Evaluation of fungal extracts to determine immunomodulatory properties.

BACKGROUND: Immunoglobulin E-mediated allergies have doubled in prevalence during recent decades in developed countries.This increase has been attributed, in part, to high hygiene standards, which have reduced exposure to microbes. The capacity of microbes to induce type 1 helper T cell (TH1) responses may imply suppression of TH2 responses. However, little research has been performed with fungal extracts. OBJECTIVES: To evaluate the TH1-inducing properties of fungal extracts. METHODS: A total of 24 fungal extracts, including Cetavlon-precipitated polysaccharides from different yeasts, molds, and mushrooms were prepared.The extracts were screened for production of interferon (IFN)gamma in human peripheral blood mononuclear cells. The active compounds were further purified by mild acid hydrolysis and by column chromatography and studied in human peripheral blood mononuclear cells. RESULTS: Expression of IFN-gamma was induced by several extracts. The strongest expression of IFN-gamma was induced by Candida albicans. The Cetavlon-precipitated mannans of fungi induced cytokine responses that were similar or superior to those induced by whole extracts, C albicans being the most potent inducer of IFN-gamma. Column chromatography-fractionated mild acid hydrolysis of Calbicans mannan was performed. Fractions containing oligosaccharides of 12-16 mannoses induced production of tumor necrosis factor. CONCLUSIONS: Several fungal extracts induce IFN-gamma. The most promising preparations were yeast-derived oligosaccharides. Further research should be focused on purification and eventual synthesis of the extracts.

Evaluation of Fungal Extracts to Determine Immunomodulatory Properties

Antecedentes: En los países desarrollados, la prevalencia de las enfermedades alérgicas mediadas por la inmunoglobulina E se han duplicado en las últimas décadas. Este aumento ha sido, en parte, atribuido a pautas de higiene excesivas que han reducido la exposición a microbios. La capacidad de los microbios para inducir la respuesta Th1 puede dar lugar a la supresión de la respuesta Th2. En este sentido, la investigación que se ha realizado con extractos fúngicos es escasa. Objetivos: Evaluar las propiedades inmunomoduladoras Th1 que inducen los extractos de hongos. Métodos: Se evaluaron un total de 24 extractos de hongos, incluyendo polisacáridos de diferentes levaduras, mohos y hongos. Se estudió la capacidad de estos extractos de inducir la producción de interferón- ƴ (IFN- ƴ) en células mononucleares de sangre periférica (PBMC) humanas. Los extractos fueron posteriormente sometidos a una hidrólisis ácida suave y a cromatografía en columnas. Resultados: Los extractos procedentes de diferentes levaduras, mohos y hongos indujeron un incremento en la expresión de la producción de IFN- ƴ. La expresión más enérgica fue la provocada por Candida albicans (C. albicans). Los mananos fueron también capaces de conseguir un incremento de la expresión de IFN- ƴ similar o superior a la inducida por los extractos enteros, siendo el manano de C. albicans el más potente de todos ellos. Mediante los estudios de estimulación celular, con fracciones obtenidas por cromatografía del manano C. albicans, se observó que aquellas que contenían oligosacáridos de 12-16 manosas indujeron una mayor producción de TNF. Conclusiones: Son varios los extractos fúngicos capaces de inducir la producción de IFN- ƴ. Los productos más potentes fueron los oligosacáridos derivados de las levaduras. Las investigaciones futuras deberían centrarse en la purificación y síntesis final de los mismos (AU)

Background: Immunoglobulin E–mediated allergies have doubled in prevalence during recent decades in developed countries. This increase has been attributed, in part, to high hygiene standards, which have reduced exposure to microbes. The capacity of microbes to induce type 1 helper T cell (TH1) responses may imply suppression of TH2 responses. However, little research has been performed with fungal extracts. Objectives: To evaluate the TH1-inducing properties of fungal extracts. Methods: A total of 24 fungal extracts, including Cetavlon-precipitated polysaccharides from different yeasts, molds, and mushrooms were prepared. The extracts were screened for production of interferon (IFN) ƴ in human peripheral blood mononuclear cells. The active compounds were further purified by mild acid hydrolysis and by column chromatography and studied in human peripheral blood mononuclear cells. Results: Expression of IFN- ƴ was induced by several extracts. The strongest expression of IFN-􀁡 was induced by Candida albicans. The Cetavlon precipitated mannans of fungi induced cytokine responses that were similar or superior to those induced by whole extracts, C albicans being the most potent inducer of IFN- ƴ. Column chromatography–fractionated mild acid hydrolysis of C albicans mannan was performed. Fractions containing oligosaccharides of 12-16 mannoses induced production of tumor necrosis factor. Conclusions: Several fungal extracts induce IFN- ƴ. The most promising preparations were yeast-derived oligosaccharides. Further research should be focused on purification and eventual synthesis of the extracts (AU)

Immediate hypersensitivity to Malassezia furfur and Candida albicans mannans in vivo and in vitro.

BACKGROUND: Elevated and correlative Malassezia furfur (M. furfur) and Candida albicans (C. albicans) mannan-specific IgE have been demonstrated in atopic eczema dermatitis syndrome (AEDS) of the head, neck and shoulder (HNS) region of the skin. The significance of these antibodies in vivo has not been demonstrated. METHODS: Sixty-five AEDS patients with HNS distribution were included. Serum total IgE (S-IgE) and yeast antigen-specific (Cetavlon-purified mannan and whole extract antigens of M. furfur and C. albicans) IgE were measured and skin prick tests (SPT) were performed with the yeast antigens. RESULTS: Mannan-specific IgE and SPT were positive in 51 and 48% of patients with M. furfur and in 42 and 22% with C. albicans, respectively. Whole extract-specific IgE and SPT were positive in 85 and 95% of patients with M. furfur and in 91 and 57% with C. albicans, respectively. The highest correlation between specific IgE and SPT was seen with M. furfur mannan (r = 0.60; P < 0.0001). Both M. furfur mannan-specific IgE (r = 0.76; P < 0.0001) and SPT (r = 0.44; P = 0.0005) correlated with S-IgE. CONCLUSIONS: Mannan-induced immediate hypersensitivity in vivo was demonstrated in SPT. The significant correlation between M. furfur mannan-specific IgE and SPT suggests that mannan is an important allergen in yeast hypersensitive AEDS in vivo.

HLA-DR-dependent increased mannan-induced lymphoproliferative response in atopic eczema dermatitis syndrome.

BACKGROUND: In yeast-sensitive atopic eczema dermatitis syndrome (AEDS), yeast mannan induces highly elevated specific IgE levels and lymphoproliferative responses. In healthy individuals the involvement of both human leukocyte antigen (HLA)-dependent T-cell activation and non-HLA-dependent activation, e.g. by crosslinking of the cell surface mannose receptors, has been suggested. In the present study the HLA dependence and the role of crosslinking in the lymphoproliferative response to mannan in AEDS has been analyzed. METHODS: Twenty patients with AEDS and 12 controls with no history of allergic diseases were included in the study. Mannan from Candida albicans was prepared according to the Cetavlon method. Following isolation using Ficoll-Hypaque, peripheral blood mononuclear cells (PBMC) were incubated with the mannan preparation in the absence and presence of different concentrations of neutralizing anti-HLA antibodies and alpha-methylmannoside for 6 days and proliferative responses were measured by 3H-thymidine incorporation and scintilloradiography. RESULTS: In AEDS patients with elevated mannan-specific serum IgE, the C. albicans mannan induced lymphoproliferation. Mannan-induced lymphoproliferative responses could be inhibited, dose-dependently, by neutralizing anti-HLA-DR, but not anti-HLA-DQ antibodies in AEDS patients and healthy controls. The addition of alpha-methylmannoside, that blocks binding to mannose receptors, inhibited lymphoproliferative responses in a dose-dependent way by 50% only in healthy controls, but not in AEDS patients. Levels of inhibition of the proliferation by alpha-methylmannoside correlated inversely with the yeast- and mannan-specific IgE levels. CONCLUSIONS: These results show that in healthy subjects yeast mannan activates lymphocytes both in an HLA-DR-dependent manner and as a result of direct crosslinking of the cell surface. However, in AEDS the elevated lymphoproliferative response is HLA-DR-dependent, although only a slight proportion of this response results from direct crosslinking.

Pityrosporum and Candida specific and non-specific humoral, cellular and cytokine responses in atopic dermatitis patients.

BACKGROUND: Recent cytokine (RT-PCR, ELISA) analyses of inflammation in atopic dermatitis (AD) have suggested a role for IL-4, IL-5 and IFNgamma. Pityrosporum ovale and Candida albicans are important allergens in some patients with AD of the seborrhoic head, neck and shoulder region. In AD patients, the saprophytic yeasts induce IgE responses while they usually induce TH1 type responses. The cytokine responses induced by yeasts in AD are sparsely investigated. OBJECTIVE: To characterize the P. ovale- and C. albicans-specific and non-specific humoral, lymphoproliferative and cytokine (IL-2, 4, 5 and IFNgamma) responses in AD. METHODS: Fifteen AD patients and seven healthy controls (HC) were included. Ficoll-isolated PBMC were stimulated by PHA and laboratory-generated extracts of P. ovale and C. albicans. Lymphocyte proliferation was measured by 3H-thymidine incorporation and cytokine production by sandwich-ELISAs. The antigen-specific IgG and IgE antibodies were analysed by ELISA and nitrocellulose RAST. RESULTS: Pityrosporum ovale- and C. albicans-specific IgE (both P < 0.001) and P. ovale-induced PBMC proliferation (P < 0.02) were elevated in AD. In general, the IL-4/IFNgamma ratio induced by P. ovale was higher than that induced by C. albicans (P < 0.01). The PHA-induced IL-2 (P < 0.05) and IL-4 responses (P < 0.005), and the C. albicans-induced IL-5 response (P < 0.02) and IFNgamma response (P < 0.01), were elevated in AD. A network of correlations was seen between serum total and the yeast-specific IgE, P. ovale-specific lymphoproliferation, PHA-induced IL-2, IL-4 and IL-5, and C. albicans-induced IL-5. CONCLUSION: The cytokine profiles found in this study support the role of TH0 or TH1 cells by the side of TH2 cells in the pathogenesis of atopic dermatitis. Pityrosporum ovale appears to be associated more with IL-4 responses and C. albicans with IFNgamma responses.

Candida albicans mannan- and protein-induced humoral, cellular and cytokine responses in atopic dermatitis patients.

BACKGROUND: The cytokine observed most often in atopic dermatitis (AD) is IL-4, but a role for IL-5 and IFN-gamma in the late and delayed phase reactions has been suggested. In AD with head, neck and shoulder distribution, hypersensitivity to saprophytic yeasts is an important pathogenetic factor. The yeast allergens include both the mannan polysaccharides and the proteins. Mannans are major cross-reacting allergens likely to be involved in the pathogenesis of AD. OBJECTIVE: To characterize the humoral, lymphoproliferative and cytokine (IL-2, 4, 5 and IFN-gamma) responses of peripheral blood mononuclear cells (PBMCs) induced by Candida albicans mannan and protein antigens in AD. METHODS: Fifteen AD patients and seven healthy controls were included. Ficoll-isolated PBMCs were stimulated by PHA and laboratory-generated mannan and protein extracts of C. albicans. Lymphocyte proliferation was measured and cytokine production was studied by ELISA. The antigen-specific IgG and IgE antibodies were analysed by ELISA and nitrocellulose RAST. RESULTS: In AD mannan (P < 0.005) and protein (P < 0.002), specific IgE levels were higher than in healthy controls. Both mannan and protein-specific lymphoproliferations (both: P < 0.02) were higher in AD than in healthy controls. Mannan, but not protein, induced long lasting IL-2 and IL-4 productions from 24 h lasting up to 66-96 h and IL-5 and IFN-gamma productions with elevated levels at 66 and 96 h. The mannan-induced IL-2 (P = 0.015) and IFN-gamma (P < 0.005) were increased in AD as compared with healthy controls. Significant correlations were seen between the protein-induced proliferation responses and both serum total IgE (r = 0.59, P < 0.01) and protein-specific IgE (r = 0.65, P < 0.005). The mannan-induced IL-2 responses correlated with the specific IgE (r = 0.62, P < 0.01) and proliferation (r = 0.51, P < 0.02) and S-IgE level (r = 0.71, P < 0. 002). Mannan-induced IL-4 and IFN-gamma productions also correlated (r = 0.43, P < 0.05). CONCLUSIONS: C. albicans mannan induced elevated IL-2 and IFN-gamma responses in AD patients. The correlations of the cytokine responses with mannan-induced IgE and proliferation responses suggest that C. albicans mannan induced TH1 type cytokine responses are involved in AD.

Forced expirations and maximum expiratory flow-volume curves during sustained microgravity on SLS-1.

Gravity is known to influence the mechanical behavior of the lung and chest wall. However, the effect of sustained microgravity (microG) on forced expirations has not previously been reported. Tests were carried out by four subjects in both the standing and supine postures during each of seven preflight and four postflight data-collection sessions and four times during the 9 days of microG exposure on Spacelab Life Sciences-1. Compared with preflight standing values, peak expiratory flow rate (PEFR) was significantly reduced by 12.5% on flight day 2 (FD2), 11.6% on FD4, and 5.0% on FD5 but returned to standing values by FD9. The supine posture caused a 9% reduction in PEFR. Forced vital capacity and forced expired volume in 1 s were slightly reduced (approximately 3-4%) on FD2 but returned to preflight standing values on FD4 and FD5, and by FD9 both values were slightly but significantly greater than standing values. Forced vital capacity and forced expiratory volume in 1 s were both reduced in the supine posture (approximately 8-10%). Forced expiratory flows at 50% and between 25 and 75% of vital capacity did not change during microG but were reduced in the supine posture. Analysis of the maximum expiratory flow-volume curve showed that microG caused no consistent change in the curve configuration when individual in-flight days were compared with preflight standing curves, although two subjects did show a slight reduction in flows at low lung volumes from FD2 to FD9. The interpretation of the lack of change in curve configuration must be made cautiously because the lung volumes varied from day to day in flight. Therefore, the flows at absolute lung volumes in microG and preflight standing are not being compared. The supine curves showed a subtle but consistent reduction in flows at low lung volumes. The mechanism responsible for the reduction in PEFR is not clear. It could be due to a lack of physical stabilization when performing the maneuver in the absence of gravity or a transient reduction in respiratory muscle strength.

Pulmonary gas exchange and its determinants during sustained microgravity on Spacelabs SLS-1 and SLS-2.

We measured resting pulmonary gas exchange in eight subjects exposed to 9 or 14 days of microgravity (microG) during two Spacelab flights. Compared with preflight standing measurements, microG resulted in a significant reduction in tidal volume (15%) but an increase in respiratory frequency (9%). The increased frequency was caused chiefly by a reduction in expiratory time (10%), with a smaller decrease in inspiratory time (4%). Anatomic dead space (VDa) in microG was between preflight standing and supine values, consistent with the known changes in functional residual capacity. Physiological dead space (VDB) decreased in microG, and alveolar dead space (VDB-VDa) was significantly less in microG than in preflight standing (-30%) or supine (-15%), consistent with a more uniform topographic distribution of blood flow. The net result was that, although total ventilation fell, alveolar ventilation was unchanged in microG compared with standing in normal gravity (1 G). Expired vital capacity was increased (6%) compared with standing but only after the first few days of exposure to microG. There were no significant changes in O2 uptake, CO2 output, or end-tidal PO2 in microG compared with standing in 1 G. End-tidal PCO2 was unchanged on the 9-day flight but increased by 4.5 Torr on the 14-day flight where the PCO2 of the spacecraft atmosphere increased by 1-3 Torr. Cardiogenic oscillations in expired O2 and CO2 demonstrated the presence of residual ventilation-perfusion ratio (VA/Q) inequality. In addition, the change in intrabreath VA/Q during phase III of a long expiration was the same in microG as in preflight standing, indicating persisting VA/Q inequality and suggesting that during this portion of a prolonged exhalation the inequality in 1 G was not predominantly on a gravitationally induced topographic basis. However, the changes in PCO2 and VA/Q at the end of expiration after airway closure were consistent with a more uniform topographic distribution of gas exchange.

Determination of disodium clodronate in bulk material and pharmaceuticals by ion chromatography with post-column derivatization.

A validated ion chromatographic method for the determination of disodium clodronate in bulk material and pharmaceuticals is described. Separations are performed on a poly(styrene-divinylbenzene) copolymer column using 40 mM nitric acid as mobile phase at a flow rate of 0.5 ml min-1. The analyte is detected by UV absorption at 300 nm after post-column derivatization with acidic iron(III) solution (0.25 ml min-1). The proposed ion chromatographic method is validated in terms of selectivity, precision, linearity, accuracy and ruggedness.