Tofacitinib inhibits inflammatory cytokines from ulcerative colitis and healthy mucosal explants and is associated with pSTAT1/3 reduction in T-cells

Tofacitinib downregulates JAK1 and JAK3 on human intestinal monocytes and macrophages without affecting dendritic cells phenotype or function

Background

Ulcerative colitis (UC) is an inflammatory disorder of the gastrointestinal tract. Although Tofacitinib, which inhibits the JAK1 and JAK3 signalling pathway, is approved to treat patients with UC, its specific mechanism of action remain elusive. Given the central role that conventional dendritic cells (cDC) elicit in gut homeostasis, we hypothesised that Tofacitinib acts modulating cDC function in UC.

Methods

Human biopsies were obtained from colon of controls, and patients with UC (active and quiescent). Lamina propria mononuclear cells (LPMC) were ex-vivo cultured in the presence/absence of Tofacitinib. The specific effect elicited over human intestinal cDC, monocytes and macrophages was assessed by flow cytometry. cDC were also enriched following Tofacitinib conditioning in order to assess its effect over naïve T-cells.

Results

Several human intestinal cDC, monocyte and macrophage subsets can be found in the human colon, with these cells being more similar between controls and patients with qUC referred to patients with aUC. Following ex-vivo culture, Tofacitinib downregulated JAK1 expression on intestinal monocytes from patients with both active and quiescent UC. As for macrophages, JAK1 was decreased on patients with active UC while JAK was downregulated on macrophages from patients with quiescent disease. Tofacitinib did not modulate the phenotype or function of human intestinal cDC.

Conclussion

Tofacitinib does not modulate the phenotype and function of human intestinal cDC in UC. On the contrary, it displays a differential capacity to modulate intestinal monocyte and macrophage phenotype. Future studies should address whether it also translates into a differential function of these cells.

Discordant Effects of Janus Kinase Inhibition Ex Vivo on Inflammatory Responses in Colonic Compared to Ileal Mucosa

BACKGROUND AND AIMS

Janus kinase [JAK] inhibitors are used for treating inflammatory bowel diseases [IBD]. We aimed to identify the molecular effects of JAK inhibition in human intestinal mucosa, considering IBD location and phenotype.

METHODS

Colonic and ileal explants from patients with ulcerative colitis [UC], Crohn's disease [CD], and non-IBD controls [NC] were assessed for levels of phosphorylated signal transducers and activators of transcription [p-STAT] and expression of inflammatory genes in response to an ex vivo JAK inhibitor [tofacitinib]. Cytokine production by lamina propria lymphocytes in response to tofacitinib was assessed. Human intestinal organoids were used to investigate the effects of JAK inhibitors on inducible nitric oxide synthase [iNOS] expression.

RESULTS

Explants were collected from 68 patients [UC = 20, CD = 20, NC = 28]. p-STAT1/3/5 inhibition rates varied, being higher in colonic compared to ileal explants. p-STAT1/3 inhibition rates negatively correlated with levels of C-reactive protein [CRP]. While significant alterations in 120 of 255 inflammatory genes were observed in colonic explants, only 30 were observed in ileal NC explants. In colonic explants from UC, significant alterations were observed in five genes, including NOS2. JAK inhibition significantly decreased Th1/Th2/Th17-related cytokine production from lamina propria lymphocytes. Various JAK inhibitors reduced the interferon-γ-induced increase in iNOS expression in organoids.

CONCLUSIONS

A site-specific anti-inflammatory effect of JAK inhibition by tofacitinib was noted, whereby the colon was more robustly affected than the ileum. The ex vivo response to tofacitinib is individual. JAK inhibition may attenuate inflammation by decreasing iNOS expression. Ex vivo mucosal platforms may be a valuable resource for studying personalized drug effects in patients with IBD.

Acalypha australis L. Extract Attenuates DSS-Induced Ulcerative Colitis in Mice by Regulating Inflammatory Factor Release and Blocking NF-κB Activation

Ulcerative colitis (UC) is a chronic gastroenteric inflammatory disease that may cause life-threatening complications. Currently available therapeutic drugs are not as effective as expected, necessitating the development of new targets and drugs. The etiology and pathogenetic mechanisms of UC are largely unclear; thus, the treatment effects are limited. The aqueous extract of Acalypha australis L. (AAL) has shown good therapeutic efficacy in treating UC. AAL is used in traditional Chinese medicine owing to its hemostasis, detoxification, and heat clearance effects. Although astragalus has such broad-spectrum biological activities closely related to inflammation, its therapeutic efficacy for UC treatment has not been reported, the underlying mechanism remains unknown. We studied the therapeutic effect of AAL on UC in mice and explored its potential mechanism. Mice were treated with AAL aqueous extract for 7 days (20 mg/kg), after which the colon tissue was assessed for damage (colon mucosal damage index [CMDI]), apoptosis (immunohistochemistry), and release of cytokines (enzyme-linked immunosorbent assay). The concentration of AAL aqueous extract at 20 mg/kg significantly improved the CMDI score and colon injury of UC model. It also reduced the serum levels of IL-2, IL-8, IL-17A, IL-22, IFN-γ, and TNF-α, and decreased apoptosis in the colon. AAL water extract also significantly reduced the expression level of NF-κB pathway-related proteins. In conclusion, AAL can protect against UC mainly by inhibiting the expression level of NF-κB pathway-related proteins and reducing the release of inflammatory factors.

Tofacitinib fails to prevent T cell transfer colitis in mice but ameliorates disease activity

Tofactinib is a JAK inhibitor approved for ulcerative colitis in humans. Despite of its' proven effectiveness in humans, mechanistic data are scarce on the effectiveness of Tofactinib in experimental colitis in mice. We induced experimental colitis by transfer of CD4+CD25- isolated T cells into RAG2-/- (T and B cell deficient) mice and treated these mice with tofacitinib for 5-6 weeks either with a dosage of 10 or 40 mg/kg body weight immediately after CD4+ transfer or started treatment after first symptoms of disease for several weeks. While treatment with tofacitinib immediately after transfer resulted in an enhanced expansion of CD4+ T cells and did not prevent occurrence of colitis, treatment after start of symptoms of colitis ameliorated disease activity on a clinical basis and in histological analyses. Tofacitinib is effective in the treatment of murine experimental T cell transfer colitis, however does not prevent occurrence of disease.

rxCOV is a quantitative metric for assessing immunoassay analyte fidelity

Immunoassay based bioanalytical measurements are widely used in a variety of biomedical research and clinical settings. In these settings they are assumed to faithfully represent the experimental conditions being tested and the sample groups being compared. Although significant technical advances have been made in improving sensitivity and quality of the measurements, currently no metrics exist that objectively quantify the fidelity of the measured analytes with respect to noise associated with the specific assay. Here we introduce ratio of cross-coefficient-of-variation (rxCOV), a fidelity metric for objectively assessing immunoassay analyte measurement quality when comparing its differential expression between different sample groups or experimental conditions. We derive the metric from first principles and establish its feasibility and applicability using simulated and experimental data. We show that rxCOV assesses fidelity independent of statistical significance, and importantly, identifies when latter is meaningful. We also discuss its importance in the context of averaging experimental replicates for increasing signal to noise ratio. Finally, we demonstrate its application in a Lynch Syndrome case study. We conclude by discussing its applicability to multiplexed immunoassays, other biosensing assays, and to paired and unpaired data. We anticipate rxCOV to be adopted as a simple and easy-to-use fidelity metric for performing robust and reproducible biomedical research.

Oral administration of Helianthus annuus leaf extract ameliorates atopic dermatitis by modulation of T cell activity in vivo

BACKGROUND

Atopic dermatitis (AD) is multifactorial disease that is highly involved in the activity of T cells from the skin lesion. Seeds of Helianthus annuus extract have been traditionally used as anti-inflammatory reagent but few studies have been reported on leaf of H. annuus that are discarded uselessly as an immunomodulator.

PURPOSE

Therefore, here, the regulatory effect of Helianthus annuus extract (HAE) on AD via suppression of T cell activity was investigated.

METHODS

The efficacy of HAE was evaluated in T cells stimulated with CD3/CD28 antibody and PMA/A23187. And demonstration of the alleviating effect of HAE on AD in the ears of Balb/c female mice stimulated with mite extract and DNCB.

RESULTS

Pre-treatment with HAE abrogates IL-2 production from activated T cells. It was also found that HAE suppresses the expression of surface molecules in activated T cells. Cell viability results demonstrated that HAE is not associated with cytotoxicity in resting and activated T cells. Besides, we exhibited that regulated phosphorylation of MAPK through TAK1-IKKα-NFκB by pre-treatment with HAE leads to the suppressive effect of HAE on T cell activation. Oral administration of HAE attenuates manifestations of AD including reduced thickness of dermis and epidermis, decreased IgE level in serum, and declined mRNA levels of atopic cytokines on ear tissues. The ameliorative effect of HAE on AD was found to be associated with suppressed activity of T cells from draining lymph nodes.

CONCLUSION

Therefore, our results provide that HAE alleviates AD symptoms via modulation of T cell activity. In addition, these results suggest the immunomodulatory effect of HAE on T-cell mediated diseases.

Association Between Ex Vivo Human Ulcerative Colitis Explant Protein Secretion Profiles and Disease Behaviour

BACKGROUND

The clinical course of ulcerative colitis (UC) is variable. There is an unmet clinical need for biomarkers of UC disease behaviour. We aimed to evaluate the association between ex vivo human UC explant conditioned media (explant-CM) secreted protein profiles and UC disease behaviour.

METHODS

UC patients undergoing endoscopy were prospectively recruited. Endoscopic biopsies were collected and explant-CM generated. Association between explant-CM protein secretion profiles and disease progression was evaluated. Disease progression was defined as the requirement for corticosteroid therapy, UC-related hospitalisation, UC-related surgery or the introduction of a new immunomodulatory agent. Association between explant-CM secreted protein profiles and anti-TNF failure status was also evaluated. p values < 0.05 were considered significant in analyses.

RESULTS

Twenty-four UC patients were included (age [median, range]) 55 [21-72] years; 50% female. Disease progression during follow-up occurred in twelve (50%) patients. Multivariate analysis, including endoscopic remission status, demonstrated reduced IL-2 secretion to be independently associated with UC disease progression, p = 0.01. In univariate analysis, anti-TNF failure status was associated with significantly increased IL-17A/F (p = 0.015) and IL-12 / IL-23p40 (p = 0.044) concentrations. In multivariate analysis, there was a trend towards an association between IL-17A/F and anti-TNF failure status (p = 0.069); FLT-1 was demonstrated to be independently associated with anti-TNF failure status (p = 0.016).

CONCLUSION

Reduced explant-CM secreted IL-2 is associated with UC disease progression. Increased secretion of IL-23 pathway-associated cytokines was observed in anti-TNF failure status consistent with previous reports. Ex vivo human UC explants, generated from endoscopic biopsies, have potential as precision medicine tools in inflammatory bowel disease.