Th2 Cytokine Gene Expression Research Articles

Cytokines and antibodies in experimental infection of wild and laboratory rodents (rodentia) with tick-borne encephalitis virus

Persistence modeling was performed by means of infection of the wild rodents: northern red-backed vole Myodes rutilus (Pallas, 1779) and striped field mouse Apodemus agrarius (Pallas, 1771), as well as of laboratory mice with the tick-borne encephalitis virus (TBEV) in tick suspensions with subsequent detection of the TBEV, hemagglutination inhibition and virus-neutralizing antibodies, as well as expression of cytokine genes during 4 months. Detection rate of the TBEV RNA and antigen E remained high during the whole period of observations; however, virus pathogenic for laboratory suckling mice was isolated mainly during a period of 8 days post infection. At the late stages of the persistent infection (1-4 months) the TBEV RNA detection rate in northern red-backed voles and laboratory mice remained high, whereas in striped field mice it significantly declined (p < 0.001). The viral loads were significantly higher (p < 0.001) in the wild rodents compared to the laboratory mice. Average frequencies of Th2 cytokine gene expression were similar for M. rutilus (50.0 ± 8.5%) and A. agrarius (50.0 ± 9.6%) during the whole period, but Th1 cytokine mRNA detection rate after transcription activation in 2 days post infection and subsequent return to the original values were different (22.2 ± 5.0% and 38.1 ± 7.6%, respectively (p > 0.05)). Meanwhile, a part of animals with interleukin 1β mRNA was significantly higher among A. agrarius than among M. rutilus (p < 0.05), which might cause low levels of spontaneous TBEV infection of field mice compared to red voles. Hemagglutination inhibition and virus-neutralizing antibodies were revealed in wild rodents in 30 days post infection and remained at detectable levels during 4 months. Thus, the TBEV persistence in small rodents was accompanied by the detection of the pathogenic virus in the early period, the viral RNA and antigen E during 4 months with high viral loads in wild animals exceeding the values in laboratory mice. Changes in the proinflammatory cytokine gene expression frequencies and the TBEV-specific antibodies pointed at immunomodulation as the possible mechanism of the TBEV persistence.

Role of Th1/Th2 cells and related cytokines in autoimmune hepatitis.

Dysregulation of T cell response is thought to play an important role in the immunopathogenesis of autoimmune hepatitis. However, no consensus has yet been reached regarding the implications of a distinct T cell subset in the pathogenesis of this progressive liver disease. Therefore, T-bet and GATA-3 expression was examined in patients with autoimmune hepatitis (AIH) and in healthy controls. Moreover, the profile of Th1 (IFN-γ) and Th2 (IL-4) cytokine gene expression was analyzed. Levels of mRNA transcripts were measured in peripheral blood mononuclear cells (PBMCs) using a two-step reverse transcription quantitative real-time polymerase chain reaction with SYBR Green. T-bet and IFN-γ mRNA expression was significantly higher in AIH patients compared to healthy controls (p<0.05), whereas no differences were observed for either GATA-3 or IL-4 mRNA expression (p>0.05). Alterations in the Th1/Th2 cell balance may be responsible for both disease progression and the resulting complications.

RHS6-mediated chromosomal looping and nuclear substructure binding is required for Th2 cytokine gene expression

Subset-specific gene expression is a critical feature of CD4 T cell differentiation. Th2 cells express Th2 cytokine genes including Il4, Il5, and Il13 and mediate the immune response against helminths. The expression of Th2 cytokine genes is regulated by Rad50 hypersensitive site 6 (RHS6) in the Th2 locus control region; however, the molecular mechanisms of RHS6 action at the chromatin level are poorly understood. Here, we demonstrate that RHS6 is crucial for chromosomal interactions and nuclear substructure binding of the Th2 cytokine locus. RHS6-deficient cells had a marked reduction in chromatin remodeling and in intrachromosomal interactions at the Th2 locus. Deficiency of RHS6-binding transcription factors GATA3, SATB1, and IRF4 also caused a great reduction in chromatin remodeling and long-range chromosomal interactions involving the Th2 locus. RHS6 deficiency abrogated association of the Th2 locus with the nuclear substructure and RNA polymerase II. Therefore, RHS6 serves as a crucial cis-acting hub for coordinate regulation of Th2 cytokine genes by forming chromosomal loops and binding to a nuclear substructure.

Tomatidine Attenuates Airway Hyperresponsiveness and Inflammation by Suppressing Th2 Cytokines in a Mouse Model of Asthma.

Tomatidine is isolated from the fruits of tomato plants and found to have anti-inflammatory effects in macrophages. In the present study, we investigated whether tomatidine suppresses airway hyperresponsiveness (AHR) and eosinophil infiltration in asthmatic mice. BALB/c mice were sensitized with ovalbumin and treated with tomatidine by intraperitoneal injection. Airway resistance was measured by intubation analysis as an indication of airway responsiveness, and histological studies were performed to evaluate eosinophil infiltration in lung tissue. Tomatidine reduced AHR and decreased eosinophil infiltration in the lungs of asthmatic mice. Tomatidine suppressed Th2 cytokine production in bronchoalveolar lavage fluid. Tomatidine also blocked the expression of inflammatory and Th2 cytokine genes in lung tissue. In vitro, tomatidine inhibited proinflammatory cytokines and CCL11 production in inflammatory BEAS-2B bronchial epithelial cells. These results indicate that tomatidine contributes to the amelioration of AHR and eosinophil infiltration by blocking the inflammatory response and Th2 cell activity in asthmatic mice.

RHS6 coordinately regulates the Th2 cytokine genes by recruiting GATA3, SATB1, and IRF4.

Asthma is a Th2 cell-driven inflammatory disease and a major public health concern. The cis-acting element Rad50 hypersensitive site 6 (RHS6) in the Th2 locus control region is essential for regulation of the Th2 cytokine genes; however, its role in allergic airway inflammation and underlying molecular mechanisms of the regulation by RHS6 are poorly understood. We sought to understand the role of RHS6 in the development of allergic airway inflammation and its molecular mechanism for Th2 cytokine expression. We used an ovalbumin-induced allergic inflammation model with RHS6-deficient mice to examine the role of RHS6 in this process. To examine molecular mechanism of RHS6 for Th2 cytokine expression, we used DNA affinity chromatography and mass spectrometry, quantitative RT-PCR, ELISA, intracellular cytokine staining, chromatin immunoprecipitation, and co-immunoprecipitation. Deletion of RHS6 caused a dramatic resistance to allergic airway inflammation. RHS6 recruited transcription factors GATA3, SATB1, and IRF4, which play important roles in expression of all three Th2 cytokine genes. RHS6 deficiency caused inhibition of transcription factor-induced Th2 cytokine gene expression. RHS6 is a critical regulatory element for allergic airway inflammation and for coordinate regulation of Th2 cytokine genes by recruiting GATA3, SATB1, and IRF4.

Mouse Model of Cat Allergic Rhinitis and Intranasal Liposome-Adjuvanted Refined Fel d 1 Vaccine.

Cats (Felis domesticus) are rich source of airborne allergens that prevailed in the environment and sensitized a number of people to allergy. In this study, a mouse model of allergic rhinitis caused by the cat allergens was developed for the first time and the model was used for testing therapeutic efficacy of a novel intranasal liposome-entrapped vaccines made of native Fel d 1 (major cat allergen) in comparison with the vaccine made of crude cat hair extract (cCE). BALB/c mice were sensitized with cCE mixed with alum intraperitoneally and intranasally. The allergic mice were treated with eight doses of either liposome (L)-entrapped native Fel d 1 (L-nFD1), L-cCE), or placebo on every alternate day. Vaccine efficacy evaluation was performed one day after provoking the treated mice with aerosolic cCE. All allergenized mice developed histological features of allergic rhinitis with rises of serum specific-IgE and Th2 cytokine gene expression. Serum IgE and intranasal mucus production of allergic mice reduced significantly after vaccination in comparison with the placebo mice. The vaccines also caused a shift of the Th2 response (reduction of Th2 cytokine expressions) towards the non-pathogenic responses: Th1 (down-regulation of the Th1 suppressive cytokine gene, IL-35) and Treg (up-regulation of IL-10 and TGF-β). In conclusions, a mouse model of allergic rhinitis to cat allergens was successfully developed. The intranasal, liposome-adjuvanted vaccines, especially the refined single allergen formulation, assuaged the allergic manifestations in the modeled mice. The prototype vaccine is worthwhile testing further for clinical use in the pet allergic patients.

Transcription Factors Oct-1 and GATA-3 Cooperatively Regulate Th2 Cytokine Gene Expression via the RHS5 within the Th2 Locus Control Region.

The T helper type 2 (Th2) locus control region (LCR) regulates Th2 cell differentiation. Several transcription factors bind to the LCR to modulate the expression of Th2 cytokine genes, but the molecular mechanisms behind Th2 cytokine gene regulation are incompletely understood. Here, we used database analysis and an oligonucleotide competition/electrophoretic mobility shift assays to search for transcription factors binding to RHS5, a DNase I hypersensitive site (DHS) within the Th2 LCR. Consequently, we demonstrated that GATA-binding protein-3 (GATA-3), E26 transformation-specific protein 1 (Ets-1), octamer transcription factor-1 (Oct-1), and Oct-2 selectively associate with RHS5. Furthermore, chromatin immunoprecipitation and luciferase reporter assays showed that Oct-1 and Oct-2 bound within the Il4 promoter region and the Th2 LCR, and that Oct-1 and GATA-3 or Oct-2 synergistically triggered the transactivational activity of the Il4 promoter through RHS5. These results suggest that Oct-1 and GATA-3/Oct-2 direct Th2 cytokine gene expression in a cooperative manner.

A novel benzofuran, 4-methoxybenzofuran-5-carboxamide, from Tephrosia purpurea suppressed histamine H1 receptor gene expression through a protein kinase C-δ-dependent signaling pathway

Histamine H1 receptor (H1R) gene is upregulated in patients with allergic rhinitis (AR), and its expression level is strongly correlated with the severity of allergic symptoms. We previously reported isolation of the putative anti-allergic compound, 4-methoxybenzofuran-5-carboxamide (MBCA) from Tephrosia purpurea and its chemical synthesis (Shill et al., Bioorg Med Chem 2015;23:6869–6874). However, the mechanism underlying its anti-allergic activity remains to be elucidated. Here, we report the mechanism of MBCA on phorbol 12-myristate-13-acetate (PMA)- or histamine-induced upregulation of H1R gene expression in HeLa cells, and in vivo effects of MBCA were also determined in toluene-2,4-diisocyanate (TDI)-sensitized rats. MBCA suppressed PMA- and histamine-induced upregulation of H1R expression at both mRNA and protein levels and inhibited PMA-induced phosphorylation of PKCδ at Tyr311 and subsequent translocation to the Golgi. Furthermore, MBCA ameliorated allergic symptoms and suppressed the elevation of H1R and helper T cell type 2 (Th2) cytokine mRNAs in TDI-sensitized rats. Data suggest that MBCA alleviates nasal symptoms in TDI-sensitized rats through the inhibition of H1R and Th2 cytokine gene expression. The mechanism of its H1R gene suppression underlies the inhibition of PKCδ activation.

Inhalation exposure to ethylene induces eosinophilic rhinitis and nasal epithelial remodeling in Fischer 344 rats

This study investigated the time- and concentration-dependent effects of inhaled ethylene on eosinophilic rhinitis and nasal epithelial remodeling in Fisher 344 rats exposed to 0, 10, 50, 300, or 10,000 ppm ethylene, 6 h/day, 5 days/week for up to 4 weeks. Morphometric quantitation of eosinophilic inflammation and mucous cell metaplasia/hyperplasia (MCM) and nasal mucosal gene expression were evaluated at anatomic sites previously shown to undergo ethylene-induced epithelial remodeling. Serum levels of total IgE, IgG1 and IgG2a were measured to determine if ethylene exposure increased the expression of Th2-associated (IgE and IgG1) relative to Th1-associated (IgG2a) antibody isotypes. Rats exposed to 0 or 10,000 ppm for 1, 3, 5, 10, or 20 days were analyzed to assess the temporal pattern of ethylene-induced alterations in nasal epithelial cell proliferation, morphology and gene expression. Rats exposed to 0, 10, 50, 300, and 10,000 ppm ethylene for 20 days were analyzed to assess concentration-dependent effects on lesion development. Additional rats exposed 4 weeks to 0, 300, or 10,000 ppm ethylene were held for 13 weeks post-exposure to examine the persistence of ethylene-induced mucosal alterations. The data indicate that cell death and reparative cell proliferation were not a part of the pathogenesis of ethylene-induced nasal lesions. Enhanced gene expression of Th2 cytokines (e.g., IL-5, IL-13) and chitinase (YM1/2) in the nasal mucosa was much greater than that of Th1 cytokines (e.g., IFNγ) after ethylene exposure. A significant increase in MCM was measured after 5 days of exposure to 10,000 ppm ethylene and after 20 days of exposure 10 ppm ethylene. Ethylene-induced MCM was reversible after cessation of exposure. No increase in total serum IgE, IgG1 or IgG2a was measured in any ethylene-exposed group. These data do not support involvement of an immune-mediated allergic mechanism in the pathogenesis of ethylene-induced nasal lesions in rats. Repeated inhalation of ethylene can induce a local Th2-mediated response in the nasal mucosa of rats, however the mechanisms which induce nasal inflammatory and epithelial responses are yet to be determined.

Trichloroethylene and Its Oxidative Metabolites Enhance the Activated State and Th1 Cytokine Gene Expression in Jurkat Cells.

Trichloroethylene (TCE) is an occupational and ubiquitous environmental contaminant, and TCE exposure will increase the risk of autoimmune diseases and allergic diseases. T cells play an important role in the pathogenesis of TCE-related immune disorders, but the effect of TCE and its oxidative metabolites, trichloroacetic acid (TCA) and dichloroacetic acid (DCA), on the activation of human T cells is still unknown. In this study, Jurkat cells were pre-treated with TCE, TCA and DCA overnight and then stimulated with phorbol 12-myristate 13-acetate and ionomycin for another 4, 8 and 24 hours. IL-2 secretion was detected by ELISA; the expressions of CD25 and CD69 were tested by flow cytometry; and IFN-γ and IL-2 mRNA expression levels were investigated by real-time PCR. The results showed that TCE and its oxidative metabolites, TCA and DCA, significantly enhanced IL-2 releasing and the expression of T cell activation markers, CD25 and CD69. Consistent with this result, these compounds markedly up-regulated the expression levels of IFN-γ and IL-2 mRNA. Collectively, these findings suggest that TCE and its metabolites, TCA and DCA, might enhance the activation of T cells and disrupt various activities of peripheral T cells.

Suppression of Th2 and Tfh immune reactions by Nr4a receptors in mature T reg cells.

Regulatory T (T reg) cells are central mediators of immune suppression. As such, T reg cells are characterized by a distinct pattern of gene expression, which includes up-regulation of immunosuppressive genes and silencing of inflammatory cytokine genes. Although an increasing number of transcription factors that regulate T reg cells have been identified, the mechanisms by which the T reg cell-specific transcriptional program is maintained and executed remain largely unknown. The Nr4a family of nuclear orphan receptors, which we recently identified as essential for the development of T reg cells, is highly expressed in mature T reg cells as well, suggesting that Nr4a factors play important roles even beyond T reg cell development. Here, we showed that deletion of Nr4a genes specifically in T reg cells caused fatal systemic immunopathology. Nr4a-deficient T reg cells exhibited global alteration of the expression of genes which specify the T reg cell lineage, including reduction of Foxp3 and Ikzf4. Furthermore, Nr4a deficiency abrogated T reg cell suppressive activities and accelerated conversion to cells with Th2 and follicular helper T (Tfh) effector-like characteristics, with heightened expression of Th2 and Tfh cytokine genes. These findings demonstrate that Nr4a factors play crucial roles in mature T reg cells by directly controlling a genetic program indispensable for T reg cell maintenance and function.

Obesity Drives Th17 Cell Differentiation by Inducing the Lipid Metabolic Kinase, ACC1

Chronic inflammation due to obesity contributes to the development of metabolic diseases, autoimmune diseases, and cancer. Reciprocal interactions between metabolic systems and immune cells have pivotal roles in the pathogenesis of obesity-associated diseases, although the mechanisms regulating obesity-associated inflammatory diseases are still unclear. In the present study, we performed transcriptional profiling of memory phenotype CD4 T cells in high-fat-fed mice and identified acetyl-CoA carboxylase 1 (ACC1, the gene product of Acaca) as an essential regulator of Th17 cell differentiation in vitro and of the pathogenicity of Th17 cells in vivo. ACC1 modulates the DNA binding of RORγt to target genes in differentiating Th17 cells. In addition, we found a strong correlation between IL-17A-producing CD45RO(+)CD4 T cells and the expression of ACACA in obese subjects. Thus, ACC1 confers the appropriate function of RORγt through fatty acid synthesis and regulates the obesity-related pathology of Th17 cells.

Improvement in allergic and nonallergic rhinitis: A secondary benefit of adenoidectomy in children.

Chronic rhinitis (CR) is a common disorder in children. Allergic rhinitis (AR) is a risk factor for CR, and children with AR tend to suffer more from hypertrophic adenoids than do patients with nonallergic rhinitis (NAR). Few studies have addressed the issue of alleviating symptoms of pediatric CR or AR following adenoidectomy alone. We conducted a retrospective chart review to determine whether CR in children improves after adenoidectomy and whether children with AR will benefit more than those with NAR. Charts of 47 children who had undergone adenoidectomy for nasal obstruction and chronic middle ear effusion were reviewed. AR and NAR subgroups were classified based on symptoms, signs, blood IgE, and nasal smear (allergic criteria). Hypertrophic adenoids were graded using the adenoid-to-nasopharyngeal ratio (ANr >0.8). A questionnaire was used to assess the change in chronic rhinitis postoperatively. Improvement in CR was reported in 37 of 47 (79%) children. Patients with AR improved to a higher extent than those with NAR (12 of 14 [86%] vs. 25 of 33 [76%], respectively), but the difference was not statistically significant. A total of 41 lateral postoperative nasopharyngeal x-rays were obtained. The x-rays revealed that 20 of 26 (77%) of patients with ANr >0.8 had complete and 4 of 26 (15%) had partial resolution of symptoms of CR for a total resolution rate of 92%, compared to only a 53% resolution in the ANr <0.8 subgroup (6 of 15 and 2 of 15 patients, respectively [p <0.05]). The correlation between adenoid size and resolution of CR was not related to any of the AR/NAR subgroups. We conclude that symptoms of CR may improve after adenoidectomy in children who are experiencing nasal obstruction and chronic otitis media with effusion. Clinical improvement did not differ between AR and NAR patients, and was more prominent in children with hypertrophic adenoids (ANr >0.8).

Impairment of host resistance to helminthes with age in murine small intestine.

Age-associated alterations of Th2 immune responses against nematode parasites are largely unknown. We investigated primary and memory responses against two types of gastrointestinal nematode parasites, Heligmosomoides polygyrus (Hp) and Nippostrongylus brasiliensis (Nb), in aged mice. The small intestinal gene expression of Th2 cytokines was almost unchanged after primary (Nb and Hp) and secondary infection (Hp) in aged mice in contrast to strongly increased small intestinal gene expression of Th2 cytokines in young (3-month-old) mice. Mucus production decreased (Nb), and worm expulsion was impaired (Nb and Hp) compared with the young mice. Immunofluorescent staining revealed that after Hp infection, the number of alternatively activated macrophages, which are induced by Th2 cytokines, was lower in the aged mice. On the other hand, the number of CD4(+) T cells recruited to the worm cysts was normal compared with the young mice. These results suggest that migration of CD4(+) T cells to the host-parasite interface is not affected by ageing. Alterations in Th2 immune responses in aged mice might be due to inappropriate or insufficient activation of CD4(+) T cells in the submucosa.

Gene Expression Profile of Dendritic Cell-Tumor Cell Hybrids Determined by Microarrays and Its Implications for Cancer Immunotherapy.

Background. Dendritic cell- (DC-) tumor fusion cells stimulate effective in vivo antitumor responses. However, therapeutic approaches are dependent upon the coadministration of exogenous 3rd signals. The purpose of this study was to determine the mechanisms for inadequate 3rd signaling by electrofused DC-tumor cell hybrids. Methods. Murine melanoma cells were fused with DCs derived from C57BL/6 mice. Quantitative real-time PCR (qPCR) was used to determine relative changes in Th (T helper) 1 and Th2 cytokine gene expression. In addition, changes in gene expression of fusion cells were determined by microarray. Last, cytokine secretion by fusion cells upon inhibition of signaling pathways was analyzed by ELISA. Results. qPCR analyses revealed that fusion cells exhibited a downregulation of Th1 associated cytokines IL-12 and IL-15 and an upregulation of the Th2 cytokine IL-4. Microarray studies further showed that the expression of chemokines, costimulatory molecules, and matrix-metalloproteinases was deregulated in fusion cells. Lastly, inhibitor studies demonstrate that inhibition of the PI3K/Akt/mTOR signaling pathway could restore the secretion of bioactive IL-12p70 by fusion cells. Conclusion. Our results suggest that combining fusion cell-based vaccination with administration of inhibitors of the PI3K/Akt/mTOR signaling pathway may enhance antitumor responses in patients.

Inhibition of Epithelial CC-Family Chemokine Synthesis by the Synthetic Chalcone DMPF-1 via Disruption of NF-κB Nuclear Translocation and Suppression of Experimental Asthma in Mice.

Asthma is associated with increased pulmonary inflammation and airway hyperresponsiveness. The interaction between airway epithelium and inflammatory mediators plays a key role in the pathogenesis of asthma. In vitro studies evaluated the inhibitory effects of 3-(2,5-dimethoxyphenyl)-1-(5-methylfuran-2-yl)prop-2-en-1-one (DMPF-1), a synthetic chalcone analogue, upon inflammation in the A549 lung epithelial cell line. DMPF-1 selectively inhibited TNF-α-stimulated CC chemokine secretion (RANTES, eotaxin-1, and MCP-1) without any effect upon CXC chemokine (GRO-α and IL-8) secretion. Western blot analysis further demonstrated that the inhibitory activity resulted from disruption of p65NF-κB nuclear translocation without any effects on the mitogen-activated protein kinase (MAPK) pathway. Treatment of ovalbumin-sensitized and ovalbumin-challenged BALB/c mice with DMPF-1 (0.2–100 mg/kg) demonstrated significant reduction in the secretion and gene expression of CC chemokines (RANTES, eotaxin-1, and MCP-1) and Th2 cytokines (IL-4, IL-5, and IL-13). Furthermore, DMPF-1 treatment inhibited eosinophilia, goblet cell hyperplasia, peripheral blood total IgE, and airway hyperresponsiveness in ovalbumin-sensitized and ovalbumin-challenged mice. In conclusion, these findings demonstrate the potential of DMPF-1, a nonsteroidal compound, as an antiasthmatic agent for further pharmacological evaluation.

Proton pump inhibitor‐responsive oesophageal eosinophilia correlates with downregulation of eotaxin‐3 and Th2 cytokines overexpression

The molecular basis and effects of proton pump inhibitor (PPI) therapy on PPI-responsive oesophageal eosinophilia (PPI-REE) and eosinophilic oesophagitis (EoE) remain unknown. To compare symptom-histological and cytokine gene expression in PPI-REE and EoE patients, at baseline and after specific treatment. In consecutive adult patients with an EoE phenotype (dysphagia/food impaction, typical endoscopic findings and > 15 eos/HPF), gene expression of eotaxin-3, IL-13, and IL-5 were determined in distal and proximal oesophagus, at baseline and after omeprazole 40 mg b.d. for 8 weeks. PPI-REE was defined by clinicohistological response. PPI nonresponders (EoE) were offered treatment with topical steroids. Fifty three patients were re-evaluated on PPI therapy. 23 patients (43%) had PPI-REE and 30 patients (57%) had EoE. At baseline, eotaxin-3/IL-13/IL-5 gene expression was indistinguishable between EoE and PPI-REE, excepting increased IL-5 expression in proximal oesophagus (12.54 vs. 57, P = 0.029). PPI therapy significantly decreased eotaxin-3/IL-13 in PPI-REE, at both oesophageal sites (P ≤ 0.008), and IL-5 in distal (P = 0.016), but not in proximal oesophagus. Patients with steroid-responsive EoE also showed a significant decrease in eotaxin-3/IL-5 expression at both oesophageal sites. In EoE patients, initial PPI trial significantly decreased distal oesophageal eosinophilia (63.78 to 41.79 eos/HPF, P = 0.025) and led to symptom remission in 16%, but did not influence Th2 markers. Baseline cytokine gene expression in PPI-REE was nearly indistinguishable from EoE. PPI therapy significantly downregulated oesophageal eotaxin-3/Th2-cytokine gene expression in PPI-REE, similarly to that seen in steroid-responsive EoE. A subset of EoE patients showed clinicohistological improvement on PPI therapy.

Treatment with the C5a receptor/CD88 antagonist PMX205 reduces inflammation in a murine model of allergic asthma.

Allergic asthma is a chronic inflammatory airway disease arising from an aberrant immune response following exposure to environmental stimuli in genetically susceptible persons. The complement component 5 (C5)/C5a Receptor (C5aR/CD88) signaling pathway has been implicated in both experimental allergic asthma and human asthmatic disease. Targeting the C5a/C5aR signaling pathway in rodent models has been shown to either enhance or reduce allergic asthma consequences. Treatment with a recombinant humanized monoclonal antibody directed against C5 has shown unclear results in patients with asthma. The objective of this proof-of-concept animal study was to determine whether the low molecular weight C5aR peptidomimetic antagonist, PMX205, would reduce experimental allergic asthma consequences in mice. PMX205 or vehicle control was administered subcutaneously to BALB/c mice prior to and during standard ovalbumin (OVA) allergen sensitization and aerosolized challenge phases. PMX205 substantially reduced OVA-induced total cell (60%), neutrophil (66%) and eosinophil (65%) influxes in lavage fluid sampling. There were also significant reductions in OVA-induced lavage fluid IL-13 protein and lung Th2 cytokine gene expression with PMX205 administration. PMX205 treatment also diminished OVA-induced lung parenchyma cellular infiltration. PMX205 administration did not reduce OVA-induced serum IgE levels or epithelial mucous/goblet cell generation. There was no evidence of toxicity observed with PMX205 treatment in saline or OVA-challenged animals. These data provide evidence that pharmacologic blockade of C5aR by a low molecular weight antagonist (PMX205) reduces airway inflammatory cell and cytokine responses in experimental allergic asthma, and suggests that PMX205 might represent a novel therapeutic agent for reducing asthmatic outcomes.

‘All things considered’: transcriptional regulation of T helper type 2 cell differentiation from precursor to effector activation

T helper type 2 (Th2) cells are critical to host defence against helminth infection and the pathogenesis of allergic diseases. The differentiation of Th2 cells from naive CD4 T cells is controlled by intricate transcriptional mechanisms. At the precursor stage of naive CD4 T cells, transcriptional mechanisms maintain the potential and in the meantime prevent spontaneous differentiation to Th2 fate. In addition, intrachromosomal interactions important for co-ordinated expression of Th2 cytokines pre-exist in naive CD4 T cells. Upon T-cell receptor (TCR) engagement, naive CD4 T cells are induced by polarizing signals of the interleukin-4/Stat6 and Jagged/Notch pathways to up-regulate the expression of GATA-3. Once up-regulated, GATA-3 drives Th2 and suppresses Th1 differentiation in a cell autonomous fashion. In this stage of differentiation, the Th2 cytokine locus, as well as the interferon-γ locus, undergoes chromatin remodelling and epigenetic modifications that contribute to the somatic memory of Th2 cytokine gene expression pattern. Once differentiated, Th2 effector cells promptly produce Th2 cytokines upon TCR stimulation, which is regulated by concerted actions of GATA-3, TCR signalling, enhancers and the Th2 locus control region. This review provides a detailed account of the transcriptional regulatory events at these different stages of Th2 differentiation.

Th1 and Th2 cytokine gene expression in primary infection and vaccination against Fasciola gigantica in buffaloes by real-time PCR

Th1 and Th2 cytokine gene expression in buffalo calves during primary infection with Fasciola gigantica as well as in response to immunization with the parasite recombinant fatty acid binding protein (rFABP) and recombinant glutathione S-transferase (rGST) proteins was measured at 14th week of infection by real-time PCR with the double-stranded DNA-binding dye SYBR Green. Experimental animals were randomly distributed into FABP, GST, cocktail, challenge and healthy groups. Animals in groups FABP and GST were immunized with 400 μg rFABP and rGST, respectively, and cocktail group with a mixture of 400 μg each of rFABP and rGST in the neck and thigh muscles. All animals received three immunizations at 3-week interval. Calves were challenged per os with 400 viable metacercariae along with the unimmunized challenge control group 1 month after the last immunization. Expression of various cytokines in response to the immunization and parasite primary infection was measured by real-time PCR. Expression of IL-2 (4.5-fold) and IFN-γ (3.2-fold), followed by IL-6 (1.7-fold) and IL-4 (1.6-fold), with downregulation of TNF-α and IL-10 was observed in response to F. gigantica infection in these animals. However, there was a sharp increase in the expression of the IL-4 (211.93 and 111.81-fold) and IL-6 mRNA (219.22 and 48.29-fold) to GST and FABP immunizations, respectively. A downregulation of the IL-1α, a Th1 cytokine in response to FABP and GST immunization in these calves, was also observed. Overall, a mixed type of Th1 and Th2 cytokine environment was evoked to chronic F. gigantica infection and immunization with the above two recombinant proteins in buffaloes.