Helper Cytokines Research Articles

Elevated Semaphorin 5A correlated with Th1 polarization in patients with chronic immune thrombocytopenia

BackgroundPrimary immune thrombocytopenia (ITP) is an immune-mediated disorder in which cellular immunity deficiency and disturbed cytokine profiles have been found. Semaphorin 5A (Sema5A) has been showed to be implicated in cellular immune response. We aimed to evaluate the role of Sema5A in patients with chronic ITP. MethodsPlasma levels of Sema5A, T helper (Th) cytokines (interferon [IFN] -γ,interleukin [IL]-4,IL-17A) were determined by enzyme-linked immunosorbent assay (ELISA) in ITP patients and healthy controls. Using real-time quantitative polymerase chain reaction (RT-PCR), mRNA levels of Sema5A and its receptor plexin-B3, plexin-A1 in peripheral blood mononuclear cells(PBMCs)were studied in all subjects. Specific anti-platelet autoantibodies were measured by the Pak Auto method. The dynamic change of plasma Sema5A and mRNA levels of its receptors was measured in 9 patients after effective therapy. ResultsPlasma Sema5A levels were significantly increased in active patients with chronic ITP compared to patients in remission and healthy controls. Elevated levels of Sema5A were found positively correlated with higher levels of plasma IFN-γ, IFN-γ/IL-4 ratio and negatively correlated with lower levels of plasma IL-4, platelet counts in ITP patients. The mRNA plexin-B3 was decreased in active ITP patients and inversely correlated with plasma Sema5A levels. Additionally, plasma levels of Sema5A and IFN-γ were reduced with up-regulation of plexin-B3 expression after effective treatment. ConclusionsOur data demonstrated elevated plasma Sema5A in chronic ITP patients might be involved in Th1 polarization by down-regulating receptor plexin-B3 expression and correlated with disease activity.

Anti-apoptotic Effects of House Dust Mite, S100A8 and S100A9 on Spontaneous Apoptosis of Neutrophils in Coculture with Immune Cells and in the Presence of T Helper Cytokines

House dust mite (HDM) as a major allergen and damage-associated molecular pattern (DAMP) such as S100A8 and S100A9 trigger the pathogenesis and severity of allergic disease such as asthma. Regulation of neutrophil apoptosis is an important immune response and its dysregulation is involved in pathogenesis of allergic diseases. In this study, we examined the effects of HDM, S100A8 and S100A9 on spontaneous apoptosis of normal neutrophils. We considered the importance of the difference between in vitro and in vivo results and developed a new in vitro system consisting of a combination of immune cells and T helper (Th) cytokines. Extract of Dermatophagoides pteronyssinus (DP), S100A8, and S100A9 inhibited neutrophil apoptosis in culture of neutrophils alone without other leukocytes. DP and S100A8 more strongly suppressed neutrophil apoptosis in combinations of neutrophils, eosinophils, lymphocytes or monocytes than in a culture of neutrophils alone. Anti-apoptotic effect of S100A9 in the mixture of immune cells was similar to that in neutrophils. DP, S100A8, and S100A9 blocked neutrophil apoptosis, regardless of pretreatment with a T helper (Th) 1 cytokine (IFN-γ), Th2 cytokines (IL-4 and IL-10), a Th9 cytokine (IL-9), a Th17 cytokine (IL-17), a Treg-producing cytokine (TGF-β). These findings may enable elucidation of allergy pathogenesis due to HDM and DAMP.

Tannic acid modulates NFκB signaling pathway and skin inflammation in NC/Nga mice through PPARγ expression

Polyphenolic compound tannic acid, which is mainly found in grapes and green tea, is a potent antioxidant with anticarcinogenic activities. In this present study, we hypothesized that tannic acid could inhibit nuclear factor (NF)κB signaling and inflammation in atopic dermatitis (AD) NC/Nga mice. We have analyzed the effects of tannic acid on dermatitis severity, histopathology and expression of inflammatory signaling proteins in house dust mite extract induced AD mouse skin. In addition, serum levels of T helper (Th) cytokines (interferon (IFN)γ, interleukin (IL)-4) were measured by enzyme-linked immunosorbent assay. Treatment with tannic acid ameliorated the development of AD-like clinical symptoms and effectively inhibited hyperkeratosis, parakeratosis, acanthosis, mast cells and infiltration of inflammatory cells in the AD mouse skin. Serum levels of IFNγ and IL-4 were significantly down-regulated by tannic acid. Furthermore, tannic acid treatment inhibited DfE induced tumor necrosis factor (TNF)α, high mobility group protein (HMG)B1, receptor for advanced glycation end products (RAGE), extracellular signal-regulated kinase (ERK)1/2, NFκB, cyclooxygenase (COX)2, IL-1β and increased the protein expression of peroxisome proliferator-activated receptor (PPAR)γ. Taken together, our results demonstrate that, DfE induced skin inflammation might be mediated through NFκB signaling and tannic acid may be a potential therapeutic agent for AD, which may possibly act via induction of PPARγ protein.

Age-Related Conjunctival Disease in the C57BL/6.NOD-Aec1Aec2 Mouse Model of Sjögren Syndrome Develops Independent of Lacrimal Dysfunction.

To investigate parameters of ocular surface disease in C57BL/6.NOD-Aec1Aec2 (Aec) mice with aging and their correlation with development of Sjögren syndrome (SS)-like lacrimal gland (LG) disease. Aec and C57BL/6 wild-type (B6) female mice were evaluated at 4, 12, and 20 weeks of age. Whole LG and eyes and adnexa were excised for histology and gene expression analysis and evaluated by flow cytometry and immunohistochemistry. Tear volume and goblet cell density was measured. Quantitative PCR evaluated T-cell-related cytokine expression in cornea and conjunctiva. Both strains showed age-related conjunctival goblet cell loss that was more pronounced in the Aec strain and significantly greater than in B6 mice at 12 weeks. This was accompanied by CD4+ T-cell infiltration of the conjunctiva that was greater in Aec strain at 20 weeks. Aec mice had higher levels of IL-17A, IL-17R, IL-1α, IL-1β, and TNF-α in the conjunctiva, and they significantly increase with aging. Aec mice had greater lymphocytic infiltration of the LG and conjunctiva at 20 weeks that consisted of a mixture of CD4+ and CD8+ cells. Flow cytometry showed a significant increase in CD4+ T cells in Aec LG compared to B6 mice. Tear volume was significantly increased in both strains at 20 weeks. Aec mice developed greater conjunctival goblet cell loss associated with lymphocytic infiltration of the LG and conjunctiva with aging. Increased expression of certain T helper or inflammatory cytokines in these tissues was observed in Aec mice. The conjunctival disease appeared to be due to inflammation and not a decrease in tear volume.

Modulation of HMGB1 translocation and RAGE/NFκB cascade by quercetin treatment mitigates atopic dermatitis in NC/Nga transgenic mice.

Quercetin, glycosylated form of flavonoid compound, has potent antioxidant and anti-inflammatory properties. In this study, we have investigated the effects of quercetin on skin lesion, high-mobility group box (HMGB)1 cascade signalling and inflammation in atopic dermatitis (AD) mouse model. AD-like lesion was induced by the application of house dust mite extract to the dorsal skin of NC/Nga transgenic mouse. After AD induction, quercetin (50 mg/kg, p.o) was administered daily for 2 weeks. We evaluated dermatitis severity, histopathological changes and changes in protein expression by Western blotting for HMGB1, receptor for advanced glycation end products (RAGE), toll-like receptor (TLR)4, nuclear factor (NF)κB, nuclear factor erythroid-2-related factor (Nrf)2, kelch-like ECH-associated protein (Keap)1, extracellular signal-regulated kinase (ERK)1/2, cyclooxygenase (COX)2, tumor necrosis factor (TNF)α, interleukin (IL)-1β, IL-2Rα and other inflammatory markers in the skin of AD mice. In addition, serum levels of T helper (Th) cytokines (interferon (IFN)γ, IL-4) were measured by enzyme-linked immunosorbent assay. Quercetin treatment attenuated the development of AD-like skin lesions. Histological analysis showed that quercetin inhibited hyperkeratosis, parakeratosis, acanthosis, mast cells and infiltration of inflammatory cells. Furthermore, quercetin treatment downregulated cytoplasmic HMGB1, RAGE, nuclear p-NFκB, p-ERK1/2, COX2, TNFα, IL-1β, IL-2Rα, IFNγ and IL-4 and upregulated nuclear Nrf2. Our data demonstrated that the HMGB1/RAGE/NFκB signalling might play an important role in skin inflammation, and quercetin treatment could be a promising agent for AD by modulating the HMGB1/RAGE/NFκB signalling and induction of Nrf2 protein.

Altered balance of interleukin-13/interferon-gamma contributes to lacrimal gland destruction and secretory dysfunction in CD25 knockout model of Sjögren's syndrome.

IntroductionThe lacrimal gland (LG) of the CD25-/- model of Sjögren’s syndrome (SS) has high interleukin (IL)-17, IL-13 and interferon-gamma (IFN-γ) cytokines. The specific contribution of these cytokines to the onset and severity of dacryoadenitis in the CD25-/- mice has not been evaluated.MethodsCD25−/−IL-17A−/−, CD25−/−IL-17−/−IFN-γ−/− and CD25−/−IFN-γ−/− were used at 4, 8, 12, 16 weeks (W). Total lymphocytic infiltration was evaluated by histology and characterized by flow cytometry. Epidermal growth factor (EGF) concentration was measured in tears. Immunofluorescent staining evaluated expression of IFN-γ receptor (IFN-γR) and apoptosis. Real-time PCR evaluated inflammatory and T cell-related cytokines expression in LG. Caspase-3, -8, -9 activities was assayed in LG lysates. T helper cytokines were measured in serum by Luminex assay.ResultsThe greatest total LG infiltration at 8 W was seen in CD25−/−IL-17A−/− (95%), followed by CD25−/− (71%) and IL-17−/− (12%). Tear EGF concentration was in normal range in CD25−/− at 4 W and in very low levels in both CD25−/− and CD25−/−IL-17A−/−. CD25−/− had high levels of inflammatory cytokines transcripts in LG compared to IL-17−/− mice; however, CD25−/−IL-17A−/− had even higher IL-1β, IFN-γR, caspase-3, -8, -9 mRNA levels, greater immunoreactivity to IFN-γR in LG acini, greater number of apoptotic+ cells and greater caspases activities in the LG at 8 W. CD25−/−IL-17A−/− had lower IL-13 concentration and lower IL-13/IFN-γ ratio compared to CD25−/− in serum. CD25−/−IFN-γ−/− had lower number of apoptotic+ cells and decreased caspase-3 expression in LG. CD25−/−IL-17−/−IFN-γ−/− had lower total lymphocytic cell infiltration at 8 W (48%), CD4+T cell infiltration and expression of IFN-γR and apoptotic+ cells in the LG and increased tear EGF concentration in tears.ConclusionsIFN-γ is critical for LG destruction and secretory dysfunction in the CD25−/− model of SS. Altered balance between IFN-γ and IL-13 in the CD25−/−IL-17A−/− mice accelerates LG destruction by increasing glandular apoptosis and facilitating apoptosis through increased expression of IFN-γR by glandular epithelium and activation of caspases. Targeting both IFN-γ and IL-17 may be beneficial for treating the LG inflammation in SS.

Choice and Design of Adjuvants for Parenteral and Mucosal Vaccines.

The existence of pathogens that escape recognition by specific vaccines, the need to improve existing vaccines and the increased availability of therapeutic (non-infectious disease) vaccines necessitate the rational development of novel vaccine concepts based on the induction of protective cell-mediated immune responses. For naive T-cell activation, several signals resulting from innate and adaptive interactions need to be integrated, and adjuvants may interfere with some or all of these signals. Adjuvants, for example, are used to promote the immunogenicity of antigens in vaccines, by inducing a pro-inflammatory environment that enables the recruitment and promotion of the infiltration of phagocytic cells, particularly antigen-presenting cells (APC), to the injection site. Adjuvants can enhance antigen presentation, induce cytokine expression, activate APC and modulate more downstream adaptive immune reactions (vaccine delivery systems, facilitating immune Signal 1). In addition, adjuvants can act as immunopotentiators (facilitating Signals 2 and 3) exhibiting immune stimulatory effects during antigen presentation by inducing the expression of co-stimulatory molecules on APC. Together, these signals determine the strength of activation of specific T-cells, thereby also influencing the quality of the downstream T helper cytokine profiles and the differentiation of antigen-specific T helper populations (Signal 3). New adjuvants should also target specific (innate) immune cells in order to facilitate proper activation of downstream adaptive immune responses and homing (Signal 4). It is desirable that these adjuvants should be able to exert such responses in the context of mucosal administered vaccines. This review focuses on the understanding of the potential working mechanisms of the most well-known classes of adjuvants to be used effectively in vaccines.

Migration of splenic lymphocytes promotes liver fibrosis through modification of T helper cytokine balance in mice.

Sustained liver injury causes liver fibrosis and eventually cirrhosis. Understanding the pathophysiological mechanisms of liver fibrosis and interventions in the fibrotic process is crucial for improving the prognosis of patients with chronic liver diseases. Although studies have shown that splenectomy suppresses liver fibrosis, the mechanism by which this occurs is poorly understood. The present study focuses on the immunological functions of the spleen to investigate its role in liver fibrosis. BALB/c and severe combined immunodeficiency (SCID) mice underwent splenectomies or sham operations prior to induction of liver fibrosis with carbon tetrachloride or thioacetamide. Sirius red staining and hydroxyproline assays showed that splenectomy suppressed liver fibrogenesis in BALB/c mice. Reverse transcription PCR analysis of Thelper type1 (Th1) and Thelper type2 (Th2) cytokines demonstrated that splenectomy shifted the Th1/Th2 balance in the liver towards Th1 dominance. In SCID mice, the inhibitory effect on liver fibrosis was abrogated. The number of CD4(+) T helper lymphocytes in the spleen decreased after liver injury. Green fluorescent protein positive (GFP(+)) splenocytes were transplanted into the spleens of syngeneic wild-type mice to trace their destination after fibrosis induction. GFP(+)CD4(+) lymphocytes appeared in the liver after induction of fibrosis, and flow cytometry revealed the vast majority of them were Th2 lymphocytes. Transfer of splenocytes via the portal vein into syngeneic splenectomized mice cancelled the suppressive effect of splenectomy on liver fibrosis. The present study demonstrated that Th2-dominant splenic lymphocytes migrate into the liver and promote liver fibrosis by shifting the cytokine balance towards Th2 dominance. Splenectomy suppresses the progression of fibrosis at least partly by restoring the Th1/Th2 balance.

Clinical profiles of circulating plasmacytoid dendritic cells in chronic hepatitis B patients in response to pegylated-interferon alfa-2a treatment

To investigate the changes in circulating plasmacytoid dendritic cells (pDCs) in patients with chronic hepatitis B (CHB) during the course of treatment with pegylated-interferon alfa-2s (peg-IFNa-2a) and to determine the correlations with therapeutic response. Forty-one patients with CHB who were receiving peg-IFNa-2a antiviral treatment for 48 weeks were enrolled in the study.Expression of the Toll-like receptor 9 (TLR9) on and frequency and functionality of the pDCs were analyzed at treatment weeks 0, 2, 12, 24, 36 and 48. All patients exhibited an initially rapid decrease in the numbers of circulating pDCs and showed CpG-induced endogenous IFNa production within the first 2 weeks of treatment.Subsequently, all responders displayed a continuous increase in pDC numbers as well as functionality, both of which peaked around week 12 of treatment; in addition, these treatment responses were accompanied by significantly increased levels of type 1 T helper cytokines (P less than 0.05), which did not occur in the non-responders. pDCs are involved in the initial therapeutic immune response stimulated by peg-IFNa-2a treatment.Recovery of blood pDC number and functionality may represent a predictor of favorable response to peg-IFNa-2a antiviral treatment in patients with CHB.

Quantifying helper cell function of human TFH cells in vitro.

Blood-circulating CXCR5(+) CD4(+) T cells and T follicular helper (TFH) cells, which participate in germinal center (GC) reactions within secondary lymphoid organs, are specialized in providing help to B cells. This chapter describes ways to isolate TFH-like cells out of peripheral blood or tonsils and to quantify their B cell helper function. This comprises different co-culture approaches of TFH-like cells and B cells and the evaluation of their capacity to induce immunoglobulin secretion and plasma cell differentiation. In addition, B cell helper function of CD4 T cells can be estimated indirectly by quantifying the expression of B cell helper cytokines and co-stimulatory and TFH-associated molecules.

Serum IL-9, IL-17, and TGF-β levels in subjects with diabetic kidney disease (CURES-134)

The role of inflammation in both diabetes and diabetic kidney disease (DKD) is becoming more widely accepted. However, the role of recently characterized T cell cytokines interleukin (IL)-9 and IL-17 in diabetes and especially DKD is less well studied. Transforming growth factor beta (TGF-β) controls the secretion of both of these cytokines. In this study, we estimated the levels of IL-9, IL-17, and TGF-β in the serum of subjects with normal glucose tolerance (NGT=88) and subjects with type 2 diabetes without (diabetes mellitus (DM)=65) and with DKD (DKD=97) using enzyme-linked immunosorbent assay (ELISA), and we correlated these levels with the clinical risk factors of diabetes and DKD. IL-17 levels showed a serial decline and TGF-β levels showed a serial increase from NGT to DM to DKD (p<0.001). However, the IL-9 levels were significantly reduced in the DM group compared to the NGT and DKD group (p<0.001). While TGF-β and IL-17 showed a positive and negative correlation, respectively, with fasting and postprandial glucose levels and glycated hemoglobin (HbA1c), IL-9 showed positive correlation with urea and microalbuminuria. Apart from pro-inflammatory cytokines, T helper (Th) cytokines might play an important role in insulin resistance and DKD.

Relationship between certain T helper cytokines and ANA staining: who is the helper?

This study investigated some T helper cytokines' association with different ANA positive sera. Sera of 53 ANA-positive subjects (11 were stained of homogeneous pattern, 12 of speckled particle pattern, 9 of nucleolar pattern, 15 of centromere pattern, and 6 of the peripheral nuclear type) were collected and analyzed by ELISA for related cytokines and concentrations were compared with each other and 16 healthy donors. Investigated cytokines including IL-12(p70) and IFN-γ varied differently in the ANA sera. This study demonstrated that some T helper cytokines varied with different ANA-positive sera, suggesting that they may play different roles in related autoimmune diseases.

Resveratrol attenuates HMGB1 signaling and inflammation in house dust mite-induced atopic dermatitis in mice.

Resveratrol is a polyphenol abundantly found in red grape skin and is effective against antiaging and anti-inflammation associated with immune responses. In this study, we have investigated the effect of resveratrol on skin lesion, high mobility group box (HMGB)1 and inflammation pathway in an atopic dermatitis (AD) mouse model. AD-like lesion was induced by the application of house dust mite extract to the dorsal skin of NC/Nga mouse. After AD induction, resveratrol (20 mg/kg, p.o.) was administered daily for 2 weeks. We evaluated dermatitis severity, histopathological changes, serum levels of T helper (Th) cytokines (interferon (IFN)γ, interleukin (IL)-4) and changes in protein expression by Western blotting for HMGB1, receptor for advanced glycation end products (RAGE), toll like receptor (TLR)4, nuclear factor (NF)κB, phosphatidylinositide 3-kinase (PI3K), extracellular signal-regulated kinase (ERK)1/2, cyclooxygenase (COX)2, tumor necrosis factor (TNF)α, IL-1β, IL-2Rα and other inflammatory markers in the skin of AD mice. Treatment of resveratrol inhibited the development of the AD-like skin lesions. Histological analysis showed that resveratrol inhibited hypertrophy, intracellular edema, mast cells and infiltration of inflammatory cells. Furthermore, resveratrol treatment down-regulated HMGB1, RAGE, p-NFκB, p-PI3K, p-ERK1/2, COX2, TNFα, IL-1β, IL-2Rα, IFNγ and IL-4. Considering all these findings together, the HMGB1 pathway might be a potential therapeutic target in skin inflammation, and resveratrol treatment could have beneficial effects on AD by modulating the HMGB1 protein expression.

Bursin-like peptide (BLP) enhances H9N2 influenza vaccine induced humoral and cell mediated immune responses

Vaccination with H9N2 avian influenza whole-inactivated virus (WIV) has been shown to be ineffective at eliciting sufficient humoral and cellular immunity against H9N2 avian influenza virus. This study assessed the effects of a synthetic Bursin-like epitope peptide (BLP) as adjuvant for H9N2 WIV in mice. Titers HI and avian influenza virus neutralizing antibodies, subtypes of HA antibodies, T helper (Th) cytokine levels, cytotoxic T-lymphocyte activities and changes in spleen T-cell subsets and natural killer cells were determined. We found that BLP induced a balance between IgG1 and IgG2a secretion levels. WIV antigen alone induced mainly Th1 cytokines secretion, whereas BLP showed increased secretion of Th1 and Th2 cytokines, including interleukin (IL)-2, interferon-γ (IFN-γ) and IL-4, but not IL-10, and may be resembles a Th0 like response. BLP significantly promoted growth and expansion of natural killer cells and of CD4+ and CD8+ T-cell subsets in the spleen. Meanwhile, BLP induced a better cytotoxic T-lymphocyte response to H9N2 virus. Furthermore, virus challenge experiments confirmed that BLP contributed to inhibition replication of the virus from mouse lungs. Taken together, these findings suggest that BLP may be an effective adjuvant for H9N2 avian influenza vaccine.

Aspectos inmunogenéticos de la psoriasis con énfasis en micro-ARN

Psoriasis is a chronic inflammatory disease of the skin, of autoimmune origin, with different cells implicated in the aetiopathology, such as T helper lymphocytes (Th1 and Th17), keratinocytes, and cytokines produced by these cells. The epigenetic regulatory mechanisms are the junction between environmental exposure and genetic factors. It is known that microRNAs (miRNAs), single chain RNAs, are actively involved in epigenetic regulation. Alterations in the miR-125b, miR-424, miR- 21 and miR-203 expression, and others, have been involved in different aspects of the disease. Global studies of miRNA expression performed using microarrays and by direct RNA sequencing revealed important differences in miRNA expression in normal skin and psoriatic individuals. These miRNAs can be considered as potential therapeutic targets or biomarkers of disease.

Antigen 43/Fcε3 chimeric protein expressed by a novel bacterial surface expression system as an effective asthma vaccine.

The IgE Fcε3 domain is an active immunotherapeutic target for asthma and other allergic diseases. However, previous methods for preparing IgE fusion protein vaccines are complex. Antigen 43 (Ag43) is a surface protein found in Escherichia coli that contains α and β subunits (the α subunit contains multiple T epitopes). Here we constructed a novel Ag43 surface display system (Ag43 system) to express Ag43 chimeric proteins to disrupt immune tolerance against IgE. The Ag43 system was constructed from the E. coli strain Tan109, in which the Ag43 gene was deleted and a recombinant plasmid (pETAg43) expressing a partial Ag43 gene was introduced. The Fcε3 domain of the IgE gene was then subcloned into plasmid pETAg43, resulting in a recombinant plasmid pETAg43/Fcε3, which was used to transform Tan109 for Ag43/Fcε3 surface expression. Thereafter, Ag43/Fcε3 was investigated as an asthma vaccine in a mouse model. Ag43/Fcε3 was expressed on and could be separated from the bacterial surface by heating to 60° while retaining activity. Ag43/Fcε3, as a protein vaccine, produced neutralizing autoantibodies to murine IgE, induced significant anti-asthma effects, and regulated IgE and T helper cytokines in a murine asthma model. Data show that Ag43/Fcε3 chimeric protein is a potential model vaccine for asthma treatment, and that the Ag43 system may be an effective tool for novel vaccine preparation to break immune tolerance to other self-molecules.

Lung tumours reprogram pulmonary dendritic cell immunogenicity at the microRNA level.

Lung cancer arises in a context of tumour-induced immune suppression. Dendritic cells (DCs) are central players in the induction of anti-tumoural immunity, providing critical signals that drive the induction of cytotoxic T-cell responses. Meanwhile, microRNAs are associated with tumour development as well as immune regulation. We postulated that lung tumours escape immune control by reprogramming DC immunogenicity at the microRNA level. Using an orthotopic model of lung cancer, we first identified the DC population responsible for transport and cross-presentation of lung tumour-derived antigens to naïve T cells in the draining mediastinal lymph nodes (LNs). Profiling the full microRNA repertoire of these DCs revealed a restricted set of microRNAs that was consistently dysregulated in the presence of lung tumours, with miR-301a as one of the top upregulated transcripts. Overexpression of miR-301a in DCs suppressed IL-12 secretion, decreased IFN-γ release from antigen-specific cytotoxic T cells, and shifted antigen-specific T helper cytokine profile away from IFN-γ towards IL-13 and IL-17A-secreting T cells. Strikingly, DC-selective Dicer1 gene deletion resulted in delayed lung tumour growth and a survival benefit. Taken together, our data reveal that lung tumours induce an immunosuppressive microRNA signature in pulmonary DCs. Interfering with the DC-intrinsic capacity to remodel microRNA repertoires affects lung tumour outcome.

Linker for activation of T cells (LAT) in the regulation of T cell activation and autoimmunity (BA2P.121)

Abstract The transmembrane adaptor protein LAT (Linker for Activation of T cells) is essential in T cell development, activation, survival, and homeostasis. Upon T cell activation, it is tyrosine phosphorylated and interacts with many signaling proteins, such as Grb2, Gads, and PLC-γ1. The mutation of tyrosine 136 on LAT abrogates its interaction with PLC-γ1, causing defective TCR-mediated signaling. Mice harboring this mutation, LATY136F, have significantly impaired thymocyte development; however, they rapidly develop a severe lymphoproliferative disease marked by the uncontrolled expansion of Th2-skewed CD4+ T cells, high levels of IgE and IgG1, and autoantibody production. In this study, we assessed the contribution of multiple signaling pathways in this disease using mice deficient in Gads and RasGRP1 and mice with constitutive activation of the NFAT and NF-κB pathways. We also examined the role of MHC and CD4 in the development of these pathogenic T cells and further investigated how T follicular helper cells and cytokines contribute to LAT-mediated autoimmunity.

Suppression of Cytokine Release by Fluticasone Furoate vs. Mometasone Furoate in Human Nasal Tissue Ex-Vivo

BackgroundTopical glucocorticosteroids are the first line therapy for airway inflammation. Modern compounds with higher efficacy have been developed, but head-to-head comparison studies are sparse.ObjectiveTo compare the activity of two intranasal glucocorticoids, fluticasone furoate (FF) and mometasone furoate (MF) with respect to the inhibition of T helper (Th)1, Th2 and Th17 cytokine release in airway mucosa.MethodsWe used an ex-vivo human nasal mucosal tissue model and employed pre- and post- Staphylococcus aureus enterotoxin B (SEB)-challenge incubations with various time intervals and drug concentrations to mimic typical clinical situations of preventive or therapeutic use.ResultsAt a fixed concentration of 10−10 M, FF had significantly higher suppressive effects on interferon (IFN)-γ, interleukin (IL)-2 and IL-17 release, but not IL-5 or tumor necrosis factor (TNF)-α, vs. MF. While the maximal suppressive activity was maintained when FF was added before or after tissue stimulation, the cytokine suppression capacity of MF appeared to be compromised when SEB-induced cell activation preceded the addition of the drug. In a pre-challenge incubation setting with removal of excess drug concentrations, MF approached inhibition of IL-5 and TNF-α after 6 and 24 hours while FF maximally blocked the release of these cytokines right after pre-incubation. Furthermore, FF suppressed a wider range of T helper cytokines compared to MF.ConclusionThe study demonstrates the potential of our human mucosal model and shows marked differences in the ability to suppress the release of various cytokines in pre- and post-challenge settings between FF and MF mimicking typical clinical situations of preventive or therapeutic use.

Peripheral CD4CD8 Double Positive T Cells with a Distinct Helper Cytokine Profile Are Increased in Rheumatoid Arthritis

Peripheral CD4CD8 double positive (DP) T cells have been reported to play a role in several autoimmune diseases, virus infections and cancer. In rheumatoid arthritis (RA), both CD4 and CD8 single positive (SP) T cells are known to be involved in the pathogenesis, but the role of peripheral CD4CD8 DP T cells has not been investigated in detail. Anti cyclic citrullinated antibodies (ACPA) positive and ACPA negative RA patients, patients with systemic lupus erythematodes (SLE) and age matched healthy donors (HD) were enrolled in the analysis. The frequencies and phenotype of DP T cells in PBMC were investigated. In addition, DP T cells were quantified in biopsies from rheumatoid synovium. After in vitro restimulation, the cytokine production of DP T cells was investigated in cultures of PBMC. CMV specific cytokine secretion as well as proliferation was analyzed following antigen specific restimulation after an appropriate culture duration. DP T cells were found more frequently in RA patients than in healthy controls or patients with SLE. These DP T cells express αβ TCRs, are of a memory phenotype and share features of both CD4 as well as CD8 SP T cells. Importantly, DP T cells were found to also be present in the rheumatoid synovium. Further characterization of DP T cells from RA patients revealed increased production of IL-21 and IL-4, implying a possible role as T helper cells. In addition, DP T cells in RA seem to contribute to the inflammatory process, because they produce significantly more IFNγ than counterparts from HD and are increased in CMV+ RA patients. Given their capacity to produce a variety of cytokines (IL4, IL21 and IFNγ), their association with ACPA positive RA and their presence in the synovium, we suggest an important role of double positive T cells in the pathogenesis of rheumatoid arthritis.