TNF-α enhance Th2 and Th17 immune responses regulating by IL23 during sensitization in asthma model.

BACKGROUND: TNF-α has been postulated to be a critical mediator contributing to airway inflammation. The purpose of this study was to evaluate the role of TNF-α in the induction of Th17 and Th2 cells related to asthma pathogenesis. OBJECTIVE: To evaluate detailed mechanisms for the modulation of IL-23 by TNF-α in sensitization period. METHODS: During sensitization period, 10µg of rat anti-mouse TNF-α mAb was intravenously administrated one hour before the application of OVA and 0.1µg of LPS. To see the relation between TNF-α and associated effectors cytokine, we replenished TNF-α KO mice with IL-23 during sensitization period. To assess cellular resources, CD11c+ cells isolated from lung tissue after sensitization were treated with anti-TNF-α Ab. RESULTS: Treatment of anti-TNF-α mAb during sensitization period significantly reduced airway eosinophilia, serum OVA-specific IgE levels and methacholine AHR compared to isotype Ab. Anti-TNF-α mAb treated mice showed significant reduction in the levels of IL-23 after sensitization in bronchoalveolar lavage fluid (BALF) as well as IL-17A, IL-4 levels in BALF after challenge compared with isotype Ab treated mice. Supplementation of IL-23 in TNF-α KO mice resulted in complete restoration of eosinophilic airway inflammation, AHR, and IL-17A and IL-4 expression in CD4+ T cells. Anti-TNF-α mAb treatment after sensitization significantly diminished the population of IL-23p19-secreting CD11c+ cells in lung. CONCLUSION: TNF-α plays an important role in the development of airway inflammation by enhancing IL-23/Th17 and Th2 immune responses.

Activation of p38α in T cells regulates the intestinal host defense against attaching and effacing bacterial infections.

Intestinal infections by attaching and effacing (A/E) bacterial pathogens cause severe colitis and bloody diarrhea. Although p38α in intestinal epithelial cells (IEC) plays an important role in promoting protection against A/E bacteria by regulating T cell recruitment, its impact on immune responses remains unclear. In this study, we show that activation of p38α in T cells is critical for the clearance of the A/E pathogen Citrobacter rodentium. Mice deficient of p38α in T cells, but not in macrophages or dendritic cells, were impaired in clearing C. rodentium. Expression of inflammatory cytokines such as IFN-γ by p38α-deficient T cells was reduced, which further reduced the expression of inflammatory cytokines, chemokines, and antimicrobial peptide by IECs and led to reduced infiltration of T cells into the infected colon. Administration of IFN-γ activated the mucosal immunity to C. rodentium infection by increasing the expression of inflammation genes and the recruitment of T cells to the site of infection. Thus, p38α contributes to host defense against A/E pathogen infection by regulating the expression of inflammatory cytokines that activate host defense pathways in IECs.

Expression of semaphorin 3A and neuropilin 1 in asthma.

Neuropilin 1 (NP1) is a part of essential receptor complexes mediating both semaphorin3A (SEMA3A) and vascular endothelial growth factor (VEGF) which is one of important mediators involved in the pathogenesis of asthma. Therefore, it is possible that SEMA3A plays a role in the pathogenesis of asthma through attenuation of VEGF-mediated effects. In the present study, we aimed to evaluate expression levels of SEMA3A and NP1 using induced sputum of asthmatics and a murine model of asthma. Firstly, SEMA3A and NP1 expressions in induced sputum of asthmatics and SEMA3A and NP1 expression on bronchoalveolar lavage (BAL) cells and lung homogenates of asthmatic mice were determined. Then we evaluated the immunolocalization of VEGF receptor 1 (VEGFR1), VEGF receptor 2 (VEGFR2), and NP1 expressions on asthmatic mice lung tissue and their subcellular distributions using fibroblast and BEAS2B cell lines. Sputum SEMA3A and NP1 expressions were significantly higher in asthmatics than controls. Similarly, SEMA3A and NP1 expressions on BAL cells and lung homogenates were significantly elevated in asthmatic mice compared to control mice. Immunohistochemical analysis showed that VEGFR1, VEGFR2, and NP1 expressions were also uniformly increased in asthmatic mice. Our observations suggest that SEMA3A and NP1 may play important roles in the pathogenesis of asthma.

Toll-like receptor expression on peripheral blood mononuclear cells in asthmatics; implications for asthma management.

BACKGROUND: Accumulating evidence indicates that cells expressing Toll-like receptors (TLRs) play an important role in allergic diseases. The authors undertook this study to explore the hypothesis that TLR-mediated inflammatory signals are important from the perspective of asthma management. METHODS: The expressions of TLR1, TLR2, TLR3, TLR4, TLR6, and TLR9 and levels of pro-inflammatory cytokines (TNF-alpha, IL-1beta, IL-6, IL-8, and IFN-gamma) on the peripheral blood mononuclear cells (PBMCs) of 36 stable asthmatics on treatment (the on-treatment group), 15 asthmatics (the treatment-naïve group) before and after a 7-day course of oral prednisolone (30 mg/day), and on the PBMCs of 15 healthy controls were measured after in vitro stimulation using TLR-specific ligands. RESULTS: In the on-treatment group, TLR1, TLR2, TLR6, and TLR9 expressions on PBMCs were significantly different between asthmatics and controls. And the expression of TLR4 on PBMCs and TNF-alpha production stimulated by lipopolysaccharide (LPS), were significantly higher in mild to moderate than in severe asthmatics. Interestingly, in the treatment-naïve group, short-term prednisolone significantly increased LPS-induced TNF-alpha and IFN-gamma productions by PBMCs. CONCLUSION: TLR-mediated inflammatory signals contribute to the development and severity of asthma and are not reduced by glucocorticoid treatment, which suggests that a TLR-specific antagonist and glucocorticoid are required for the effective control of airway inflammation in asthmatics.

Regulation of NKT cell-mediated immune responses to tumours and liver inflammation by mitochondrial PGAM5-Drp1 signalling.

The receptor-interacting protein kinase 3 (RIPK3) plays crucial roles in programmed necrosis and innate inflammatory responses. However, a little is known about the involvement of RIPK3 in NKT cell-mediated immune responses. Here, we demonstrate that RIPK3 plays an essential role in NKT cell function via activation of the mitochondrial phosphatase phosphoglycerate mutase 5 (PGAM5). RIPK3-mediated activation of PGAM5 promotes the expression of cytokines by facilitating nuclear translocation of NFAT and dephosphorylation of dynamin-related protein 1 (Drp1), a GTPase is essential for mitochondrial homoeostasis. Ripk3(-/-) mice show reduced NKT cell responses to metastatic tumour cells, and both deletion of RIPK3 and pharmacological inhibition of Drp1 protects mice from NKT cell-mediated induction of acute liver damage. Collectively, the results identify a crucial role for RIPK3-PGAM5-Drp1/NFAT signalling in NKT cell activation, and further suggest that RIPK3-PGAM5 signalling may mediate crosstalk between mitochondrial function and immune signalling.

Eosinophils Modulate CD4(+) T Cell Responses via High Mobility Group Box-1 in the Pathogenesis of Asthma.

Eosinophils have been reported to modulate T cell responses. Previously, we reported that high-mobility group box 1 protein (HMGB1) played a key role in the pathogenesis of asthma. This study was conducted to test our hypothesis that eosinophils could modulate T cell responses via HMGB1 in the pathogenesis of asthma characterized by eosinophilic airway inflammation. We performed in vitro experiments using eosinophils, dendritic cells (DCs), and CD4(+) T cells obtained from a murine model of asthma. The supernatant of the eosinophil culture was found to significantly increase the levels of interleukin (IL)-4 and IL-5 in the supernatant of CD4(+) T cells co-cultured with DCs. HMGB1 levels increased in the supernatant of the eosinophil culture stimulated with IL-5. Anti-HMGB1 antibodies significantly attenuated increases of IL-4 and IL-5 levels in the supernatant of CD4(+) T cells co-cultured with DCs that were induced by the supernatant of the eosinophil culture. In addition, anti-HMGB1 antibodies significantly attenuated the expressions of activation markers (CD44 and CD69) on CD4(+) T cells. Our data suggest that eosinophils modulate CD4(+) T cell responses via HMGB1 in the pathogenesis of asthma.

A case of allopurinol-induced fixed drug eruption confirmed with a lymphocyte transformation test.

Allopurinol is one of the causative drugs that induce fixed drug eruption (FDE). The lymphocyte transformation test (LTT) is a safe and reliable diagnostic procedure for drug allergy, but is reported to be rarely positive in patients with FDE. In the current case, we performed an LTT and successfully confirmed allopurinol as the offending drug. This case report suggests that an LTT should be an optional diagnostic tool for FDE or delayed reaction due to allopurinol.

Alveolar macrophages modulate allergic inflammation in a murine model of asthma.

The role of alveolar macrophages (AMs) in the pathogenesis of asthma is still unknown. The aim of the present study was to investigate the effects of AM in the murine model of asthma. AMs were selectively depleted by liposomes containing clodronate just before allergen challenges, and changes in inflammatory cells and cytokine concentrations in bronchoalveolar lavage (BAL) fluid were measured. AMs were then adoptively transferred to AM-depleted sensitized mice and changes were measured. Phenotypic changes in AMs were evaluated after in vitro allergen stimulation. AM-depletion after sensitization significantly increased the number of eosinophils and lymphocytes and the concentrations of IL-4, IL-5 and GM-CSF in BAL fluid. These changes were significantly ameliorated only by adoptive transfer of unsensitized AMs, not by sensitized AMs. In addition, in vitro allergen stimulation of AMs resulted in their gaining the ability to produce inflammatory cytokines, such as IL-1ß, IL-6 and TNF-α, and losing the ability to suppress GM-CSF concentrations in BAL fluid. These findings suggested that AMs worked probably through GM-CSF-dependent mechanisms, although further confirmatory experiments are needed. Our results indicate that the role of AMs in the context of airway inflammation should be re-examined.

Cancer of unknown primary finally revealed to be a metastatic prostate cancer: a case report.

The vast majority of patients with metastatic prostate cancer present with bone metastases and high prostate specific antigen (PSA) level. Rarely, prostate cancer can develop in patients with normal PSA level. Here, we report a patient who presented with a periureteral tumor of unknown primary site that was confirmed as prostate adenocarcinoma after three years with using specific immunohistochemical examination. A 64-year old man was admitted to our hospital with left flank pain associated with masses on the left pelvic cavity with left hydronephrosis. All tumor markers including CEA, CA19-9, and PSA were within the normal range. After an exploratory mass excision and left nephrectomy, the pelvic mass was diagnosed as poorly differentiated carcinoma without specific positive immunohistochemical markers. At that time, we treated him as having a cancer of unknown primary site. After approximately three years later, he revisited the hospital with a complaint of right shoulder pain. A right scapular mass was newly detected with a high serum PSA level (101.7 ng/ml). Tissues from the scapular mass and prostate revealed prostate cancer with positive immunoreactivity for P504S, a new prostate cancer-specific gene. The histological findings were the same as the previous pelvic mass; however, positive staining for PSA was observed only in the prostate mass. This case demonstrates a patient with prostate cancer and negative serological test and tissue staining that turned out to be positive during progression. We suggest the usefulness of newly developed immunohistochemical markers such as P504S to determine the specific primary site of metastatic poorly differentiated adenocarcinoma in men.

TH2 and TH1 lung inflammation induced by airway allergen sensitization with low and high doses of double-stranded RNA.

BACKGROUND: Although respiratory viral infections in early childhood can enhance the development of airway allergen sensitization, the exact mechanisms of the effects of viral infections on the adaptive immune response to inhaled allergens are controversial. OBJECTIVE: We sought to evaluate the effects of double-stranded RNA (dsRNA) on airway sensitization to inhaled allergens. METHODS: Novel mouse models were created through simultaneous airway sensitization to an allergen and low or high doses of dsRNA. The mouse models were applied to Toll-like receptor 3-, IL-13-, IL-4-, signal transducer and activator of transcription (STAT) 6-, IFN-gamma-, and T-box expressed in T cells (T-bet)-deficient mice to evaluate underlying pathophysiologic mechanisms in the development of allergic lung inflammation. RESULTS: We found that airway allergen sensitization with dsRNA induced lung inflammation that was not present in Toll-like receptor 3-deficient mice. Moreover, lung inflammation enhanced by low-dose dsRNA was impaired in IL-13-deficient mice, whereas lung inflammation by high-dose dsRNA was impaired in IFN-gamma-deficient mice. The models also demonstrated that low-dose dsRNA enhanced IL-4 expression during allergen sensitization and that inflammation enhanced by low-dose dsRNA was not present in IL-4- or STAT6-deficient mice. In contrast, the present study showed that high-dose dsRNA enhanced IFN-gamma expression during allergen sensitization and that the development of lung inflammation enhanced by high-dose dsRNA was impaired in T-bet-deficient mice. CONCLUSION: These findings suggest that airway allergen exposure during respiratory viral infections might induce asthma induced by both T(H)1 and T(H)2 immune responses to inhaled allergens. CLINICAL IMPLICATIONS: Targeting both T(H)1 and T(H)2 lung inflammation might be important in the treatment of virus-associated asthma.