The Distribution and the Fibrotic Role of Elevated Inflammatory Th17 Cells in Patients With Primary Biliary Cirrhosis

T helper (Th) 17 cells were reported to have the property of proinflammation and profibrosis. We first investigate the levels of Th17 cells in primary biliary cirrhosis (PBC) patients, and then explore their distribution and fibrotic role in the disease.We compared the circulating Th17 and hepatic interleukin (IL)-17-positive cells between patients and healthy controls (HCs) at different disease stages by flow cytometry and immunohistochemistry, respectively. The levels of chemokine (c-c motif) ligand (CCL) 20 were then measured. For exploration of the reason why Th17 cells increased, CD4⁺CD161⁺ populations were sorted and cultured with IL-23 and IL-1β to analyze their proliferation and IL-17 secretions. The serum IL-23 and IL-1β were tested by enzyme-linked immunosorbent assay. The proliferation and expressions of α-smooth muscle actin and IL-8 of hepatic stellate cells (HSCs) were identified after stimulated by different concentrations of IL-17.Circulating and hepatic Th17 cells were elevated in PBC patients compared with HCs. Early PBC patients presented with more Th17 cells in periphery blood and less in the liver than advanced PBC patients. Accordingly, the levels of both serum and hepatic CCL20 for Th17 cells were higher, especially in those with advanced disease. The progenitor of Th17, CD4⁺CD161⁺ cell was increased in PBC. Moreover, the percentage of Th17 cells was positively related with CD4⁺CD161⁺ cell. After stimulation with IL-23 and IL-1β which were improved in PBC patients, CD4⁺CD161⁺ cells from PBC patients expressed more IL-17, although their proliferation were not different between 2 groups. IL-17 can promote the proliferation of HSCs at a dose-dependent method, and also increase the IL-8 expression in a dose/time-dependent way. Anti-IL-17 can neutralize the above reactions.CD4⁺CD161⁺ cells are a source of increased Th17 in PBC patients. With disease progression, Th17 population decreased in the circulation, accompanied by greater accumulation in the liver, which is regulated by CCL20 in advanced patients. IL-17 may be involved in the process of PBC fibrosis.     

Assessment of frequency of micronucleated exfoliated buccal cells in relation to oxidative stress in oral lichen planus in coastal Karnataka,India

ObjectiveTo assess the frequency of micronucleus in exfoliated buccal mucosa cells of patients with oral lichen planus (OLP) in relation to free radical toxicity since OLP is considered to be a precancerous lesion.MethodsThe micronucleus frequency in exfoliated buccal mucosa cells of patients with OLP was assessed and compared to those in healthy subjects.ResultsA significant increase (P<0.004) in frequency of micronucleated exfoliated cells (MEC) was observed in patients with OLP when compared to normal subjects.ConclusionsIt can be concluded that DNA damage in MEC of OLP patients may be a consequence of increased free radical toxicity.     

Human Langerhans cells induce distinct IL-22-producing CD4+ T cells lacking IL-17 production

IL-22 is a cytokine that acts mainly on epithelial cells. In the skin, it mediates keratinocyte proliferation and epidermal hyperplasia and is thought to play a central role in inflammatory diseases with marked epidermal acanthosis, such as psoriasis. Although IL-22 was initially considered a Th17 cytokine, increasing evidence suggests that T helper cells can produce IL-22 even without IL-17 expression. In addition, we have shown the existence of this unique IL-22-producing T cell in normal skin and in the skin of psoriasis and atopic dermatitis patients. In the present study, we investigated the ability of cutaneous resident dendritic cells (DCs) to differentiate IL-22-producing cells. Using FACS, we isolated Langerhans cells (LCs; HLA-DR⁺CD207⁺ cells) and dermal DCs (HLA-DR^hiCD11c⁺BDCA-1⁺ cells) from normal human epidermis and dermis, respectively. Both LCs and dermal DCs significantly induced IL-22-producing CD4⁺ and CD8⁺ T cells from peripheral blood T cells and naive CD4⁺ T cells in mixed leukocyte reactions. LCs were more powerful in the induction of IL-22-producing cells than dermal DCs. Moreover, in vitro-generated LC-type DCs induced IL-22-producing cells more efficiently than monocyte-derived DCs. The induced IL-22 production was more correlated with IFN-γ than IL-17. Surprisingly, the majority of IL-22-producing cells induced by LCs and dermal DCs lacked the expression of IL-17, IFN-γ, and IL-4. Thus, LCs and dermal DCs preferentially induced helper T cells to produce only IL-22, possibly “Th22” cells. Our data indicate that cutaneous DCs, especially LCs, may control the generation of distinct IL-22 producing Th22 cells infiltrating into the skin.     

Generation and regulation of human CD4+ IL-17-producing T cells in ovarian cancer

Despite the important role of Th17 cells in the pathogenesis of many autoimmune diseases, their prevalence and the mechanisms by which they are generated and regulated in cancer remain unclear. Here, we report the presence of a high percentage of CD4⁺ Th17 cells at sites of ovarian cancer, compared with a low percentage of Th17 cells in peripheral blood mononuclear cells from healthy donors and cancer patients. Analysis of cytokine production profiles revealed that ovarian tumor cells, tumor-derived fibroblasts, and antigen-presenting cells (APCs) secreted several key cytokines including IL-1β, IL-6, TNF-α and TGF-β, which formed a cytokine milieu that regulated and expanded human IL-17-producing T-helper (Th17) cells. We further show that IL-1β was critically required for the differentiation and expansion of human Th17 cells, whereas IL-6 and IL-23 may also play a role in the expansion of memory Th17 cells, even though IL-23 levels are low or undetectable in ovarian cancer. Further experiments demonstrated that coculture of naïve or memory CD4⁺ T cells with tumor cells, APCs, or both could generate high percentages of Th17 cells. Treatment with anti-IL-1 alone or a combination of anti-IL-1 and anti-IL-6 reduced the ability of tumor cells to expand memory Th17 cells. Thus, we have identified a set of key cytokines secreted by ovarian tumor cells and tumor-associated APCs that favor the generation and expansion of human Th17 cells. These findings should accelerate efforts to define the function of this important subset of CD4⁺ T cells in the human immune response to cancer.     

Optimal induction of T helper 17 cells in humans requires T cell receptor ligation in the context of Toll-like receptor-activated monocytes

Recently, a new lineage of CD4⁺ T cells has been described in the mouse that specifically secretes IL-17 [T helper (Th) 17]. This discovery has led to a revision of the hypothesis that many autoimmune diseases are predominantly a Th1 phenomenon and may instead be critically dependent on the presence of Th17 cells. Murine Th17 cells differentiate from naïve T cell precursors in the presence of TGF-β and IL-6 or IL-21. However, given their putative importance in human autoimmunity, very little is known about the pathways that control the expression of IL-17 in humans. Here we show that the factors that determine the expression of IL-17 in human CD4⁺ T cells are completely different from mice. IL-6 and IL-21 were unable to induce IL-17 expression in either naïve or effector T cells, and TGF-β actually inhibited IL-17 expression. The expression of IL-17 was maximally induced from precommitted precursors present in human peripheral blood by cell–cell contact with Toll-like receptor-activated monocytes in the context of T cell receptor ligation. Furthermore, unlike IFN-γ, IL-17 expression was not suppressed by the presence of FOXP3⁺ regulatory CD4⁺ T cells. Taken together, these data indicate that human and mouse Th17 cells have important biological differences that may be of critical importance in the development of therapeutic interventions in diseases characterized by aberrant T cell polarization.     

Regulatory Role of CD4+CD25+Foxp3+ Regulatory T Cells on IL-17-Secreting T Cells in Chronic Hepatitis B Patients

Background

Both interleukin (IL)-17-secreting CD4⁺ T (Th17) and CD4⁺CD25⁺Foxp3⁺ T regulatory (Treg) cells have been shown to be associated with disease progression or liver damage in chronic hepatitis B (CHB) patients. However, the relationship between Treg cells and IL-17-secreting T cells in hepatitis B virus (HBV) infections is unclear.

Methods

The frequencies of Treg cells and IL-17-secreting T cells in hepatitis B e antigen (HBeAg)-positive CHB patients and healthy subjects were measured by flow cytometric analysis. The role of Treg cells on the differentiation of Ag-specific IL-17-secreting T cells was determined by removing the Treg cells from peripheral blood mononuclear cells (PBMCs) in HBeAg-positive CHB patients.

Results

The frequencies of both Th17 (1.71 ± 0.58 vs. 1.08 ± 0.36 %; P < 0.01) and Treg cells (8.92 ± 4.11 vs. 6.45 ± 1.56 %; P < 0.01) were increased in the peripheral blood of HBeAg-positive CHB patients compared with healthy controls, but in not the IL-17-secreting CD8⁺ T (Tc17) cells. The frequency of Treg cells was significantly associated with that of Th17 cells (r = 0.625, P = 0.001) in CHB patients. Spearman analysis showed a positive correlation between the frequency of Treg cells and HBV DNA load (r = 0.508, P = 0.008), as well as between the frequency of Th17 cells and serum alanine aminotransferase level (r = 0.516, P = 0.007). The deletion of Treg cells significantly enhanced both Th17 and Tc17 cell development in PBMCs following recombinant HBV core antigen stimulation.

Conclusions

Our data indicate a clear inverse relationship between Th17 cells and Treg cells and that Treg cells can inhibit Th17 cell development in CHB patients.     

Increased levels of circulating Th17 cells in quiescent versus active Crohn's disease

Background and aimsTh17 cells, a subset of CD4 + T cells that produce interleukin (IL)-17A, IL-17F, IL-21, IL-22, IL-26, and the chemokine CCL20 are critically involved in the mucosal inflammation observed in Crohn's disease (CD). However, their role as mediators of inflammation in CD has been questioned by a recent clinical trial in which anti-IL-17A (secukinumab) treatment was ineffective. Besides being pro-inflammatory, Th17-related cytokines mediate mucosal protective functions. We aimed to investigate the role of Th17 cells in CD inflammation.MethodsBlood samples from 26 patients with active CD and 10 healthy controls (HC) were analyzed for levels of IL-17A-, IL-21- and IL-22-producing CD45RO+CD4 + T cells using multicolor flow cytometry. Samples were analyzed before and during adalimumab treatment to compare intra-individual changes during active and quiescent disease.ResultsCD patients had statistically significantly higher levels of IL-17-A-, IL-21- and IL-22-producing CD45RO+CD4 + T cells in both active and quiescent disease compared with HC. Baseline levels of IL-21 and IL-22 producing CD45RO+CD4 + T cells correlated inversely with mucosal inflammation estimated by fecal calprotectin. Patients who responded to adalimumab treatment demonstrated a 2- to 3-fold increase in levels of IL-17A- and IL-21-producing CD45RO+CD4 + T cells in quiescent disease compared with active disease.ConclusionOur data support the involvement of Th17 cells and IL-21- and IL-22-producing CD45RO+CD4 + T cells in CD. Because patients had higher levels in quiescent disease compared with active CD, we question whether Th17 cells are promoters of inflammation. Instead, Th17 cells may counterbalance inflammation and maintain gut homeostasis.     

Th17 lymphocytes in atypical cutaneous leishmaniasis caused by Leishmania (L.) infantum chagasi in Central America

Skin lesions in nonulcerated cutaneous leishmaniasis (NUCL) caused by Leishmania (L.) infantum chagasi are characterized by a mononuclear inflammatory infiltrate in the dermis, which is composed mainly of lymphocytes, followed by macrophages, few plasma cells and epithelioid granulomas with mild tissue parasitism. Previous studies have shown that the main population of lymphocytes present in the dermal infiltrate is CD8⁺ T cells, followed by CD4⁺ T cells, which are correlated with IFN-γ⁺ cells. To improve the knowledge of cellular immune responses in NUCL, skin biopsies were submitted to immunohistochemistry using anti-ROR-γt, anti-IL-17, anti-IL-6, anti-TGF-β, and anti-IL-23 antibodies to characterize the involvement of Th17 cells in the skin lesions of patients affected by NUCL. ROR-γt⁺, IL-17⁺, IL-6⁺, TGF-β⁺ and IL-23⁺ cells were observed in the dermal inflammatory infiltrate of NUCL skin lesions. A positive correlation between CD4⁺ T-lymphocytes and ROR-γt⁺ and IL-17⁺ cells suggests that some of the CD4⁺ T-lymphocytes in NUCL could be Th17 lymphocytes. Moreover, a positive correlation between ROR-γt⁺ cells and TGF-β⁺, IL-6⁺, IL-17⁺ and IL-23⁺ cells could indicate the role of these cytokines in the differentiation and maintenance of Th17 lymphocytes. Our findings improve knowledge of the pathogenesis of this rare and atypical clinical form of leishmaniasis.     

A potential immunopathogenic role for reduced IL-35 expression in allergic asthma

Objective: Allergic asthma is a chronic airway inflammation resulting from an imbalance of T helper (Th) cell responses to allergens. Interleukin (IL)-35 has been shown to have potent immunoregulatory properties. Whether IL-35 participates in the immunopathogenesis of allergic asthma patients is still unknown. Methods: CD4⁺ T cells and CD4⁺CD25^? T cells were obtained from peripheral blood mononuclear cells (PBMCs) using magnetic separation. The concentration of IL-35 in plasma was measured by enzyme-linked immunosorbent assay (ELISA). The mRNA expression levels of the IL-35 subunits, EBI3 and IL-12p35, were detected by quantitative real-time PCR (qPCR). The proliferative responses of CFSE-labeled CD4⁺CD25^? T cells in the presence or absence of rhIL-35 were evaluated by flow cytometry. Cytokine production of activated CD4⁺CD25^? T cells was examined by flow cytometry and ELISA. Results: IL-35 protein and mRNA levels were decreased in allergic asthmatics. The frequencies of CD4⁺CD25⁺Foxp3⁺ Tregs and CD4⁺IL-12p35⁺ T cells in allergic asthma patients were lower than in healthy controls. Moreover, the addition of rhIL-35 suppressed CFSE⁺CD4⁺CD25^? T cell proliferation in vitro in a dose-dependent manner, and the suppression induced by rhIL-35 was associated with decreases in IL-4 but not IFN-γ and IL-17 production of activated CD4⁺CD25^? T cells. The increased level of Th1/Th2 was observed in allergic asthmatics in the presence of rhIL-35. Conclusions: Our data suggest that IL-35 can effectively suppress the proliferation and IL-4 production of activated CD4⁺CD25^? T cells in allergic asthma, and that IL-35 may be a new immunotherapy for asthma patients.     

MMP-28在口腔扁平苔藓中的表达及意义

目的探讨基质金属蛋白酶-28（MMP-28）在口腔扁平苔藓（OLP）形成中的机制。方法分别采用免疫组化和Western Blot法检测MMP-28蛋自在37例不同类型OLP中的表达,并与11份正常口腔黏膜标本进行比较。结果OLP息者中MMP-28表达明显高于正常口腔黏膜组织,且糜烂型表达明显高于其他类型;OLP患者中MMP-28表达与性别、年龄及病损面积无明显相关。结论MMP-28表达与OLP分型密切相关,随病变程度加重逐渐升高;检测MMP-28蛋白表达有助于预测OLP的恶性行为;抑制MMP-28有望成为OLP治疗的新途径。     

Peroxisome proliferator-activated receptor (PPAR)α and -γ regulate IFNγ and IL-17A production by human T cells in a sex-specific way

Women develop certain autoimmune diseases more often than men. It has been hypothesized that this may relate to the development of more robust T-helper (Th)1 responses in women. To test whether women exhibit a Th1 bias, we isolated naïve cluster of differentiation (CD)4⁺ T cells from peripheral blood of healthy women and men and measured the proliferation and cytokine production by these cells in response to submaximal amounts of anti-CD3 and anti-CD28. We observed that CD4⁺ T cells from women produced higher levels of IFNγ as well as tended to proliferate more than male CD4⁺ T cells. Intriguingly, male CD4⁺ T cells instead had a predilection toward IL-17A production. This sex dichotomy in Th cytokine production was found to be even more striking in the Swiss/Jackson Laboratory (SJL) mouse. Studies in mice and humans indicated that the sexual dimorphism in Th1 and Th17 cytokine production was dependent on the androgen status and the T-cell expression of peroxisome proliferator activated receptor (PPAR)α and PPARγ. Androgens increased PPARα and decreased PPARγ expression by human CD4⁺ T cells. PPARα siRNA-mediated knockdown had the effect of increasing IFNγ by male CD4⁺ T cells, while transfection of CD4⁺ T cells with PPARγ siRNAs increased IL-17A production uniquely by female T cells. Together, our observations indicate that human T cells exhibit a sex difference in the production of IFNγ and IL-17A that may be driven by expressions of PPARα and PPARγ.     

Oral lichen planus pathogenesis: A role for the HCV-specific cellular immune response

Hepatitis C virus infection can be associated with different extrahepatic manifestations, including lichen planus; however, no clear role for HCV in their pathogenesis has been established. T cells were isolated from lichen biopsy specimens of 7 HCV positive patients with oral lichen planus. HCV-specific CD4(+) T-cell lines were obtained in 4 patients from lichen lesions but only in 2 of them from the peripheral blood. Different clonal populations were found in oral tissue and peripheral blood of individual patients, as shown by TCR-Vbeta analysis of antigen-specific T cells. Frequency of HCV-specific CD8(+) cells tested with 4 different HCV tetramers was significantly higher in the lichen tissue than in the circulation; moreover, lichen-derived HCV-specific CD8(+) T cells showed the phenotype of recently activated T cells because most of them were CD69(+) and produced interferon gamma (IFN-gamma) but expanded poorly in vitro upon antigen stimulation. The specificity of HCV-reactive T-cell recruitment into the lichen tissue was further confirmed by the absence of HBV-specific T cells within lichen lesions in 3 additional patients with lichen planus associated with HBV infection. Our study shows HCV-specific T-cell responses at the site of the lesions of an HCV-associated dermatologic disease, sustained by HCV-specific T cells with phenotypic and functional characteristics of terminally differentiated effector cells. In conclusion, this finding and the detection of HCV RNA strands in the lichen tissue strongly suggest a role for HCV-specific T-cell responses in the pathogenesis of oral lichen planus associated with HCV infection.     

T-regulatory cell/T helper 17 cell imbalance functions as prognostic biomarker of oral squamous cell carcinoma – CONSORT

Background:The role of T cells in the pathogenesis of oral squamous cell carcinoma (OSCC) was clarified by examining the levels of differentiated CD4⁺CD25⁺FOXP3⁺ T-regulatory cells (Treg cells) and CD4+IL17+ T helper 17 (Th17) cells in OSCC patients.Methods:Flow cytometry was conducted to measure the proportions of Treg/Th17 cells in different sample groups to identify a proper maker indicative of the progression and prognosis of OSCC.Results:The results showed that a higher Treg/Th17 ratio led to poorer prognosis. Also, the proportions of both Treg cells and Th17 cells were significantly elevated in OSCC patients compared with those in the control groups, suggesting a correlation between Treg/Th17 imbalance and the prognosis of OSCC. Furthermore, the ratios of Treg/Th17 cells in OSCC patients differed at different time points of cancer progression. For example, stage III-IV patients showed the most evident increase in the Treg/Th17 ratio, while the Treg/Th17 ratio in control subjects was the lowest.Conclusions:Therefore, a higher ratio of Treg/Th17 indicated the progression of OSCC and a larger tumor size. Therefore, Treg and Th17 imbalance was implicated in OSCC progression.     

Increased IL-6 expression on THP-1 by IL-34 stimulation up-regulated rheumatoid arthritis Th17 cells

IL-34 is a pleiotropic cytokine, which is a key regulator of monocytes/macrophages and might participate in the pathogenesis of RA. In this study, we aimed to explore the effect of IL-34 on the monocyte-like cell line THP-1 and the quantitative variation of Th17 cells in THP-1 and RA CD4⁺T cells coculture system. CD4⁺T cells were purified from RA PBMC using immunomagnetic beads. THP-1 were cultured with RA CD4⁺T cells. The frequency of Th17 cells was determined by FACS. Fluorscence indensity and expression of ROS were detected by FACS and cell staining, respectively. The expression of IL-6, IL-23, IL-21, TNF-α and IL-1β in the coculture supernatants were detected by ELISA. We found that CSF-1R was constitutively expressed on peripheral monocytes as well as THP-1, but not on the T/B cells. IL-34-CSF-1R binding could activate THP-1 to secret IL-6. IL-34 could up-regulate the numbers of Th17 cells in coculture system, which was possibly via the production of IL-6. We further observed ROS levels were increased in the coculture system. The percentage of Th17 cells was reduced when ROS production was inhibited by NAC, a specific inhibitor of ROS production. In addition, TNFRII antagonist but not IL-1βR antagonist could restrict the production of ROS, expression of IL-6 and generation of Th17 cells. In conclusion, IL-34-stimulated THP-1 can produce higher levels of ROS, which promoted IL-6 secretion and up-regulated Th17 cells. Our study suggests a novel mechanistic insight into how the interaction of IL-34-stimulated monocytes and CD4⁺T cells participates in the RA pathogenesis.     

The imbalance between regulatory and IL-17-secreting CD4+ T cells in lupus patients

It has been well recognized that a deficit of numbers and function of CD4⁺CD25⁺Foxp3⁺ cells (Treg) is attributed to the development of some autoimmune diseases; however, there are controversial data regarding the suppressive effect of Treg cells on the T cell response in systemic lupus erythematosus (SLE). Additionally, IL-17-producing cells (Th17) have been recently emerged as a new pathogenic cell, but their role in lupus remains unclear. In this study, we studied the connection between Treg and Th17 cells in lupus patients. We observed that, while Treg or Th17 cells alone were not correlated to SLE development, the ratio of Treg to Th17 cells in active SLE patients is significantly lower than that in inactive SLE patients and healthy controls, and we also found corticosteroid treatment increased the ratio of Treg to Th17 cells in active SLE patients. Moreover, this ratio is inversely correlated with the severity of active SLE. The present study indicates that active SLE appears to exist as an imbalance between Treg and Th17 cells. Correction of this Treg/Th17 imbalance may have therapeutic impact for patients with SLE.     

Low TCR signal strength induces combined expansion of Th2 and regulatory T cell populations that protect mice from the development of type 1 diabetes

Aims/hypothesis

Weak stimulation of CD4⁺ T cells induces expansion of CD4⁺ forkhead box P3⁺ regulatory T cells (Tregs) and can also promote T helper (Th) 2 responses, which have demonstrable beneficial effects on autoimmune diabetes. This study explored the feasibility of combined Treg/Th2 expansion for immunotherapy of type 1 diabetes in NOD mice.

Methods

We compared Treg and Th responses to dendritic cells (DC) presenting scaled antigen doses to islet-specific NOD CD4⁺ T cells. Flow cytometric and Luminex analyses were performed to determine the phenotype and cytokine profile of expanded T cells. The ability of expanded T cells to prevent type 1 diabetes was tested in an adoptive transfer model.

Results

In vitro studies revealed a hierarchical, selective expansion of Treg and T effector (Teff) populations at different antigen doses. Thus, a single low dose produced a mixture of Tregs Th2 and type 1 regulatory (Tr1) cells, which prevented diabetes in NOD-SCID mice and increased the ratio of Treg/Teff cells infiltrating the pancreatic islets. Subcutaneous injection of DC, previously shown to prevent diabetes in NOD mice, induced expansion of the same mixture of Tregs Tr1 and Th2 cells. Low-dose expansion of Treg required MHC–T cell receptor interaction and was partly dependent on T cell derived TGF-β and IL-2. Autocrine IFN-γ was required for the promotion of diabetogenic Th1 cells at high antigen doses.

Conclusions/interpretation

Weak stimulation of CD4⁺ T cells with DC and low-dose antigen expands a combination of antigen-specific Tregs Th2 and Tr1 cells that prevent autoimmunity, without the need to target or purify specific Treg populations.