Expression of death receptor 3 on peripheral blood mononuclear cells differes in adult IBD patients and children with newly diagnosed IBD

Analysis of therapeutic potential of preclinical models based on DR3/TL1A pathway modulation (Review)

Death receptor 3 (DR3) and its corresponding ligand, tumor necrosis factor-like ligand 1A (TL1A), belong to the tumor necrosis factor superfamily. Signaling via this receptor-ligand pair results in pro-inflammatory and anti-inflammatory effects. Effector lymphocytes can be activated to exert pro-inflammatory activity by triggering the DR3/TL1A pathway. By contrast, DR3/TL1A signaling also induces expansion of the suppressive function of regulatory T cells, which serve an important role in exerting anti-inflammatory functions and maintaining immune homeostasis. Preclinical evidence indicates that neutralizing and agonistic antibodies, as well as ligand-based approaches targeting the DR3/TL1A pathway, may be used to treat diseases, including inflammatory and immune-mediated diseases. Accumulating evidence has suggested that modulating the DR3/TL1A pathway is a promising therapeutic approach for patients with these diseases. This review discusses preclinical models to gauge the progress of therapeutic strategies for diseases involving the DR3/TL1A pathway to aid in drug development.

TL1A: A New Potential Target in the Treatment of Inflammatory Bowel Disease

Inflammatory bowel diseases (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), are chronic inflammatory diseases of the gastrointestinal tract. In the last few years, the development of biological agents targeting cytokines and receptors involved in IBD pathogenesis has led to better outcomes and has improved the course of the disease. Despite their effectiveness, drugs such as tumor necrosis factor (TNF) inhibitors, anti-Interleukin-12/23 and anti-integrins, do not induce a response in about one-third of patients, and 40% of patients lose response over time. Therefore, more efficient therapies are required. Recent studies showed that TL1A (Tumor necrosis factor-like cytokine 1A) acts as a regulator of mucosal immunity and participates in immunological pathways involved in the IBD pathogenesis. In this review article, we analyze the role of TL1A as a new potential target therapy in IBD patients.

Candidate single nucleotide polymorphisms of irritable bowel syndrome: a systemic review and meta-analysis

Background

Genetic factors increase the risk of irritable bowel syndrome (IBS). Analysis of single nucleotide polymorphisms (SNPs) has been used in IBS patients, but the findings are inconsistent. The goal of this review was to synthesize all the published SNPs studies of IBS through meta-analysis to objectively evaluate the relevance of SNPs to IBS risks.

Methods

IBS - related polymorphisms studies from 2000 to 2018 were searched. Pooled odds ratios with a 95% confidence interval for each SNP were evaluated through five genetic models. Ethnicity, ROME criteria and IBS subtypes were defined for subgroup analyze.

Results

Ten relevant genes were evaluated. SNPs rs4263839 and rs6478108 of TNFSF15 associated with an increased risk of IBS; IL6 rs1800795 increased the risk for Caucasian IBS patients which diagnosed by Rome III criteria; and IL23R rs11465804 increased the risk for IBS-C patients. IL10 rs1800896 GG genotype associated with a decreased risk of IBS. No evidence supported the association of GNβ3 rs5443, TNFα rs1800629, and IL10 rs1800871 to IBS in this study.

Conclusions

This meta-analysis presents an in-depth overview for IBS SNPs analysis. It was confirmed that polymorphisms of TNFSF15 associated with increased IBS risk, while IL10 rs1800896 associated with decreased IBS risk. It might offer some insights into polymorphisms of inflammation factors which might affect IBS susceptibility. Moreover, the analysis also emphasizes the importance of diagnostic criteria and phenotype homogeneity in IBS genetic studies.

Oestrogen-deficiency induces bone loss by modulating CD14+ monocyte and CD4+ T cell DR3 expression and serum TL1A levels

Background

Oestrogen-deficiency induced by menopause is associated with reduced bone density and primary osteoporosis, resulting in an increased risk of fracture. While the exact etiology of menopause-induced primary osteoporotic bone loss is not fully known, members of the tumour necrosis factor super family (TNFSF) are known to play a role. Recent studies have revealed that the TNFSF members death receptor 3 (DR3) and one of its ligands, TNF-like protein 1A (TL1A) have a key role in secondary osteoporosis; enhancing CD14⁺ peripheral blood mononuclear cell (PBMC) osteoclast formation and bone resorption. Whether DR3 and TL1A contribute towards bone loss in menopause-induced primary osteoporosis however, remains unknown.

Methods

To investigate this we performed flow cytometry analysis of DR3 expression on CD14⁺ PBMCs isolated from pre- and early post-menopausal females and late post-menopausal osteoporotic patients. Serum levels of TL1A, CCL3 and total MMP-9 were measured by ELISA. In vitro osteoclast differentiation assays were performed to determine CD14⁺ monocyte osteoclastogenic potential. In addition, splenic CD4⁺ T cell DR3 expression was investigated 1 week and 8 weeks post-surgery, using the murine ovariectomy model.

Results

In contrast to pre-menopausal females, CD14⁺ monocytes isolated from post-menopausal females were unable to induce DR3 expression. Serum TL1A levels were decreased approx. 2-fold in early post-menopausal females compared to pre-menopausal controls and post-menopausal osteoporotic females; no difference was observed between pre-menopausal and late post-menopausal osteoporotic females. Analysis of in vitro CD14⁺ monocyte osteoclastogenic potential revealed no significant difference between the post-menopausal and post-menopausal osteoporotic cohorts. Interestingly, in the murine ovariectomy model splenic CD4⁺ T cell DR3 expression was significantly increased at 1 week but not 8 weeks post-surgery when compared to the sham control.

Conclusion

Our results reveals for the first time that loss of oestrogen has a significant effect on DR3; decreasing expression on CD14⁺ monocytes and increasing expression on CD4⁺ T cells. These data suggest that while oestrogen-deficiency induced changes in DR3 expression do not affect late post-menopausal bone loss they could potentially have an indirect role in early menopausal bone loss through the modulation of T cell activity.

TL1A (TNFSF15) and DR3 (TNFRSF25): A Co-stimulatory System of Cytokines With Diverse Functions in Gut Mucosal Immunity

TL1A and its functional receptor DR3 are members of the TNF/TNFR superfamilies of proteins. Binding of APC-derived TL1A to lymphocytic DR3 provides co-stimulatory signals for activated lymphocytes. DR3 signaling affects the proliferative activity of and cytokine production by effector lymphocytes, but also critically influences the development and suppressive function of regulatory T-cells. DR3 was also found to be highly expressed by innate lymphoid cells (ILCS), which respond to stimulation by TL1A. Several recent studies with transgenic and knockout mice as well as neutralizing or agonistic antibodies for these two proteins, have clearly shown that TL1A/DR3 are important mediators of several chronic immunological disorders, including Inflammatory Bowel Disease (IBD). TL1A and DR3 are abundantly localized at inflamed intestinal areas of patients with IBD and mice with experimental ileitis or colitis and actively participate in the immunological pathways that underlie mucosal homeostasis and intestinal inflammation. DR3 signaling has demonstrated a dichotomous role in mucosal immunity. On the one hand, during acute mucosal injury it exerts protective functions by ameliorating the severity of acute inflammatory responses and facilitating tissue repair. On the other hand, it critically participates in the pro-inflammatory pathways that underlie chronic inflammatory responses, such as those that take place in IBD. These effects are mediated through modulation of the relative mucosal abundance and function of Th1, Th2, Th17, Th9, and Treg lymphocytes, but also of all types of ILCs. Recently, an important role was demonstrated for TL1A/DR3 as potential mediators of intestinal fibrosis that is associated with the presence of gut inflammation. These accumulating data have raised the possibility that TL1A/DR3 pathways may represent a valid therapeutic target for chronic immunological diseases. Nevertheless, applicability of such a therapeutic approach will greatly rely on the net result of TL1A/DR3 manipulation on the various cell populations that will be affected by this approach.

Expression of death receptor 3 (DR3) on peripheral blood mononuclear cells of patients with psoriasis vulgaris

BACKGROUND

A series of previous reports indicated that tumour necrosis factor-like ligand 1A (TL1A) and its receptor death receptor 3 (DR3) are involved in the pathogenesis of psoriasis vulgaris (PV), which is a common chronic skin disease accompanied by a number of comorbidities, although their exact roles remain unclear. Our previous studies demonstrated that serum TL1A levels were substantially elevated in patients with PV, but the detection of DR3 expression in peripheral blood mononuclear cells (PBMCs) of patients with PV had not been reported. Therefore, we detected DR3 expression on CD4+, CD8+, CD14+ and CD19+ PBMCs of patients with PV, atopic dermatitis (AD) and healthy volunteers.

METHODS

Blood samples were collected from participants with PV before and after treatment. Then, PBMCs from patients with PV were isolated. The Psoriasis Area Severity Index (PASI) was used to assess severity in patients with PV. The DR3 on CD4+, CD8+, CD14+ and CD19+ PBMCs were detected by flow cytometry analysis. Pearson's correlation analysis was then used to investigate the relationship between DR3 expression and PASI scores in patients with PV.

RESULTS

Comparing with the healthy volunteers and patients with AD, the percentage of DR3-expressing on CD8+ and CD14+ PBMCs in patients with PV was elevated, but the percentage of DR3-expressing on CD8+ and CD14+ cells decreased after anti-inflammatory treatment, which was correlated with PASI scores.

CONCLUSIONS

Taken together, these findings suggest that DR3 may play a key role in the pathogenesis of PV.