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T A Out

Publications and source records attributed to T A Out.

At least 55 records · Page 3Linked to original sources
PubMed1996

Soluble interleukin-2 receptor (sIL-2R) is a marker of disease activity in psoriasis: a comparison of sIL-2R, sCD27, sCD4, sCD8 and sICAM-1.

Psoriasis is a T-cell-mediated inflammatory skin disease which can be treated successfully with immunosuppressive drugs. Our purpose was to evaluate disease activity of psoriasis and the effect of immunosuppressive treatment by monitoring the soluble T-cell products sIL-2R, sCD27, sCD4, sCD8 and sICAM-1. Twenty-two patients were treated orally with escalating dosages of cyclosporin A (n = 17)(3-5 mg/kg/day) or FK506 (n = 5)(0.05-0.15 mg/kg/day). The Psoriasis Area and Severity Index (PASI) was used to monitor clinical activity of psoriasis. Serum samples were analyzed by ELISA. sIL-2R levels showed the highest correlation with psoriasis disease activity (rs = 0.89; p < 0.05). The longitudinal part of this study showed that levels of sIL-2R and sCD27 decreased during immunosuppressive treatment but remained above normal even in patients successfully treated. Our data indicate that sIL-2R levels are well correlated with disease activity in patients with psoriasis. sIL-2R levels closely follow the decrease of disease activity during immunosuppressive treatment.

Adolescent↗
PubMed1996

Cytokine production by T-cell clones from bronchoalveolar lavage fluid of patients with asthma and healthy subjects.

Cytokines produced by T-lymphocytes play an important regulatory role in inflammation in the airways of asthmatic patients. Our aim was to analyse the cytokine production by T-cell clones from bronchoalveolar lavage fluid (BAL) of patients with allergic asthma and the cytokine production of clones from the patients' peripheral blood (PB), as well as from BAL and blood from healthy controls. In 75 randomly selected CD4+ T-cell clones, we assessed the production of interleukin (IL)-2, IL-4 and interferon-gamma (IFN-gamma). After stimulation with anti-CD3, the clones from the asthmatic patients' BAL (A-BAL) produced significantly more IL-4 and IFN-gamma (median 0.32 and 4.17 ng.mL-1, respectively) than clones from A-PB (0.11 and 1.12 ng.mL-1, respectively). No evidence was found for a dominance of a type 1 or type 2 T-helper cell (Th1- or Th2)-cytokine profile in any of the groups. In three out of nine clones tested, the stimulation with anti-CD2/CD28/phorbol myristate acetate (PMA) induced a shift of the IFN-gamma/IL-4 ratio towards a Th2-type cytokine profile. Our results suggest that the clones from the asthmatic patients' bronchoalveolar lavage were derived from a more differentiated T-cell population. In several clones, the cytokine profile was still modulated by the stimulus applied. Similarly, local conditions in the airways may be involved in directing the cytokine production of T-cells.

Adult↗
PubMed1995

Plasma protein leakage and local secretion of proteins assessed in sputum in asthma and COPD. The effect of inhaled corticosteroids.

Asthma and chronic obstructive pulmonary disease (COPD) are characterized by chronic airway inflammation with cell infiltration, increased plasma exudation and abnormal local secretion of proteins. We have analysed whether sputum differs in this respect between asthma (n = 9) and COPD (n = 9), and whether inflammatory markers in sputum are affected by treatment. In non-smoking asthma patients there was more plasma protein leakage, based on the relative coefficient of excretion Q alpha 2macroglobulin/QIgG (P = 0.03). There was less local secretion of sIgA and lactoferrin than in COPD (P < 0.05). Tryptase was slightly higher in sputum from asthma than from COPD (P < 0.05), whereas eosinophil cationic protein and myeloperoxidase were similar. After treatment with glucocorticosteroids, there was a reduction in the Q alpha 2macroglobulin/Qalbumin (P < 0.015), but no effect was seen on the levels of products from local cells. We conclude that sputum analysis is useful to study the local inflammatory process in asthma and COPD.

Administration, Inhalation↗
PubMed1995

Physical interaction between lung epithelial cells and T lymphocytes.

The present results support a role for epithelial cells in the activation of T cells in an apparent antigen-independent manner. The transient expression of CD25 indicates a short acting T cells activation. Possibly, this event primes T cells to respond swiftly upon antigen-specific stimulation or to synthesize mediators that affect the local milieu. The molecular mechanism of interaction, although not well defined possibly involves LFA3-CD2 interactions. In T cell activation, via LFA3-CD2 interaction, the density of presented LFA3 molecules is critical. With the increase in the level of expression of LFA3 by epithelial cells this critical density may have been reached. However, based on what is known about T cell activation and CD25 expression in particular it is likely that additional signals such as soluble mediators are required for T cell activation by epithelial cells. Whether this mode of activation occurs in vivo remains to be established by studying ex vivo and in situ material. Not much is known about the expression of LFA3 by epithelial cells in vivo, nor about the stimuli that induce the upregulation of LFA3. In preliminary experiments with fluorescence microscopy we found that neither TNF-alpha nor IL-1 beta induce LFA3 in the same fashion as IFN-gamma. In conclusion, T cell activation by epithelial cells could be an important feature in inflammatory and immunological processes in mucosal systems such as the bronchi and deserves further research.

Antigens, CD↗
PubMed1994

Fc gamma receptor IIa (CD32) polymorphism in fulminant meningococcal septic shock in children.

Antibodies are essential in host defense against Neisseria meningitidis. Therefore, interactions among IgG and Fc receptors (Fc gamma R) on phagocytes may be crucial. Genetic polymorphic forms of Fc gamma RIIa (CD32) express different functional activities. In a retrospective study, Fc gamma R polymorphisms were determined in 25 children who survived fulminant meningococcal septic shock: 11 had Fc gamma RIIa-R/R131, the poor IgG2-binding allotype, which is a significantly more frequent rate than found in a healthy white population (44% vs. 23%; P = .028; odds ratio = 2.67; 95% confidence interval, 1.09-6.53). The relevance of this finding was further supported by the fact that neutrophils with the Fc gamma RIIa-R/R131 allotype phagocytized N. meningitidis opsonized with polyclonal IgG2 antibodies less effectively than did IIa-H/H131 neutrophils. Our findings suggest an important role for anti-N. meningitidis IgG2 and the Fc gamma RIIa polymorphism in host defense against systemic meningococcal infections.

Adolescent↗
PubMed1994

Expression of activation markers by human lung T cells after adherence to lung epithelial cells.

Both increased T cell numbers and their increased activation state have implicated an important role for T cells in chronic inflammatory reactions seen in the airways of (allergic) asthmatics. Airway epithelial cells are frequently exposed to stimuli that cause the release of mediators and the expression of cell adhesion molecules. We have examined whether human airway epithelial cells can activate lung-derived T cells. Clonal lung T cells showed an increased adherence to transformed airway epithelial cells that had been exposed previously for 2 h to human recombinant interferon-gamma (IFN-gamma; 100 U/ml). After an additional 16-24 h of culturing in the absence or presence of epithelial cells, T cells expressed increased levels of both the alpha-chain of the interleukin-2 receptor (IL-2R, CD25) and the transferrin receptor (CD71), both markers of T cell activation. T cells apparently activated by epithelial cells, however, did not produce IFN-gamma or IL-4 nor showed an increased proliferation on the addition of IL-2 (5-50 U/ml). The induced adherence to and the activation of T cells by epithelial cells is mediated largely by CD2 and its ligand lymphocyte functional antigen-3, a pathway known to up- and downregulate T cell functions.

Antigens, CD↗
PubMed1994

Analysis of plasma-protein leakage and local secretion in sputum from patients with asthma and chronic obstructive pulmonary disease.

In order to assess the usefulness of sputum analysis in studying plasma-protein exudation and local secretion of proteins in the airways, we measured specific proteins in the sputum sol phase (SSP) and sputum gel phase (SGP) from patients with stable asthma or chronic obstructive pulmonary disease (COPD). Protein levels in SSP showed relatively small variations between two subsequent visits of each patient (n = 22), as also reflected by intraclass correlation coefficients above 0.79. Protein levels differed between SSP and SGP, but inclusion of the SGP data did not affect the variation of protein levels in sputum. The degree of plasma-protein leakage was estimated from the relative coefficients of excretion (RCE) of alpha 2-macroglobulin and albumin (QA2M/QALB), and of alpha 2-macroglobulin and ceruloplasmin (QA2M/QCP), which do not depend on variable dilution of sputum. Despite the heterogeneity of the study group of 26 patients with asthma (atopic [13] smokers [13], including five patients using inhaled steroids), QA2M/QALB and QA2M/QCP correlated both with bronchial hyperreactivity (Spearman rank: r = -0.45 and r = -0.36, p < 0.05) and with blood eosinophil counts (r = 0.37 and 0.56, p < 0.05). We conclude that protein levels in SSP are relatively constant in patients with stable asthma or COPD; in patients with asthma, the plasma-protein leakage, as measured with the RCE in SSP, appears to correlate with indirect indices of airway inflammation.

Adult↗
PubMed1994

Role of neutrophil Fc gamma RIIa (CD32) and Fc gamma RIIIb (CD16) polymorphic forms in phagocytosis of human IgG1- and IgG3-opsonized bacteria and erythrocytes.

The four subclasses of IgG have different biological activities associated with their Fc regions. Fc gamma receptors on leucocytes (Fc gamma R) mediate binding and phagocytosis of opsonized particles. Two structurally and functionally distinct allelic polymorphisms of the Fc gamma R have been defined: the H/R131 forms of Fc gamma RIIa (CD32), and the neutrophil antigen 1 (NA1)/NA2 forms of Fc gamma RIIIb (CD16). In this study the activities of allotypes of CD16 are analysed with antibacterial IgG subclass antibodies and with IgG1 and IgG3 anti-Rhesus D, and the activities of CD32 with IgG1 and IgG3 anti-Rhesus D. With respect to the allotypes of CD16, polymorphonuclear leucocytes (PMN) homozygous for Fc gamma RIIb-NA2 exhibited a lower (21-25%) IgG1-mediated phagocytosis of Staphylococcus aureus strain Wood (STAW), Haemophilus influenzae type b (Hib), and Neisseria meningitidis group B (NMen) than IIIb-NA1 PMN. The difference was apparent only when the micro-organisms were opsonized in the absence of complement, and was furthermore enhanced (34-52%) upon blockade of Fc gamma RIIa. In addition, monoclonal IgG3 anti-D-mediated rosette formation and phagocytosis was consistently found to be lower (16%) with Fc gamma RIIIb-NA2 than with IIIb-NA1 PMN. For the allotypes of CD32 we now show that IgG3 anti-D sensitized erythrocytes formed more (50%) rosettes and were phagocytosed at a higher rate with PMN carrying Fc gamma RIIa-H131 than with PMN carrying IIa-R131. Heterozygous Fc gamma RIIa-H/R131 PMN exhibited intermediate phagocytic activity in this respect. This study illustrates a critical role of Fc gamma R allotypes in functional interactions with biologically relevant IgG subclass antibodies.

Antigens, CD↗
PubMed1993

Phagocytosis of Staphylococcus aureus and Haemophilus influenzae type B opsonized with polyclonal human IgG1 and IgG2 antibodies. Functional hFc gamma RIIa polymorphism to IgG2.

To assess the function of IgG subclass antibodies we studied the opsonization of Staphylococcus aureus (STAW) and Haemophilus influenzae type b (Hib) by natural IgG1 and IgG2 antibodies from five healthy individuals. Phagocytosis by polymorphonuclear leukocytes (PMN) was analyzed using FITC-labeled bacteria and flow cytometry. All PMN donors were typed for the High- and Low-Responder phenotype of the human Fc gamma receptor (hFc gamma) type IIa (CD32) and the NA1/NA2 allotype of the hFc gamma RIIIb (CD16). When PMN were used that were heterozygous for hFc gamma RIIa and hFc gamma RIIIb, phagocytosis of STAW opsonized with IgG1 antibodies was similar to that with IgG2, both in the presence and absence of a source of complement (agammaglobulinemic serum). Phagocytosis of Hib opsonized with IgG2 anti-Hib proved significantly lower (p < 0.05) than with IgG1 anti-Hib using preparations from 4 of the 5 individuals tested. IgG2 anti-Hib from one donor, however, proved more effective than IgG1 anti-Hib. The properties of PMN with hFc gamma RIIaLR,LR and hFc gamma RIIaHR,HR were compared, using hFc gamma RIIIb NA1/NA2-matched PMN. hFc gamma RIIaHR,HR PMN were virtually incapable of phagocytosing STAW and Hib opsonized with IgG2 anti-bodies without complement, in contrast to hFc gamma RIIaLR,LR PMN. Phagocytosis of IgG2-oposonized bacteria by hFc gamma RIIaLR,LR PMN was effectively inhibited by mAb against hFc gamma RIIa (IV.3). IgG1-mediated phagocytosis was blocked by mAb against hFc gamma RIIIb (CLB/FcRGran 1) to a greater extent than by anti-hFc gamma RIIa mAb. Inhibition studies with mAb against CR3 (B2.12) and hFc gamma RIIa showed that both receptors cooperated in phagocytosis. We conclude that PMN phagocytosis can be effectively mediated by antibacterial IgG2 anti-STAW and anti-Hib. Thus, IgG2 may have a critical role in the immune defense against these bacteria. However, the role of antibacterial IgG2 in opsonization and phagocytosis may be limited in individuals homozygous for hFc gamma RIIaHR.

Haemophilus influenzae↗
PubMed1993

Soluble and cellular markers of T cell activation in patients with pulmonary sarcoidosis.

We have characterized the activation state of T cells in the bronchoalveolar lavage fluid (BALF) and peripheral blood (PB) from patients with sarcoidosis, to obtain more information about their mechanisms of activation. We analyzed the expression of activation markers (CD25, HLA-DR, Leu-8, and two recently defined markers, CD69 and CD27) on T cells by two-color flow cytometry. We also measured the levels of soluble CD27 and soluble CD25 in nonconcentrated BALF and in serum by ELISA. We found that most T cells in BALF from patients, but not in the peripheral blood, expressed CD69, whereas they did not express CD27. The phenotype (CD69+CD27-) of most BALF T cells and the coexpression of CD69 with HLA-DR and/or VLA-1 indicates that they are in a state of recent and persistent activation. We confirmed previous findings of expression of CD25, HLA-DR, and Leu-8 by T lymphocytes in BALF from patients. We also confirmed increased levels of soluble CD25 in the serum from these patients. The levels of sCD27 and sCD25 in the epithelial lining fluid (ELF) were calculated on the basis of urea in BALF and serum. They were increased in the patients compared with control subjects. In both patients and control subjects, levels in ELF were higher than in the peripheral blood. This indicates shedding of sCD27 (and sCD25) in the lung compartment, which likely contributes to levels in the serum. It is known that in vitro CD27+ cells become CD27- after repeated stimulation and that CD27- cells, after restimulation, do not shed sCD27.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Heterogeneous effects of histamine on proliferation of lung- and blood-derived T-cell clones from healthy and asthmatic persons.

We have studied the effects of histamine on the proliferation and the intracellular cyclic adenosine monophosphate (cAMP) levels of T-lymphocyte clones (TLC) generated from bronchoalveolar lavage fluid (BALF) or peripheral blood (PB) from healthy and asthmatic persons. TLC from either compartment and from both groups of donors were heterogeneous in their response to histamine. In BALF-derived TLC, three types of responses were observed: histamine inhibited, stimulated, or did not modulate the anti-CD3-induced proliferation. Histamine directly and dose dependently inhibited the anti-CD3-induced proliferation of six (two asthmatic) of 12 CD4+ BALF TLC, stimulated two BALF TLC (both nonasthmatic), and did not modulate the proliferation of four BALF TLC. The maximal inhibition was 70%, the maximal stimulation 200%, both at 10(-3) M histamine. The stimulation of proliferation was associated with increased interleukin-2 (IL-2) production, whereas the inhibition of proliferation was associated with decreased IL-2 production and downregulation of IL-2 receptor expression. The inhibitory effects could be partly reversed by H2-receptor antagonists and could be mimicked by an H2-receptor agonist. In contrast, the stimulatory effect was not reversed or mimicked by H1 or H2 antagonists or agonists. The majority of CD4+ TLC responded to histamine with a rise in the intracellular cAMP levels. A rise in cAMP, however, was often but not always associated with an inhibition of proliferation. In addition, stimulation of proliferation occurred in the absence of a rise in cAMP. We compared cAMP rises in panels of TLC obtained with high cloning efficiencies from the PB from a healthy person and from an asthmatic person.(ABSTRACT TRUNCATED AT 250 WORDS)

Asthma↗
PubMed1992

ELISA of complement C3a in bronchoalveolar lavage fluid.

Activated complement factors within the lung may induce several local biological effects. In order to investigate local complement activation we have developed non-competitive two-site ELISAs of C3a and total C3 in bronchoalveolar lavage fluid (BALF). For the assay of C3a, both C3 and C3(H2O) were removed from the samples by precipitation with polyethylene glycol. It was necessary to add carrier proteins to BALF to remove C3 and C3(H2O) fully. The ELISA of C3a has the lowest limit of detection reported thus far, namely 0.045 nM (= 0.405 ng/ml). In BALF from healthy persons (n = 9) the C3a concentration was 0.20 nM (0.12-0.31 nM) (median, range). C3a was higher in BALF from patients with asthma or with sarcoidosis; asthma (n = 10), 0.45 nM (0.20-5.79 nM); sarcoidosis (n = 19), 1.31 nM (0.095-5.65 nM) (Mann-Whitney U test, p less than 0.005). In BALF from patients with Pneumocystis carinii pneumonitis (n = 10) the C3a concentration was 0.18 nM (0.07-0.57 nM). C3a concentrations in BALF may reflect local complement activation in the lung and/or diffusion into the lumen. This was studied by normalizing C3a concentrations in BALF into values for epithelial lining fluid (ELF), and calculating serum-to-ELF quotients of C3a, and C3a/total C3 quotients.

Adolescent↗
PubMed1992

Complement activation by polyclonal immunoglobulin G1 and G2 antibodies against Staphylococcus aureus, Haemophilus influenzae type b, and tetanus toxoid.

To obtain information on effector functions of human immunoglobulin G2 (IgG2), we have measured the complement-activating properties of polyclonal IgG subclass antibodies against bacterial antigens. IgG1 and IgG2 were purified from serum samples from five healthy individuals, and complement activation was measured with different bacterial antigens. We used Staphylococcus aureus Wood 46 (STAW), which is a common antigen, Haemophilus influenzae type b (Hib), which is a common pathogenic microorganism in children, and formaldehyde-inactivated tetanus toxin (TT). Bacteria were incubated with antibodies and then incubated with sera from agammaglobulinemic patients as a complement source, and C3c deposition was measured by enzyme-linked immunosorbent assay. We found that anti-STAW IgG2 activated complement to a level similar to that of anti-STAW IgG1. Anti-Hib IgG1 complement activation was as much as seven times higher than that of anti-Hib IgG2 in four individuals. In one individual, anti-Hib IgG2 was more effective in complement activation than anti-Hib IgG1. Anti-TT antibodies showed patterns similar to those of anti-Hib. Our results indicate that IgG2 antibodies may contribute significantly to antibacterial defense. Also, individual differences in antibody effector functions should be taken into account when evaluating the immune status of patients and during early phase 1 studies of new vaccines.

Antibodies, Bacterial↗
PubMed1992

Cloning of T lymphocytes from bronchoalveolar lavage fluid.

We have prepared T-cell clones from bronchoalveolar lavage fluid (BALF) from four healthy, nonsmoking persons and from four patients with allergic asthma. T cells were cloned by direct limiting dilution and with the use of a fluorescent activated cell sorter with an automated cell deposition unit. T-cell clones from the blood (PB) were prepared as well. The cloning efficiencies of T cells from BALF ranged from 3 to 40% and were lower than those obtained from PB T cells (18 to 72%). The cloning conditions generated CD4+ as well as CD8+ clones. The very late antigen-4, VLA-4, was more frequently expressed on CD4+ T-cell clones from BALF than from the blood (P < 0.05). CD8+ clones from BALF were more frequently VLA-1+ than those from blood (P < < 0.01). Mitogen- and monoclonal antibody-driven proliferation of CD4+ clones showed that BALF clones were well responsive to proliferation stimuli similar to those from the blood. Analysis of interleukin-4 production by 10 BALF and 10 PB clones showed large variations between individual CD4+ clones (BALF: range, < 100 to 700 pg/ml; PB: range, < 100 to 1,100 pg/ml), indicating the generation of different types of clones, which was also clear from analysis of interferon-gamma production. The analysis of properties of BALF T-cell clones and their regulation will improve insight into immunologic reactions in the lungs.

Adult↗
PubMed1992

Surfactant protein A in bronchoalveolar lavage fluid.

We measured surfactant protein A and phosphatidylcholine in the bronchoalveolar lavage fluid from healthy volunteers and several groups of patients with lung diseases to obtain information on surfactant in the lung. We developed three types of enzyme-linked immunosorbent assays that used combinations of polyclonal antiserum and monoclonal antibodies. Phosphatidylcholine was assessed by enzymatic measurement. The median amounts of surfactant protein A in bronchoalveolar lavage fluid determined by the enzyme-linked immunosorbent assay with monoclonal antibodies were as follows: control subjects (n = 10), 2.82 mg/L (range, 0.92 to 5.17 mg/L); patients with asthma (n = 13), 1.89 mg/L (range, 0.45 to 2.95 mg/L); and patients with pulmonary sarcoidosis (n = 20), 2.98 mg/L (range, 0.68 to 7.02 mg/L). The median phosphatidylcholine concentrations in the bronchoalveolar lavage fluid were as follows: control subjects (n = 10), 20 mumol/L (range, 3 to 37 mumol/L); patients with asthma (n = 12), 24 mumol/L (range, 3 to 55 mumol/L); and patients with pulmonary sarcoidosis (n = 20), 26 mumol/L (range, 4 to 76 mumol/L). As a group, the patients with asthma had less surfactant protein A in bronchoalveolar lavage fluid than did the control subjects (Mann-Whitney U test, p less than 0.05). The surfactant protein A levels measured by the enzyme-linked immunosorbent assay with polyclonal antiserum and by a competitive enzyme-linked immunosorbent assay were also lower in bronchoalveolar lavage fluid from patients with asthma than in that from control subjects. The phosphatidylcholine concentrations in all groups were similar.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

ELISA procedures for the measurement of IgG subclass antibodies to bacterial antigens.

We have developed enzyme-linked immunosorbent assays (ELISA) of IgG subclass antibodies against whole bacteria and bacterial antigens using enzyme-labelled mouse monoclonal antibodies. The properties of different anti-subclass antibodies were compared. In sera from 18 healthy adults we measured the IgG subclass distribution of specific antibodies against Staphylococcus aureus and Haemophilus influenzae b and against distinct bacterial components: pneumococcal capsular polysaccharides, dextran and tetanus toxoid. We found that antibodies against protein (tetanus toxoid) were mainly IgG1, with some contribution of IgG4 and IgG2. Antibodies against polysaccharides (pneumococcal PS and dextran) and whole bacteria were restricted mainly to IgG1 and IgG2.

Antibodies, Monoclonal↗