Biomedical subjects

W Luttmann

Publications and source records attributed to W Luttmann.

At least 19 recordsLinked to original sources

PubMed2006

Decrease of cytotoxic T cells in allergic asthma correlates with total serum immunglobulin E.

BACKGROUND: Allergic asthma has been linked to an increase in T-helper type 2-like cytokines and T cells, but there is growing evidence for a role of lymphocyte-mediated cytotoxic mechanisms in the pathogenesis of asthma. Therefore, we investigated the cytotoxic potential of different lymphocyte subpopulations in patients with allergic asthma. METHODS: Granzyme A, B, K, and perforin expression in peripheral blood lymphocytes was analyzed using flow cytometry. Soluble granzymes were measured in serum using specific enzyme-linked immunosorbent assays. RESULTS: Asthmatics had significantly decreased percentages of granzyme and perforin-positive CD4 T cells compared with non-atopic controls. In patients with asthma, the granzyme B and perforin-positive subset of CD8(+) T cells and natural killer T cells, which represent more differentiated cell populations, were significantly reduced, while this was not observed in the less differentiated granzyme K(+) subsets. In addition, the serum concentrations of granzyme B were significantly reduced in patients with asthma, while granzyme K concentrations were not different. Interestingly, there was a negative correlation between granzyme A, B and perforin expression in T cell subsets as well as serum granzyme B concentrations and total serum immunglobulin E. In CD3-negative natural killer cells, no differences in granzyme or perforin expression between patients with asthma and controls were detected. CONCLUSION: In allergic asthma, cytotoxic T lymphocyte subsets of a more differentiated phenotype are significantly decreased and this is correlated to serum immunglobulin E levels.

Adult↗

PubMed2005

Chemokine-receptor expression on T cells in lung compartments of challenged asthmatic patients.

BACKGROUND: The interaction of chemokines with their receptors strongly influences the migration of leucocytes. OBJECTIVE: In order to assess the contribution of these molecules to the local recruitment of T cells in bronchial asthma, we analysed the expression of 14 chemokine receptors on lung-derived T cells. METHODS: Chemokine-receptor expression by T cells derived from the peripheral blood, the bronchoalveolar lavage fluid and the bronchial mucosa was analysed by flow cytometry and immunohistochemistry. Expression profiles in healthy and mildly asthmatic individuals were compared, the latter prior and after segmental allergen provocation. RESULTS: Compared with peripheral blood, alveolar T cells expressed significantly more CCR2, CCR5, CCR6, CXCR3 and CCR4. However, no differences were observed between healthy controls and unchallenged asthmatics. In patients developing significant inflammatory responses following specific allergen challenge, a marked increase in the percentage of CCR4+ and CCR7+, and reduced numbers of CXCR3-bearing alveolar T cells were detected. Following specific allergen challenge, chemokine-receptor expression profiles of T cells from the alveolar space and the mucosa or the submucosa were similar, excluding a particular subcompartmentalization of the chemokine/chemokine-receptor system. CONCLUSION: The expression of certain chemokine receptors by lung T cells suggests a contribution to the physiological recruitment of T cells to the lungs, both in healthy controls and unchallenged mild asthmatics. However, strong allergen-induced airway responses were associated with a specific chemokine-receptor profile, suggesting the involvement of certain chemokine receptors in the pathogenesis of allergic bronchial inflammation.

Adult↗

PubMed2005

Increase in killer-specific secretory protein of 37 kDa in bronchoalveolar lavage fluid of allergen-challenged patients with atopic asthma.

BACKGROUND: Atopic asthma is linked to a T-helper type 2 dominated pathogenesis, but there is increasing evidence of Th1/Tc1-mediated processes in the aetiopathology of asthma. Killer-specific secretory protein of 37 kDa (Ksp37) is expressed in cytotoxic lymphocytes, selectively in the effector subsets of CD8+- and CD4+ T lymphocytes and in CD16+/CD56dim natural killer cells and gamma/delta T cells. This effector cell-specific expression of Ksp37 and its coexpression with perforin suggest that Ksp37 might be involved in processes mediated by cytotoxic cells. OBJECTIVE: We hypothesize that Ksp37 could indicate the involvement of cytotoxic lymphocytes in the pathogenesis of atopic asthma, and investigated Ksp37 concentration in bronchoalveolar lavage fluid (BALF) collected 10 min, 18, 42 or 162 h after segmental allergen provocation and in serum of patients with atopic asthma (n=25). METHODS: Ksp37 concentrations in BALF and serum were detected by ELISA. Flow cytometric analysis was used to assess numbers and cell subsets in BALF. RESULTS: Ksp37 increased significantly in BALF 10 min, 18 and 42 h, but not 162 h after allergen challenge compared with saline-challenged controls, while Ksp37 serum levels did not change significantly at all time-points. In addition, the increase in Ksp37 concentrations in BALF correlated with the corresponding numbers of lymphocytes. CONCLUSIONS: We conclude that Ksp37 level increased in BALF 10 min, 18 and 42 h after allergen challenge but not in peripheral blood. Our findings suggest that segmental allergen challenge in asthma is associated with an increase in Ksp37 concentrations in BALF and an influx of potentially cytotoxic T lymphocytes into the lungs.

Adolescent↗

PubMed2004

Interleukin-5 receptors on human lung eosinophils after segmental allergen challenge.

BACKGROUND: IL-5 is a specific cytokine for eosinophil accumulation, activation and prolongation of survival and can be recovered in elevated concentrations from the bronchoalveolar compartment in atopic asthma following allergen challenge. OBJECTIVE: The action of IL-5 is mediated via the specific IL-5 receptor-alpha (IL-5Ralpha). Although in vitro data suggest that IL-5R expression is regulated by cytokines such as IL-3, IL-5 and GM-CSF, IL-5R regulation in vivo and its kinetics following allergen provocation are incompletely understood. METHODS: We investigated IL-5R regulation in vivo following segmental allergen provocation (SAP) with an individually standardized dose of allergen in 12 patients with atopic asthma. Lavage was performed 10 min and 18 h (eight patients) and 10 min and 42 h (eight patients) after allergen challenge. In addition to differential cell counts, IL-5Ralpha was measured by flow cytometry and IL-5 concentrations in bronchoalveolar lavage (BAL) fluid were determined by ELISA. RESULTS: IL-5Ralpha expression decreased significantly on peripheral blood and on BAL eosinophils 18 and 42 h after SAP. In contrast, IL-5 concentrations increased significantly in BAL fluid 18 and 42 h after SAP. In four and two patients, respectively, there were detectable IL-5 concentrations in serum 18 or 42 h after allergen exposure. CONCLUSIONS: Although there was no correlation between IL-5 concentrations and IL-5Ralpha expression on eosinophils in BAL, our data support previous in vitro and in vivo findings of a negative feedback mechanism between IL-5 concentrations and IL-5Ralpha expression on eosinophils.

Adult↗

PubMed2004

Increase in granzyme B+ lymphocytes and soluble granzyme B in bronchoalveolar lavage of allergen challenged patients with atopic asthma.

Asthma has been linked to a chronic, T-cell-mediated bronchial inflammation. Because other T-lymphocyte-mediated, chronic inflammatory disorders have been associated with elevated granzyme B (grB) expression we tested the hypothesis that atopic asthma might be associated with elevated grB levels in the bronchoalveolar compartment. Therefore we performed intracellular grB staining in lymphocytes from bronchoalveolar lavage (BAL) collected 42 h after segmental allergen provocation (SAP) in allergic patients with bronchial asthma. There was a significant increase in CD3(+), CD8(+), and CD16/56(+) lymphocytes expressing grB in BAL 42 h after SAP as compared to saline challenged controls. However, compared to peripheral blood the percentages of these lymphocyte subsets detected as grB(+) in BAL remained significantly lower. Measurement of extracellular grB in BAL fluids by a particle immunoassay revealed significantly elevated grB levels in the allergen challenged bronchoalveolar compartment 42 h following SAP in six of the eight patients (range, <1.0-348.1 pg/ml) as compared to saline challenged controls (range, <1.0-70.5 pg/ml). We conclude that total cell numbers of grB(+) lymphocyte subsets increase 42 h after SAP in the lower respiratory tract. In addition there is evidence to suggest that grB is released into the airways of asthmatic patients. This suggests a role for grB in the pathophysiological processes following SAP but its definitive role in allergic bronchial asthma needs to be established.

Adolescent↗

PubMed2004

Increase in Ksp37-positive peripheral blood lymphocytes in mild extrinsic asthma.

Killer-specific secretory protein of 37 kDa (Ksp37), identified as a Th1/Tc1 specific secretory protein is expressed preferentially in cytotoxic T lymphocytes (CTL) and natural killer (NK) cells and might be involved in essential processes of CTL-mediated immunity. Although extrinsic asthma is linked currently to a Th2-dominated pathogenesis, there is increasing evidence for Th1/Tc1-mediated processes in the aetiopathology of asthma. CTL from patients with asthma have been shown to express cytokines and effector molecules which were different from healthy controls. We hypothesized that Ksp37 could indicate the involvement of CTL in the pathogenesis of extrinsic asthma. We therefore investigated Ksp37 expression in PBMC from patients with mild extrinsic asthma (n = 7) and healthy controls (n = 7). Flow cytometric analysis was used to quantify Ksp37+ cells and to investigate cellular Ksp37 expression as relative mean fluorescence intensities (MFI). We found a significantly (P = 0.016) higher percentage of Ksp37+ cells within the total lymphocyte population obtained from patients with mild extrinsic asthma compared with healthy controls. Subdifferentiation revealed a significant difference limited exclusively to the CD8+ subset (P = 0.010). In addition, Ksp37 secretion from cultured peripheral blood mononuclear cells (PBMC) and MFI of Ksp37+ lymphocytes were increased in patients with asthma compared with healthy controls. We conclude that mild extrinsic asthma appears to be associated with an increased expression of the Tc1 related protein Ksp37. The functional role of Ksp37 in the pathogenesis of asthma remains to be elucidated.

Adult↗

PubMed2001

Functional characterization of P2Y and P2X receptors in human eosinophils.

Activation of purinoceptor by ATP induces in eosinophils various cell responses including calcium transients, actin polymerization, production of reactive oxygen metabolites, CD11b-expression, and chemotaxis. Here, the effect of ion channel-gated P2X and/or G protein-coupled P2Y receptor agonists ATP, ATPgammaS, alpha,beta-meATP, 2-MeSATP, BzATP, ADP, CTP, and UTP on the intracellular Ca(2+)-mobilization, actin polymerization, production of reactive oxygen metabolites, CD11b expression and chemotaxis of human eosinophils were measured and the biological activity was analyzed. Although all tested nucleotides were able to induce all these cell responses, the biological activity of the analyzed nucleotides were distinct. Agonists of the G protein-coupled P2Y receptors such as 2-MeSATP, UTP, and ADP have a higher biological activity for production of reactive oxygen metabolites, actin polymerization and chemotaxis in comparison to the ion channel-gated P2X agonists alphabeta-meATP, BzATP, and CTP. In contrast, P2Y and P2X agonist showed similar potencies in respect to intracellular calcium transient and CD11b up-regulation. This conclusion was further supported by experiments with receptor iso-type antagonist KN62, EGTA or with the G(i) protein-inactivating pertussis toxin. These findings indicate participation of different purinorecptors in the regulation of cell responses in eosinophils.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

PubMed2001

Effect of a specific cysteinyl leukotriene-receptor 1-antagonist (montelukast) on the transmigration of eosinophils across human umbilical vein endothelial cells.

BACKGROUND: Leukotrienes have been implicated in the selective infiltration of eosinophils into the bronchial mucosa in asthma. OBJECTIVE: We studied whether eosinophil transmigration through cultured human umbilical vein endothelial cells (HUVECs) can be blocked by a specific cysteinyl LT1-receptor-antagonist. METHODS: Unstimulated and stimulated eosinophils from patients with asthma and normal controls were subjected to confluent human umbilical vein endothelial cell (HUVEC) monolayers separating the upper and lower chamber of Transwell culture plates. Unstimulated eosinophils or cells pre-incubated in the presence of the eosinophil activating cytokines GM-CSF or IL-13 were placed in the upper chambers while PAF, a potent chemoattractant factor for eosinophils, was added to the lower chamber. Migration of eosinophils was quantified by a beta-glucuronidase assay. RESULTS: The assumption that eosinophils express CysLT1 (cysteinyl-leukotriene 1)-receptors was based on our demonstration of mRNA-expression for the CysLT-1-receptor by polymerase chain reaction on purified eosinophils. The chemotactic response to PAF was significantly reduced when eosinophils were pre-incubated with montelukast for 15 min. When eosinophils were pre-incubated with GM-CSF and/or IL-13, the migratory response to PAF was also significantly reduced by montelukast. CONCLUSION: From these data we conclude that the specific cysteinyl LT1-receptor antagonist montelukast can inhibit PAF-induced eosinophil transmigration through cultured HUVEC monolayers.

Acetates↗

PubMed2001

Interferon-gamma secretion of peripheral blood CD8+ T lymphocytes in patients with bronchial asthma: in vitro stimulus determines cytokine production.

It has been postulated that T lymphocytes orchestrate the chronic inflammation in bronchial asthma. In animal models, infiltration of CD8+ T lymphocytes into the bronchial mucosa prevented bronchial hyperresponsiveness and decreased early and late phase reaction. IFN-gamma antagonizes IL-4-dependent IgE production as well as IL-5-induced proliferation and activation of eosinophils. We therefore investigated the secretion of IFN-gamma of isolated CD8+ T lymphocytes from peripheral blood of patients with allergic asthma (n = 6) and from healthy controls (n = 7) in vitro. In this setting we compared the effect of stimulation with anti-CD3 antibodies with that of phorbol myristate acetate (PMA) and calcium-ionophore. As expected, CD8+ T lymphocytes from peripheral blood of healthy volunteers produced significantly more IFN-gamma in the presence of PMA and calcium-ionophore than after stimulation with anti-CD3 antibodies. However, in subjects with allergic asthma, IFN-gamma secretion of CD8+ T cells was significantly higher when incubated with anti-CD3 antibodies than after activation with PMA and calcium-ionophore. While IFN-gamma secretion of CD8+ T lymphocytes of patients with allergic asthma was lower than that of healthy controls in the presence of PMA/calcium-ionophore, it was significantly elevated when compared with normal controls after stimulation with anti-CD3 antibodies. Thus, potent activators of cytokine secretion, such as PMA and calcium-ionophore, induce a cytokine profile different from that induced by weaker stimulants, such as anti-CD3 antibodies. These findings have implications for further studies investigating cytokine production of inflammatory cells in vitro.

Adult↗

PubMed2000

P2 purinergic receptors of human eosinophils: characterization and coupling to oxygen radical production.

Extracellular nucleotides elicit multiple responses in eosinophils but no information on expression of purinergic receptors in these cells is available so far. In the present study we show that human eosinophils express the following P2Y and P2X subtypes: P2Y(1), P2Y(2), P2Y(4), P2Y(6), P2Y(11), and P2X(1), P2X(4), P2X(7), whose stimulation results in intracellular Ca(2+) increase and production of large amounts of reactive oxygen intermediates. These events are stimulated or inhibited, respectively, by P2 receptor agonists or antagonists.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

PubMed2000

Adenosine triphosphate-induced oxygen radical production and CD11b up-regulation: Ca(++) mobilization and actin reorganization in human eosinophils.

Eosinophils are major effector cells in cellular inflammatory conditions such as parasitic infections, atopic diseases, bullous dermatoses, and vasculitis. Biological activities of adenosine triphosphate (ATP) were characterized in human eosinophils and compared with those of other eosinophil activators such as complement fragment product C5a, platelet-activating factor (PAF), and eotaxin. ATP initiated production of reactive oxygen metabolites, as demonstrated by lucigenin-dependent chemiluminescence. Furthermore, ATP caused up-regulation of the integrin CD11b. In addition, fluorescence microscope measurements labeled with fura-2 (1-[2-(5-carboxy-oxazol-2-yl)-6-aminobenzofuran-5-oxy]-2-(2' -amino-5' -methyl-phenoxy)-ethane-N, N, N, N'-tetraacetic acid, pentaacetoxymethyl ester) eosinophils in the presence or absence of ethyleneglycotetraacetic acid (EGTA) indicated that there was Ca(++) mobilization from intracellular stores by ATP. Flow cytometric studies showed transient actin polymerization upon stimulation with ATP and its stable analogues adenosine 5'-0-(3-thiotriphosphate) and 2-methylthioadenosine triphosphate tetrasodium (met-ATP). The reactions induced by ATP were comparable to those obtained by C5a, PAF, and eotaxin. Production of reactive oxygen metabolites and actin polymerization after stimulation with ATP was inhibited by pertussis toxin, which indicated involvement of receptor-coupled guanine nucleotide-binding proteins (G(i) proteins). In addition, experiments with oxidized ATP also suggest involvement of P2X receptors in this activation process. The results show that ATP is a strong activator of eosinophils and has biological activity comparable to those of the eosinophil chemotaxins C5a, PAF, and eotaxin. The findings strongly suggest a role of ATP in the pathogenesis of eosinophilic inflammation as an activator of proinflammatory effector functions.

Actin Cytoskeleton↗

PubMed2000

Change in perforin-positive peripheral blood lymphocyte (PBL) subpopulations following exercise.

Perforin, one of the cytotoxic proteins of the immune system, plays a prominent role in protection against viral and bacterial infections. We investigated its expression in PBL and their CD3+, CD4+, CD8+ and CD16+ and/or CD56+ subpopulations in endurance athletes before and after a triathlon. Lymphocyte subpopulations were analysed by flow cytometry following separation of peripheral blood mononuclear cells and staining with antibodies against specific membrane antigens and intracellular perforin. The number of total lymphocytes decreased from 2.1 x 10(3)/microl before the triathlon to 1.0 x 10(3)/microl 1 h after the triathlon (P < 0.01). Interestingly, there was already a significant spontaneous decline in the percentage of CD3+/perforin+, and in CD8+/perforin+ cells, in the week proceeding the triathlon, when subjects were instructed to refrain from strenuous exercise training. The percentage of CD3+/perforin+, CD8+/perforin+ and CD16+ and/or CD56+/perforin+ cells in each lymphocyte subpopulation decreased 1 h after exercise even further from 14.3% to 5.8% (P < 0.05), 18.5% to 6.5% (P < 0.05) and 77.3% to 67.3%, respectively. However, at 18 h and 48 h after exercise the percentage of perforin-expressing CD3+, CD8+ and CD16+/56+ cells increased again towards baseline levels. Compared with normal controls, baseline perforin co-expression in CD3+ and CD8+ lymphocytes was significantly higher in trained athletes. From our data we conclude that trained athletes have an increased percentage of perforin+ PBL and that following exercise the percentage of perforin+ and therefore potentially cytotoxic lymphocytes transiently decreases in peripheral blood.

Adult↗

PubMed2000

Th1 cytokine pattern in sarcoidosis is expressed by bronchoalveolar CD4+ and CD8+ T cells.

The pathogenesis of pulmonary sarcoidosis has been related to an increased production of Th1-like cytokines. However, cytokine expression in sarcoidosis has not been systematically studied at a single-cell level. We therefore investigated the expression of IL-2, IL-4, IL-13, tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) intracellularly in bronchoalveolar lavage (BAL) and peripheral blood CD3+ T lymphocytes from patients with pulmonary sarcoidosis (radiologic stage II-III, n = 8) and normal controls (n = 9) by flow cytometry. In contrast to IL-4 and IL-13, the percentage of T lymphocytes expressing intracellular IL-2 (49.3 +/- 21.3% versus 14.5 +/- 15.6%), IFN-gamma (75.5 +/- 14.9% versus 32.6 +/- 18.7%) and TNF-alpha (68.3 +/- 18.7% versus 36.8 +/- 20.8%) was significantly higher in patients with sarcoidosis than in normal controls (each P < 0.005). In contrast to BAL lymphocytes, expression of these cytokines in peripheral blood lymphocytes did not differ between patients with sarcoidosis and normal controls. Close correlations were observed between the percentages of BAL lymphocytes expressing intracellular IL-2, IFN-gamma and TNF-alpha, but not for IL-4 or IL-13. Analysis of the expression of these cytokines in T lymphocyte subsets revealed IL-2, IFN-gamma, and TNF-alpha in CD4+ as well as CD8+ T lymphocytes, suggesting a contribution of TC1 cells to the production of proinflammatory cytokines in sarcoidosis. We conclude that a Th1-like cytokine pattern can be observed in CD4+ as well as in CD8+ BAL T lymphocytes in patients with pulmonary sarcoidosis.

Adult↗

PubMed2000

Effects of interferon-gamma and tumour necrosis factor-alpha on CD95/Fas ligand-mediated apoptosis in human blood eosinophils.

Many cells, including eosinophils, express CD95 (Fas), a surface receptor that mediates apoptosis when ligated by specific antibodies or its natural ligand, Fas ligand (FasL). As apoptosis may play an important role in the regulation of tissue eosinophilia, factors that modulate eosinophil sensitivity to apoptosis are of great interest. It has previously been shown that interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha) together increase CD95 surface expression on eosinophils. However, the functional consequences of this increase in CD95 expression have not been demonstrated in detail. We therefore investigated whether the increase in CD95 expression mediated by IFN-gamma/TNF-alpha indeed translates into increased, FasL-mediated apoptosis of eosinophils. For this purpose, purified eosinophils from normal donors were incubated with different concentrations of FasL and induction of apoptosis was assessed by annexin-V/propidium iodide assay. Unlike Jurkat cells, which became apoptotic within 2 h after incubation with FasL, an increase in eosinophil apoptosis could first be dedicated after 6 h incubation with FasL. Prestimulation with IFN-gamma/TNF-alpha for 24 h significantly enhanced FasL-induced apoptosis in eosinophils. This increase in CD95/FasL-mediated apoptosis was correlated with an IFN-gamma/TNF-alpha-mediated increase in CD95 expression. From these findings we conclude that the combination of IFN-gamma and TNF-alpha enhances CD95 expression, which results in an increase in FasL-mediated apoptosis of eosinophils in vitro.

Apoptosis↗

PubMed2000

[Increase in perforin-positive peripheral blood lymphocytes in extrinsic and intrinsic asthma].

The cause of asthma which has been linked to a chronic, T-cell-mediated bronchial inflammation, remains unclear. A number of other T-lymphocyte-mediated, chronic inflammatory disorders have been associated with autoimmunity and there are data indicating that autoimmune phenomena might also be present in asthma. Expression of perforin, a cytotoxic molecule produced by lymphocytes, has been implicated in the pathogenesis of autoimmune disease. We therefore tested the hypothesis that allergic and intrinsic asthma might be associated with an increase in lymphocytes producing perforin by comparing the expression of intracellular perforin in peripheral blood lymphocytes of patients with extrinsic asthma (n = 13), intrinsic asthma (n = 7), and healthy (control subjects (n = 18). Lymphocytes were identified using flow cytometry and subdivided into CD3(+), CD4(+), CD8(+), CD16(+), and CD56(+) subpopulations after staining with appropriate monoclonal antibodies. The percentage of perforin-positive total lymphocytes as significantly elevated in patients with allergic as well as intrinsic asthma when compared with normal control subjects. Analysis of lymphocyte subpopulations also revealed a significant increase in the percentage of CD3(+), CD4(+), CD8(+), and CD56(+) cells expressing perforin in allergic asthma and a significant increase in the percentage of CD4(+), and CD56(+) cells in intrinsic asthma when compare with healthy control subjects. Perforin expression in CD4(+) cells in intrinsic asthma was also significantly elevated compared with allergic asthma. We conclude that allergic and intrinsic asthma is associated with increased expression of perforin in T-lymphocyte subsets.

Adult↗

PubMed2000

Increase in perforin-positive peripheral blood lymphocytes in extrinsic and intrinsic asthma.

The cause of asthma, which has been linked to a chronic, T-cell-mediated bronchial inflammation, remains unclear. A number of other T-lymphocyte-mediated, chronic inflammatory disorders have been associated with autoimmunity and there are data indicating that autoimmune phenomena might also be present in asthma. Expression of perforin, a cytotoxic molecule produced by lymphocytes, has been implicated in the pathogenesis of autoimmune diseases. We therefore tested the hypothesis that allergic and intrinsic asthma might be associated with an increase in lymphocytes producing perforin by comparing the expression of intracellular perforin in peripheral blood lymphocytes of patients with extrinsic asthma (n = 13), intrinsic asthma (n = 7), and healthy control subjects (n = 18). Lymphocytes were identified using flow cytometry and subdivided into CD3(+), CD4(+), CD8(+), CD16(+), and CD56(+) subpopulations after staining with appropriate monoclonal antibodies. The percentage of perforin-positive total lymphocytes was significantly elevated in patients with allergic as well as intrinsic asthma when compared with normal control subjects. Analysis of lymphocyte subpopulations also revealed a significant increase in the percentage of CD3(+), CD4(+), CD8(+), and CD56(+) cells expressing perforin in allergic asthma and a significant increase in the percentage of CD4(+) and CD56(+) cells in intrinsic asthma when compared with healthy control subjects. Perforin expression in CD4(+) cells in intrinsic asthma was also significantly elevated compared with allergic asthma. We conclude that allergic and intrinsic asthma is associated with increased expression of perforin in T-lymphocyte subsets.

Adult↗

PubMed1999

Differential modulation of interleukin-4 and interleukin-13 secretion from human peripheral blood mononuclear cells.

Interleukin-4 (IL-4) and IL-13 which have been implicated in the pathogenesis of atopic reactions elicit many of the same biologic responses. Therefore, time- and stimulus-dependent differences in the regulation of IL-4 and IL-13 production could be of relevance to their biological effects. In this study we tested the hypothesis that stimulation of peripheral blood mononuclear cells (PBMCs) with different inducers of cell activation would result in a differential expression of IL-4 and IL-13. For this purpose, PBMCs of nonatopic volunteers were incubated with phytohaemagglutinin (PHA), phorbolester (PMA), calcium ionophore A23187, or IL-3. The effect of these stimuli on IL-4 and IL-13 production were analysed by enzyme-linked immunoassay (ELISA) in supernatants of cultured PBMCs. Incubation of PBMCs with A23167 and PHA induced both a dose- and time-dependent increase in IL-4 and IL-13 release. A23187 induced concentrations of IL-4 were higher than those of IL-13 whereas IL-4 release following stimulation with PHA was considerably higher for IL-13 compared to IL-4. In contrast, there was a selective increase in IL-13 but not IL-4 concentrations following stimulation of PBMCs with PMA and IL-3 in vitro. In conclusion in this study evidence is provided that IL-4 and IL-13 production are regulated differently which might explain their functional redundancy.

Calcimycin↗

PubMed1999

Modulation of cytokine release from mononuclear cells by prostacyclin, IL-4 and IL-13.

In a previous study, we reported that cicaprost, a stable prostacyclin analogue can inhibit the release of granulocyte-macrophage colony-stimulating factor (GM-CSF) from activated human peripheral mononuclear blood cells (PBMCs). Since interleukin (IL-4) and IL-13 have been shown to inhibit the release of cytokines from PBMCs we tested the hypothesis that prostacyclin in combination with IL-4 or IL-13 can act synergistically to modulate the release of IL-10, generally associated with anti-inflammatory properties, and the pro-inflammatory cytokine tumour necrosis factor alpha (TNF-alpha). For this purpose, PBMCs were isolated over Ficoll, stimulated with lipopolysaccharide (LPS) and incubated in the presence of cicaprost, IL-4 or IL-13. There was a significant reduction in TNF-alpha as well as IL-10 secretion from LPS-stimulated PBMCs following incubation with IL-4 or IL-13. In contrast, cicaprost reduced the secretion of TNF-alpha but led to a slight enhancement of IL-10 release from PBMCs. When LPS-activated PBMCs were incubated in the presence of cicaprost and IL-4 or IL-13 there was a selective, synergistic inhibition of the TNF-alpha release which was not observed for IL-10. Thus, our data suggest that prostacyclin can synergize with cytokines to selectively inhibit the release of pro-inflammatory cytokines from PBMCs.

Cell Survival↗