Short-chain fatty acids activate GPR41 and GPR43 on intestinal epithelial cells to promote inflammatory responses in mice

BACKGROUND & AIMS

Short-chain fatty acids (SCFAs), the most abundant microbial metabolites in the intestine, activate cells via G-protein-coupled receptors (GPRs), such as GPR41 and GPR43. We studied regulation of the immune response by SCFAs and their receptors in the intestines of mice.

METHODS

Inflammatory responses were induced in GPR41(-/-), GPR43(-/-), and C57BL6 (control) mice by administration of ethanol; 2, 4, 6-trinitrobenzene sulfonic-acid (TNBS); or infection with Citrobacter rodentium. We examined the effects of C rodentium infection on control mice fed SCFAs and/or given injections of antibodies that delay the immune response. We also studied the kinetics of cytokine and chemokine production, leukocyte recruitment, intestinal permeability, and T-cell responses. Primary colon epithelial cells were isolated from GPR41(-/-), GPR43(-/-), and control mice; signaling pathways regulated by SCFAs were identified using immunohistochemical, enzyme-linked immunosorbent assay, and flow cytometry analyses.

RESULTS

GPR41(-/-) and GPR43(-/-) mice had reduced inflammatory responses after administration of ethanol or TNBS compared with control mice, and had a slower immune response against C rodentium infection, clearing the bacteria more slowly. SCFAs activated intestinal epithelial cells to produce chemokines and cytokines in culture and mice after administration of ethanol, TNBS, or C rodentium. These processes required GPR41 and GPR43 and were required to recruit leukocytes and activate effector T cells in the intestine. GPR41 and GPR43 activated extracellular signal-regulated kinase 1/2 and p38 mitogen-activated protein kinase signaling pathways in epithelial cells to induce production of chemokines and cytokines during immune responses.

CONCLUSIONS

SCFAs activate GPR41 and GPR43 on intestinal epithelial cells, leading to mitogen-activated protein kinase signaling and rapid production of chemokines and cytokines. These pathways mediate protective immunity and tissue inflammation in mice.

Human umbilical cord blood mesenchymal stem cells reduce colitis in mice by activating NOD2 signaling to COX2

BACKGROUND & AIMS

Decreased levels or function of nucleotide-binding oligomerization domain 2 (NOD2) are associated with Crohn's disease. NOD2 regulates intestinal inflammation, and also is expressed by human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs), to regulate their differentiation. We investigated whether NOD2 is required for the anti-inflammatory activities of MSCs in mice with colitis.

METHODS

Colitis was induced in mice by administration of dextran sulfate sodium or trinitrobenzene sulfonic acid. Mice then were given intraperitoneal injections of NOD2-activated hUCB-MSCs; colon tissues and mesenteric lymph nodes were collected for histologic analyses. A bromodeoxyuridine assay was used to determine the ability of hUCB-MSCs to inhibit proliferation of human mononuclear cells in culture.

RESULTS

Administration of hUCB-MSCs reduced the severity of colitis in mice. The anti-inflammatory effects of hUCB-MSCs were greatly increased by activation of NOD2 by its ligand, muramyl dipeptide (MDP). Administration of NOD2-activated hUCB-MSCs increased anti-inflammatory responses in colons of mice, such as production of interleukin (IL)-10 and infiltration by T regulatory cells, and reduced production of inflammatory cytokines. Proliferation of mononuclear cells was inhibited significantly by co-culture with hUCB-MSCs that had been stimulated with MDP. MDP induced prolonged production of prostaglandin (PG)E2 in hUCB-MSCs via the NOD2-RIP2 pathway, which suppressed proliferation of mononuclear cells derived from hUCB. PGE2 produced by hUCB-MSCs in response to MDP increased production of IL-10 and T regulatory cells. In mice, production of PGE2 by MSCs and subsequent production of IL-10 were required to reduce the severity of colitis.

CONCLUSIONS

Activation of NOD2 is required for the ability of hUCB-MSCs to reduce the severity of colitis in mice. NOD2 signaling increases the ability of these cells to suppress mononuclear cell proliferation by inducing production of PGE2.

Oral delivery of IL-27 recombinant bacteria attenuates immune colitis in mice

BACKGROUND & AIMS

Treatment of inflammatory bowel disease would benefit from specific targeting of therapeutics to the intestine. We developed a strategy for localized delivery of the immunosuppressive cytokine interleukin (IL)-27, which is synthesized actively in situ by the food-grade bacterium Lactococcus lactis (LL-IL-27), and tested its ability to reduce colitis in mice.

METHODS

The 2 genes encoding mouse IL-27 were synthesized with optimal codon use for L lactis and joined with a linker; a signal sequence was added to allow for product secretion. The construct was introduced into L lactis. Colitis was induced via transfer of CD4(+)CD45RB(hi) T cells into Rag(-/-) mice to induce colitis; 7.5 weeks later, LL-IL-27 was administered to mice via gavage. Intestinal tissues were collected and analyzed.

RESULTS

LL-IL-27 administration protected mice from T-cell transfer-induced enterocolitis and death. LL-IL-27 reduced disease activity scores, pathology features of large and small bowel, and levels of inflammatory cytokines in colonic tissue. LL-IL-27 also reduced the numbers of CD4(+) and IL-17(+) T cells in gut-associated lymphoid tissue. The effects of LL-IL-27 required production of IL-10 by the transferred T cells. LL-IL-27 was more effective than either LL-IL-10 or systemic administration of recombinant IL-27 in reducing colitis in mice. LL-IL-27 also reduced colitis in mice after administration of dextran sodium sulfate.

CONCLUSIONS

LL-IL-27 reduces colitis in mice by increasing the production of IL-10. Mucosal delivery of LL-IL-27 could be a more effective and safer therapy for inflammatory bowel disease.

Modeling TH 2 responses and airway inflammation to understand fundamental mechanisms regulating the pathogenesis of asthma

In this review, we highlight experiments conducted in our laboratories that have elucidated functional roles for CD4⁺ T-helper type-2 lymphocytes (T_H 2 cells), their associated cytokines, and eosinophils in the regulation of hallmark features of allergic asthma. Notably, we consider the complexity of type-2 responses and studies that have explored integrated signaling among classical T_H 2 cytokines (IL-4, IL-5, and IL-13), which together with CCL11 (eotaxin-1) regulate critical aspects of eosinophil recruitment, allergic inflammation, and airway hyper-responsiveness (AHR). Among our most important findings, we have provided evidence that the initiation of T_H 2 responses is regulated by airway epithelial cell-derived factors, including TRAIL and MID1, which promote T_H 2 cell development via STAT6-dependent pathways. Further, we highlight studies demonstrating that microRNAs are key regulators of allergic inflammation and potential targets for anti-inflammatory therapy. On the background of T_H 2 inflammation, we have demonstrated that innate immune cells (notably, airway macrophages) play essential roles in the generation of steroid-resistant inflammation and AHR secondary to allergen- and pathogen-induced exacerbations. Our work clearly indicates that understanding the diversity and spatiotemporal role of the inflammatory response and its interactions with resident airway cells is critical to advancing knowledge on asthma pathogenesis and the development of new therapeutic approaches.

Interleukin-22: a likely target for treatment of autoimmune diseases

Interleukin-22 (IL-22) is a member of IL-10 family cytokines that is produced by many different types of lymphocytes including both those of the innate and adaptive immune systems. This includes activated T cells, most notably Th17 and Th22 cells, and NK cells, γδ T cells, LTi cells and LTi-like cells. IL-22 mediates its effects via the IL-22-IL-22R complex and subsequent Janus kinase-signal transducer and activators of transcription (JAK-STAT) signaling pathway. Recently accumulated evidence has indicated that IL-22 also plays an important role in the pathogenesis of many autoimmune diseases. In this review, we discuss the recent findings and advancement of the role for IL-22 in several autoimmune diseases, such as psoriasis, rheumatoid arthritis (RA), hepatitis, graft versus host disease (GHVD) and allergic diseases, implicating that target IL-22 may have a therapeutic potential in those autoimmune diseases.

Transcriptional and epigenetic regulation of T-helper lineage specification

Combined with TCR stimuli, extracellular cytokine signals initiate the differentiation of naive CD4(+) T cells into specialized effector T-helper (Th) and regulatory T (Treg) cell subsets. The lineage specification and commitment process occurs through the combinatorial action of multiple transcription factors (TFs) and epigenetic mechanisms that drive lineage-specific gene expression programs. In this article, we review recent studies on the transcriptional and epigenetic regulation of distinct Th cell lineages. Moreover, we review current study linking immune disease-associated single-nucleotide polymorphisms with distal regulatory elements and their potential role in the disease etiology.

Impact of effective tumor necrosis factor-alfa inhibitor treatment on arterial intima-media thickness in psoriasis: results of a pilot study

BACKGROUND

Psoriasis is associated with higher incidence of atherosclerotic comorbidities. Sustained arterial wall inflammation mediated by common cytokines of psoriasis and atherogenesis precedes atherosclerotic plaque development. Increased intima-media thickness (IMT) is an accepted indicator of subclinical atherosclerosis and has been reported in severe psoriasis.

OBJECTIVE

This pilot study aimed to clarify whether effective long-term tumor necrosis factor-alfa inhibition decreases IMT in psoriasis.

METHODS

In 16 patients with severe psoriasis, the Psoriasis Area and Severity Index score was calculated before therapy (etanercept, infliximab, adalimumab) and after 6-month treatment. Simultaneously, carotid and brachial IMT was measured by high-resolution, B-mode ultrasonography. Difference between initial and 6-month IMT values was determined for monitored arteries collectively and separately in carotid and brachial arteries.

RESULTS

All of 16 patients achieved Psoriasis Area and Severity Index 75, and 14 of 16 achieved Psoriasis Area and Severity Index 90 improvement. In the group of patients without initial calcified atherosclerotic plaques (13 of 16) significant IMT decrease was detected when arteries were measured collectively (P = .0002). Initial and follow-up data differed significantly also at individual analysis of carotid (P = .011) and brachial (P = .006) arteries. Eleven of 13 patients had initial carotid IMT exceeding age-adjusted normal values. The other group (3 of 16) with initial manifest plaques showed increasing IMT tendency. Their baseline ultrasonography revealed carotid IMT above the upper limit of healthy adults' age-adjusted values.

LIMITATIONS

Study limitation involves small patient numbers, self-controlled study design, and lack of patients' stratification according to common cardiovascular risk factors.

CONCLUSION

In our pilot study effective tumor necrosis factor-alfa inhibition was found to decrease IMT in psoriatic patients without irreversible atherosclerotic plaques. Further analysis is recommended to confirm and complete our primary observations.

Dual oxidase regulates neutrophil recruitment in allergic airways

Enhanced reactive oxygen species production in allergic airways is well described and correlates with increased airway contractions, inflammatory cell infiltration, goblet cell metaplasia, and mucus hypersecretion. There is also an abundance of interleukin-4/interleukin-13 (IL-4/IL-13)- or interleukin-5-secreting cells that are thought to be central to the pathogenesis of allergic asthma. We postulated that the dual oxidases (DUOX1 and DUOX2), members of the nicotinamide adenine dinucleotide phosphate oxidase family that release hydrogen peroxide (H2O2) in the respiratory tract, are critical proteins in the pathogenesis of allergic airways. DUOX activity is regulated by cytokines, including IL-4 and IL-13, and DUOX-mediated H2O2 influences several important features of allergic asthma: mucin production, IL-8 secretion, and wound healing. The objective of this study was to establish the contribution of DUOXs to the development of allergic asthma in a murine model. To accomplish this goal, we utilized a DUOXA-deficient mouse model (Duoxa(-/-)) that lacked maturation factors for both DUOX1 and DUOX2. Our results are the first to demonstrate evidence of DUOX protein and DUOX functional activity in murine airway epithelium. We also demonstrate that DUOXA maturation factors are required for airway-specific H2O2 production and localization of DUOX to cilia of fully differentiated airway epithelial cells. We compared wild-type and Duoxa(-/-) mice in an ovalbumin exposure model to determine the role of DUOX in allergic asthma. In comparison to DUOX-intact mice, Duoxa(-/-) mice had reduced mucous cell metaplasia and lower levels of TH2 cytokine levels in bronchoalveolar fluid. In addition, increased airway resistance in response to methacholine was observed in Duoxa(+/+) mice, as expected, but was absent in Duoxa(-/-) mice. Surprisingly, Duoxa(-/-) mice had decreased influx of neutrophils in bronchoalveolar fluid and lung tissue sections associated with a lower level of the chemotactic cytokine IL-6. These findings suggest that DUOX-derived H2O2 has an important role in signaling neutrophils into allergic airways.

Oral Immunization against PEDV with Recombinant Lactobacillus casei Expressing Dendritic Cell-Targeting Peptide Fusing COE Protein of PEDV in Piglets

Porcine epidemic diarrhea (PED) is a highly contagious disease in newborn piglets. In our previous study, a genetically engineered Lactobacillus casei oral vaccine (pPG-COE-DCpep/L393) expressing a dendritic cell (DC)-targeting peptide fused with porcine epidemic diarrhea virus (PEDV) COE antigen was developed. This vaccine induced significant levels of anti-PEDV specific IgG and IgA antibody responses in mice, indicating a potential strategy against PEDV infection. In this study, pPG-COE-DCpep/L393 was used for oral vaccination of newborn piglets against PEDV. We then assessed the immune responses and protection efficacy of pPG-COE-DCpep/L393. An indirect enzyme-linked immunosorbent assay (ELISA) showed that the recombinant Lactobacillus vaccine elicits a specific systemic and mucosal immune response. The T-helper cells mediated by pPG-COE-DCpep/L393 and PEDV infection display a Th1 phenotype. The histopathological results showed that pPG-COE-DCpep/L393 promotes lymphocyte proliferation and effectively protects piglets against PEDV infection. The transforming growth factor-β level indicated that the recombinant Lactobacillus vaccine plays a role in anti-inflammatory responses in mesenteric lymph nodes during PEDV infection. These results show that pPG-COE-DCpep/L393 is a potential vaccine against PEDV infection.

Caspases and therapeutic potential of caspase inhibitors in moderate-severe SARS-CoV-2 infection and long COVID

BACKGROUND

COVID-19 can present with lymphopenia and extraordinary complex multiorgan pathologies that can trigger long-term sequela.

AIMS

Given that inflammasome products, like caspase-1, play a role in the pathophysiology of a number of co-morbid conditions, we investigated caspases across the spectrum of COVID-19 disease.

MATERIALS & METHODS

We assessed transcriptional states of multiple caspases and using flow cytometry, the expression of active caspase-1 in blood cells from COVID-19 patients in acute and convalescent stages of disease. Non-COVID-19 subject presenting with various comorbid conditions served as controls.

RESULTS

Single-cell RNA-seq data of immune cells from COVID-19 patients showed a distinct caspase expression pattern in T cells, neutrophils, dendritic cells, and eosinophils compared with controls. Caspase-1 was upregulated in CD4+ T-cells from hospitalized COVID-19 patients compared with unexposed controls. Post-COVID-19 patients with lingering symptoms (long-haulers) also showed upregulated caspase-1activity in CD4+ T-cells that ex vivo was attenuated with a select pan-caspase inhibitor. We observed elevated caspase-3/7levels in red blood cells from COVID-19 patients compared with controls that was reduced following caspase inhibition.

DISCUSSION

Our preliminary results suggest an exuberant caspase response in COVID-19 that may facilitate immune-related pathological processes leading to severe outcomes. Further clinical correlations of caspase expression in different stages of COVID-19 will be needed.

CONCLUSION

Pan-caspase inhibition could emerge as a therapeutic strategy to ameliorate or prevent severe COVID-19.

Assessment of intracellular cytokines and regulatory cells in patients with autoimmune diseases and primary immunodeficiencies - novel tool for diagnostics and patient follow-up

Serum and intracytoplasmic cytokines are mandatory in host defense against microbes, but also play a pivotal role in the pathogenesis of autoimmune diseases by initiating and perpetuating various cellular and humoral autoimmune processes. The intricate interplay and fine balance of pro- and anti-inflammatory processes drive, whether inflammation and eventually organ damage will occur, or the inflammatory cascade quenches. In the early and late, as well as inactive and active stages of autoimmune diseases, different cellular and molecular patterns can dominate in these patients. However, the simultaneous assessment of pro- and anti-inflammatory biomarkers aids to define the immunological state of a patient. A group of the most useful inflammatory biomarkers are cytokines, and with increasing knowledge during the last decade their role have been well-defined in patients with autoimmune diseases and immunodeficiencies. Multiple pathological processes drive the development of autoimmunity and immunodeficiencies, most of which involve quantitative and qualitative disturbances in regulatory cells, cytokine synthesis and signaling pathways. The assessment of these biomarkers does not aid only in the mechanistic description of autoimmune diseases and immunodeficiencies, but further helps to subcategorize diseases and to evaluate therapy responses. Here, we provide an overview, how monitoring of cytokines and regulatory cells aid in the diagnosis and follow-up of patients with autoimmune diseases and immunodeficiencies furthermore, we pinpoint novel cellular and molecular diagnostic possibilities in these diseases.

Altered Th17 cells and Th17/regulatory T-cell ratios indicate the subsequent conversion from undifferentiated connective tissue disease to definitive systemic autoimmune disorders

A shift in the balance between Th17-cells and regulatory T-cells (Treg) is an important feature of systemic autoimmune diseases (SAID), and may also contribute to their development. Hereby, we assessed the distribution of peripheral Th17 and Treg-cells in patients with undifferentiated connective tissue disease (UCTD), the forerunner of SAIDs and followed these parameters during the development towards definitive SAIDs. Fifty-one UCTD patients were investigated and followed-up for 3 years. Flow cytometry was used to identify and follow three cell-populations: Th17-cells (CD4+IL-17+ T-cells), natural regulatory T-cells (CD4(+)CD25(bright)FoxP3(+); nTregs) and IL-10 producing Type-1 regulatory T-cells (CD4+IL-10+ T-cells; Tr1). Altogether 37.3% of these patients progressed into SAIDs. Th17-cells were increased in UCTD vs. controls, which further increased in those, whom developed SAIDs eventually. The Th17/nTreg ratio gradually increased from controls through UCTD patients, reaching the highest values in SAID-progressed patients. Regarding the Th17/Tr1 ratios, a similar tendency was observed moreover Th17/Tr1 could distinguish between UCTD patients with, or without subsequent SAID progression in a very early UCTD stage. Various immunoserological markers showed association with Th17 and Th17/nTreg at baseline, indicating the consecutive development of a distinct SAID. The derailed Th17/Treg balance may contribute to disease progression therefore could function as a prognostic marker.

The Peripheral Immune System and Traumatic Brain Injury: Insight into the role of T-helper cells

Emerging evidence suggests that immune-inflammatory processes are key elements in the physiopathological events associated with traumatic brain injury (TBI). TBI is followed by T-cell-specific immunological changes involving several subsets of T-helper cells and the cytokines they produce; these processes can have opposite effects depending on the disease course and cytokine concentrations. Efforts are underway to identify the T-helper cells and cytokine profiles associated with prognosis. These predictors may eventually serve as effective treatment targets to decrease morbidity and mortality and to improve the management of TBI patients. Here, we review the immunological response to TBI, the possible molecular mechanisms of this response, and therapeutic strategies to address it.

Effects of anesthetic methods on preserving anti-tumor T-helper polarization following hepatectomy

AIM: To investigate the impact of different anesthetic techniques on T-helper (Th) cell subsets in hepatocellular carcinoma (HCC) patients undergoing hepatectomy.

METHODS: Sixty-one HCC patients who received hepatectomies were randomized into an epidural combined general anesthesia (G + E; n = 31) or a general anesthesia (G; n = 30) group. Blood samples were obtained the morning before the operation (d0), and on the second (d2) and seventh (d7) day after the operation. Th cell contents were evaluated using flow cytometry, real-time reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay.

RESULTS: In all 61 patients, Th1 and Th2 cell frequencies, and interferon-γ (IFN-γ) mRNA expression markedly increased on d2, compared to d0. They recovered slightly on d7, and the Th1/Th2 ratio increased markedly on d7, compared with d2. In contrast, Th17, regulatory T cell (Treg), and interleukin-17 (IL-17) levels and FOXP3 mRNA expression showed no significant change on d2, and then markedly decreased on d7. Similarly, plasma IFN-γ concentration on d2 was much higher than that on d0, and then partly recovered on d7. As compared with the G group, in the G + E group, Th1 cell frequencies and the Th1/Th2 ratio were slightly higher on d2 and significantly higher on d7, while Th2, Th17, and Treg cell frequencies were slightly lower on d2, and significantly lower on d7. Consistently, on d7, IFN-γ mRNA and protein levels and the IFN-γ/IL-4 ratio in the G + E group were higher than those in the G group. In contrast, the IL-17 mRNA level, and IL-17 and transforming growth factor-β₁ concentrations in the G + E group were lower than those in the G group.

CONCLUSION: G + E is superior to G in shifting the Th1/Th2 balance towards Th1, while decreasing Th17 and Treg, potentially benefiting HCC patients by promoting anti-tumor Th polarization.

Endometriosis Patients Show an Increased M2 Response in the Peritoneal CD14+low/CD68+low Macrophage Subpopulation Coupled with an Increase in the T-helper 2 and T-regulatory Cells

Endometriosis is a chronic inflammatory disease associated with an impaired immune response at the site of lesion implantation. The ability of macrophages to respond to changes in their environment is critical for an effective immune response. However, the existing knowledge of the peritoneal immune cell populations, their activation state and contribution to the immunological changes that occur in endometriosis are still controversial and inconclusive. In this study, we have examined the relative abundance of peritoneal macrophage subtypes, in women with (n = 21) versus without (n = 18) endometriosis and disease-associated changes in the adaptive T cell response. Using flow cytometry, we showed that peritoneal fluid monocyte/macrophages are composed of two populations of cells that exhibit major differences in the levels of the CD14 and CD68 markers, which we classified as the CD14^+low/CD68^+low and CD14^+high/CD68^+high subpopulations. Moreover, endometriosis-associated changes in the macrophage subtypes occurred only in the CD14^+low/CD68^+low subpopulation. In this subpopulation, we found an increased macrophage type 2 response that was coupled with an increase in peritoneal T-helper 2 and T-regulatory cell populations in women with endometriosis, compared with controls. In summary, this study resolves conflicting data in the literature regarding changes in the peritoneal immune cell population in endometriosis and identifies CD14^+low/CD68^+low macrophages as the subpopulation that changes in response to the disease.

Recent advances in understanding chronic rhinosinusitis endotypes

Chronic rhinosinusitis (CRS) is a heterogeneous inflammatory disease with an as-yet-undefined etiology. The management of CRS has historically been phenotypically driven, and the presence or absence of nasal polyps has frequently guided diagnosis, prognosis, and treatment algorithms. Research over the last decade has begun to question the role of this distinction in disease management, and renewed attention has been placed on molecular and cellular endotyping and a more personalized approach to care. Current research exploring immunologic mechanisms, inflammatory endotypes, and molecular biomarkers has the potential to more effectively delineate distinct and clinically relevant subgroups of CRS. The focus of this review will be to discuss and summarize the endotypic characterization of CRS and the potential diagnostic and therapeutic implications of this approach to disease management.

Shenghua Decoction reduces uterine bleeding and regulates T-cell paradigm in human deciduas of RU486 medical abortion

ETHNOPHARMACOLOGICAL RELEVANCE

Excessive uterine bleeding is the most common and problematic side effect of RU486 medical abortion. Shenghua Decoction (SHD) is a well-known traditional Chinese herbal prescription for reducing uterine bleeding induced by RU486 medical abortion. However, its therapeutic mechanism still remains unclear. The Th1/Th2/Th17/Treg paradigm plays an important role in achieving maternal-fetal immunotolerance and its bias participates in RU486-induced abortion. Our previous research on mice demonstrated that the uterine bleeding volume is negatively related to the proportions of Th1 and Th17 cells whereas positively related to the proportions of Th2 and Treg cells. Additionally, Th1-type cytokine inducing effect was identified in our previous study. Therefore, it was hypothesized that SHD reduced the uterine bleeding in RU486 medical abortion by inducing Th1/Th2/Th17/Treg paradigm bias. The purpose of this study was to determine the regulatory effect and the mechanism of SHD on human decidual Th1/Th2/Th17/Treg paradigm for alleviating uterine bleeding in RU486 medical abortion.

MATERIALS AND METHODS

90 women within seven weeks of a normal intrauterine pregnancy, who elected for termination of pregnancy, were divided into three groups; vacuum aspiration group, RU486 group, and SHD-RU486 group. Duration of uterine bleeding was recorded and volume of uterine bleeding was measured by the method of alkaline hematin photometric. To determine the regulatory effect of SHD on Th1/Th2/Th17/Treg paradigm, the proportions of Th1/Th2/Th17/Treg cells in the decidua of different groups were analyzed using a FACS calibur. Correlation was analyzed in order to demonstrate the relationship between the Th1/Th2/Th17/Treg paradigm and the uterine bleeding in RU486 medical abortion. Moreover, to elucidate the mechanism underlying the T-cell paradigm regulating of SHD, the mRNA and protein expressions of subset-specific transcription factors (T-bet, GATA-3, RORγt, and Foxp3) for the differentiation of Th1/Th2/Th17/Treg paradigm in human decidual CD4(+) T cells were detected by reverse transcription-polymerase chain reaction (RT-PCR) assay and western blot analysis respectively. Moreover, the mRNA expression of the characteristic cytokines of Th1/Th2/Th17/Treg paradigm (IFNγ, IL-4, IL-17A, TGF-β) were analyzed by RT-PCR assay.

RESULT

Compared with RU486 group, both the uterine bleeding volume and duration reduced significantly in SHD-RU486 group. Both the duration and the volume of the uterine bleeding demonstrated negative correlation with the proportions of Th1 and Th17 cells, whereas showed positive correlation with Th2 and Treg cells. SHD increased the proportions of Th1 and Th17 cells whereas decreased those of Th2 and Treg cells. Thus, the ratios of Th1/Th2 and Th17/Treg cells elevated markedly after SHD treatment. SHD promoted the mRNA as well as the protein expressions of subset-specific transcription factors for the differentiation of Th1 and Th17 subsets (T-bet and RORγt) while inhibited those of Th2 and Treg cells (GATA-3 and Foxp3). Moreover, the mRNA expression of Th1- and Th17- type cytokines (IFNγ and IL-17A) was up-regulated while that of Th2-type and Treg-produced cytokines (IL-4 and TGF-β) was down-regulated significantly after SHD administration.

CONCLUSION

Th1/Th2/Th17/Treg paradigm bias was involved in RU486 medical abortion. SHD reduced the uterine bleeding efficiently by inducing Th1 and Th17 skews in the maternal-fetal of RU486 medical abortion patients. The regulatory effect of SHD on Th1/Th2/Th17/Treg paradigm in RU486 medical abortion is attributed to the modulation of transcription and protein expression of subset-specific transcription factors for T-cell subsets differentiation and their characteristic cytokines.

Genomic Analysis of Oral Lichen Planus and Related Oral Microbiome Pathogens

Oral lichen planus (OLP) is a common chronic inflammatory disease affecting the oral mucosa. The pathogenesis of OLP is incompletely understood but is thought to be related to the immune system. As the oral cavity is a major reservoir and transmission gateway for bacteria, viruses, and fungi, the microbial composition of the oral cavity could play a role in the pathogenesis of OLP. However, limited by analytic technology and knowledge of the microbial community in the oral cavity, it is not yet clear which pathogens are associated with OLP. Next generation sequencing (NGS) is a powerful tool to identify pathogens for many infectious diseases. In this study, we compared the host cell gene expression profiles and the microbial profiles between OLP patients and matched healthy individuals. We identified the activation of the hepatocyte nuclear factor alpha (HNF4A) network in OLP patients and potential pathogens, including Corynebacterium matruchotii, Fusobacterium periodonticum, Streptococcus intermedius, Streptococcus oralis, and Prevotella denticola. Prevotella denticola is capable of activating the HNF4A gene network. Our findings shed light on the previously elusive association of OLP with various diseases like hepatitis, and indicate that OLP is a T-helper type 17 (Th17) mediated mucosal inflammatory process. The identified molecular pathways and microbes could be used to inform future investigations into OLP pathogenesis and to develop novel therapeutics for OLP treatment.

T-helper cell receptors from long-term survivors after telomerase cancer vaccination for use in adoptive cell therapy

We herein report retargeting of T-helper (Th) cells against the universal cancer antigen telomerase for use in adoptive cell therapy. The redirected Th cells may counter tumor tolerance, transform the inflammatory milieu, and induce epitope spreading and cancer senescence. We have previously conducted a series of trials evaluating vaccination with telomerase peptides. From long-term survivors, we isolated >100 CD4⁺ Th-cell clones recognizing telomerase epitopes. The clones were characterized with regard to HLA restriction, functional avidity, fine specificity, proliferative capacity, cytokine profile, and recognition of naturally processed epitopes. DP4 is the most prevalent HLA molecule worldwide. Two DP4-restricted T-cell clones with different functional avidity, C13 and D71, were selected for molecular T-cell receptor (TCR) cloning. Both clones showed a high proliferative capacity, recognition of naturally processed telomerase epitopes, and a polyfunctional and Th1-weighted cytokine profile. TCR C13 and D71 were cloned into the retroviral vector MP71 together with the compact and GMP-applicable marker/suicide gene RQR8. Both TCRs were expressed well in recipient T cells after PBMC transduction. The transduced T cells co-expressed RQR8 and acquired the desired telomerase specificity, with a polyfunctional response including production of TNFa, IFNγ, and CD107a. Interestingly, the DP4-restricted TCRs were expressed and functional both in CD4⁺ and CD8⁺ T cells. The findings demonstrate that the cloned TCRs confer recipient T cells with the desired hTERT-specificity and functionality. We hypothesize that adoptive therapy with Th cells may offer a powerful novel approach for overcoming tumor tolerance and synergize with other forms of immunotherapy.

T-cell clones from Th1, Th17 or Th1/17 lineages and their signature cytokines have different capacity to activate endothelial cells or synoviocytes

OBJECTIVE

To compare the direct effect of cytokines on synoviocytes and endothelial cells to the effects of supernatants from Th1, Th17 and Th1/17 clones and the direct cell-cell interactions with the same clones.

METHODS

Th17 and Th1/17 clones were obtained from the CD161+CCR6+ fraction and Th1 clones from the CD161-CCR6- fraction of human CD4+ T-cells. Endothelial cells or synoviocytes were cultured in the presence of either isolated pro-inflammatory cytokines (IL-17 and/or TNF-α) or supernatants from the T-cell clones or co-cultured with T-cell clones themselves. IL-6 and IL-8 expression and production were analyzed.

RESULTS

IL-17 and TNF-α induced IL-6 and IL-8 expression, although IL-17 alone had a limited effect on endothelial cells compared to synoviocytes. Supernatants from activated T-helper clones also induced IL-6 and IL-8 expression but with discrepancies between endothelial cells and synoviocytes. Endothelial cells were mostly activated by Th1 clone supernatants whereas synoviocytes were activated by all T-cell subtypes. Finally, cell-cell contact experiments showed a great heterogeneity among cell clones, even from the same lineage. IL-6 expression was mostly induced by contact with Th1 clones both in endothelial and mesenchymal cells whereas IL-8 expression was induced by all T-cell clones whatever their phenotype.

CONCLUSION

We showed that endothelial cells were much more sensitive to Th1 activation whereas synoviocytes were activated by all T-helper lineages. This work highlights the heterogeneity of interactions between T-cells and stromal cells through soluble factors or direct cell contact.

T-helper-associated cytokines expression by peripheral blood mononuclear cells in patients with polypoidal choroidal vasculopathy and age-related macular degeneration

Background

Immune responses play a key role in the pathogenesis and progression of polypoidal choroidal vasculopath (PCV) and age-related macular degeneration (AMD). In this study, we determined the Th cell-associated immune responses by measuring the cytokine expression of peripheral blood mononuclear cells (PBMC) in both PCV and neovascular AMD (nAMD) patients.

Methods

Twenty-seven nAMD patients, 33 PCV patients and a gender- and age-matched group of 18 healthy individuals were involved in this study. The Th-cell cytokine profiles including levels of interferon-gamma (INF-γ), interleukin (IL)-17A and IL-4 in cultures of PBMCs were determined by enzyme-linked immunosorbent assay (ELISA).

Results

IFN-γ,IL-17A and IL-4 production was significantly increased after stimulation with PHA. The levels of IFN-γ and IL-4 in PHA-stimulated cultures were higher in PCV and nAMD patients than that in healthy controls (P = 0.038,P = 0.014), while no difference was found between PCV and nAMD (all P > 0.05). No significant difference in IL-17A level in PHA-stimulated cultures was found among PCV, nAMD and control groups (P > 0.05).

Conclusions

These findings suggest that circulating IFN-γ and IL-4 producing Th1 and Th2 cells may involve in the pathogenesis of PCV and nAMD. PCV may have the similar immune responses with nAMD.

Therapeutic actions of melatonin on gastrointestinal cancer development and progression

Melatonin exerts a multitude of physiological functions including the regulation of the sleep cycle and circadian rhythm. Although the synthesis of melatonin in the pineal gland is regulated by changes in the light/dark cycle, the release of melatonin in the gastrointestinal tract is related to food consumption. Melatonin regulates antioxidative processes and it improves T-helper cell response by stimulating the production of specific cytokines. Melatonin is directly involved in preventing tumor initiation, promotion, and progression in a variety of cancers of the gastrointestinal tract including colorectal cancer, cholangiocarcinoma, hepatocarcinoma, and pancreatic carcinoma. This paper is a review of the literature regarding melatonin in the gastrointestinal tract and as a potential therapy for gastrointestinal cancers.

Transient redirection of T cells for adoptive cell therapy with telomerase-specific T helper cell receptors isolated from long term survivors after cancer vaccination

Adoptive cell therapy (ACT) with retargeted T cells has produced remarkable clinical responses against cancer, but also serious toxicity. Telomerase is overexpressed in most cancers, but also expressed in some normal cells, raising safety concerns. We hypothesize that ACT with T-helper cell receptors may overcome tumour tolerance, mobilize host immune cells and induce epitope spreading, with limited toxicity. From long term survivors after cancer vaccination, we have isolated telomerase-specific T cell receptors (TCRs) from T-helper cells. Herein, we report the development of transient retargeting of T cells with mRNA-based TCRs. This strategy allows for safer clinical testing and meaningful dose escalation. DP4 is the most common HLA molecule. We cloned two telomerase-specific, DP4-restricted TCRs into the mRNA expression vector pCIpA102, together with the sorter/marker/suicide gene RQR8. Donor T cells were electroporated with mRNA encoding TCR_RQR8. The results showed that both TCR_RQR8 constructs were expressed in >90% of T cells. The transfected T cells specifically recognized the relevant peptide, as well as naturally processed epitopes from a 177aa telomerase protein fragment, and remained functional for six days. A polyfunctional and Th1-like cytokine profile was observed. The TCRs were functional in both CD4+and CD8+recipient T cells, even though DP4-restricted. The findings demonstrate that the cloned TCRs confer recipient T cells with the desired telomerase-specificity and functionality. Preclinical experiments may provide limited information on the efficacy and toxicity of T-helper TCRs, as these mobilize the host immune system. We therefore intend to use the mRNA-based TCRs for a first-in-man trial.

3,3'-Diindolylmethane alleviates acute atopic dermatitis by regulating T cell differentiation in a mouse model

Atopic dermatitis is a severe, chronic relapsing inflammatory disease of the skin with family clustering. It is characterized into acute phase, which is dominated by T helper 2-type immune responses, and chronic phase, which is dominated by T helper 1-type immune responses. Studies have shown that 3,3'-diindolylmethane not only has antitumor effects but also can relieve symptoms of inflammatory diseases by inhibiting the nuclear factor-κB signaling pathway and regulating T cell differentiation. To study the effect of 3,3'-diindolylmethane on atopic dermatitis and the underlying mechanism, a mouse model of acute atopic dermatitis was established using 2,4-dinitrofluorobenzene. After intraperitoneal injection of 3,3'-diindolylmethane, skin erythema and edema in mice were significantly alleviated. Furthermore, 3,3'-diindolylmethane reduced immune activation, probably by inhibiting the secretion of thymic stromal lymphopoietin by keratinocytes. 3,3'-Diindolylmethane also promoted the differentiation of regulatory T cells and inhibited the activation of T helper 2 and T helper 17 cells to reduce atopic dermatitis-related immune responses. However, it showed no significant effect on the differentiation of T helper 1 cells. These results indicate that 3,3'-diindolylmethane has a significant inhibitory effect on T helper 2 cells in the acute phase of atopic dermatitis. Our findings may provide not only more insights into the pathological mechanism of AD, but also a new candidate medicine for it.

Interleukin-22: a likely target for treatment of autoimmune diseases

Interleukin-22 (IL-22) is a member of IL-10 family cytokines that is produced by many different types of lymphocytes including both those of the innate and adaptive immune systems. This includes activated T cells, most notably Th17 and Th22 cells, and NK cells, γδ T cells, LTi cells and LTi-like cells. IL-22 mediates its effects via the IL-22-IL-22R complex and subsequent Janus kinase-signal transducer and activators of transcription (JAK-STAT) signaling pathway. Recently accumulated evidence has indicated that IL-22 also plays an important role in the pathogenesis of many autoimmune diseases. In this review, we discuss the recent findings and advancement of the role for IL-22 in several autoimmune diseases, such as psoriasis, rheumatoid arthritis (RA), hepatitis, graft versus host disease (GHVD) and allergic diseases, implicating that target IL-22 may have a therapeutic potential in those autoimmune diseases.