PubMed Health⌕ Search

Biomedical subjects

U Schauer

Publications and source records attributed to U Schauer.

At least 19 recordsLinked to original sources
PubMed2006

Evaluation of respiratory syncytial virus detection by rapid antigen tests in childhood.

BACKGROUND: Rapid and reliable diagnosis is crucial for clinical management of respiratory syncytial virus infection in childhood. We assessed the performance characteristics of respiratory syncytial virus antigen immunoassays in children hospitalized for respiratory infection. METHOD: A total of 1600 children up to three years of age hospitalized for diseases potentially caused by RSV were included in the study. Nasopharyngeal secretions were obtained in a standardized manner in the first 24 hours after hospital admission and tested in parallel by PCR and rapid antigen tests for RSV. The following parameters were recorded: recruitment center, gender, age, presence of fever, rhinitis, stridor, barking cough, cough, wheezing, vomiting, disturbed eating or sleep, tachypnea, tachycardia, increased body temperature, decreased oxygen saturation, C-reactive protein, erythrocyte sedimentation rate and chest X-ray results. RESULTS: Considering PCR testing as gold standard, rapid antigen testing had a specificity of 89.9% and a sensitivity of 66.2% for all samples tested. Logistic regression analysis revealed age and recruitment center as the only parameters influencing sensitivity whereas no such influence on specificity was found. Positive likelihood ratios ranged from 4,9 to 6.9 in different age groups. Negative likelihood ratio was 0.24 (95% CI: 0.18-0.42) in children aged up to 3 months but 0.67 (95% CI: 0.53-0.84) for children older than 2 years. CONCLUSION: Rapid detection of RSV antigen in this study was useful in detection of RSV mediated disease in younger infants but shows decreasing sensitivity in children older than three months.

Antigens, Viral↗
PubMed2004

Severe respiratory syncytial virus infections and reduced interferon-gamma generation in vitro.

To study the consequences of the interaction of respiratory syncytial virus (RSV) with dendritic cells in vitro, we established a model of the primary immune response using dendritic cells, autologous naive T cells and the superantigen toxic shock syndrome toxin 1 (TSST 1). About 10% of the naive T cells express the T cell receptor chain Vbeta2. These cells were stimulated by TSST 1 and could be analysed by flow cytometry. Cultures infected with RSV produced significantly less interferon-gamma compared to uninfected cultures. In a first set of experiments we evaluated whether this culture model using isolated CD4(+) CD45RA(+) T cells, in fact, reflects the primary immune response. In a prospective study, cells were isolated from 13 children at birth, at 1 year of age and at 4 years of age. RSV reduced interferon-gamma production at all the age groups analysed and the results were stable over time within a given individual. In a second set of experiments, we asked whether clinical differences in the course of RSV infection are due to variations in the cellular immune response. At the age of 1 year (5-9 months after the RSV epidemic) dendritic cells and naive T cells were obtained from 27 children with a history of bronchiolitis, from 15 children with a benign course of RSV infection and from 26 controls without RSV infection. The frequency of interferon-gamma-producing cells in RSV infected cultures was significantly lower (P < 0.001) in cultures from children with a history of RSV bronchiolitis compared to children with mild RSV infection. Cultures from children without infection displayed a wide range of results. Overall, interferon-gamma generation in this group was still lower (P < 0.05) than in the group with mild RSV infection. Because we have ruled out that memory cells play a role in the experiments performed, the most likely explanation for our results is that a high generation of interferon-gamma in the primary immune response protects from severe RSV mediated disease.

Bacterial Toxins↗
PubMed2004

The co-seasonal application of anti-IgE after preseasonal specific immunotherapy decreases ocular and nasal symptom scores and rescue medication use in grass pollen allergic children.

BACKGROUND: Specific immunotherapy (SIT) and treatment with anti-immunoglobulin (Ig)E antibody are complementary approaches to treat allergic rhinoconjunctivitis, which may be used for single or combined treatment. OBJECTIVE: A randomized, double-blind, placebo-controlled trial was conducted to compare the efficacy of single and combined treatment with SIT and anti-IgE (Omalizumab) in reducing symptom severity and rescue medication use. METHODS: A total of 221 subjects with birch and grass pollen allergic rhinoconjunctivitis aged 6-17 years were analysed during the grass pollen season. Group A (SITbirch + placebo) served as a reference group obtaining no effective treatment for grass pollen allergy. Group B received anti-IgE monotherapy during grass pollen season, group C SIT grass pollen monotherapy, and group D the combined treatment of SIT and Omalizumab. RESULTS: Preseasonal treatment with grass pollen SIT alone compared with SIT with the nonrelated allergen did not reduce symptoms or rescue medication use. Anti-IgE monotherapy significantly diminished rescue medication use and number of symptomatic days. The combined treatment with SIT and anti-IgE showed superior efficacy on symptom severity compared with anti-IgE alone. CONCLUSIONS: Co-seasonal Omalizumab therapy showed considerable effects in children with seasonal allergic rhinitis. The combination of SIT plus Omalizumab was clinically superior to each treatment alone during the first year of observation.

Adolescent↗
PubMed2004

Enhanced virulence, airway inflammation and impaired lung function induced by respiratory syncytial virus deficient in secreted G protein.

BACKGROUND: Respiratory syncytial virus (RSV) infection can cause bronchial hyperresponsiveness and asthma exacerbations. In mice it results in airway inflammation and airway hyperresponsiveness. Since viral factors influencing these responses are not well defined, a study was undertaken to investigate the role of secreted G protein of human RSV in determining virulence, inflammatory responses, and changes in lung function. METHODS: BALB/c mice were infected with a spontaneous mutant of RSV deficient in secreted G protein (RSV-DeltasG) or with wild type RSV (RSV-WT). Viral titres, numbers of pulmonary inflammatory cells, and concentrations of interferon (IFN)-gamma, interleukin (IL)-4, IL-5 and IL-10 in bronchoalveolar lavage (BAL) fluid were determined. Airway function was assessed at baseline and following methacholine provocation using barometric whole body plethysmography. RESULT: Following infection with RSV-DeltasG, viral titres were increased 50-fold compared with RSV-WT. Influx of eosinophils and macrophages to the lung and concentrations of IFN-gamma and IL-10 in BAL fluid were also significantly higher following infection with RSV-DeltasG. Airway function, both at baseline and after methacholine provocation, was significantly decreased following infection with RSV-DeltasG compared with RSV-WT. CONCLUSION: Secreted G protein is likely to be a regulatory factor in RSV infection limiting infectivity of the virus, inflammatory responses in the lungs, and reduction in lung function.

Animals↗
PubMed2003

Large-scale isolation of immature dendritic cells with features of Langerhans cells by sorting CD34+ cord blood stem cells cultured in the presence of TGF-beta1 for cutaneous leukocyte antigen (CLA).

Epidermal Langerhans cells (LCs) are a subset of immature dendritic cells (DCs) and play a key role in the initiation and regulation of T cell responses. Upon antigenic stimulation, LCs differentiate into mature DCs undergoing profound morphologic and functional changes. Studies of the biological details of this conversion process have been hampered by difficulties in generating immature dendritic cells of a defined lineage. We propose a new method of purifying homogenous immature DCs in large numbers by sorting for CLA (Langerhans-like cells) from cord-blood-derived haematopoietic progenitor cells (HPCs). Established protocols describe the generation of LCs from CD34(+) HPCs by sorting for CD1a after 5 days of culture in the presence of GM-CSF and TNF-alpha. However, the numbers of LCs obtained by this method remain within the low range. Furthermore, CD1a is also expressed on interstitial DCs. LCs but not interstitial DCs express the cutaneous leukocyte antigen (CLA). The expression of CLA by cells stimulated with TNF-alpha and GM-CSF peaks on day 10. This expression can be raised further by stimulating the cells with TGF-beta1 and omitting TNF-alpha from day 6 onwards. CLA(+) cells were isolated on day 10 by AutoMACS. Their LC phenotype was established by the presence CD207. The immaturity of Langerhans-like cells was shown by the lack of CD83 and CD208 expression as well as their lower ability to activate allogeneic naive T cells as compared to maturing dendritic cells. However, CLA(+) cells cannot be termed Langerhans cells as they do not express Birbeck granules. Compared to sorting for CD1a (on day 6), sorting for CLA (on day 10) results in isolates of higher purity (80% vs. 50%) and a yield eight times higher (4.9x10(6) vs. 6.5x10(5) cells) when using identical numbers of input cells (5x10(5) cells). This novel method guarantees large numbers of pure and functionally active immature dendritic cells.

Antigens, CD1↗
PubMed2003

Respiratory syncytial virus decreases the capacity of myeloid dendritic cells to induce interferon-gamma in naïve T cells.

Respiratory syncytial virus (RSV) is the most common cause of bronchiolitis in infants under 6 months of age. Since an RSV infection does not necessarily prevent a reinfection, we asked whether RSV might subvert an effective immune response by interfering with the function of dendritic cells (DCs). Immature DCs cultured from cord blood stem cells and infected with RSV reduced the rate of interferon-gamma (IFN-gamma) production in co-cultured autologous naïve T cells stimulated with the superantigen TSST-1. Maturation of DCs in response to poly(IC) but not to CD40 ligand did overcome the inhibitory effect of RSV. Further experiments demonstrated that induction of apoptosis, a selective increase in CD86 expression and lack of release of pro-inflammatory cytokines were associated with inhibition of IFN-gamma generation. In addition, RSV replication seemed to be essential for modulation of IFN-gamma production because a virus preparation inactivated by UV irradiation had no effect. Hence, one reason for multiple reinfections by RSV might be the subversion of antiviral immune responses by interference of RSV with DC function.

Antigens, CD↗
PubMed2003

Antigen dose, type of antigen-presenting cell and time of differentiation contribute to the T helper 1/T helper 2 polarization of naive T cells.

Antigenic encounter by T cells induces immunological synapse formation and T-cell activation. Using different concentrations of toxic shock syndrome toxin-1 (TSST-1) as stimulus, we examined the capacities of dendritic cells (DC) and macrophages (Mphi) to prime syngeneic naive T cells. DCs were, under all experimental settings, more efficient than Mphi at clustering T cells. Translocation of the T-cell receptor (TCR) to the contact area was found to be induced by DCs, as well as by Mphi, in an antigen-dependent manner, although Mphi were less efficient at inducing TCR translocation. Capping of protein kinase C theta (PKCtheta) was also antigen dependent but induced exclusively by DCs. Likewise, DCs were found to be more potent inducers of interleukin-2 (IL-2) production and proliferation of naive T cells than Mphi. After 3 days of culture, DCs presenting 100 ng/ml TSST-1 induced interferon-gamma (IFN-gamma)-secreting cells, whereas Mphi did not. After 7 days of culture, DCs presenting 0.1 ng/ml TSST-1, and Mphi presenting high (as well as low) doses of TSST-1, induced IL-4-producing cells. We therefore provide evidence to show that antigen dose, type of antigen-presenting cell and time of differentiation can contribute to T-cell differentiation.

Antigen-Presenting Cells↗
PubMed2002

Respiratory syncytial virus induces prostaglandin E2, IL-10 and IL-11 generation in antigen presenting cells.

Bronchiolitis caused by respiratory syncytial virus (RSV) infection is a major cause of hospitalization in children under 1 years of age. The disease characteristically does not induce protective immunity. However, a mononuclear peribronchiolar and perivascular infiltrate during RSV infection is suggestive of an immune-mediated pathogenesis. Macrophages and dendritic cells (DCs) play an essential role in the initiation and maintenance of immune response to pathogens. To analyse interactions of RSV and immune cells, human cord blood derived macrophages and dendritic cells were infected with RSV. Both cells were found to be infected with RSV resulting in the activation of macrophages and maturation of dendritic cells as reflected by enhanced expression of several surface antigens. In the next set of experiments, generation of mediators was compared between cells infected with RSV, parainfluenza (PIV3) and influenza virus as well as ultracentrifuged virus free supernatant. Whereas the supernatant did not induce release of mediators, all three live virus infections induced IL-6 production from macrophages and DC. Influenza virus infection induced predominantly IL-12 p75 generation in DC. In contrast, RSV induced strong IL-11 and prostaglandin E2 release from both macrophages and DCs. In addition, RSV but not influenza and parainfluenza virus induced a strong IL-10 generation particularly from macrophages. Since IL-10, IL-11 and PGE2 are known to act immunosuppressive rather than proinflammatory, these mediators might be responsible for the delayed protective RSV specific immune response.

Antigen-Presenting Cells↗
PubMed2002

Age-related changes in human blood dendritic cell subpopulations.

It is well known that the human immune system is functionally less mature at birth and, within the first years of life, undergoes a process of sequential development. Two subsets of dendritic cells (DCs) were identified in the blood: plasmacytoid and myeloid DCs. DCs stain negative for CD3, CD14, CD16, CD19, CD20 and CD56, and positive for human leucocyte antigen (HLA)-DR. In addition, plasmacytoid DCs strongly express CD123 while myeloid DCs express CD11. The number of the two different subsets was measured by flow cytometry in the peripheral blood from 44 healthy infants and children, aged 8 months to 18 years. While the number of CD11c+ myeloid cells (mean 11 cells/microl) did not change with age, the proportion of CD123+ plasmacytoid DCs decreased significantly (P < 0.001) from about 20 cells/microl to 8 cells/microl with age. In addition, we found a direct correlation between the number of plasmacytoid DC and interferon (IFN)-alpha production. As the two subsets of DC preferentially recognize different pathogens, age-related changes may have an impact on the maturation of the immune response.

Adolescent↗
PubMed2002

RSV bronchiolitis and risk of wheeze and allergic sensitisation in the first year of life.

Severe respiratory syncytial virus (RSV) infection has been hypothesised to be a risk factor for the development of allergy and asthma, but epidemiological studies in older children have been inconclusive. The current study hypothesises that the effect of RSV bronchiolitis might be most prominent during the first year after bronchiolitis. Forty-two infants had experienced RSV bronchiolitis severe enough to cause hospitalisation. For each child with RSV infection, two controls were acquired from a birth cohort and matched for date of birth and sex. All the children were followed prospectively and underwent a follow-up examination at a mean age of 1 yr, which included physical examination, and serum immunoglobulin (Ig) E tests for common food and inhaled allergens. Risk factors for the development of recurrent wheezing and IgE antibodies were analysed for the whole group of 126 children. A positive test for IgE antibodies was noted in 14 of 42 (33%) RSV children and in 2 of 84 (2.3%) children in the control group. RSV bronchiolitis was the most important risk factor for allergic sensitisation. Likewise, 13 children (15.5%) of the RSV group and three (3.6%) children of the control group suffered from recurrent wheezing, and RSV bronchiolitis posed a considerable risk for recurrent wheezing. Severe respiratory syncytial virus bronchiolitis during the first year of life is an important risk factor for the development of recurrent wheezing and sensitisation to common allergens during the subsequent year.

Bronchiolitis, Viral↗
PubMed2001

Ochratoxin A-induced tumor formation: is there a role of reactive ochratoxin A metabolites?

Ochratoxin A is a nephrotoxic and tumorigenic mycotoxin which contaminates a variety of food items, resulting in chronic human exposure. Biotransformation reactions have been implicated in the tumorigenicity of ochratoxin A. The biotransformation of ochratoxin A by cytochromes P450 and other mammalian enzymes was investigated to optimize conditions for bacterial mutagenicity testing. Metabolite formation was assessed by HPLC with UV and fluorescence detection and by LC/MS/MS. When ochratoxin A was incubated with liver microsomes from rats and mice, formation of 4R- and 4S-hydroxyochratoxin A was observed at very low rates. However, oxidation of ochratoxin A was not observed using kidney microsomes from rats and mice. Significantly higher rates of oxidation were seen in liver microsomes from rats pretreated with 3-methylcholanthrene and dexamethasone. Other reported or postulated that ochratoxin A-metabolites were not formed in detectable concentrations. Human cytochromes P450 (3A4, 1A2, and 2C9-1 Supersomes((R))) also showed very low activity with ochratoxin A (<60 fmole/min x pmol P450). Other enzyme systems used to study possible biotransformation of ochratoxin A were rat and human liver and kidney S-9 fortified with NADPH and glutathione, semipurified glutathione S-transferases, horseradish peroxidase, and soybean lipoxygenase; none of these resulted in detectable biotransformation of ochratoxin A. Using rat liver microsomes with high activity for ochratoxin A oxidation and the other enzyme systems to activate ochratoxin A for mutagenicity testing in the Ames test, mutagenicity was not observed in Salmonella typhimurium TA 100 and TA 2638. The obtained results suggest that oxidative biotransformation of ochratoxin A occurs at low rates, is catalyzed by cytochromes P450, and is unlikely to form reactive intermediates capable of binding to DNA.

Animals↗
PubMed1999

Infants colonized with enterotoxin-producing staphylococci at 3 months display a decreased frequency of interferon-gamma-producing CD45RO lymphocytes upon stimulation with staphylococcal enterotoxin A at birth but not at 6 months of age.

The aim of the study was to elucidate the relationship between the cytokine response to staphylococcal enterotoxin A (SEA) at birth and subsequent staphylococcal colonization in the first months of life. In a cohort of 45 newborns, cord blood lymphocytes were stimulated with SEA (10 ng/ml) in vitro, re-stimulated with PMA (phorbol myristate acetate) and ionomycin at day 3 and assessed for CD45RO expression and cytokine generation by flow cytometry. The infants were classified into three groups according to nasal staphylococcal colonization and enterotoxin generation at 3 months: There were 16 infants with either no colonization or non-enterotoxin-producing staphylococci, 16 infants with enterotoxins B, C, D and E, and 13 infants colonized with SEA-producing staphylococci. At birth, the group without subsequent colonization displayed a significantly higher frequency of CD45RO-positive interferon-gamma-producing cells (1.7%; range 0.0-9.3%) in comparison to the SEA-positive group (0.1%; range 0.0-0.4%) and also to the group positive for other enterotoxins (0.50%; range 0.0-2.5%). Comparable but less pronounced results were found for interleukin-5 but not for interleukins 2 and 4. At 6 months, no differences in cytokine generation were detected between the three groups. The results provide evidence that a non-specific immunologic immaturity at birth is a risk factor for early bacterial colonization. Furthermore, it is remarkable that this immaturity is similar to that seen in infants destined to be atopic with respect to disequilibrium of interferon-gamma to interleukin-4 generation. Thus the link between early staphylococcal colonization and subsequent atopy requires further investigation.

Age Factors↗
PubMed1999

Intracellular expression and serum levels of eosinophil peroxidase (EPO) and eosinophil cationic protein in asthmatic children.

BACKGROUND: Eosinophils are involved in the chronic inflammatory response in asthma and their basic proteins are thought to play a major pathophysiological role in this process. While serum levels of basic proteins have been used to monitor the ongoing allergic disease, little is known about the intracellular expression of these proteins in clinical situations. OBJECTIVE: The aim of the study was to determine the intracellular expression of eosinophil cationic protein (ECP) and eosinophil peroxidase (EPO) in asthmatic children and control subjects and relate it to serum levels of both proteins, lung function tests and immunoglobulin (Ig)E levels. METHODS: Serum ECP and EPO concentrations were determined by immunoassays in 13 asthmatic children (mean age: 9 +/- 1 years, mean FEV1: 92 +/- 10% predicted, geometric mean PC20 histamine 0.5 mg/mL) and 10 age-matched, healthy control subjects. A flow cytometric single cell assay was employed to detect intracellular ECP and EPO in peripheral blood eosinophils. RESULTS: While serum concentrations of both ECP (asthma: median 15.0 microg/L [range 3.6-57.7] vs control: 5.9 microg/L [2.7-9.1]; P = 0.02) and EPO (22.9 microg/L [5.2-82.5] vs 7. 2 microg/L [2.5-12.7]; P = 0.008) were significantly elevated in asthmatics, the intracellular expression of ECP and EPO (measured as mean fluorescence intensity) was decreased (EG1: 55.3 [17.7-120.8] vs 100.3 [46.5-264.4]; P = 0.01; EG2: 80.2 [24.1-135.3] vs 133.7 [32. 1-244.9]; P = 0.04 and EPO: 49.7 [23.1-155.8] vs 94.9 [28.8-115.2]; P = 0.03). In asthmatics there was a significant correlation of FEV1 with intracellular ECP and of bronchial hyperresponsiveness with serum EPO and ECP. Furthermore, total IgE levels were positively correlated with serum EPO only. CONCLUSION: We conclude that in asthmatics the intracellular content of ECP and EPO in peripheral eosinophils is reduced possibly due to degranulation. Epitope masking in activated eosinophils or a shift to early bone marrow-derived progenitors with less granule proteins are further possible explanations.

Asthma↗
PubMed1998

Increased number of T cells committed to IL-5 production after respiratory syncytial virus (RSV) infection of human mononuclear cells in vitro.

We examined changes in the cytokine profile of T cells induced by in vitro infection with RSV. Isolated mononuclear cells from 27 healthy adults and six infants were infected with RSV at a concentration of 3 MOI (multiplicity of infection). After 48 h cells were restimulated with phorbol ester and ionomycin in the presence of monensin for 5 h. The intracellular expression of viral antigen, the cytokines IL-2, IL-4, IL-5, interferon-gamma (IFN-gamma), and the expression of surface markers were assessed by immunofluorescent staining and flow cytometry. There was a significant (P<0.001) rise of IL-5 expression in RSV-infected cultures in comparison with uninfected cultures from the same individuals, whereas there were no changes in the expression of the other lymphokines. The increase in IL-5 generation depended on viable infectious RSV rather than inactivated virus. RSV infection as well as IL-5 production in T cells were confined to the CD8 subpopulation. However, there was no simultaneous expression of RSV antigen and IL-5. Purified T cells did not show any increase in IL-5 generation. However, when the rate of RSV infection was enhanced in monocytes by means of a specific monoclonal antibody, co-cultured T cells displayed an increase of IL-5 production compared with samples with ordinary low rate RSV infection. It is therefore likely that the increased commitment of lymphocytes to produce IL-5 after RSV infection in vitro is mediated by monocytes or other antigen-presenting cells.

Adult↗
PubMed1998

Frequencies of T cells expressing interleukin-4 and interleukin-5 in atopic asthmatic children. Comparison with atopic asthmatic adults.

T-cell-derived cytokines have been implicated in the pathogenesis of asthma and it has been suggested that Th2-type cytokines (interleukin-4 [IL-4], interleukin-5 [IL-5]) are pivotal in the allergic inflammation. However, there are little data on human cytokine production by individual T cells at the protein level, in particular in asthmatic children. In this study we analyzed the cytokine production at the single cell level in peripheral blood from mild atopic asthmatic (AA) children and adults and age-matched atopic nonasthmatic (AN) and nonatopic nonasthmatic (NN) control subjects (n = 9 in each group) using the technique of intracellular cytokine detection by flow cytometry. Comparing asthmatic children with atopic and nonatopic control subjects, an increased percentage of IL-5-producing T cells (AA: median 4.9% [range 1.1 to 8.9%]; AN: 0.3% [0.2 to 0.9%], p = 0.003; NN: 0.4% [0.1 to 3.8%], p = 0.001) was detectable, with a positive correlation to the number of peripheral eosinophils and to bronchial hyperresponsiveness. The frequency of IL-4-producing T cells was increased in both atopic groups compared with nonatopic controls (AA: 1.2% [0.2 to 2.6%], p = 0.011; AN: 0.8% [0.4 to 3.7%], p = 0.007; NN: 0.4% [0.2 to 0.9%]) with a positive correlation to total IgE concentration. In adults there were no differences in IL-5- or IL-4-producing T cells between all three groups. A substantial proportion of T cells coproducing IL-4 and IL-5 was not detectable in children and adults. These findings indicate that in asthmatic children the frequencies of Th2-type-producing T cells are increased and that expression of IL-4 and IL-5 is regulated independently.

Adult↗
PubMed1997

Neonates at risk of atopy show impaired production of interferon-gamma after stimulation with bacterial products (LPS and SEE)

Recent studies demonstrate reduced interferon-gamma (IFN-gamma) secretion in neonates who became atopic later in life. The underlying pathomechanism is still unknown. We therefore examined the effects of bacterial products on neonatal IFN-gamma production acting through different T-cell- or antigen-presenting-cell (APC)-stimulating mechanisms: cord-blood mononuclear cells (CBMC) were incubated with lipopolysaccharide (LPS), staphylococcal enterotoxin E (SEE), or a combination of both and restimulated with PMA and ionomycin. LPS and SEE as single stimuli induced IFN-gamma production to the same extent in CBMC of neonates with high and low risk of atopy. In contrast, a combination of LPS and SEE had a multiplying effect on IFN-gamma secretion only in CBMC of neonates with low risk of atopy. Phenotype analysis revealed that only memory T cells showed impaired IFN-gamma synthesis (median 3.6% IFN-gamma-producing cells vs 14.2% in controls: P < 0.01), whereas IFN-gamma production by naive T cells did not differ in either group. Taken together, these results point to the existence of a disturbed function of costimulatory mechanisms in neonates at high risk of atopy, provoking reduced memory T-cell IFN-gamma production.

Antigen Presentation↗
PubMed1997

[Cell biology of bronchial asthma: interesting new methods. Intracellular determination of cytokines in T-cells and basic proteins in eosinophilic granulocytes using flow cytometry].

Clinical studies on pathophysiological mechanisms of asthma bronchiale require methods of investigation that are simple, reproducible and rapid in respect of analysing relevant inflammatory cells and mechanisms. The article presents two new flow cytometric methods enabling on single-cell level the determination of expression of intracellular cytokines in T-cells and of basic proteins in eosinophilic granulocytes. Both techniques of examination can be performed either with whole blood or with cells from bronchoalveolar lavage without preceding cell separation techniques. First results reveal interesting new aspects with regard to the expression of IFN-gamma, IL-2, IL-4 and IL-5 in T-cells, and of ECP and EPO in eosinophils in bronchial asthma.

Asthma↗