Expression of Fas antigen and Fas ligand in bronchoalveolar lavage from silicosis patients.

OBJECTIVE: To understand the role of apoptosis through Fas/Fas ligand (FasL) interaction in the pathogenesis of silicosis, we examined the expression of Fas antigen, FasL and apoptosis in bronchoalveolar lavage fluid lymphocytes obtained from patients with silicosis. MATERIALS AND METHODS: Ten patients with silicosis, and 10 healthy controls were studied. Non-adherent cells were separated and analysed by cytometry for the expression of Fas antigen, FasL, and the co-expression of Fas/FasL. By double staining, we studied the FasL expression on CD4, CD8, CD56 and CD45RO-positive cells. DNA fragmentation was investigated by the terminal deoxy(d) UTP nick end labelling (TUNEL) method. RESULTS: We have found Fas and FasL expression in silicosis patients to be significantly higher than those in healthy controls. Interestingly, 6-18% of lymphocytes from silicosis patients co-expressed Fas and FasL. In silicosis patients, FasL was highly expressed on CD4+, CD56+ and CD45RO+ bronchoalveolar lavage cells. Fas antigen expressing cells showed DNA fragmentation characteristic for apoptosis. CONCLUSION: FasL was significantly expressed on cytotoxic effector and memory cells. The Fas/FasL system is implicated in the inflammatory process observed in silicosis patients

T cells expressing the gammadelta receptor are essential for Th2-mediated inflammation in patients with acute exacerbation of asthma.

OBJECTIVE: T lymphocytes have a central regulatory role in the pathogenesis of asthma. The objective of this study was to characterize immunologically the activation stage of asthma and the functional profile of lymphocytes from induced sputum, with particular emphasis on gammadelta T cells. METHODS: Induced sputum was collected from 10 patients with acute exacerbation of asthma, and from healthy controls. The expression of activation markers on freshly isolated induced sputum lymphocytes and T-cell subsets was analyzed by double immunofluorescent staining and flow cytometry. Fas ligand (FasL) was determined by reverse transcriptase-polymerase chain reaction analysis. The phenotype of gammadelta T-cell subpopulations was tested by A13 and BB3 monoclonal antibodies. In this context, the functional profile of gammadelta T cells was tested in a chromium releasing test. RESULTS: A significantly decreased proportion of alphabeta T cells and an increased proportion of gammadelta T cells, CD56+ cells and CD8+ gammadelta T cells were found in asthma patients compared with healthy controls. In asthmatic patients, there is a significantly increased proportion of T cells expressing CD69 and CD25 antigen. After stimulation of gammadelta T cells, an increased expression of intracellular tumour necrosis factor-alpha, interleukin (IL)-4 and IL10 cytokines were found at higher levels than controls. Interferon-gamma was observed at similar levels in asthma patients and healthy controls. Freshly isolated T-cell receptor (TCR) gammadelta+ cells exhibited an increased percentage of FasL in our patient group. FasL mRNA was detected in TCR gammadelta+ cells before and after IL2 stimulation. TCR gammadelta+ cells were cytotoxic against the K562 cell line. This natural killer activity was mediated by the A13-positive subpopulation. CONCLUSION: The presence of cytokines producing gammadelta cells in induced sputum of asthmatic patients is consistent with regulatory activities. These cells display also cytotoxic function

Release of B cell-activating factor of the TNF family in bronchoalveolar lavage from Behçet disease with pulmonary involvement

Pulmonary artery aneurysms, arterial and venous thrombosis, pulmonary infarction, recurrent pneumonia, bronchiolitis obliterans organized pneumonia, and pleurisy are the main features of pulmonary involvement in Behçet disease. The objective of this study was to investigate the production of B-cell-activating factor of the TNF family (BAFF), an important regulator of B-cell survival and immunoglobulin class-switch recombination, in bronchoalveolar lavage (BAL) fluid from BD patients having pulmonary manifestation. Bronchoalveolar lavage (BAL) was performed in 15 BD patients with pulmonary manifestation and 18 BAL from healthy controls. Concentrations of B-cell-active cytokines, including BAFF, IL-6 and IL-13, were measured by using specific ELISA and cytometric bead array assays. Levels of BAFF protein were significantly increased in BAL fluid from active BD (109 ± 21.78 pg/mL) compared with those oh healthy controls (4.83 ± 1.75 pg/mL; p < 0.0001). In the BAL fluid, BAFF levels were significantly correlated with absolute numbers of total cells (r = 0.823; p < 0.0001), lymphocytes (r = 0.709; p < 0.0001), neutrophils (r = 0.809; p < 0.0001) and macrophages (r = 0.742; p < 0.0001). Normalization to albumin indicated that BAFF production occurred locally in the airways. BAFF levels were also significantly correlated with the other B-cell-activating cytokines IL-6 (r = 0.882, p < 0.001) and IL-13 (r = 0.659, p < 0.001). The antigen-induced production of BAFF in the lung of active BD with pulmonary manifestations might contribute to immunoglobulin synthesis by B-cells. The cells residing in the lung might affect each other through BAFF

Inflammatory Process of CD8(+)CD28(−) T Cells in Induced Sputum From Asthmatic Patients

Previously unreported CD8(+)CD28(−) and CD8(+)CD28(+) T-cell subsets occur in healthy individuals and expand in patients suffering from autoimmune disease. Here we studied, for the first time, the expression of CD8(+)CD28(+), CD8(+)CD28(−), and CD8(+)CD56(+) subpopulations in induced sputum from asthmatics. Using sputum samples, purified CD8(+) T cells were stained for surface antigen CD28, CD56, FITC-conjugated anti-perforin, and anti-IFN-γ. Cytotoxic activity was evaluated in a chromium releasing test. Induced sputum CD8(+)CD28(−) T cells were found to be more expanded and expressed low levels of IFN-γ in severe asthmatics than mild asthma and age-matched healthy controls. The predominance of CD8(+)CD28(−) T cells can be in part explained by the expansion of CD8(+)CD56(+). CD8(+)CD28(−) T cells from severe asthmatics produced high intracytoplasmic perforin and exerted a potent cytotoxic activity. Considering their phenotyping and functional properties, the CD8(+)CD28(−) T-cell subset may constitute an intermediate phenotype in the process of CD8(+) T-cell differentiation of effector-type cells in severe asthmatics. Functional studies showed that CD8(+)CD28(−) T cells had cytotoxic function

Association of GST Genes Polymorphisms with Asthma in Tunisian Children

Background. A positive association between genetic polymorphism and asthma may not be extrapolated from one ethnic group to another based on intra- and interethnic allelic and genotype frequencies differences. Objective. We assessed whether polymorphisms of GST genes (GSTM1, GSTT1, and GSTP1) are associated with asthma and atopy among Tunisian children. Methods. 112 unrelated healthy individuals and 105 asthmatic (73 atopic and 32 nonatopic) children were studied. Genotyping the polymorphisms in the GSTT1 and GSTM1 genes was performed using the multiplex PCR. The GSTP1 ILe105Val polymorphism was determined using PCR-RFLP. Results. GSTM1 null genotype was significantly associated with the increased risk of asthma (P = .002). Asthmatic children had a higher prevalence of the GSTP1Ile105 allele than the control group (43.8% and 33.5%, respectively; P = .002). Also, the presence of the GSTP1 homozygote Val/Val was less common in subjects with asthma than in control group. We have found that GSTT1 null genotype (GSTT1 *0/*0) was significantly associated with atopy (P = .008). Conclusion. Polymorphisms within genes of the GST superfamily were associated with risk of asthma and atopy in Tunisia

Association of Vascular Endothelial Growth Factor Polymorphisms with Asthma in Tunisian Children

Background: Previous studies demonstrated that the vascular endothelial growth factor (VEGF) was being implicated in the airways inflammation and remodeling process in patients with asthma.Aims: We explored the relationship of three polymorphisms in the VEGF gene with asthma in both case control and family studies.Methods: We Genotyped a total of 210 children with asthma, 224 unrelated controls and 160 parents for the +936 C > T (rs3025039), −634 G > C (rs2010963) and −2549 –2567 del 18 of the VEGF promoter region. The Mutations were identified with polymerase chain reaction followed by restriction fragment length polymorphism (RFLP) analysis for the +936 C > T, and −634 G > C polymorphisms.Results: Of the three polymorphisms studied, a borderline association with asthma was found for the G allele in the −634 G > C polymorphism (p = 0.059). No Statistically significant differences were observed for both +936 C > T, and −2549 –2567 del 18 polymorphisms between asthmatic patients and controls, considering either allelic or genotypic frequencies.The distribution of genotypes according to the severity status revealed a significant differences for the +936 C > T, and −2549 –2567 del 18 polymorphisms. In addition, association was found with the haplotypes inferred by the three polymorphisms and asthma susceptibility.Conclusion: We suggest that VEGF Gene polymorphisms can be implicated in asthma

Tc1/Tc2 ratio in the inflammatory process in patients with Behçet's disease.

BACKGROUND: Peripheral blood CD8+ T cells expressing interferon gamma and interleukin-4 (IL-4), and lacking CD28 molecules, were responsible for the dynamic interplay between peripheral blood and inflammatory sites. INTRODUCTION: The aim of the current study was to define in Behçet's disease (BD), CD8+ T-cell subsets using CD28 and CD11b monoclonal antibodies, and the characterization of the Tc1/Tc2 ratio and perforin expression. METHODS: Flow cytometry was used for intracytoplasmic cytokines and perforin expression. Effector cells were investigated by adhesion of CD8+ T cells to human microvascular endothelial cells and by chemotaxis using beta-chemokine. RESULTS: Interferon-gamma-producing CD8+ T cells in active and remission BD patients were increased, which induce a significant increase of the Tc1:Tc2 ratio in BD. CD8(+)CD28(-)CD11b+ T cells were found to be more expanded in BD patients than in age-matched healthy controls. The expression of CD11b molecules in active BD allowed to CD8(+)CD28+/CD8(+)CD28- subsets to adhere to human microvascular endothelial cells, with more efficiency in BD. Using MIP-1alpha, we observed that the migratory process of CD28(-)CD11b(+) is more important in BD. CD28(-)CD11b+ exhibited an increased perforin expression in BD patients. CONCLUSION: Taken together these results suggest the presence of immune activation, probably in response to a profound inflammation affecting BD patients. The physiopathological significance of these results were toward autoimmune diseases and/or infectious process