Th22 and related cytokines in inflammatory and autoimmune diseases

Dual Functions of T Lymphocytes in Breast Carcinoma: From Immune Protection to Orchestrating Tumor Progression and Metastasis

Breast cancer (BC) is the most common cancer type in women and the second leading cause of death. Despite recent advances, the mortality rate of BC is still high, highlighting a need to develop new treatment strategies including the modulation of the immune system and immunotherapies. In this regard, understanding the complex function of the involved immune cells and their crosstalk with tumor cells is of great importance. T-cells are recognized as the most important cells in the tumor microenvironment and are divided into several subtypes including helper, cytotoxic, and regulatory T-cells according to their transcription factors, markers, and functions. This article attempts to provide a comprehensive review of the role of T-cell subsets in the prognosis and treatment of patients with BC, and crosstalk between tumor cells and T-cells. The literature overwhelmingly contains controversial findings mainly due to the plasticity of T-cell subsets within the inflammatory conditions and the use of different panels for their phenotyping. However, investigating the role of T-cells in BC immunity depends on a variety of factors including tumor types or subtypes, the stage of the disease, the localization of the cells in the tumor tissue and the presence of different cells or cytokines.

Recent Progress in Multiple Sclerosis Treatment Using Immune Cells as Targets

Multiple sclerosis (MS) is an autoimmune-mediated demyelinating disease of the central nervous system. The main pathological features are inflammatory reaction, demyelination, axonal disintegration, reactive gliosis, etc. The etiology and pathogenesis of the disease have not been clarified. The initial studies believed that T cell-mediated cellular immunity is the key to the pathogenesis of MS. In recent years, more and more evidence has shown that B cells and their mediated humoral immune and innate immune cells (such as microglia, dendritic cells, macrophages, etc.) also play an important role in the pathogenesis of MS. This article mainly reviews the research progress of MS by targeting different immune cells and analyzes the action pathways of drugs. The types and mechanisms of immune cells related to the pathogenesis are introduced in detail, and the mechanisms of drugs targeting different immune cells are discussed in depth. This article aims to clarify the pathogenesis and immunotherapy pathway of MS, hoping to find new targets and strategies for the development of therapeutic drugs for MS.

The role of tolerogenic dendritic cells in systematic lupus erythematosus progression and remission

Systematic lupus erythematosus (SLE) is an autoimmune disease reflecting an imbalance between effector and regulatory immune responses. Dendritic cells (DC) are a link between innate and adaptive immunity. Inflammatory DCs (inflDC) can initiate and trigger lymphocyte responses in SLE with over-expression of surface molecules and pro-inflammatory cytokine, including Interferon (IFN) α, Interleukin (IL) 1α, IL-1β, and IL-6, resulting in the overreaction of T helper cells (Th), and B cells immune responses. On the opposite side, tolerogenic DCs (tolDC) express inhibitory interacting surface molecules and repressive mediators, such as IL-10, Transforming growth factor beta (TGF-β), and Indoleamine 2, 3-dioxygenase (IDO), which can maintain self-tolerance in SLE by induction of regulatory T cells (Treg), T cells deletion and anergy. Hence, tolDCs can be a therapeutic candidate for patients with SLE to suppress their systematic inflammation. Recent pre-clinical and clinical studies showed the efficacy of tolDCs therapy in autoimmune diseases. In this review, we provide a wide perspective on the effect of inflDCs in promoting inflammation and the role of tolDC in the suppression of immune cells' overreaction in SLE. Furthermore, we reviewed the finding of clinical trials and experimental studies related to autoimmune diseases, particularly SLE.

Interleukin-35 dampens T helper 22 phenotype shift in CD4+CD25+CD127dim/- regulatory T cells in primary biliary cholangitis

The phenotype shift in regulatory T cells (Tregs) contributes to immunopathogenesis of autoimmune diseases. The current study was aimed to investigate the regulatory function of interleukin-35 (IL-35) to T helper 22 (Th22) cell phenotype shift in Tregs in primary biliary cholangitis (PBC). Fifty-five PBC patients and twenty-four controls were enrolled. CD4+CD25+CD127dim/- Tregs and Th22 cells were investigated by flow cytometry. Forkhead box P3 (FoxP3) and aryl hydrocarbon receptor (AhR) mRNA levels were assessed by real-time polymerase chain reaction. Plasma IL-10 and IL-22 levels were measured by ELISA. Purified Tregs were stimulated with exogenous IL-35, and were co-cultured with autologous CD4+CD25- T cells. Cellular proliferation and cytokine production was measured. Purified Tregs were also cultured into Th22 condition in the presence or absence of exogenous IL-35, and Th22 phenotype were assessed. PBC patients had lower levels of Treg percentage, FoxP3 mRNA, and plasma IL-10, while had higher levels of Th22 proportion, AhR mRNA, and plasma IL-22. Tregs from PBC patients showed reduced immunosuppressive activity, which presented as increased cellular proliferation, interferon-γ production and decreased IL-35/IL-10 secretion in co-culture system. Tregs shifted into Th22 phenotype in PBC patients with elevated CCR4, CCR6, and CCR10 expression as well as increased IL-22 production. IL-35 not only enhanced inhibitory function of Tregs but also suppressed phenotype shift of Tregs into Th22 phenotype in PBC patients. This process was accompanied by elevation of IL-10 and transforming growth factor-β1 secretion by Tregs from PBC patients. The present data suggested that reduced IL-35 might be insufficient to maintain Tregs function and phenotype shift from Tregs into Th22 phenotype in PBC patients.

The Role of T Helper 22 Cells in Dermatological Disorders

T helper 22 (Th22) cells are a newly identified subset of CD4+ T cells that secrete the effector cytokine interleukin 22 (IL-22) upon specific antigen stimulation, barely with IFN-γ or IL-17. Increasing studies have demonstrated that Th22 cells and IL-22 play essential roles in skin barrier defense and skin disease pathogenesis since the IL-22 receptor is widely expressed in the skin, especially in keratinocytes. Herein, we reviewed the characterization, differentiation, and biological activities of Th22 cells and elucidated their roles in skin health and disease. We mainly focused on the intricate crosstalk between Th22 cells and keratinocytes and provided potential therapeutic strategies targeting the Th22/IL-22 signaling pathway.

Interleukin 22 is related to development and poor prognosis of hepatocellular carcinoma

BACKGROUND AND AIMS

Immune response against hepatitis B virus (HBV) infection is an important risk factor for the development of hepatocellular carcinoma (HCC). Studies have reported that interleukin 22 (IL-22) exhibits both protective and pathological properties in liver diseases. Our aim was to explore the importance of IL-22 in the development of HCC, and to characterize the relationship between IL-22 levels and the prognosis of HCC.

METHODS

Totally, 136 liver biopsy specimens from 46 patients with chronic hepatitis B (CHB), 37 with atypical hyperplasia (AH), 53 with HCC, patient-matched tumors and peritumoral surgical specimens from 56 HCC patients included in the study. The expression of IL-22 and CD8 was evaluated by immunochemistry. Corresponding serum samples were collected from 30 CHB, 30 AH, and 30 HCC patients. IL-22 expression was determined by an enzyme linked immunosorbent assay.

RESULTS

Liver-infiltrating IL-22+ cells increased in a stepwise manner from CHB to AH and HCC (CHB vs. AH, P=0.002; AH vs. HCC, P=0.010), whereas a decreasing trend was observed for CD8+ T cells (CHB vs. AH, P=0.031; AH vs. HCC, P=0.652). Serum IL-22 levels also increased from CHB to AH and HCC (CHB vs. AH, P=0.024; AH vs. HCC, P=0.026). Tumor-infiltrating IL-22+ cells and serum IL-22 were associated with histologic grade (P=0.024 and P=0.033). Additionally, CD8+ T cells correlated with tumor size (P=0.032). Furthermore, the high intratumoral IL-22+ cell group and high serum IL-22 group showed lower overall survival (OS; P=0.001, P=0.017) and disease-free survival (DFS; P=0.005, P<0.001). Multivariate analysis revealed that intratumoral IL-22+ cells and serum IL-22 levels were independent prognostic factors for both OS and DFS.

CONCLUSIONS

These findings indicate that IL-22 promotes the progression of HCC in CHB patients. High tumor-infiltrating IL-22+ cells and serum IL-22 levels are thought to be unfavorable prognostic indicators for HCC.

The expression of Th9 and Th22 cells in rats with cerebral palsy after hUC-MSC transplantation

BACKGROUND

This study aimed to investigate the expression of Th9 and Th22 cells in rats with cerebral palsy (CP) after human umbilical cord-derived mesenchymal stem cell (hUC-MSC) transplantation.

METHODS

First, hUC-MSCs were isolated from fresh umbilical cords and identified. Rats were divided into the normal group, CP group, and hUC-MSC transplantation group. The Morris water maze and balance beam tests were performed to evaluate the neurobehavioral ability of the rats. The levels of TNF-α, IL-6, IL-9, and IL-22 in rat brain tissues were detected by ELISA. Th9 and Th22 proportions in brain tissues were detected by flow cytometric analysis. The mRNA levels of IL-9, IL-22, PU.1, and AHR in brain tissues were determined by qRT-PCR.

RESULTS

hUC-MSC transplantation enhanced the neurobehavioral ability of CP rats. Furthermore, Th9 and Th22 proportions were decreased in brain tissues from CP rats after hUC-MSC transplantation. The levels of proinflammatory cytokines (TNF-α and IL-6), Th9-related IL-9 and PU.1, and Th22-related IL-22 and AHR were markedly higher in brain tissues from CP rats than in brain tissues from control rats, but their levels were significantly decreased after hUC-MSC transplantation.

CONCLUSION

Our data indicate that Th9 and Th22 proportions are decreased in CP rats after hUC-MSC transplantation.

MiR-31 promotes Th22 differentiation through targeting Bach2 in coronary heart disease

The aim of the present study was to investigate the role of miR-31 in Th22 differentiation in coronary heart disease (CHD). Th22 frequencies in peripheral blood of CHD patients and controls as well as in CD4+ T cells were detected by flow cytometry. The mRNA expression of Th22-associated transcription factor aryl hydrocarbon receptor (AHR) and Th22-effector cytokine interleukin (IL)-22, as well as miR-31 were examined by quantitative real-time PCR (qRT-PCR). The protein level of BTB domain and CNC homolog 2 (Bach2) was measured by Western blotting. The interaction between miR-31 and Bach2 was verified using dual luciferase reporter assay. The results showed that Th22 frequency and miR-31 expression were elevated in CHD patients. Furthermore, miR-31 mimic and Bach2 silencing significantly promoted Th22 frequency and the levels of AHR and IL-22 in CD4+ T cells from CHD patients. Further studies showed that miR-31 facilitated Th22 cell differentiation by targeting and inhibiting Bach2. Our data indicate that miR-31 promotes Th22 differentiation through targeting Bach2 in CHD.

The role of interleukin 22 in multiple sclerosis and its association with c-Maf and AHR

The aim of this paper was to summarise knowledge of IL-22 involvement in multiple sclerosis (MS) and the possible link between IL-22 and two transcription factors - AHR and c-Maf. The conclusion is that despite numerous studies, the exact role of IL-22 in the pathogenesis of MS is still unknown. The expression and function of c-Maf in MS have not been studied. It seems that the functions of c-Maf and AHR are at least partly connected with IL-22, as both directly or indirectly influence the regulation of IL-22 expression. This possible connection has never been studied in MS.

Characterization of CD4+ T Cell Subsets in Patients with Abdominal Aortic Aneurysms

BACKGROUND

The mediators produced by CD4+ T lymphocytes are involved in the pathogenesis of aneurysmal lesions in abdominal aortic aneurysm (AAA) patients. The aim of this study was to identify and characterize the CD4+ T cell subsets involved in human AAA.

METHODS

The CD4+ T cell subsets in 30 human aneurysmal lesions were determined using flow cytometry (FC) and immunohistochemistry (IHC). The peripheral blood mononuclear cells (PBMCs) from patients with AAA were also analyzed by FC and compared with control subjects.

RESULTS

Human aneurysmal lesions contained IFN-γ, IL-12p35, IL-4, IL-23p19, IL-17R, and IL-22 positive cells. PBMCs from AAA patients had higher expression levels of IFN-γ, TNF-α, IL-4, and IL-22 when compared to controls.

CONCLUSIONS

Our results show the presence of TH1, TH2, TH17, and TH22 subsets in aneurysmal lesions of AAA patients and suggest that these cells may be mainly activated in situ, where they can induce tissue degradation and contribute to the pathogenesis of AAA.

Repetitive Exposure of IL-17 Into the Murine Air Pouch Favors the Recruitment of Inflammatory Monocytes and the Release of IL-16 and TREM-1 in the Inflammatory Fluids

The infiltration of Th17 cells in tissues and organs during the development of many autoimmune diseases is considered a key step toward the establishment of chronic inflammation. Indeed, the localized and prolonged release of IL-17 in specific tissues has been associated with an increased severity of the inflammatory response that remains sustained over time. The cellular and molecular mechanisms behind these effects are far from being clear. In this study we investigated the effects of two repetitive administration of recombinant IL-17 into the murine air pouch to simulate a scenario where IL-17 is released over time in a pre-inflamed tissue. Consistent with our previous observations, mice receiving a single dose of IL-17 showed a transitory influx of neutrophils into the air pouch that peaked at 24 h and declined at 48 h. Conversely, mice receiving a double dose of the cytokine—one at time 0 and the second after 24 h—showed a more dramatic inflammatory response with almost 2-fold increase in the number of infiltrated leukocytes and significant higher levels of TNF-α and IL-6 in the inflammatory fluids. Further analysis of the exacerbated inflammatory response of double-injected IL-17 mice showed a unique cellular and biochemical profile with inflammatory monocytes as the second main population emigrating to the pouch and IL-16 and TREM-1 as the most upregulated cytokines found in the inflammatory fluids. Most interestingly, mice receiving a double injection of IL-1β did not show any change in the cellular or biochemical inflammatory response compared to those receiving a single injection or just vehicle. Collectively these results shed some light on the function of IL-17 as pro-inflammatory cytokine and provide possible novel ways to target therapeutically the pathogenic effects of IL-17 in autoimmune conditions.

Increased Expression of Aryl Hydrocarbon Receptor in Peripheral Blood Mononuclear Cells of Patients with Autoimmune Hepatitis

BACKGROUND

Previous studies have indicated an elevated level of serum Interleukin (IL)-22 in patients with autoimmune hepatitis (AIH). However, there are no experimental data on the master transcription factor (aryl hydrocarbon receptor) that plays an important role in the development of T helper type 22 (Th22) cells as major producers of IL-22. The aim of the present study was to examine the expression of aryl hydrocarbon receptor in patients with AIH and in normal controls.

METHODS

Levels of mRNA transcripts were measured in the peripheral blood mononuclear cells of 18 patients with AIH and compared with 18 normal controls by a quantitative real-time polymerase chain reaction.

RESULTS

mRNA expression of aryl hydrocarbon receptor was significantly higher in patients with AIH compared with the healthy control group (P = 0.006).

CONCLUSION

Th22 cells may play an important role in the pathogenesis of AIH.

Increased IL-22- and IL-17A-Producing Mucosal-Associated Invariant T Cells in the Peripheral Blood of Patients With Ankylosing Spondylitis

The IL-23/T helper 17 (Th17) axis plays an important role in joint inflammation in ankylosing spondylitis (AS). Conventional CD4⁺ Th17 cells are a major source of IL-17A. IL-22 is another cytokine implicated in AS pathophysiology and is produced by Th17 and Th22 cells. In this study, we aimed to analyze conventional and non-conventional T cell subsets producing IL-17A and IL-22 in patients with AS. We thus evaluated the intracellular staining for IL-17A, IL-22, and IFN-γ in peripheral blood mononuclear cells of 36 patients with AS and 55 age- and sex-matched healthy controls (HC). Conventional CD4⁺ and CD8⁺ T cells, γδ T cells, and mucosal-associated invariant T (MAIT) cells were evaluated. In patients with AS, we found a decreased frequency and number of γδ T cells, of MAIT cells and of IFN-γ⁺ CD4⁺ and CD8⁺ T cells. Th17-related IL-17A⁺/IFN-γ^- CD4⁺ T cells were decreased in AS. The number of IL-22⁺ MAIT cells was higher in AS compared with HC, as well as the number of IFN-γ⁺/IL-17A⁺ MAIT cells. The number of IFN-γ^-/IL-17A⁺ MAIT cells was higher only in female patients with AS compared with female HC. The cellular source of IL-17A was thus not restricted to conventional Th17 CD4⁺ T cells and might involve innate-like T cells, such as MAIT cells. Circulating MAIT cells producing IL-22 were increased in AS. These results strengthen the importance of innate and innate-like sources of IL-17A and/or IL-22.

Elevated Th22 cells and related cytokines in patients with epithelial ovarian cancer

This study is conducted to investigate the involvement of T-helper (Th) cells and regulatory T cells in epithelial ovarian cancer (EOC).The percentages of Th22, Th17, Th1, and regulatory T cells in the peripheral blood of EOC patients, benign ovarian epithelial neoplasm (BOEN) patients, and healthy control (HC) were examined by flow cytometry. Enzyme-linked immunosorbent assay was used to determine serum levels of interleukin (IL)-22, IL-17, interferon-γ (IFN-γ), and tumor necrosis factor-α (TNF-α).Th22 and Th17 were significantly increased in EOC patients. The plasma concentrations of IL-22 and TNF-α were significantly elevated in EOC patients compared with BOEN patients and HC. In EOC patients, there was an increased trend of Th22, IL-22, and TNF-α in stage III-IV patients compared with stage I-II patients. A positive correlation was seen among Th22, Th17, and Th1 cells in EOC patients. Similarly, positive correlations were detected between Th22 cells and IL-22 or TNF-α and between Th1 cells and interferon-γ (IFN-γ) in EOC patients. Besides, no significant difference was found in Th1 cells and regulatory T cells among EOC and BOEN patients and HC.There is a higher circulating frequency of Th22, Th17 cells, IL-22, and TNF-α concentration in EOC patients, which may conjointly participate in the pathogenesis and growth of EOC.

Minimal hepatic encephalopathy is associated with expansion and activation of CD4+CD28-, Th22 and Tfh and B lymphocytes

Peripheral inflammation acts synergistically with hyperammonemia in inducing neurological alterations in cirrhotic patients with minimal hepatic encephalopathy (MHE). We hypothesized that appearance of MHE would be associated to some specific qualitative change in peripheral inflammation. The aim of this work was to characterize the changes in peripheral inflammation associated to appearance of MHE. We analyzed it by immunophenotyping and cytokine profile analysis, in cirrhotic patients without or with MHE and controls. The main alterations associated specifically with MHE are: 1) increased activation of all subtypes of CD4⁺ T-lymphocytes, with the increased expression of CD69; 2) increased amount of CD4⁺CD28⁻ T lymphocytes, associated with increased levels of CX3CL1 and of IL-15; 3) increased differentiation of CD4⁺ T lymphocytes to Th follicular and Th22; 4) increased activation of B lymphocytes and serum IgG. This study has identified some specific alterations of the immune system associated with appearance of the neurological alterations in MHE patients.

Increased circulating Th22 cells correlated with Th17 cells in patients with severe preeclampsia

OBJECTIVE

We aimed to investigate Th22 cells and their association with Th17 and Treg cells in the etiology of severe preeclampsia (sPE).

METHODS

Thirty sPE patients and 30 healthy pregnant women were recruited in this study. The percentages of Th17, Th22, and regulatory T cells (Tregs) in the peripheral blood were measured by flow cytometry. ELISA was used to measure the plasma concentrations of interleukin (IL)-17, IL-22, and IL-10.

RESULTS

The percentages of Th17 and Th22 cells and the plasma concentrations of IL-17 and IL-22 were significantly increased in sPE patients along with a decreased percentage of Treg cells and a decreased plasma IL-10 concentration. There was a positive correlation between the levels of Th22 cells and Th17 cells in sPE patients. Moreover, a positive correlation was found between plasma IL-22 concentration and the percentage of Th22 cells in sPE patients.

CONCLUSIONS

Increased circulating Th22 cells, which were correlated with Th17 cells, were observed in patients with sPE. The immune imbalance between T helper (Th) cells may contribute to the pathogenesis of sPE.

How pregnancy can affect autoimmune diseases progression?

Autoimmune disorders are characterized by tissue damage, caused by self-reactivity of different effectors mechanisms of the immune system, namely antibodies and T cells. Their occurrence may be associated with genetic and/or environmental predisposition and to some extent, have implications for fertility and obstetrics. The relationship between autoimmunity and reproduction is bidirectional. This review only addresses the impact of pregnancy on autoimmune diseases and not the influence of autoimmunity on pregnancy development. Th17/Th1-type cells are aggressive and pathogenic in many autoimmune disorders and inflammatory diseases. The immunology of pregnancy underlies the role of Th2-type cytokines to maintain the tolerance of the mother towards the fetal semi-allograft. Non-specific factors, including hormonal changes, favor a switch to Th2-type cytokine profile. In pregnancy Th2, Th17/Th2 and Treg cells accumulate in the decidua but may also be present in the mother’s circulation and can regulate autoimmune responses influencing the progression of autoimmune diseases.

Aberrant expression of interleukin-22 and its targeting microRNAs in oral lichen planus: a preliminary study

BACKGROUND

Oral lichen planus (OLP) is a T cell-mediated autoimmune disease involving oral mucosa. Interleukin-22 (IL-22) as the signature cytokine of T helper 22 cells is increasingly recognized as a key regulator in various autoimmune diseases. Our previous study reported that IL-22 immunoexpression in OLP was significantly increased compared with the normal controls.

METHODS

The objective of this preliminary study was to compare the IL-22 expression levels in oral biopsies from patients with OLP (n = 50) against normal oral mucosa (n = 19) using RT-qPCR and Western blot, identify the potential targeting miRNAs of IL-22, and examine the miRNA expression levels in OLP.

RESULTS

Interleukin-22 expression level in OLP was significantly increased compared with the normal controls. The Dual-Luciferase reporter assay system in human embryonic kidney 293 (HEK293) cells demonstrated that miR-562 and miR-203 were the target miRNAs of IL-22, which was consistent with predictions from bioinformatics software analyses. Interestingly, miR-562 expression in OLP was significantly decreased, but miR-203 expression in OLP was significantly increased compared with the normal controls.

CONCLUSION

This preliminary study for the first time reported that aberrant expression levels of miR-562 and miR-203 were associated with high expression of IL-22 and demonstrated the target relationship between miRNAs and IL-22 in HEK293 cells. Our data indicated that IL-22 and its targeting miRNAs contribute to the pathogenesis of OLP. Further studies are required to investigate the regulatory pathways of IL-22 and miR-562 and miR-203 in OLP.

Early-Life Exposure to Clostridium leptum Causes Pulmonary Immunosuppression

INTRODUCTION

Low Clostridium leptum levels are a risk factor for the development of asthma. C. leptum deficiency exacerbates asthma; however, the impact of early-life C. leptum exposure on cesarean-delivered mice remains unclear. This study is to determine the effects of early-life C. leptum exposure on asthma development in infant mice.

METHODS

We exposed infant mice to C. leptum (fed-CL) and then induced asthma using the allergen ovalbumin (OVA).

RESULTS

Fed-CL increased regulatory T (Treg) cells in cesarean-delivered mice compared with vaginally delivered mice. Compared with OVA-exposed mice, mice exposed to C. leptum + OVA did not develop the typical asthma phenotype, which includes airway hyper-responsiveness, cell infiltration, and T helper cell subset (Th1, Th2, Th9, Th17) inflammation. Early-life C. leptum exposure induced an immunosuppressive environment in the lung concurrent with increased Treg cells, resulting in the inhibition of Th1, Th2, Th9, and Th17 cell responses.

CONCLUSION

These findings demonstrate a mechanism whereby C. leptum exposure modulates adaptive immunity and leads to failure to develop asthma upon OVA sensitization later in life.

T-helper 22 cells as a new player in chronic inflammatory skin disorders

T-helper 22 (Th22) cell is a new subset of CD4+ T cells that secrets interleukin (IL)-22 but not IL-17 or interferon-γ. Th22 is distinct from Th17 and other known CD4+ T-cell subsets with distinguished gene expression and function. Th22 subsets have chemokine receptors CCR6+ CCR4+ CCR10+ phenotype and aryl hydrocarbon receptor as the key transcription factor. This T-helper subset, by producing cytokines such as IL-22, IL-13, and tumor necrosis factor-α, is implicated in the pathogenesis of inflammatory skin disorder. This review discusses the role of Th22 and its cytokine IL-22 in the immunopathogenesis of inflammatory skin disorders such as psoriasis and atopic dermatitis.

Decreased circulating Th22 and Th17 cells in patients with aplastic anemia

BACKGROUND

Aplastic anemia (AA) is an immune-mediated disorder and mainly related to active destruction of hematopoietic cells by effector T lymphocytes. T helper (Th) 22 cells characterized as a novel subset of CD4+ T cells participate in the pathogenesis of autoimmune and hematological diseases. However, the role of Th22 subset in AA remains unknown.

METHODS

31 untreated AA patients and 30 healthy controls were included in this study. The percentages of Th22, Th17 and pure Th17 cells in peripheral blood were detected by flow cytometry. ELISA to measure interleukin (IL)-22 and IL-17A plasma levels and qRT-PCR for the mRNA levels of Th22 and Th17 related molecules were performed.

RESULTS

The proportions of Th22, pure Th17, Th17 cells and plasma levels of IL-22 were significantly lower in untreated AA patients than those in normal controls. A positive correlation was found between Th22 and pure Th17 cells in AA. Moreover, percentages of Th22 cells correlated positively with reticulocyte counts and percentages. In addition, STAT3/STAT5 mRNA expression ratio was elevated in AA patients.

CONCLUSION

Together, our results showed Th22 cells correlating with clinical characteristics of AA patients, indicating a possible role of Th22 immune response in the pathogenesis and therapeutic intervention of AA.

The alteration and clinical significance of Th22/Th17/Th1 cells in patients with chronic myeloid leukemia

T helper- (Th-) cell immunodeficiency plays important roles in tumor development and their effects in chronic myeloid leukemia (CML) remain unclear. In the present study, we mainly investigated the role of Th22, Th17, and Th1 cell and their related cytokines (IL-22, IL-17, and IFN-r) in the pathophysiology of CML. Bone marrow (BM) and peripheral blood (PB) were extracted from newly diagnosed (ND), chronic phase- (CP-) CML patients, and controls. Th subsets were examined by flow cytometry. Plasma IL-22, IL-17, and IFN-r concentrations were measured by ELISA. AHR and RORC mRNA expressions were examined by RT-PCR. The frequencies of Th22, Th17, and Th1 cells, along with the expression of specific transcription factors RORC and AHR, were significantly decreased in ND patients compared with healthy controls, while all these abnormality recovered in CP patients. In addition, there existed a significantly positive relationship between Th22 and Th17 cells in PB or BM. A significantly negative relationship was found between Th cells (Th22, Th17, or Th1) and BCR-ABL (%) IS or the number of PB white blood cells. All these results demonstrated that Th22, Th17, and Th1 cells might be important therapeutic targets in CML and could facilitate a better outcome for tumor immunotherapy.

Th22 cell accumulation is associated with colorectal cancer development

AIM

To investigate the expression of Th22 cells and related cytokines in colorectal cancer (CRC) tissues, and the probably mechanism.

METHODS

CRC tumor and paratumor tissues were collected to detect the expression levels of Th22 cells and of related cytokines by immunohistochemistry, flow cytometry and real-time quantitative polymerase chain reaction (RT-qPCR). Interleukin (IL)-22 alone or with a STAT3 inhibitor was co-cultured with RKO cells in vitro to study the effects of IL-22 on colon cancer cells. IL-22 alone or with a STAT3 inhibitor was injected into a BALB/c nude mouse model with subcutaneously transplanted RKO cells to study the effects of IL-22 on colon cancer growth.

RESULTS

The percentage of Th22 cells in the CD4(+) T subset was significantly higher in tumor tissues compared with that in paratumor tissues (1.47% ± 0.083% vs 1.23% ± 0.077%, P < 0.05) as determined by flow cytometry. RT-qPCR analysis revealed that the mRNA expression levels of IL-22, aryl hydrocarbon receptor, CCL20 and CCL22 were significantly higher in tumor tissues compared with those in paratumor tissues. CCL27 mRNA also displayed a higher expression level in tumor tissues compared with that in paratumor tissues; however, these levels were not significantly different (2.58 ± 0.93 vs 2.30 ± 0.78, P > 0.05). IL-22 enhanced colon cancer cell proliferation in vitro and displayed anti-apoptotic effects; these effects were blocked by adding a STAT3 inhibitor. IL-22 promoted tumor growth in BALB/c nude mice; however, this effect was reversed by adding a STAT3 inhibitor.

CONCLUSION

Th22 cells that accumulate in CRC may be associated with the chemotactic effect of the tumor microenvironment. IL-22 is associated with CRC development, most likely via STAT3 activation.

Faecalibacterium prausnitzii prevents physiological damages in a chronic low-grade inflammation murine model

BACKGROUND

The human gut houses one of the most complex and abundant ecosystems composed of up to 10(13)-10(14) microorganisms. The importance of this intestinal microbiota is highlighted when a disruption of the intestinal ecosystem equilibrium appears (a phenomenon called dysbiosis) leading to an illness status, such as inflammatory bowel diseases (IBD). Indeed, the reduction of the commensal bacterium Faecalibacterium prausnitzii (one of the most prevalent intestinal bacterial species in healthy adults) has been correlated with several diseases, including IBD, and most importantly, it has been shown that this bacterium has anti-inflammatory and protective effects in pre-clinical models of colitis. Some dysbiosis disorders are characterized by functional and physiological alterations. Here, we report the beneficial effects of F. prausnitzii in the physiological changes induced by a chronic low-grade inflammation in a murine model. Chronic low-grade inflammation and gut dysfunction were induced in mice by two episodes of dinitro-benzene sulfonic acid (DNBS) instillations. Markers of inflammation, gut permeability, colonic serotonin and cytokine levels were studied. The effects of F. prausnitzii strain A2-165 and its culture supernatant (SN) were then investigated.

RESULTS

No significant differences were observed in classical inflammation markers confirming that inflammation was subclinical. However, gut permeability, colonic serotonin levels and the colonic levels of the cytokines IL-6, INF-γ, IL-4 and IL-22 were higher in DNBS-treated than in untreated mice. Importantly, mice treated with either F. prausnitzii or its SN exhibited significant decreases in intestinal permeability, tissue cytokines and serotonin levels.

CONCLUSIONS

Our results show that F. prausnitzii and its SN had beneficial effects on intestinal epithelial barrier impairment in a chronic low-grade inflammation model. These observations confirm the potential of this bacterium as a novel probiotic treatment in the management of gut dysfunction and low-grade inflammation.

T cell subsets and their signature cytokines in autoimmune and inflammatory diseases

CD4(+) T helper (Th) cells are critical for proper immune cell homeostasis and host defense, but are also major contributors to pathology of autoimmune and inflammatory diseases. Since the discovery of the Th1/Th2 dichotomy, many additional Th subsets were discovered, each with a unique cytokine profile, functional properties, and presumed role in autoimmune tissue pathology. This includes Th1, Th2, Th17, Th22, Th9, and Treg cells which are characterized by specific cytokine profiles. Cytokines produced by these Th subsets play a critical role in immune cell differentiation, effector subset commitment, and in directing the effector response. Cytokines are often categorized into proinflammatory and anti-inflammatory cytokines and linked to Th subsets expressing them. This article reviews the different Th subsets in terms of cytokine profiles, how these cytokines influence and shape the immune response, and their relative roles in promoting pathology in autoimmune and inflammatory diseases. Furthermore, we will discuss whether Th cell pathogenicity can be defined solely based on their cytokine profiles and whether rigid definition of a Th cell subset by its cytokine profile is helpful.

Long-term therapeutic effects of mesenchymal stem cells compared to dexamethasone on recurrent experimental autoimmune uveitis of rats

PURPOSE

We tested the long-term effects of different regimens of mesenchymal stem cell (MSC) administration in a recurrent experimental autoimmune uveitis (rEAU) model in rats, and compared the efficacy of MSC to that of dexamethasone (DEX).

METHODS

One or two courses of MSC treatments were applied to R16-specific T cell-induced rEAU rats before or after disease onsets. The DEX injections were given for 7 or 50 days continuously after disease onsets. Clinical appearances were observed until the 50th day after transfer. On the 10th day, T cells from control and MSC groups were analyzed by flow cytometry. Supernatants from the proliferation assay and aqueous humor were collected for cytokine detection. Functions of T cells and APCs in spleens also were studied by lymphocyte proliferation assays.

RESULTS

One course of MSC therapy, administered after disease onset, led to a lasting therapeutic effect, with a decreased incidence, reduced mean clinical score, and reduced retinal impairment after 50 days of observation, while multiple courses of treatment did not improve the therapeutic benefit. Although DEX and MSCs equally reduced the severity of the first episode of rEAU, the effect of DEX was shorter lasting, and DEX therapy failed to control the disease even with long periods of treatment. The MSCs significantly decreased T helper 1 (Th1) and Th17 responses, suppressed the function of antigen-presenting cells, and upregulated T regulatory cells.

CONCLUSIONS

These results suggested that MSCs might be new corticosteroid spring agents, while providing fewer side effects and longer lasting suppressive effects for recurrent uveitis.

Immunopathogenesis of ocular Behçet's disease

Behçet's disease (BD) is a chronic recurrent systemic inflammatory disorder of unknown etiology characterized by oral and genital ulcerations, skin lesions, and uveitis. The ocular involvement of BD, or Behçet's uveitis (BU), is characterized by panuveitis or posterior uveitis with occlusive retinal vasculitis and tends to be more recurrent and sight threatening than other endogenous autoimmune uveitides, despite aggressive immunosuppression. Although pathogenesis of BD is unclear, researches have revealed that immunological aberrations may be the cornerstone of BD development. General hypothesis of BD pathogenesis is that inflammatory response is initiated by infectious agents or autoantigens in patients with predisposing genetic factors and perpetuated by both innate and acquired immunity. In addition, a network of immune mediators plays a substantial role in the inflammatory cascade. Recently, we found that the immunopathogenesis of BU is distinct from other autoimmune uveitides regarding intraocular effector cell profiles, maturation markers of dendritic cells, and the cytokine/chemokine environment. In addition, accumulating evidence indicates the involvement of Th17 cells in BD and BU. Recent studies on genetics and biologics therapies in refractory BU also support the immunological association with the pathogenesis of BU. In this review, we provide an overview of novel findings regarding the immunopathogenesis of BU.

Increased circulating T‑helper 22 cells in patients with dilated cardiomyopathy

Recently, the newly determined interleukin (IL)‑22‑producing T-helper (Th) 22 cell has been implicated to be involved in the pathogenesis of autoimmune diseases. However, its role in the pathogenesis of dilated cardiomyopathy (DCM) has yet to be elucidated. A total of 30 patients with DCM and 30 healthy controls were enrolled in the present study. The levels of Th22, Th17 and Th1 cells in the peripheral blood were analyzed by flow cytometry. Levels of plasma IL‑22 and autoantibody adenine nucleotide translocator (ANT) were assessed using the ELISA. The key transcription factor of Th22, aryl hydrocarbon receptor (AHR), was assessed using quantitative polymerase chain reaction. Additionally, clinical data on the brain natriuretic peptide (BNP), C‑reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were collected. In comparison with those in the control group, significantly elevated levels of Th22, Th17 and Th1 cells were detected in patients with DCM (all P<0.01). Similarly, elevated mRNA levels of peripheral AHR were detected in patients with DCM. The percentage of Th22 cells was higher in ANT‑positive compared with ANT‑negative patients with DCM. The levels of BNP and CRP, but not ESR, showed a significant positive correlation with those of Th22 cells. With regard to the concentrations of plasma IL‑22, no statistical difference was found between patients with DCM and the healthy controls, nor did it demonstrate a statistical correlation with the percentage of Th22 cells. In conclusion, the present study showed that patients with DCM, particularly those of the ANT autoantibody positive subjects, exhibit elevated levels of peripheral Th22 cells, indicating that a Th22 immune response may be implicated in the pathogenesis of DCM.

Interleukin 1 (IL-1)- and IL-23-mediated expansion of filarial antigen-specific Th17 and Th22 cells in filarial lymphedema

Lymphatic filarial disease is known to be associated with elevated Th1 responses and normal or diminished Th2 responses to parasite-specific antigens. The roles of Th17 cells and the recently described Th22 cells have not been examined in detail in either filarial infection itself or in filarial disease (e.g., lymphedema and elephantiasis). To explore the roles of Th17 and Th22 cells and their subsets, we examined the frequencies of these cells in individuals with filarial lymphedema (chronic pathology [CP]), in clinically asymptomatic infected (INF) individuals, and in uninfected (UN) individuals ex vivo and in response to parasite and nonparasite antigens. Those with disease (CP) had significantly expanded frequencies of Th17 and Th22 cells, compared with either INF or UN individuals, at baseline (ex vivo) and in response to parasite antigens. This antigen-driven expansion of Th17 and Th22 cells was dependent on interleukin 1 (IL-1), IL-23, and, to lesser extent, transforming growth factor β (TGF-β), as blockade of any of these cytokines resulted in significantly diminished frequencies of Th17 and Th22 cells. Our findings, therefore, suggest that filarial parasite-driven expansion of Th17 and Th22 cells is associated with the pathogenesis of filarial infections and disease.

Helper T-cell differentiation in graft-versus-host disease after allogeneic hematopoietic stem cell transplantation

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an effective therapeutic option for many malignant diseases. However, the efficacy of allo-HSCT is limited by the occurrence of destructive graft-versus-host disease (GVHD). Since allogeneic T cells are the driving force in the development of GVHD, their activation, proliferation, and differentiation are key factors to understanding GVHD pathogenesis. This review focuses on one critical aspect: the differentiation and function of helper T (Th) cells in acute GVHD. We first summarize well-established subsets including Th1, Th2, Th17, and T-regulatory cells; their flexibility, plasticity, and epigenetic modification; and newly identified subsets including Th9, Th22, and T follicular helper cells. Next, we extensively discuss preclinical findings of Th-cell lineages in GVHD: the networks of transcription factors involved in differentiation, the cytokine and signaling requirements for development, the reciprocal differentiation features, and the regulation of microRNAs on T-cell differentiation. Finally, we briefly summarize the recent findings on the roles of T-cell subsets in clinical GVHD and ongoing strategies to modify T-cell differentiation for controlling GVHD in patients. We believe further exploration and understanding of the immunobiology of T-cell differentiation in GVHD will expand therapeutic options for the continuing success of allo-HSCT.

Elevated peripheral frequencies of Th22 cells: a novel potent participant in obesity and type 2 diabetes

OBJECTIVE

Chronic low-grade inflammation has long been recognized as the central link between obesity and type 2 diabetes (T2D). The novel subset of T helper (Th) cells, Th22, plays an emerging role in chronic inflammation. We investigated the potential association between Th22 and the pathogenesis of obesity and T2D.

METHODS

Ninety T2D inpatients (T2D group), 30 healthy participants with BMI ranged from 19 to 23.9 kg/m2 (CTL group) and 30 metabolically healthy obese controls with BMI ≥ 30 kg/m2 (MHO group) were employed in our study. Peripheral frequencies of Th22 and Th1 and Th17 cells were determined by flow cytometry based on their specific cytokine patterns. Cytokine levels in fresh plasma were quantified by ELISA.

RESULTS

Compared to that in CTL group (1.18±0.06%, n = 28), peripheral frequency of Th22 cells was significantly increased in MHO group (1.88±0.10%, n = 30) and in T2D group (2.247±0.10%, n = 89). There was a consistent notable increase in plasma interleukin (IL)-22 of T2D patients [47.56 (30.55-76.89) pg/mL] as compared with that of MHO group [36.65 (29.52-55.70) pg/ml; *P<0.0001] and CTLs [36.33 (31.93-40.62) pg/mL; *P<0.0001]. Furthermore, other than Th1/Th17, previously frequently described participants in obesity and T2D, there was a strong correlation between Th22 frequency and the homeostasis model of assessment for insulin resistance index (r = 0.6771, *P<0.0001) and HOMA for β-cell function (r = -0.7264, *P<0.0001).

CONCLUSIONS

There were increased Th22 frequencies and IL-22 levels in obesity and T2D. Elevated Th22 and IL-22 also aided in the differentiation of MHO from T2D patients. The notable correlation implied that Th22 might play a more determinant role in both insulin resistance and β-cell impairment.

T helper cytokines in dry eye disease

Dry eye is an inflammatory disease that results from activation of innate inflammatory pathways in resident ocular surface cells, as well as cytokines produced by recruited T helper (Th) cells. Cytokines produced by the infiltrating Th cells alter the normal cytokine balance on the ocular surface and cause ocular surface epithelial pathology. Changes in levels of Th cytokines on the ocular surface have been measured in dry eye and the biological effects of these cytokines have been documented in experimental culture and mouse model systems. The Th2 cytokine IL-13 has a homeostatic role in promoting goblet cell differentiation. In contrast, The Th1 cytokine IFN-γ antagonizes IL-13 and promotes apoptosis and squamous metaplasia of the ocular surface epithelia. The Th17 cytokine, IL-17 promotes corneal epithelial barrier disruption. The ocular surface epithelium expresses receptors to all of these Th cytokines. Therapies that maintain normal IL-13 signaling, or suppress IFN-γ and IL-17 have potential for treating the ocular surface disease of dry eye.

Immunoexpression of interleukin-22 and interleukin-23 in oral and cutaneous lichen planus lesions: a preliminary study

Interleukin- (IL-) 22 is the signature cytokine of T-helper (Th) 22 cells, and IL-23 is required for IL-22 production. The objective of this study was to examine the immunoexpression of IL-22 and IL-23 in archival paraffin-embedded biopsy specimens from oral LP (n = 42) and cutaneous LP (n = 38) against normal control tissues. The results showed that the percentage of cells expressing IL-22 and IL-23 in LP were significantly higher in LP compared to controls, respectively (both P < 0.001). The correlation between IL-22 and IL-23 expression was significant (P < 0.05). Moreover, the percentage of cells expressing IL-22 and IL-23 in oral LP were significantly higher than cutaneous LP (P < 0.05). Collectively, our findings demonstrated that the increased expression of IL-22 and IL-23 in LP lesions could play roles in the pathogenesis of LP. Moreover, oral LP expressing IL-22 and IL-23 was higher than cutaneous LP, probably due to Th22 cells as an important component of oral mucosal host defense against oral microbiota and tissue antigens. This may be associated with the difference in clinical behaviour of the two variants of the disease.

Dietary caffeine and alcohol consumption by rats

The alcohol consumption of malnourished rats increased slowly but substantially during a 4-week period in which caffeine was added to their marginally adequate diet. Consumption fell to precaffeine levels as soon as caffeine was withdrawn.