transforming-growth-factor-beta and Bronchiolitis

Respiratory syncytial virus (RSV) is the leading cause of bronchiolitis and hospitalization that lead to high morbidity and mortality among young infants. T helper 17 (Th17) cells and regulatory T cells (Tregs) play essential roles in the pathogenesis of autoimmune, cancer, and inflammatory diseases. However, whether changes in T-cell subsets are related to the systemic immune responses in RSV-caused bronchiolitis merit further investigation. Three-week-old Sprague Dawley (SD) rats were randomly divided into the normal control (NC) and RSV bronchiolitis (RSV-B) groups. An RSV-B model was successfully established using nasal drip containing RSV. Furthermore, pathological changes in the lung tissues were observed using hematoxylin and eosin staining. Flow cytometry determined the levels of Th17 and Treg subsets. The related cytokines were measured using enzyme-linked immunosorbent assay (ELISA). The expression levels of related transcription factors, such as RORγt and FOXP3, were examined using real-time quantitative PCR and western blot analysis. The RSV-B group exhibited pulmonary interstitial hyperemia and edema, inflammatory cell infiltration, wide alveolar septa, and bronchial collapse and deformation. The percentage of Th17 cells in RSV-B group was about 2.3 fold higher than that of NC group, and the concentration of IL-17, IL-23 and RORγt was higher than in NC group. In contrast, the percentage of Treg cells in the RSV-B group was approximately 0.7 fold lower than that in the NC group, and the levels of IL-10, TGF-β, and FOXP3 in the RSV-B group were lower than those in the NC group. The above results were statistically significant. The changes of Th17/Treg, and their associated cytokines, specific transcription factors, are present in RSV bronchiolitis model rats, which may play an important role in the pathogenesis of RSV bronchiolitis.

Topics: Animals; Biomarkers; Bronchiolitis; Cytokines; Disease Models, Animal; Gene Expression; Immunophenotyping; Interleukin-10; Interleukin-17; Interleukin-23; Leukocytes, Mononuclear; Lymphocyte Count; Rats; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses; T-Lymphocytes, Regulatory; Th17 Cells; Transforming Growth Factor beta

The adaptor protein p66Shc regulates intracellular oxidant levels through the modulation of a forkhead-related transcription factor (FOXO3a). The genetic ablation of p66Shc (p66Shc-/-) renders mice resistant to oxidative stress and p53-dependent apoptosis. We investigated whether p66Shc ablation in mice modifies lung cellular and molecular responses to cigarette smoke (CS) exposure. No differences between wild type (WT) and p66Shc-/- mice were observed in terms of inflammation and oxidant burden after acute CS exposure; however,p66Shc ablation modifies specific features of chronic inflammation induced by repeated exposure to CS. Unlike WT mice, p66Shc-/- mice did not develop emphysema, showing protection toward oxidative damage to DNA and apoptosis as revealed by a trivial 8-hydroxyguanosine staining and faint TUNEL and caspase-3 positivity on alveolar epithelial cells. Unexpectedly, CS exposure in p66Shc-/- mice resulted in respiratory bronchiolitis with fibrosis in surrounded alveoli. Respiratory bronchiolitis was characterized by peribronchiolar infiltrates of lymphocytes and histiocytes, accumulation of ageing pigmented macrophages within and around bronchioles, and peribronchiolar fibrosis. The blockage of apoptosis interferes with the macrophage "clearance" from alveolar spaces, favouring the accumulation of aging macrophages into alveoli and the progressive accumulation of iron pigment in long-lived senescent cells. The presence of areas of interstitial and alveolar fibrosis in peripheral parenchyma often accompanied the bronchiolar changes. Macrophages from smoking p66Shc-/- mice elaborate M2 cytokines (i.e., IL-4 and IL-13) and enzymes (i.e., chitinase and arginase I), which can promote TGF-beta expression, collagen deposition, and fibrosis in the surrounding areas. We demonstrate here that resistance to oxidative stress and p53-dependent apoptosis can modify tissue responses to CS caused by chronic inflammation without influencing early inflammatory response to CS exposure.

Topics: Animals; Apoptosis; Arginase; Bronchiolitis; Chitinases; Desmosine; Fibrosis; Hydroxyproline; Interleukin-13; Interleukin-4; Lung; Macrophages; Mice; Mice, Knockout; Oxidative Stress; Oxidoreductases; Pulmonary Emphysema; Shc Signaling Adaptor Proteins; Smoking; Src Homology 2 Domain-Containing, Transforming Protein 1; Transforming Growth Factor beta; Tumor Suppressor Protein p53

alpha-Defensins, antimicrobial peptides produced mainly by neutrophils, have been reported to be associated with a wide variety of lung diseases, including idiopathic pulmonary fibrosis (IPF), cystic fibrosis (CF), and diffuse panbronchiolitis (DPB). In each disease, alpha-defensins are located in different areas, such as around the alveolar septa in IPF and around the airways in CF and DPB, suggesting that alpha-defensins play different roles. Meanwhile, growth factors are known to contribute to IPF, CF, and DPB. alpha-Defensins are known to induce interleukin (IL)-8 in airway epithelial cells, but the effects of alpha-defensins on the release of growth factors from various components in the lung have not been sufficiently investigated. In the present study, the in vitro effects of human neutrophil peptide (HNP)-1 (a subtype of alpha-defensin) on the expressions of IL-8 and growth factors in lung fibroblasts, bronchial epithelial cells, and alveolar epithelial cells were examined. HNP-1 mainly enhanced the expression of IL-8 in epithelial cells, whereas it enhanced transforming growth factor-beta and vascular endothelial growth factor expressions in lung fibroblasts. These results suggest that alpha-defensins play different roles in the pathogenesis of IPF, CF, and DPB according to the location in the lung where the alpha-defensins are mainly produced.

Topics: alpha-Defensins; Bronchiolitis; Cells, Cultured; Cystic Fibrosis; Epithelial Cells; Fibroblasts; Haemophilus Infections; Humans; Idiopathic Pulmonary Fibrosis; Interleukin-8; Lung; Transforming Growth Factor beta; Vascular Endothelial Growth Factors

Human T lymphotrophic virus type-I (HTLV-I), a human retrovirus, infects CD4(+) lymphocytes and is thought to modify their function and a possible association with pulmonary diseases has also been suggested. However, little is known about the influence of HTLV-I on diffuse pan-bronchiolitis (DPB), a chronic inflammatory lung disease with infiltration of lymphocytes and hyperplasia of the bronchus-associated lymphoid tissue. In this study, 35 DPB patients with and without HTLV-I infection were examined. HTLV-I positive DPB patients were likely to have a larger affected area with lower FEV(1). The CD3(+)/CD25(+) lymphocyte percentage was significantly higher in the BALF of HTLV-I positive patients than in negative patients. MIP-1 alpha, IP-10 and levels in BALF were also significantly higher in HTLV-I positive patients than in negative patients. The levels of MCP-1 and IL-8 were not significantly different. In HTLV-I positive patients, the MIP-1 alpha and IP-10 levels showed a significant positive correlation with the percentage of CD3(+)/CD25 lymphocytes. BALF cells of all HTLV-I positive DPB patients showed expression of p40(tax) mRNA. We suggest that HTLV-I infection may modify DPB pathogenesis via activation of T cells. We also found that the frequency of ATL development in HTLV-I positive DPB patients was significantly higher than in all HTLV-I positive patients (OR = 8.22, 95% CI = 2.61-25.9, P < 0.01). The levels of TGF-beta in patients who developed ATL were significantly lower than in patients who did not develop ATL. Sensitivity and specificity were 80% and 85.7%, respectively (cut-off = 20 pg/ml). We also propose that these features should be taken into consideration in the treatment of DPB in HTLV-I infected individuals.

Topics: Adult; Aged; Bronchiolitis; Bronchoalveolar Lavage Fluid; CD4-Positive T-Lymphocytes; Chemokine CCL2; Chemokine CCL4; Chemokine CXCL10; Chi-Square Distribution; Chronic Disease; Female; HTLV-I Infections; Human T-lymphotropic virus 1; Humans; Interleukin-8; Lymphocyte Activation; Macrophage Inflammatory Proteins; Male; Middle Aged; Prevalence; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Statistics, Nonparametric; Transforming Growth Factor beta

Obliterative bronchiolitis (OB) is the major long-term complication following lung and heart-lung transplantation. In bronchoalveolar lavage fluid samples obtained from patients suffering from OB, a marked increase in the number of neutrophils and elevated expression of transforming growth factor (TGF)-beta1 had been found. The goal of the study was to evaluate whether TGF-beta1 is capable of interfering with the expression of the secretory leukoprotease inhibitor (SLPI), the dominating defence of the conducting airways against neutrophil elastase (NE). The authors analysed the effects of TGF-beta1 on gene expression and protein release of SLPI by cultured human bronchial epithelial (BEAS-2B) cells. SLPI protein levels in the supernatants were quantified with a specific enzyme-linked immunosorbent assay; SLPI messenger ribonucleic acid (mRNA) levels were measured by reverse transcriptase polymerase chain reaction. Incubation with TGF-beta1 induced a marked decrease in SLPI protein levels (1 ng x mL(-1) TGF-beta1: stimulation index (SI; protein: relation to SLPI protein release of resting cells)=0.56; 10 ng x mL(-1) TGF-beta1: SI=0.48; 50 ng x mL(-1) TGF-beta1: SI=0.37, p<0.01 each) and mRNA expression (1 ng x mL(-1) TGF-beta1: SI (SI mRNA: relation to SLPI mRNA expression of resting cells)=0.46; 10 ng x mL(-1) TGF-beta1: SI=0.31; 50 ng x mL(-1) TGF-beta1: SI=0.18, p<0.01 each) in a dose dependent fashion. Simultaneous incubation of BEAS-2B cells with TGF-beta1 and NE also caused a significant reduction in SLPI synthesis (10 ng x mL(-1) TGF-beta1 + 7.5 U x mL(-1) NE: mRNA SI=0.61, p<0.05; protein SI=0.65, p<0.05; 50 ng x mL(-1) TGF-beta1 + 7.5 U x mL(-1) NE: mRNASI=0.52, p<0.05; protein SI=0.58, p<0.05; 10 ng x mL(-1) TGF-beta1: mRNA SI=0.33, p<0.01; protein SI=0.38, p<0.01). In conclusion, the data suggest that the coincidence of neutrophilia and upregulation of transforming growth factor-beta1 in obliterative bronchiolitis may lead to uninhibited neutrophil elastase activity by downregulation of secretory leukoprotease inhibitor, with the consequence of ongoing injury to the epithelium.

Topics: Bronchi; Bronchiolitis; Cell Line; Dose-Response Relationship, Drug; Enzyme-Linked Immunosorbent Assay; Epithelial Cells; Gene Expression; Humans; Leukocyte Elastase; Lung Transplantation; Postoperative Complications; Proteinase Inhibitory Proteins, Secretory; Proteins; Respiratory Mucosa; RNA, Messenger; Secretory Leukocyte Peptidase Inhibitor; Transforming Growth Factor beta; Transforming Growth Factor beta1

Bronchus-associated Lymphoid tissue (BALT) has been reported to be present in the lungs of patients with rheumatoid arthritis (RA). However, little is known about the structure and cellular distribution of BALT in this disease, so we investigated these points using immunohistochemical methods. The subjects were eight RA patients with BALT in biopsy specimens and a histologic diagnosis of follicular bronchiolitis. Seven patients had cough and purulent sputum, and four patients had positive sputum cultures. BALT was histologically composed of four distinct regions, which were the lymphoepithelium, the dome area, the follicular area, and the parafollicular area. Surface IgM+ B cells were predominant in the follicular area, whereas IgA+ cells were scattered in the dome and parafollicular areas. T cells were mainly found in the parafollicular area (CD4+ > CD8+), and most of them expressed the T Cell receptor alpha beta (alpha beta TCR). These findings were similar to those described previously for BALT in diffuse panbronchiolitis, which manifests as a chronic respiratory infection. The present study indicated that extrinsic stimulation as well as alterations of the immune response are involved in the development of BALT in RA, although the exact mechanism requires further clarification.

Topics: Adult; Aged; Arthritis, Rheumatoid; Biopsy; Bronchi; Bronchiolitis; Female; Humans; Immunoglobulins; Immunohistochemistry; Interferon-gamma; Interleukin-4; Lymphocyte Subsets; Lymphoid Tissue; Male; Middle Aged; Transforming Growth Factor beta