral tolerance, and lymphocyte migration from secondary lymphoid tissues to the lymphatics and the immune systems. We also discuss the potential roles of these lymphatics on the pathophysiology of inflammatory bowel disease and as new targets for therapeutic management.

The role of lymphatics in intestinal inflammation

The lymphatic vasculature returns filtered interstitial arterial fluid and tissue metabolites to the blood circulation. It also plays a major role in lipid absorption and immune cell trafficking. Lymphatic vascular defects have been revealed in inflammatory diseases, Crohn's disease, obesity, cardiovascular disease, hypertension, atherosclerosis, and Alzheimer's disease. In this review, we discuss lymphatic structure and function within the gut, such as dietary lipid absorption, the transport of antigens and immune cells to lymph nodes, peripheral tolerance, and lymphocyte migration from secondary lymphoid tissues to the lymphatics and the immune systems. We also discuss the potential roles of these lymphatics on the pathophysiology of inflammatory bowel disease and as new targets for therapeutic management.

The role of lymphatics in intestinal inflammation

The lymphatic vasculature returns filtered interstitial arterial fluid and tissue metabolites to the blood circulation. It also plays a major role in lipid absorption and immune cell trafficking. Lymphatic vascular defects have been revealed in inflammatory diseases, Crohn's disease, obesity, cardiovascular disease, hypertension, atherosclerosis, and Alzheimer's disease. In this review, we discuss lymphatic structure and function within the gut, such as dietary lipid absorption, the transport of antigens and immune cells to lymph nodes, peripheral tolerance, and lymphocyte migration from secondary lymphoid tissues to the lymphatics and the immune systems. We also discuss the potential roles of these lymphatics on the pathophysiology of inflammatory bowel disease and as new targets for therapeutic management.

The role of lymphatics in intestinal inflammation

The lymphatic vasculature returns filtered interstitial arterial fluid and tissue metabolites to the blood circulation. It also plays a major role in lipid absorption and immune cell trafficking. Lymphatic vascular defects have been revealed in inflammatory diseases, Crohn's disease, obesity, cardiovascular disease, hypertension, atherosclerosis, and Alzheimer's disease. In this review, we discuss lymphatic structure and function within the gut, such as dietary lipid absorption, the transport of antigens and immune cells to lymph nodes, peripheral tolerance, and lymphocyte migration from secondary lymphoid tissues to the lymphatics and the immune systems. We also discuss the potential roles of these lymphatics on the pathophysiology of inflammatory bowel disease and as new targets for therapeutic management.

The role of lymphatics in intestinal inflammation

The lymphatic vasculature returns filtered interstitial arterial fluid and tissue metabolites to the blood circulation. It also plays a major role in lipid absorption and immune cell trafficking. Lymphatic vascular defects have been revealed in inflammatory diseases, Crohn's disease, obesity, cardiovascular disease, hypertension, atherosclerosis, and Alzheimer's disease. In this review, we discuss lymphatic structure and function within the gut, such as dietary lipid absorption, the transport of antigens and immune cells to lymph nodes, peripheral tolerance, and lymphocyte migration from secondary lymphoid tissues to the lymphatics and the immune systems. We also discuss the potential roles of these lymphatics on the pathophysiology of inflammatory bowel disease and as new targets for therapeutic management.

The role of lymphatics in intestinal inflammation

The lymphatic vasculature returns filtered interstitial arterial fluid and tissue metabolites to the blood circulation. It also plays a major role in lipid absorption and immune cell trafficking. Lymphatic vascular defects have been revealed in inflammatory diseases, Crohn's disease, obesity, cardiovascular disease, hypertension, atherosclerosis, and Alzheimer's disease. In this review, we discuss lymphatic structure and function within the gut, such as dietary lipid absorption, the transport of antigens and immune cells to lymph nodes, peripheral tolerance, and lymphocyte migration from secondary lymphoid tissues to the lymphatics and the immune systems. We also discuss the potential roles of these lymphatics on the pathophysiology of inflammatory bowel disease and as new targets for therapeutic management.

The role of lymphatics in intestinal inflammation

The lymphatic vasculature returns filtered interstitial arterial fluid and tissue metabolites to the blood circulation. It also plays a major role in lipid absorption and immune cell trafficking. Lymphatic vascular defects have been revealed in inflammatory diseases, Crohn's disease, obesity, cardiovascular disease, hypertension, atherosclerosis, and Alzheimer's disease. In this review, we discuss lymphatic structure and function within the gut, such as dietary lipid absorption, the transport of antigens and immune cells to lymph nodes, peripheral tolerance, and lymphocyte migration from secondary lymphoid tissues to the lymphatics and the immune systems. We also discuss the potential roles of these lymphatics on the pathophysiology of inflammatory bowel disease and as new targets for therapeutic management.

The role of lymphatics in intestinal inflammation

The lymphatic vasculature returns filtered interstitial arterial fluid and tissue metabolites to the blood circulation. It also plays a major role in lipid absorption and immune cell trafficking. Lymphatic vascular defects have been revealed in inflammatory diseases, Crohn's disease, obesity, cardiovascular disease, hypertension, atherosclerosis, and Alzheimer's disease. In this review, we discuss lymphatic structure and function within the gut, such as dietary lipid absorption, the transport of antigens and immune cells to lymph nodes, peripheral tolerance, and lymphocyte migration from secondary lymphoid tissues to the lymphatics and the immune systems. We also discuss the potential roles of these lymphatics on the pathophysiology of inflammatory bowel disease and as new targets for therapeutic management.

The role of lymphatics in intestinal inflammation

The lymphatic vasculature returns filtered interstitial arterial fluid and tissue metabolites to the blood circulation. It also plays a major role in lipid absorption and immune cell trafficking. Lymphatic vascular defects have been revealed in inflammatory diseases, Crohn's disease, obesity, cardiovascular disease, hypertension, atherosclerosis, and Alzheimer's disease. In this review, we discuss lymphatic structure and function within the gut, such as dietary lipid absorption, the transport of antigens and immune cells to lymph nodes, peripheral tolerance, and lymphocyte migration from secondary lymphoid tissues to the lymphatics and the immune systems. We also discuss the potential roles of these lymphatics on the pathophysiology of inflammatory bowel disease and as new targets for therapeutic management.

The role of lymphatics in intestinal inflammation

The lymphatic vasculature returns filtered interstitial arterial fluid and tissue metabolites to the blood circulation. It also plays a major role in lipid absorption and immune cell trafficking. Lymphatic vascular defects have been revealed in inflammatory diseases, Crohn's disease, obesity, cardiovascular disease, hypertension, atherosclerosis, and Alzheimer's disease. In this review, we discuss lymphatic structure and function within the gut, such as dietary lipid absorption, the transport of antigens and immune cells to lymph nodes, peripheral tolerance, and lymphocyte migration from secondary lymphoid tissues to the lymphatics and the immune systems. We also discuss the potential roles of these lymphatics on the pathophysiology of inflammatory bowel disease and as new targets for therapeutic management.

The role of lymphatics in intestinal inflammation

The lymphatic vasculature returns filtered interstitial arterial fluid and tissue metabolites to the blood circulation. It also plays a major role in lipid absorption and immune cell trafficking. Lymphatic vascular defects have been revealed in inflammatory diseases, Crohn's disease, obesity, cardiovascular disease, hypertension, atherosclerosis, and Alzheimer's disease. In this review, we discuss lymphatic structure and function within the gut, such as dietary lipid absorption, the transport of antigens and immune cells to lymph nodes, peripheral tolerance, and lymphocyte migration from secondary lymphoid tissues to the lymphatics and the immune systems. We also discuss the potential roles of these lymphatics on the pathophysiology of inflammatory bowel disease and as new targets for therapeutic management.

The role of lymphatics in intestinal inflammation

The lymphatic vasculature returns filtered interstitial arterial fluid and tissue metabolites to the blood circulation. It also plays a major role in lipid absorption and immune cell trafficking. Lymphatic vascular defects have been revealed in inflammatory diseases, Crohn's disease, obesity, cardiovascular disease, hypertension, atherosclerosis, and Alzheimer's disease. In this review, we discuss lymphatic structure and function within the gut, such as dietary lipid absorption, the transport of antigens and immune cells to lymph nodes, peripheral tolerance, and lymphocyte migration from secondary lymphoid tissues to the lymphatics and the immune systems. We also discuss the potential roles of these lymphatics on the pathophysiology of inflammatory bowel disease and as new targets for therapeutic management.

The role of lymphatics in intestinal inflammation

The lymphatic vasculature returns filtered interstitial arterial fluid and tissue metabolites to the blood circulation. It also plays a major role in lipid absorption and immune cell trafficking. Lymphatic vascular defects have been revealed in inflammatory diseases, Crohn’s disease, obesity, cardiovascular disease, hypertension, atherosclerosis, and Alzheimer’s disease. In this review, we discuss lymphatic structure and function within the gut, such as dietary lipid absorption, the transport of antigens and immune cells to lymph nodes, peripheral tolerance, and lymphocyte migration from secondary lymphoid tissues to the lymphatics and the immune systems. We also discuss the potential roles of these lymphatics on the pathophysiology of inflammatory bowel disease and as new targets for therapeutic management.

The role of lymphatics in intestinal inflammation

The lymphatic vasculature returns filtered interstitial arterial fluid and tissue metabolites to the blood circulation. It also plays a major role in lipid absorption and immune cell trafficking. Lymphatic vascular defects have been revealed in inflammatory diseases, Crohn's disease, obesity, cardiovascular disease, hypertension, atherosclerosis, and Alzheimer's disease. In this review, we discuss lymphatic structure and function within the gut, such as dietary lipid absorption, the transport of antigens and immune cells to lymph nodes, peripheral tolerance, and lymphocyte migration from secondary lymphoid tissues to the lymphatics and the immune systems. We also discuss the potential roles of these lymphatics on the pathophysiology of inflammatory bowel disease and as new targets for therapeutic management.

The role of lymphatics in intestinal inflammation

The lymphatic vasculature returns filtered interstitial arterial fluid and tissue metabolites to the blood circulation. It also plays a major role in lipid absorption and immune cell trafficking. Lymphatic vascular defects have been revealed in inflammatory diseases, Crohn's disease, obesity, cardiovascular disease, hypertension, atherosclerosis, and Alzheimer's disease. In this review, we discuss lymphatic structure and function within the gut, such as dietary lipid absorption, the transport of antigens and immune cells to lymph nodes, peripheral tolerance, and lymphocyte migration from secondary lymphoid tissues to the lymphatics and the immune systems. We also discuss the potential roles of these lymphatics on the pathophysiology of inflammatory bowel disease and as new targets for therapeutic management.

The role of lymphatics in intestinal inflammation

The lymphatic vasculature returns filtered interstitial arterial fluid and tissue metabolites to the blood circulation. It also plays a major role in lipid absorption and immune cell trafficking. Lymphatic vascular defects have been revealed in inflammatory diseases, Crohn's disease, obesity, cardiovascular disease, hypertension, atherosclerosis, and Alzheimer's disease. In this review, we discuss lymphatic structure and function within the gut, such as dietary lipid absorption, the transport of antigens and immune cells to lymph nodes, peripheral tolerance, and lymphocyte migration from secondary lymphoid tissues to the lymphatics and the immune systems. We also discuss the potential roles of these lymphatics on the pathophysiology of inflammatory bowel disease and as new targets for therapeutic management.

The role of lymphatics in intestinal inflammation

The lymphatic vasculature returns filtered interstitial arterial fluid and tissue metabolites to the blood circulation. It also plays a major role in lipid absorption and immune cell trafficking. Lymphatic vascular defects have been revealed in inflammatory diseases, Crohn's disease, obesity, cardiovascular disease, hypertension, atherosclerosis, and Alzheimer's disease. In this review, we discuss lymphatic structure and function within the gut, such as dietary lipid absorption, the transport of antigens and immune cells to lymph nodes, peripheral tolerance, and lymphocyte migration from secondary lymphoid tissues to the lymphatics and the immune systems. We also discuss the potential roles of these lymphatics on the pathophysiology of inflammatory bowel disease and as new targets for therapeutic management.

The role of lymphatics in intestinal inflammation

The lymphatic vasculature returns filtered interstitial arterial fluid and tissue metabolites to the blood circulation. It also plays a major role in lipid absorption and immune cell trafficking. Lymphatic vascular defects have been revealed in inflammatory diseases, Crohn's disease, obesity, cardiovascular disease, hypertension, atherosclerosis, and Alzheimer's disease. In this review, we discuss lymphatic structure and function within the gut, such as dietary lipid absorption, the transport of antigens and immune cells to lymph nodes, peripheral tolerance, and lymphocyte migration from secondary lymphoid tissues to the lymphatics and the immune systems. We also discuss the potential roles of these lymphatics on the pathophysiology of inflammatory bowel disease and as new targets for therapeutic management.