Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Br J Dermatol ; 166(1): 129-36, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21895621

RESUMEN

BACKGROUND: Some probiotics can ameliorate childhood atopic dermatitis (AD). Prebiotics have also shown some efficacy, although when combined with probiotics as synbiotics, their efficacy may improve. OBJECTIVE: We compared the effects of Lactobacillus salivarius and fructo-oligosaccharide (synbiotic) with fructo-oligosaccharide alone (prebiotic) on children with moderate to severe AD. METHODS: We randomly assigned 60 children aged 2-14years with moderate to severe AD [SCORing AD (SCORAD)>25] to a treatment (synbiotic) or a control (prebiotic) group (30 per group). They received one capsule twice daily for 8weeks containing either L. salivarius plus fructo-oligosaccharide (treatment) or fructo-oligosaccharide only (control). SCORAD indices were monitored at weeks 0, 4, 8 and 10 (post-treatment). Laboratory results and AD medication use were also monitored. RESULTS: Baseline demographic and clinical characteristics and SCORAD scores were similar between the two groups. At 8weeks, the treatment group SCORAD scores (27·4±12·7) were significantly lower than for the controls (36·3±14·9) (P=0·022); this difference remained at 10weeks. At 8weeks, treatment group AD intensity was significantly lower (P=0·013); more children had mild AD in the treatment group (52%; 14/27) than the control group (30%; 8/27) (P=0·024). Medication use frequency and eosinophil cationic protein levels were significantly reduced in the treatment group at 8weeks compared with 4 weeks. CONCLUSION: A synbiotic combination of L. salivarius plus fructo-oligosaccharide is superior to the prebiotic alone for treating moderate to severe childhood AD. However, continued follow-up will be necessary to ascertain long-term benefits.


Asunto(s)
Dermatitis Atópica/terapia , Lactobacillus , Oligosacáridos/uso terapéutico , Prebióticos , Simbióticos , Adolescente , Cápsulas , Niño , Preescolar , Método Doble Ciego , Proteína Catiónica del Eosinófilo/metabolismo , Femenino , Humanos , Masculino , Calidad de Vida , Resultado del Tratamiento
2.
Intern Med J ; 42(12): 1310-5, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22530688

RESUMEN

AIM: Food allergy is common in children and adults, and could be potentially fatal in minor groups. It is important for physicians to identify the prevalence of food allergies and to recognise common food allergens to make precise diagnosis and choose correct therapeutic approaches. METHODS: We used a nationwide, cross-sectional, random questionnaire-based survey to estimate the self-reported and expert-screened prevalence of food allergies and to identify the common food allergens in Taiwan. In this study, the perceptional diagnosis of food allergies was screened by physicians according to descriptions of convincing symptoms and medical recordings; in the meantime, non-allergic adverse reactions to foods, including food intolerance or food avoidance, were clarified. RESULTS: A total of 30 018 individuals who met the inclusion criteria was evaluated, and 6.95% of them were diagnosed as victims of food allergies. The prevalence was 3.44% in children under 3 years of age, 7.65% in children aged 4-18 years and 6.40% in adults respectively. About 77.33% of the food allergy population had experienced recurrent allergic attacks. Systemic reactions happened about 4.89% in food allergies group. The most commonly reported food allergen in Taiwan is seafood, including shrimp, crab, fish and mollusc. In addition, mango, milk, peanuts and eggs were also important food allergens in the general population; while milk, shellfish, peanuts and eggs were common in children. CONCLUSIONS: Less than 10% of the Taiwan population suffers from food allergy with different allergic symptoms to variable food allergens in different age groups.


Asunto(s)
Hipersensibilidad a los Alimentos/epidemiología , Adulto , Niño , Preescolar , Estudios Transversales , Encuestas Epidemiológicas , Humanos , Prevalencia , Alimentos Marinos , Encuestas y Cuestionarios , Taiwán/epidemiología
3.
Scand J Immunol ; 68(5): 502-10, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18822109

RESUMEN

Sublingual immunotherapy has been applied for allergic diseases, but whether sublingual immunization in neonates can prevent sensitization has not been studied. In this study, we evaluate the effect of neonatal sublingual vaccination with native or denatured allergens alone or plus adjuvant on allergy prevention. Newborn BALB/c mice were sublingually vaccinated daily for the first 3 days with native or denatured ovalbumin (OVA) only, or combined adjuvant CpG or cholera toxin (CT). They were sensitized with OVA adsorbed onto alum 7 weeks after the last vaccination. Specific secretory IgA antibody responses were readily induced by neonatal vaccination with antigen plus CpG or CT, but not with antigen alone. Whereas vaccination with denatured OVA plus CpG markedly enhanced T helper 1 (Th1) responses and inhibited IgE production, vaccination with denatured OVA plus CT increased cervical lymph node cell production of interleukin-4 (IL-4), IL-5, IL-6, and serum IgG1 responses. These data demonstrate that neonatal sublingual vaccination with denatured OVA and CpG not only preferentially induces systemic Th1 responses and mucosal immunity, but also simultaneously abrogates IgE production. Neonatal sublingual vaccines may play a role for the strategy of allergy prevention.


Asunto(s)
Adyuvantes Inmunológicos/farmacología , Toxina del Cólera/inmunología , Oligodesoxirribonucleótidos/inmunología , Ovalbúmina/inmunología , Vacunación/métodos , Administración Sublingual , Animales , Animales Recién Nacidos , Anticuerpos/sangre , Toxina del Cólera/farmacología , Ensayo de Inmunoadsorción Enzimática , Inmunidad Mucosa , Immunoblotting , Inmunoglobulina A/biosíntesis , Inmunoglobulina A/inmunología , Interferón gamma/inmunología , Interleucinas/inmunología , Ganglios Linfáticos/inmunología , Ratones , Ratones Endogámicos BALB C , Oligodesoxirribonucleótidos/farmacología , Ovalbúmina/administración & dosificación , Bazo/inmunología
4.
J Microbiol Immunol Infect ; 34(1): 25-34, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11321125

RESUMEN

To test the effects of Bacillus Calmette-Guérin (BCG) on ovalbumin (OVA)-induced airway hyper-reactivity in guinea pigs, a total of 40 young guinea pigs was individually vaccinated subcutaneously with 0.2 mL of 2% OVA, 50 microg BCG, or a mixture of OVA and BCG (OVA+BCG). Airways were sensitized using nebulization with 1% OVA for 3 min once a week for two applications, followed by 2% OVA nebulized challenge for 3 min 1 week after the last application. Different concentrations of methacholine were used to detect airway hyperreactivities. At the third week, the guinea pigs were nebulized with either methacholine or OVA to test airway hyperreactivity. The OVA-vaccinated group presented with severe airway hyperresponsiveness after OVA and methacholine challenges; the BCG-vaccinated group showed mild airway hyperreactivity; and the OVA+BCG group showed the least amount of airway hyperreactivity. Lung histopathology in all groups, except the OVA+BCG-vaccinated group, showed severe thickening of the alveolar walls which became firmly fibrotic, and narrowing of the alveolar spaces was also noted. The guinea pigs in the OVA+BCG-vaccinated group had similar pulmonary morphology with that of naive guinea pigs, and had mild cell infiltration in the alveolar wall. The results of the skin biopsies at 6 h (2% OVA, 0.05 mL) and 36 h (20 microg PPD, 0.05 mL) after purified protein derivative (PPD) inoculation showed that infiltration of eosinophils and activation of CD4+ T-cells occurred in the OVA-vaccinated group. In the BCG-vaccinated groups, infiltration of CD4+ T-cells, CD8+ T-cells and macrophages occurred. OVA-specific IgG2 increased in the BCG-vaccinated groups after OVA-induced airway hyperreactivity occurred. The peripheral cell subpopulation showed that there was obviously increased activation of CD4+ and CD8+ T-cells in the OVA+BCG-vaccinated group. The phagocytic activity of macrophages also increased in both BCG- and OVA+BCG-vaccinated groups. The prevention of OVA-induced airway hyperreactivities using BCG vaccination in conjugation with OVA in these young guinea pigs indicated that it might be a good approach to avoid allergic reactions in humans.


Asunto(s)
Asma/prevención & control , Vacuna BCG/inmunología , Hiperreactividad Bronquial/prevención & control , Ovalbúmina/inmunología , Animales , Asma/inmunología , Vacuna BCG/administración & dosificación , Biopsia , Hiperreactividad Bronquial/inmunología , Broncoconstrictores , Modelos Animales de Enfermedad , Citometría de Flujo , Cobayas , Inmunoglobulina G/sangre , Inmunohistoquímica , Pulmón/inmunología , Pulmón/patología , Pulmón/fisiología , Subgrupos Linfocitarios/clasificación , Masculino , Cloruro de Metacolina , Nebulizadores y Vaporizadores , Ovalbúmina/administración & dosificación , Piel/inmunología , Piel/patología , Factores de Tiempo
5.
In Vitro Cell Dev Biol Anim ; 37(4): 245-50, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11409691

RESUMEN

Using five trophoblast cell lines of different differentiation status, we have shown that trophoblasts could constitutively release the transforming growth factor beta-1 (TGFbeta1), but not TGFbeta2. Treatment of the human tumorigenic, TL, and BeWo cells with a differentiating agent and a potent protein kinase C activator--the tumor-promoting agent--or the JEG-3 cells with cholera toxin--a potent cyclic adenosine 3':5'monophosphate (cAMP) inducer--or its analogue 8-bromo-cAMP, potentiates TGFbeta production, but the two signaling pathways appear to be mutually exclusive. Surprisingly, the JAR tell line failed to respond to either type of TGFbeta activator. Based on reverse transcriptase (RT)-polymerase chain reaction (PCR), it was found that only the JAR cell line expressed messenger ribonucleic acid for decorin, a natural inhibitor of TGFbeta, and none of the cell lines had detectable protein expression as determined by immunocytochemical studies. The tell number in cultures with decorin was invariably lesser than in those without decorin under serum-free conditions for all the cell lines tested. These results suggest that TGFbeta may act as an autocrine-survival factor for transformed trophoblasts by allowing the cells to survive longer under a microenvironment which is not favorable for growth. Lastly, our results indicate that decorin, acting in a paracrine manner, may also play an important negative regulatory role in the development of transformed trophoblasts by sequestering TGFbeta, thereby preventing its action.


Asunto(s)
Supervivencia Celular/fisiología , Factor de Crecimiento Transformador beta/fisiología , Trofoblastos/citología , 8-Bromo Monofosfato de Adenosina Cíclica/farmacología , Secuencia de Bases , División Celular/efectos de los fármacos , Línea Celular Transformada , Toxina del Cólera/farmacología , Cartilla de ADN , Decorina , Activadores de Enzimas/farmacología , Proteínas de la Matriz Extracelular , Proteína Quinasa C/metabolismo , Proteoglicanos/genética , ARN Mensajero/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal , Factor de Crecimiento Transformador beta/biosíntesis
6.
J Formos Med Assoc ; 97(9): 626-32, 1998 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9795531

RESUMEN

Denatured immunogenic peptides have recently been used successfully to treat autoimmune disease in mice. Their effect on airway response is unclear. In this study, we compared the effect of native ovalbumin (OVA) and denatured ovalbumin (DN-OVA) on airway spasm and hyperreactivity in guinea pigs. The effects of immunotherapy using DN-OVA were also investigated. Airway response to antigen was determined in conscious, nose-breathing guinea pigs. Results showed that animals could be sensitized by repeated exposure to OVA, but not DN-OVA. Following OVA exposure in OVA-sensitized guinea pigs, airway resistance was significantly increased in both early (30 min, 118.8% +/- 34.2%) and late (6 h, 91.1% +/- 30.1%) phases. Tidal volumes were reduced in both early (47.5% +/- 12.0%) and late (43.8% +/- 10.3%) phases. This dual-phase airway spasm could not be induced by DN-OVA. In addition, there was no change in pulmonary function noted after DN-OVA exposure in OVA-sensitized guinea pigs. OVA-induced airway response was modulated by immunotherapy with subcutaneous DN-OVA administration for 3 weeks. OVA-specific IgG was also increased after immunotherapy. However, there was no significant change in pulmonary function after oral administration of DN-OVA in OVA-sensitized guinea pigs. We conclude that OVA, but not DN-OVA, can successfully induce dual-phase airway spasm in guinea pigs. These reactions can be modulated by immunotherapy with subcutaneously administered DN-OVA.


Asunto(s)
Hiperreactividad Bronquial/terapia , Ovalbúmina/inmunología , Animales , Cobayas , Inmunoglobulina G/sangre , Inmunoterapia , Masculino , Desnaturalización Proteica
7.
Artículo en Inglés | MEDLINE | ID: mdl-10695787

RESUMEN

The major surface antigen (P30) of the Toxoplasma gondii was expressed by an insect cell culture system infected with recombinant baculovirus. About 750 microg of purified (95% purity) P30 was obtained from a culture of 10(8) insect Sf21 cells. The recombinant P30 was used to immunize mice to induce immune response. Mice injected with the recombinant protein produced specific humoral and cellular immune responses. Immunization with P30 also prolonged the period of survival of mice infected by Toxoplasma. The average survival time of control group is 13.25+/-1.16 days, but are 16.13+/-2.1 days, 19.50+/-3.21 days, 20.38+/-3.38 days in different immunized groups, respectively.


Asunto(s)
Antígenos de Protozoos , Baculoviridae/genética , Baculoviridae/inmunología , Clonación Molecular/métodos , Regulación Viral de la Expresión Génica/genética , Regulación Viral de la Expresión Génica/inmunología , Proteínas Protozoarias/genética , Proteínas Protozoarias/inmunología , Vacunas Antiprotozoos/inmunología , Toxoplasma/inmunología , Animales , Anticuerpos Antiprotozoarios/sangre , Formación de Anticuerpos/inmunología , Western Blotting , Evaluación Preclínica de Medicamentos , Inmunidad Celular/inmunología , Ratones , Ratones Endogámicos BALB C , Reacción en Cadena de la Polimerasa , Transfección
8.
Biomed Res Int ; 2014: 359308, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25097856

RESUMEN

The aim of the meta-analysis was to provide more solid evidence for the reliability of the new classification. A systematic literature search was performed using PubMed, Armed Forces Pest Management Board Literature Retrieval System, and Google Scholar up to August 2012. A pooled odds ratio (OR) was calculated using either a random-effect or a fixed-effect model. A total of 16 papers were identified. Among the 11 factors studied, five symptoms demonstrated an increased risk for SDD, including bleeding [OR: 13.617; 95% confidence interval (CI): 3.281, 56.508], vomiting/nausea (OR: 1.692; 95% CI: 1.256, 2.280), abdominal pain (OR: 2.278; 95% CI: 1.631, 3.182), skin rashes (OR: 2.031; 95% CI: 1.269, 3.250), and hepatomegaly (OR: 4.751; 95% CI: 1.769, 12.570). Among the four bleeding-related symptoms including hematemesis, melena, gum bleeding, and epistaxis, only hematemesis (OR: 6.174; 95% CI: 2.66, 14.334; P < 0.001) and melena (OR: 10.351; 95% CI: 3.065, 34.956; P < 0.001) were significantly associated with SDD. No significant associations with SDD were found for gender, lethargy, retroorbital pain, diarrhea, or tourniquet test, whereas headache appeared protective (OR: 0.555; 95% CI: 0.455, 0.676). The meta-analysis suggests that bleeding (hematemesis/melena), vomiting/nausea, abdominal pain, skin rashes, and hepatomegaly may predict the development of SDD in patients with DF, while headache may predict otherwise.


Asunto(s)
Virus del Dengue/patogenicidad , Brotes de Enfermedades , Dengue Grave/diagnóstico , Dolor Abdominal/diagnóstico , Diarrea/diagnóstico , Diarrea/patología , Hemorragia/diagnóstico , Hemorragia/patología , Hepatomegalia/diagnóstico , Hepatomegalia/patología , Humanos , Dengue Grave/epidemiología , Dengue Grave/patología , Vómitos/diagnóstico , Vómitos/patología
9.
Naunyn Schmiedebergs Arch Pharmacol ; 386(6): 521-31, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23525487

RESUMEN

Diabetic cardiomyopathy (DC) is a unique disease frequently complicated to diabetes mellitus, manifesting endoplasmic reticulum (ER) stress and depressed calcium-handling proteins. We hypothesized that the abnormal FKBP12.6, SERCA2a, and CASQ2 are consequent to ER stress and apoptosis that are likely due to an entity of inflammation. These abnormalities may be attributed to reactive oxygen species genesis from activated NADPH oxidase which could respond to argirein (AR) through its anti-inflammatory activity. Sprague Dawley rats were randomly divided into six groups. Except the normal group, rats were injected with streptozotocin (STZ; 60 mg/kg, i.p.) once. During weeks 5 to 8 following STZ injection, rats were treated (in milligrams per kilogram per day, i.g.) with aminoguanidine (AMG, 100; an inducible nitric oxide synthase and AGEs inhibitor) or three doses of AR (50, 100, and 200). FKBP12.6, SERCA2a, and CASQ2 and ER stress chaperones Bip and PERK and apoptotic molecules were monitored in vivo and in vitro. Impaired cardiac performance and downregulated FKBP12.6, SERCA2a, and CASQ2 were significant in DC in vivo, and abnormal calcium-handling proteins were also found in high-glucose-incubated myocytes in vitro. ER stress manifested by upregulated Bip and PERK was predominant in association with DNA ladder and upregulated Bax and downregulated BCL-2 in vivo and in vitro. AR is effective to attenuate these abnormalities compared to AMG. Diabetic myocardium has inflammatory entity expressed as ER stress contributing to downregulated calcium-handling proteins. AR has potential in managing DC through attenuating depressed calcium-handling proteins, activated ER stress, and apoptosis in the myocardium.


Asunto(s)
Antraquinonas/farmacología , Antiinflamatorios/farmacología , Arginina/farmacología , Cardiomiopatías Diabéticas/tratamiento farmacológico , Estrés del Retículo Endoplásmico/efectos de los fármacos , Animales , Antraquinonas/administración & dosificación , Antiinflamatorios/administración & dosificación , Apoptosis/efectos de los fármacos , Arginina/administración & dosificación , Proteínas de Unión al Calcio/metabolismo , Diabetes Mellitus Experimental/complicaciones , Cardiomiopatías Diabéticas/fisiopatología , Relación Dosis-Respuesta a Droga , Regulación hacia Abajo , Combinación de Medicamentos , Guanidinas/farmacología , Masculino , Ratas , Ratas Sprague-Dawley , ATPasas Transportadoras de Calcio del Retículo Sarcoplásmico/metabolismo , Estreptozocina , Proteínas de Unión a Tacrolimus/metabolismo , Regulación hacia Arriba
11.
Allergy ; 61(3): 382-8, 2006 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-16436150

RESUMEN

BACKGROUND: Alkaline serine proteases from six prevalent airborne Penicillium and Aspergillus species have been identified as a group of major allergens (group 13). After entering human airways, the allergens are in initial contacts with respiratory epithelial cells. The purpose of this study is to investigate interactions between the Pen ch 13 allergen from P. chrysogenum and human lung epithelial cells. METHODS: A549 cells, 16HBE14o- cells and primary cultures of human bronchial epithelial cells (HBEpC) were exposed to purified Pen ch 13 and mediators released into culture supernatants were assayed with enzyme-linked immunosorbent assay (ELISA) kits. Cleavage of occludin in 16HBE14o- cells was analysed by immunofluorescent staining of whole cells and immunoblot analysis of whole cell extracts. Fragments generated by incubating Pen ch 13 and a synthetic peptide carrying the occludin sequence were analysed by mass spectrometry. RESULTS: Pen ch 13 induced productions of prostaglandin-E2 (PGE2), interleukin (IL)-8 and transforming growth factor (TGF)-beta1 by A549 cells, 16HBE14o- cells and primary cultures of HBEpC. The protease activity of Pen ch 13 is needed for the induction of PGE2 IL-8, TGF-beta1 and cyclo-oxygenase (COX)-2 expression. A tight junction protein occludin of 16HBE14o- cells can be cleaved by Pen ch 13 at Gln202 and Gln211 which are within the second extracellular domain of the protein. CONCLUSION: Pen ch 13 may contribute to asthma by damaging the barrier formed by the airway epithelium and stimulating the release of mediators that orchestrate local immune responses and inflammatory process from HBEpC.


Asunto(s)
Alérgenos , Antígenos Fúngicos , Células Epiteliales/inmunología , Mediadores de Inflamación/análisis , Proteínas de la Membrana/metabolismo , Alérgenos/inmunología , Antígenos Fúngicos/inmunología , Permeabilidad de la Membrana Celular/inmunología , Células Cultivadas , Ciclooxigenasa 2/análisis , Dinoprostona/análisis , Ensayo de Inmunoadsorción Enzimática , Células Epiteliales/fisiología , Humanos , Immunoblotting , Interleucina-8/análisis , Pulmón/citología , Pulmón/inmunología , Ocludina , Penicillium chrysogenum/inmunología , Probabilidad , Hipersensibilidad Respiratoria/diagnóstico , Hipersensibilidad Respiratoria/inmunología , Muestreo , Sensibilidad y Especificidad , Estadísticas no Paramétricas , Factor de Crecimiento Transformador beta/análisis
12.
Allergy ; 60(7): 927-37, 2005 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15932384

RESUMEN

BACKGROUND: Dermatophagoides pteronyssinus (Dp) and D. farinae (Df) mites are the most important source of indoor aeroallergens. Most Dp mite allergens identified to date have relatively low molecular weights (MWs). Identification of high-MW mite allergens is a crucial step in characterizing the complete spectrum of mite allergens and to provide appropriate tools for diagnostic and therapeutic application. METHODS: The full-length Der p 11 cDNA clone was isolated using cDNA library immunoscreening, the 5'-3' rapid amplification of cDNA ends (RACE) system and polymerase chain reactions (PCR). The whole cDNA insert and its PCR-derived DNA fragments (p1 to p4) were generated and expressed in the Escherichia coli expression system. The allergenicity of the recombinant protein and its peptide fragments was examined by IgE immunodot assays. The IgE-binding reactivity of rDer p 11 was analyzed in the serum of 50 asthmatic children with positive reactivity to Dp mite extract. Its recombinant peptide fragments were also examined by immunodot assays in 30 mite-allergic children. RESULTS: Der p 11 cDNA consists of a 2625-bp open reading frame encoding a 103-kDa protein with 875 amino acids. It exhibits significant homology with the paramyosin of other invertebrates. The protein sequence alignment of this newly identified Dp mite allergen (denominated as Der p 11) revealed over 89% identity with Der f 11 and Blo t 1. Among 50 Dp-sensitive asthmatic children, rDer p 11 showed positive IgE-binding reactivity to 39 patients (78%). Using immunodot assays, multiple human IgE-binding activities were demonstrated in all four fragments of Der p 11. Using immunoblot assays, the dominant IgG-binding epitope for monoclonal antibody (mAb642) was located in fragment p3 only. In immunoblot assays, cross-inhibition between rDer p 11 and rDer f 11 was up to 73-80% at concentrations of 100 microg/ml. CONCLUSIONS: This study confirms that the newly identified recombinant Der p 11 is a novel and important high-MW Dp mite allergen for asthmatic children. Our data also indicates that human IgE-binding major epitopes are scattered over the entire molecule of Der p 11.


Asunto(s)
Alérgenos/genética , Antígenos Dermatofagoides/aislamiento & purificación , Asma/inmunología , Adolescente , Alérgenos/inmunología , Antígenos Dermatofagoides/genética , Antígenos Dermatofagoides/inmunología , Niño , Preescolar , Clonación Molecular , ADN Complementario , Femenino , Humanos , Masculino , Análisis de Secuencia de Proteína
13.
Clin Exp Immunol ; 81(3): 510-5, 1990 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-2397616

RESUMEN

In an attempt to investigate the molecular basis of the mechanisms underlying oral tolerance, we have evaluated the molecular and biological features of ovalbumin subjected to intestinal processing. Immunoreactive ovalbumin absorbed by the gut was measured by a sandwich ELISA at different times after feeding 25 mg ovalbumin to adult mice. Ovalbumin was detected as early as 5 min after the feed (36.7 +/- 16 ng/ml; mean +/- 1 s.d.) and reached maximal levels at 1 h (73.3 +/- 20 ng/ml). Pooled mouse serum, collected 5 min or 1 h after the feed, was transferred intraperitoneally into the naive recipients. Suppression of systemic delayed-type hypersensitivity (DTH) was found in mice receiving 0.8 ml of serum obtained 1 h after ovalbumin feeding but not when using serum obtained 5 min after feeding. In order to transfer samples containing similar levels of ovalbumin, an increased amount (1.3 ml) of serum collected 5 min post-feed was used in further experiments but again failed to induce DTH tolerance. Serum samples obtained 5 and 60 min after ovalbumin feeding were analysed by fast-protein liquid chromatography (FPLC) fractionation followed by ELISA. Both the charge characteristics and molecular weight of intestinally absorbed ovalbumin were indistinguishable from native ovalbumin. Although intact native ovalbumin is the only molecular species detected by ELISA, the results suggest that this has no role in the suppression of DTH responses.


Asunto(s)
Antígenos/inmunología , Tolerancia Inmunológica , Ovalbúmina/inmunología , Administración Oral , Animales , Formación de Anticuerpos , Antígenos/administración & dosificación , Cromatografía en Gel , Ensayo de Inmunoadsorción Enzimática , Femenino , Hipersensibilidad Tardía/inmunología , Inmunización , Ratones , Ratones Endogámicos BALB C , Ovalbúmina/administración & dosificación , Ovalbúmina/sangre , Factores de Tiempo
14.
Immunology ; 67(3): 425-30, 1989 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-2759662

RESUMEN

We have investigated the immunological consequences of feeding a protein antigen to previously immunized animals. BALB/c mice were systemically primed with ovalbumin (OVA) in complete Freund's adjuvant (CFA) and fed with high (10 mg/g body weight), medium (1 mg/g body weight) or low (1 microgram/g body weight) doses of OVA once (Day 1, 7 or 14) or sequentially for 5 days (Days 1-5, 7-11, 14-18). The specific IgG antibody response was suppressed only by early feeds of high-dose OVA (Days 1-5). Medium-dose OVA fed on Day 14 or low-dose OVA fed at any stage after immunization enhanced the IgG antibody response. In contradistinction, systemic delayed-type hypersensitivity responses (DTH) were usually suppressed by early feeds of high or medium doses of OVA but never after feeding low-dose OVA. The results suggest that systemic DTH and IgG antibody responses to oral antigen are subject to different control mechanisms in previously primed animals. Such responses depend on the immune status of the animal and are controlled by antigen dose, time and frequency of feeding. The immunological effects observed are also demonstrable following adoptive transfer of spleen cells collected 14 days after multiple feeds of high-dose OVA to immunized mice. Our findings suggest that oral hyposensitization after systemic immunization is regulated by (suppressor) spleen cells which are activated by gut-processed antigen.


Asunto(s)
Antígenos/administración & dosificación , Hipersensibilidad Tardía , Tolerancia Inmunológica , Inmunoglobulina G/biosíntesis , Ovalbúmina/administración & dosificación , Animales , Femenino , Inmunización Pasiva , Ratones , Ratones Endogámicos BALB C , Ovalbúmina/inmunología
15.
Pediatr Res ; 26(5): 486-90, 1989 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-2812901

RESUMEN

We have examined the mechanisms that prevent the induction of oral tolerance to protein antigens in neonatal mice. Serum collected from adult mice 1 h after feeding ovalbumin (1 mg/g body wt) was adoptively transferred to mice aged 1, 3, and 42 d (40 microL/g body wt). Whereas delayed-type hypersensitivity was significantly suppressed in adult recipients relative to control groups, no suppression of systemic delayed-type hypersensitivity was found in neonatal recipients. In attempts to identify the immunologic deficiency that prevents mature reactivity to protein antigens in neonates, adult splenocytes were transferred intraperitoneally (10(8) cells/recipient) 24 h before a feed of OVA (1 mg/g body wt) to neonates. Significant suppression of their systemic DTH response, but not of their anti-ovalbumin IgG antibody response was observed, indicating that spleen cell transfer only partially confers adult-type reactivity. Similar results were obtained using a second protein antigen, BSA. Our observations suggest that the failure to induce oral tolerance to protein antigens in neonatal mice is not simply due to immature antigen processing by the gut, but probably reflects cellular and/or antigen handling immaturity of the neonatal immune system.


Asunto(s)
Antígenos/administración & dosificación , Tolerancia Inmunológica , Proteínas/inmunología , Administración Oral , Animales , Animales Recién Nacidos , Sistema Digestivo/inmunología , Hipersensibilidad Tardía , Inmunización Pasiva , Ratones , Ratones Endogámicos BALB C , Ovalbúmina/inmunología , Bazo/inmunología
16.
Scand J Immunol ; 51(5): 454-60, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10792836

RESUMEN

Antigen presentation by resting B cells has been shown to induce peripheral tolerance to intravenous (i.v.) administered soluble protein antigens. We further examined the role of resting B cells in the induction of oral tolerance. Mice were treated continuously from birth with rabbit antimouse IgM serum for 5 weeks. Immunohistological studies revealed that anti-IgM treatment depleted B cell-aggregated follicles in intestinal Peyer's patches. At 4-weeks-old, B cell-depleted mice were fed 25 mg ovalbumin or given 10% chicken egg white to drink for 5 days. Anti-IgM treatment was stopped 2 days after the last feed. Ten weeks later, the mice were immunized with 100 microg ovalbumin emulsified with complete Frund's adjuvant. Their T helper 1 (Th1) cell-regulated systemic delayed-type hypersensitivity, IgG2a antibody responses and spleen cell production of interferon-r and interleukin-2 were suppressed by prior ovalbumin or egg white feeding during anti-IgM treatment. Active suppression of Th1 immune responses was also demonstrated following adoptive transfer of egg white-fed donor spleen cells collected during anti-IgM treatment to naïve recipients. Although enormous small resting B cells are aggregated in the mantle zones of follicles of intestinal Peyer's patches, they are not the antigen-presenting cells seen in the induction of oral tolerance.


Asunto(s)
Linfocitos B/inmunología , Tolerancia Inmunológica/inmunología , Células TH1/inmunología , Administración Oral , Animales , Femenino , Humanos , Hipersensibilidad Tardía/inmunología , Inmunoglobulina G/inmunología , Inmunoglobulina M/inmunología , Interferón gamma/inmunología , Interleucina-2/inmunología , Antígenos Comunes de Leucocito/inmunología , Depleción Linfocítica , Masculino , Ratones , Ovalbúmina/inmunología , Conejos , Bazo/citología , Bazo/inmunología
17.
Arch Biochem Biophys ; 363(1): 107-15, 1999 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-10049504

RESUMEN

Cardiotoxin and neurotoxin analogues isolated from snake venom sources are highly homologous proteins (>50% homology) with similar three-dimensional structures but exhibit drastically different biological properties. In the present study, we compare the conformational stability of cardiotoxin analogue III (CTX III) and cobrotoxin (CBTX), a neurotoxin analogue, from the Taiwan cobra (Naja naja atra), using circular dichroism spectroscopy and hydrogen-deuterium (H/D) exchange techniques in conjunction with two-dimensional NMR methods. Contrary to expectations, it is found that CTX III and CBTX differ significantly in their structural stabilities. The three-dimensional structure of CBTX is less stable than that of CTX III. The amide protons of residues at the N- and C-terminal ends of the CTX III molecule are strongly protected against H/D exchange, implying that the terminal ends of the molecule are bridged together by significant numbers of hydrogen bonds. However, in CBTX, amide protons at the terminal ends of the molecule do not exhibit an significant protection against H/D exchange. Comparison of the protection factors of the various amide protons in CTX III and CBTX reveals that the extraordinary stability of CTX III stems from the strong network of interactions among the residues at the N- and C-terminal ends and also due to the tight and ordered packing of the nonpolar residues involved in the triple-stranded, anti-parallel, beta-sheet segment of the molecule.


Asunto(s)
Proteínas Cardiotóxicas de Elápidos/química , Proteínas Neurotóxicas de Elápidos/química , Venenos Elapídicos/química , Animales , Dicroismo Circular , Elapidae , Guanidina/farmacología , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Conformación Proteica/efectos de los fármacos , Desnaturalización Proteica , Espectrofotometría Ultravioleta , Temperatura , Factores de Tiempo
18.
Clin Exp Allergy ; 34(4): 663-70, 2004 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15080823

RESUMEN

BACKGROUND: For genetically predisposed atopic infants, cow's milk protein hydrolysed formulas have been widely used. OBJECTIVE: Whether hydrolysed formulas can induce oral tolerance to whey proteins will be extensively studied in naïve and sensitized mice. METHODS: Antigenicity of hydrolysed formulas was first studied using immunoblotting. Naïve mice fed hydrolysed formulas for 1-4 weeks were sensitized with whey allergens. In contrast, mice sensitized with whey allergens were fed hydrolysed formulas continually for 12 weeks. RESULTS: Whey allergens were found in Nan and Neoangelac FL. Large whey peptides with antigenicity were found in Nan-HA. Profound suppression of IgE, IgG1 and IgG responses to whey allergens were induced in those fed Nan for 1 week, or Nan-HA for 4 weeks. IgE responses to whey allergens were suppressed in those fed Neoangelac FL for 4 weeks, or Nan-HA for 1-2 weeks. In contrast, those fed extensively hydrolysed formulas for 1-4 weeks failed to show decreased responses. On the other hand, IgE responses to beta-lactoglobulin, but not to bovine serum albumin or alpha-lactalbumin, were decreased in sensitized mice fed Nan for 12 weeks. There was no suppression in sensitized mice fed hydrolysed formulas. CONCLUSION: Suppression of IgE responses to whey proteins was readily induced in naïve mice fed Nan or Nan-HA for 1 week. In contrast, it was hardly induced in sensitized mice even after prolonged feeding of Nan for 12 weeks, let alone hydrolysed formulas.


Asunto(s)
Tolerancia Inmunológica , Hipersensibilidad a la Leche/prevención & control , Proteínas de la Leche/inmunología , Leche/inmunología , Células Th2/inmunología , Animales , Electroforesis en Gel de Poliacrilamida , Femenino , Humanos , Hidrólisis , Inmunoglobulina A/biosíntesis , Inmunoglobulina G/biosíntesis , Lactante , Alimentos Infantiles , Lactalbúmina/inmunología , Lactoglobulinas/inmunología , Ratones , Ratones Endogámicos C3H , Hipersensibilidad a la Leche/inmunología , Ratas , Ratas Sprague-Dawley , Albúmina Sérica Bovina/inmunología , Proteína de Suero de Leche
19.
J Biomed Sci ; 8(4): 342-8, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11455197

RESUMEN

Cyn d Bd46K, a 46-kD component of Bermuda grass (Cynodon dactylon) pollen, had been identified as an allergenic constituent. In the present study two-dimensional (2D) gel electrophoresis illustrated the presence of five acidic isoforms in Cyn d Bd46K, and this molecule was purified by monoclonal antibody (MAb) affinity chromatography for further characterization. Using a digoxigenin-labeled lectin-binding assay, the elucidating protein was disclosed to be a glycoprotein with terminal mannose. The involvement of a carbohydrate moiety in the allergenicity and antigenicity of the elucidated molecule was demonstrated with sodium-periodate-treated Cyn d Bd46K, which reduced binding to its specific MAb and human IgE. We were unable to identify the N-terminal amino acid sequences of Cyn d Bd46K, but some internal amino acid sequences were disclosed by microsequencing some fragments cleaved by Achromobacter protease I and fractionated by reversed-phase column chromatography. The amino acid sequences of 4 identified Cyn d Bd46K internal peptide fragments were found to be 25-71% identical with that of cytochrome c oxidase III from corn grass pollen. The present study provided important information for future experiments on the molecular cloning of the elucidated allergen.


Asunto(s)
Alérgenos/aislamiento & purificación , Poaceae/inmunología , Alérgenos/química , Alérgenos/metabolismo , Secuencia de Aminoácidos , Anticuerpos Monoclonales/inmunología , Antígenos de Plantas , Cromatografía de Afinidad , Cromatografía Líquida de Alta Presión , Electroforesis en Gel Bidimensional , Lectinas/metabolismo , Oxidación-Reducción , Fragmentos de Péptidos/química , Ácido Peryódico/química , Lectinas de Plantas , Unión Proteica
20.
J Asthma ; 38(5): 391-8, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11515975

RESUMEN

This study was designed to examine the prevalence of positive serum IgE reactivity to the recombinant group 11 Dermatophagoides farinae allergen (rDer f 11) in asthmatic children in Taiwan. Using immunoblot analysis in a preliminary study of 18 asthmatic children, 13 (72.2%) reacted positively to rDer f 11 and 16 (88.9%) showed positive reactivity to D. farinae extracts. The allergenicity of rDer f 11 was further evaluated with in vivo skin tests and in vitro IgE immunodot assays in 24 mite skin-test-positive asthmatic children. Whereas 17 (70.8%) had positive skin tests to rDer f 11, 18 (75.0%) had positive serum IgE reactivity to rDer f 11. A good coincidence (87.5%) between the immunodot assay and the skin test was confirmed in these asthmatic children. Moreover, the prevalence of serum IgE reactivity to rDer f 11 was further investigated in a large panel of 49 mite skin-test-positive asthmatic children. Again, 38 (77.6%) had positive serum IgE reactivity to rDer f 11 in immunodot assays. Taken together the positive IgE reactivity to rDer f 11 in immunodot analysis ranged from 75 to 77.6% in two groups of 73 mite skin-test-positive asthmatic children. High incidence of serum IgE antibodies specific for rDer f 11 in the present study suggests that Der f 11 is a novel major allergen of house dust mites.


Asunto(s)
Asma/diagnóstico , Asma/epidemiología , Glicoproteínas , Inmunoglobulina E/sangre , Proteínas Recombinantes , Adolescente , Animales , Antígenos Dermatofagoides , Asma/sangre , Asma/inmunología , Niño , Preescolar , Electroforesis en Gel de Poliacrilamida , Femenino , Humanos , Immunoblotting , Incidencia , Masculino , Valor Predictivo de las Pruebas , Pruebas Cutáneas/normas , Taiwán/epidemiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA