Extract of Ascaris suum induces TGF-ß and early production of IgG1 in experimental autoimmune hepatitis / Extrato de Ascaris suum induz TGF-ß e produção precoce de IgG1 na hepatite autoimune experimental

Abstract In experimental autoimmune hepatitis (EAH) of Th1 profile, an extract of adult Ascaris suum worms (ASC) was previously found to deviate the immune response to a Th2/IL-10 pattern. Here, the effects of treatment with ASC on production of TGF-β and the anti-Ascaris isotypes IgG1 and IgG2a in EAH were evaluated. EAH was induced in BALB/c mice, intravenously with concanavalin A. Two hours later, these animals received ASC (EAH+ASC group) or PBS vehicle (EAH group). IgG1 and IgG2a were evaluated 8 h, 24 h and 7 d after induction. TGF-β was measured in a splenocyte culture at this last time. The isotype levels in the EAH group were low throughout the kinetics. In the EAH+ASC group, there was significant production of IgG1 at 24 h and 7 d, but of IgG2a only at 7 d. There was statistically greater production of TGF-β in the EAH+ASC group. The higher levels of IgG1 and TGF-β in this group suggest that an additional Th1 response control route exists in EAH, which needs to be investigated.

Resumo Na hepatite autoimune experimental (HAE) de perfil Th1, o extrato de vermes adultos Ascaris suum (ASC) desviou a resposta imune para um padrão Th2/IL-10. Neste trabalho, foram avaliados os efeitos do tratamento com ASC na produção TGF-β e dos isótipos de IgG1 e IgG2a anti-Ascaris na HAE. Esta foi induzida em camundongos BALB/c intravenosamente com Concanavalina A. Após duas horas, os animais receberam ASC (grupo HAE+ASC) ou veículo PBS (grupo HAE). IgG1 e IgG2a foram avaliados em 8 horas, 24 horas e 7 dias após indução. TGF-β foi mensurado em cultura de esplenócitos nesse último tempo. Os níveis dos isótipos no grupo HAE foram baixos durante toda a cinética. No grupo HAE+ASC, houve produção significativa de IgG1 em 24 horas e 7 dias, mas somente em 7 dias para IgG2a. A produção de TGF-β foi estatisticamente maior no grupo HAE+ASC. Níveis mais altos de IgG1 e TGF-β nesse grupo sugerem uma via adicional de controle da resposta Th1 na HAE que precisa ser investigada.

Evaluation of cysticercus-specific IgG (total and subclasses) and IgE antibody responses in cerebrospinal fluid samples from patients with neurocysticercosis showing intrathecal production of specific IgG antibodies / Avaliação das respostas de anticorpos anti-cisticercos IgG (total e subclasses) e IgE em amostras de líquido cefalorraquidiano de pacientes com neurocisticercose apresentando produção intratecal de anticorpos específicos IgG

In the present study, an enzyme-linked immunosorbent assay (ELISA) standardized with vesicular fluid of Taenia solium cysticerci was used to screen for IgG (total and subclasses) and IgE antibodies in cerebrospinal fluid (CSF) samples from patients with neurocysticercosis showing intrathecal production of specific IgG antibodies and patients with other neurological disorders. The following results were obtained: IgG-ELISA: 100% sensitivity (median of the ELISA absorbances (MEA)=1.17) and 100% specificity; IgG1-ELISA: 72.7% sensitivity (MEA=0.49) and 100% specificity; IgG2-ELISA: 81.8% sensitivity (MEA=0.46) and 100% specificity; IgG3-ELISA: 63.6% sensitivity (MEA=0.12) and 100% specificity; IgG4-ELISA: 90.9% sensitivity (MEA=0.85) and 100% specificity; IgE-ELISA 93.8% sensitivity (MEA=0.60) and 100% specificity. There were no significant differences between the sensitivities and specificities in the detection of IgG-ELISA and IgE-ELISA, although in CSF samples from patients with neurocysticercosis the MEA of the IgG-ELISA was significantly higher than that of the IgE-ELISA. The sensitivity and MEA values of the IgG4-ELISA were higher than the corresponding values for the other IgG subclasses. Future studies should address the contribution of IgG4 and IgE antibodies to the physiopathology of neurocysticercosis.

No presente estudo, uma reação imunoenzimática (ELISA) padronizada com o fluido vesicular de cisticercos de Taenia solium foi utilizada para avaliar as respostas de anticorpos anti-cisticercos IgG (total e subclasses) e IgE em amostras de líquido cefalorraquidiano (LCR) de pacientes com neurocisticercose apresentando produção intratecal de anticorpos específicos IgG e pacientes com outras desordens neurológicas. Os seguintes resultados foram obtidos: ELISA-IgG: 100% de sensibilidade (mediana das absorbâncias das reações ELISA (MAE)=1,17) e especificidade 100%; ELISA-IgG1: sensibilidade 72,7% (MAE=0,49) e especificidade 100%; ELISA-IgG2: sensibilidade 81,8% (MAE=0,46) e especificidade 100%; ELISA-IgG3: sensibilidade 63,6% (MAE=0,12) e especificidade 100%; ELISA-IgG4: sensibilidade 90,9% (MAE=0,85) e especificidade 100%; ELISA-IgE: sensibilidade 93,8% (MAE=0,60) e especificidade 100%. Não foram encontradas diferenças significativas entre as sensibilidades e especificidades das reações ELISA-IgG e ELISA-IgE, embora a MAE da reação ELISA-IgG em amostras de LCR de pacientes com neurocisticercose tenha sido significativamente maior que a obtida com ELISA-IgE. Os valores de sensibilidade e MAE da reação ELISA-IgG4 foram maiores que os valores correspondentes para as outras subclasses da IgG. Estudos futuros deverão abordar a contribuição dos anticorpos IgG4 e IgE na fisiopatologia da neurocisticercose.

Estandarización en Colombia de una prueba ELISA para la evaluación de los niveles séricos de anticuerpos IgG contra diez serotipos de Streptococcus pneumoniae / An immunoenzymatic test for IgG antibody levels against 10 serotypes of Streptococcus pneumoniae

Introducción. Streptococcus pneumoniae es causante de gran morbimortalidad en niños pequeños y ancianos. Sin embargo, en Colombia no está disponible una prueba que evalúe la respuesta humoral a la vacunación específica contra este microorganismo Objetivo. Estandarizar en Colombia un ensayo inmunoenzimático para evaluar los niveles séricos de anticuerpos IgG contra diez serotipos de S. pneumoniae en respuesta a la vacunación específica y caracterizar esta respuesta en individuos sanos de nuestra población. Materiales y métodos. Se hizo un ELISA en fase sólida utilizando como antígenos los polisacáridos capsulares 1, 3, 4, 5, 6B, 9V, 14, 18, 19F y 23F de S. pneumoniae. Resultados. Los sueros de referencia y control reaccionaron fuertemente contra los polisacáridos evaluados, especialmente contra 14 y 19F. En los cinco niños sanos evaluados, los polisacáridos 5 y 19F presentaron los mayores títulos antes de la vacunación. Antes de la vacunación en los niños, y antes y después de la vacunación en los adultos, los polisacáridos 14 y 19F reaccionaron fuertemente. Para todos los polisacáridos, excepto para el 5, existe una relación inversa entre títulos altos de anticuerpos IgG antes de la vacunación y la razón de incremento de los títulos después de la misma. Conclusión. Esta prueba ELISA cuantifica de forma confiable los niveles de IgG sérica contra diez serotipos de S. pneumoniae y, de acuerdo con los resultados obtenidos en individuos sanos de nuestra población, en este trabajo se validan los parámetros internacionales para considerar adecuada la respuesta a la vacuna 23-valente contra este microorganismo.

Introduction. Streptococcus pneumoniae is a major cause of morbi-mortality in early childhood and elderly. However, a test to measure the antibody responses after specific vaccination is not available in Colombia. Objective. An immunoenzymatic test was standardized for the measurement of serum IgG levels against 10 serotypes of S. pneumoniae in response to the specific vaccination. Material and methods. Capsular polysaccharides 1, 3, 4, 5, 6B, 9V, 14, 18, 19F, 23F of S. pneumoniae were used as antigens in a solid-phase ELISA. These responses were characterized in a randomized selected healthy individuals from a Colombian population. Results. The reference and control sera showed great reactivity against all the polysaccharides evaluated, especially against polysaccharide 14 and 19F. The lowest reactivity in these two sera was observed against polysaccharide 3 and 4. Among the children evaluated, polysaccharide 5/19F showed the highes pre-vaccination reactivity, and polysaccharide 14/19F showed the highest post-vaccination reactivity. Among the adults, polysaccharides 14 and 19F showed the greatest reactivity pre- and post-vaccination. For all the polysaccharides (excepting polysaccharide 5), an inverse association among high polysaccharide-specific pre-vaccination- and the increase of post-vaccination-IgG levels was observed. Conclusion. This ELISA test reliably quantifies the serum levels of specific IgG against 10 serotypes of S. pneumoniae. According to the responses by healthy individuals, the current study validates parameters used internationally as an adequate the response to the 23-valent pneumococcal vaccine.

Boosting the suppressive effects of Ascaris suum components in IFN-γ-deficient mice / Potencialização do efeito supressor de componentes do Ascaris suum em camundongos deficientes em IFN-γ

High molecular weight components from Ascaris suum extract suppress ovalbumin-specific immunity in mice. In IFN-γ-deficient mice, ovalbumin-specific delayed-type hypersensitivity reactions are more strongly downregulated by these suppressive components. Here, the cellularity of the delayed-type hypersensitivity reaction in IFN-γ-deficient mice and the increased downregulation induced by Ascaris suum components were analyzed. IL-12p40-dependent neutrophilic influx was predominant. Suboptimal doses of the suppressive fraction from this nematode completely inhibited the hypersensitivity reaction, thus indicating intensification of the immunosuppression under conditions of intense recruitment of IFN-γ-independent neutrophils.

Componentes de alto peso molecular do extrato de Ascaris suum suprimem a imunidade específica à ovalbumina em camundongos. Em camundongos geneticamente deficientes de IFN-γ a reação de hipersensibilidade tardia específica para ovalbumina foi mais fortemente prejudicada por estes componentes supressivos. Aqui, a celularidade da reação de hipersensibilidade tardia em camundongos deficientes de IFN-γ e o incremento na supressão induzida por componentes do Ascaris suum foram analisados. Influxo neutrofílico, dependente de IL-12p40, foi predominante. Dose sub-ótima da fração supressiva do nematódeo inibiu completamente a reação de hipersensibilidade, indicando uma intensificação da imunossupressão em condições de recrutamento intenso de neutrófilos independente de IFN-γ.

Immunological imbalance between IFN-³ and IL-10 levels in the sera of patients with the cardiac form of Chagas disease

The immune response is crucial for protection against disease; however, immunological imbalances can lead to heart and digestive tract lesions in chagasic patients. Several studies have evaluated the cellular and humoral immune responses in chagasic patients in an attempt to correlate immunological findings with clinical forms of Chagas disease. Moreover, immunoglobulins and cytokines are important for parasitic control and are involved in lesion genesis. Here, cytokine and IgG isotype production were studied, using total epimastigote antigen on sera of chagasic patients with indeterminate (IND, n = 27) and cardiac (CARD, n = 16) forms of the disease. Samples from normal, uninfected individuals (NI, n = 30) were use as controls. The results showed that sera from both IND and CARD patients contained higher levels of Trypanosoma cruzi-specific IgG1 (IgG1) antibodies than sera from NI. No difference in IgG2 production levels was observed between NI, IND and CARD patients, nor was a difference in IL-10 and IFN-³ production detected in the sera of IND, CARD and NI patients. However, IND patients displayed a positive correlation between IL-10 and IFN-³ levels in serum, while CARD patients showed no such correlation, indicating an uncontrolled inflammatory response in CARD patients. These findings support the hypothesis that a lack of efficient regulation between IFN-³ and IL-10 productions in CARD patients may lead to cardiac immunopathology.

Time gap between oocyst shedding and antibody responses in mice infected with Cryptosporidium parvum

We observed the time gap between oocyst shedding and antibody responses in mice (3-week-old C57BL/6J females) infected with Cryptosporidium parvum. Oocyst shedding was verified by modified acid-fast staining. The individually collected mouse sera were assessed for C. parvum IgM and IgG antibodies by enzyme-linked immunosorbent assay from 5 to 25 weeks after infection. The results showed that C. parvum oocysts were shed from day 5 to 51 post-infection (PI). The IgM antibody titers to C. parvum peaked at week 5 PI, whereas the IgG antibody titers achieved maximum levels at week 25 PI. The results revealed that IgM responses to C. parvum infection occurred during the early stage of infection and overlapped with the oocyst shedding period, whereas IgG responses occurred during the late stage and was not correlated with oocyst shedding. Hence, IgM antibody detection may prove helpful for the diagnosis of acute cryptosporidiosis, and IgG antibody detection may prove effective for the detection of past infection and endemicity.

Production, characterization, and application of antibodies against heat-labile type-I toxin for detection of enterotoxigenic Escherichia coli

Strains of enterotoxigenic Escherichia coli (ETEC) are responsible for significant rates of morbidity and mortality among children, particularly in developing countries. The majority of clinical and public health laboratories are capable of isolating and identifying Salmonella, Shigella, Campylobacter, and Escherichia coli O157:H7 from stool samples, but ETEC cannot be identified by routine methods. The method most often used to identify ETEC is polymerase chain reaction for heat-stable and heat-labile enterotoxin genes, and subsequent serotyping, but most clinical and public health laboratories do not have the capacity or resources to perform these tests. In this study, polyclonal rabbit and monoclonal mouse IgG2b antibodies against ETEC heat-labile toxin-I (LT) were characterized and the potential applicability of a capture assay was analyzed. IgG-enriched fractions from rabbit polyclonal and the IgG2b monoclonal antibodies recognized LT in a conformational shape and they were excellent tools for detection of LT-producing strains. These findings indicate that the capture immunoassay could be used as a diagnostic assay of ETEC LT-producing strains in routine diagnosis and in epidemiological studies of diarrhea in developing countries as enzyme linked immunosorbent assay techniques remain as effective and economical choice for the detection of specific pathogen antigens in cultures.

Reibergrama para la evaluación de la síntesis intratecal de C3c / Reibergram for C3c intrathecal synthesis evaluation / Reibergram for C3c intrathecal synthesis evaluation

INTRODUCCION: El diagrama de las razones de Reiber o reibergrama cobra cada día mayores usos para la caracterización de la síntesis intratecal de proteínas. El reibergrama fue definido para las clases mayores de inmunoglobulinas pero luego ha sido utilizado para evaluar otras proteínas basado en la teoría de la difusión molecular/velocidad de flujo del líquido cefalorraquídeo (LCR). MÉTODO: El C3c, producto de la degradación del factor del complemento C3 y con una masa molecular de 145 KDa, se acerca a las características moleculares de la IgG para las leyes de la difusión de Fick. Se asume las constantes de la IgG en la fórmula de Reiber para evaluar la síntesis intratecal de C3c así como su correspondiente reibergrama. Se estudiaron 27 pacientes y 27 controles a los que se les dosificó albúmina y C3c en suero y LCR por inmunodifusión radial. RESULTADOS: Con el reibergrama propuesto para el C3c se evaluaron estos pacientes. Se comprueba la validez de este reibergrama para distintas condiciones de barrera con o sin síntesis intratecal de C3c. CONCLUSION: El reibergrama y su fórmula correspondiente propuesto para la C3c puede ser usado para la evaluación de la síntesis intratecal de C3c.

INTRODUCTION: Reiber's quotient diagram or reibergram has a growing apply for characterize the intratecal synthesis of proteins. Firstly reibergrama was used for the major classes of immunoglobulins but later it was used to evaluate other proteins based on the theory about molecular flux/cerebrospinal fluid (CSF) flow rate. METHOD: C3c is a degradation product of complement factor C3 with 145 KDa and approaches to IgG molecular characteristics according with Fick's diffussion laws. It was assumed IgG constants and graphic for IgG constants and graphic to evaluate the intrathecal synthesis of C3c. Twenty-seven patients and 27 controls were studied. Serum and CSF C3c and albumin were quantified by immunodiffusion. RESULTS: The patients with the C3c proposed reibergram were evaluated. It has been proved its validity under several CSF blood barrier conditions. CONCLUSION: Reibergram for C3c can be used for the evaluation of the intrathecal synthesis of this protein.

The anti-IRBP IgG1 and IgG2a response does not correlate with susceptibility to experimental autoimmune uveitis

Susceptibility to experimental autoimmune uveitis (EAU) in inbred mice has been associated with a dominant Th1 response. Elevated anti-inter-photoreceptor retinoid-binding protein (anti-IRBP) IgG2a/IgG1 antibody ratios have been implicated as candidate markers to predict disease severity. In the present study, both the anti-IRBP antibody isotype and severity of EAU phenotypes were examined in 4 non-isogenic genetically selected mouse lines to determine if they can be used as general markers of disease. Mice between 8 and 12 weeks old selected for high (H III) or low (L III) antibody response and for maximum (AIR MAX) or minimum (AIR MIN) acute inflammatory reaction (AIR) were immunized with IRBP. Each experiment was performed with at least 5 mice per group. EAU was evaluated by histopathology 21 days after immunization and the minimal criterion was inflammatory cell infiltration of the ciliary body, choroid and retina. Serum IgG1- and IgG2a-specific antibodies were determined by ELISA. EAU was graded by histological examination of the enucleated eyes. The incidence of EAU was lower in AIR MIN mice whereas in the other strains approximately 40 percent of the animals developed the disease. Low responder animals did not produce anti-IRBP IgG2a antibodies or interferon-gamma. No correlation was observed between susceptibility to EAU and anti-IRBP isotype profiles. Susceptibility to EAU is related to the intrinsic capacity to mount higher inflammatory reactions and increased production of anti-IRBP IgG2a isotype is not necessarily a marker of this immunologic profile.

Rabbit IgG antibodies against Phospholipase A2 from Crotalus durissus terrificus neutralize the lethal activity of the venom

Crotalus durissus terrificus (C.d.t.) (South American rattlesnake) venom possesses myotoxic and neurotoxic activities, both of which are also expressed by crotoxin, the principal toxin of this venom. Crotoxin contains a basic phospholipase A2 (PLA2) and a non toxic acidic protein, crotapotin. We have produced and investigated the ability of IgG antibodies raised in rabbits against PLA2 to neutralize the lethality of the whole venom. PLA2 was isolated by gel filtration chromatography (Sephadex G-75). Specific antibodies were obtained by subcutaneous and intramuscular inoculation of PLA2 (700 µg) with Freund adjuvant. Groups of six mice (20 + 2 g) were inoculated with 0.5 ml i.p. of C. d. t. venom (4 µg) or a mixture of venom that had been preincubated with the desired volume of IgG antibodies. Mortality, recorded 24 and 48 h after inoculation, showed that IgG anti-PLA2 were more effective than anticrotalic serum in neutralizing the lethal activity. These results demonstrate that it could be possible to obtain an anti-venom made by specific antibodies with a high level of protection against the lethal component of C.d.t. venom, and/or the inclusion of these antibodies as a supplement in heterologous anti-venoms

El veneno de Crotalus durissus terrificus (C.d.t.) (Cascabel de Sud América) posee actividad miotóxica y neurotóxica, actividades que también exhibe el complejo crotoxina, principal componente tóxico de este veneno. El complejo crotoxina está constituido por una fosfolipasa A2 básica (PLA2) y una proteína acídica no tóxica, el crotapotín. En este trabajo se estudió la capacidad neutralizante de anticuerpos IgG anti-PLA2 sobre la letalidad inducida por el veneno entero. El antígeno PLA2, fue aislado por cromatografía de filtración en gel (Sephadex G-75). Se inocularon conejos machos por vía subcutánea e intramuscular, con 700 µg de PLA2 y adyuvante para la obtención de anticuerpos específicos. La capacidad neutralizante del antisuero se analizó en ratones por inoculación con diluciones de veneno entero preincubado con un volumen adecuado de anticuerpos IgG anti-PLA2. Se inocularon ratones controles con 0.5 ml i.p. de veneno (4 µg.ml-1). El número de muertes fue contabilizado a las 24 y 48 h posteriores a la inoculación, demostrándose que la capacidad neutralizante de los anticuerpos IgG anti-PLA2 fue superior a la obtenida con el antiveneno crotálico. Los resultados obtenidos demuestran la potencial aplicación de antivenenos constituidos por anticuerpos específicos contra PLA2, y/o la inclusión de estos anticuerpos como suplementos en antivenenos polivalentes

Identification of novel Leishmania major antigens that elicit IgG2a response in resistant and susceptible mice

Experimental murine models with high, intermediate and low levels of genetically based susceptibility to Leishmania major infection reproduce almost entire spectrum of clinical manifestations of the human disease. There are increasing non-comparative studies on immune responses against isolated antigens of L. major in different murine strains. The aim of the present study was to find out whether there is an antigen that can induce protective immune response in resistant and susceptible murine strains. To do that, crude antigenic extract of procyclic and metacyclic promastigotes of L. major was prepared and subjected to SDS-PAGE electrophoresis. Western-blotting was used to search for antigen(s) capable of raising high antibody level of IgG2a versus IgG1 in the sera of both infected resistant and susceptible strains. Two novel antigens from metacyclic promastigotes of L. major (140 and 152 kDa) were potentially able to induce specific dominant IgG2a responses in BALB/c and C57BL/6 mice. The 2 antigens also reacted with IgG antibody of cutaneous leishmaniasis patients. We confirm that 140 and 152 kDa proteins of L. major promastigotes are inducing IgG production in mice and humans.

Cytokines and intrathecal IgG synthesis in multiple sclerosis patients during clinical remission

Os níveis de citocinas e síntese intratecal de IgG foram dosados no líquido cefalorraquidiano (LCR) e soro, com o objetivo de avaliar a atividade inflamatória em pacientes com esclerose múltipla durante remissão clínica. Foram detectados níveis elevados de citocinas pró-inflamatórias (TNFa e IFNg) no LCR e soro, sem alterações significativas na produção de IL12 e IL10. O perfil de produção das citocinas pró-inflamatórias estava associado ao aumento de leucócitos no LCR, assim como a presença de bandas oligoclonais IgG sugerindo síntese intratecal de IgG. Estes resultados sugerem que mesmo quando a doença está clinicamente silenciosa, a atividade inflamatória está presente nestes pacientes.

Rat hippocampus and primary immune response.

During immune challenge hippocampal region shows time-dependent changes in neurotransmitter levels. Hence in the present study the effect of electrolytic lesion in the dorsolateral hippocampus (DLH) and ventral hippocampal formation (VHF) (to create a disturbance in neurotransmitter levels) on humoral immunity in albino rats has been studied along with appropriate controls. Haemagglutination titre, IgM and IgG levels were monitored on the 5th day after an immune challenge by sheep red blood cells (SRBC) suspension. Antigen challenged lesioned animals had low circulating antibody titre levels compared with the controls and their site-specific sham lesioned groups. The IgM levels were significantly lowered in both DLH and VHF lesioned and immunized animals compared to their immunized sham groups as well as immunized controls. However, only immunized VHF lesioned group showed a significant decrease in IgG level from their immunized sham group. It was concluded from the results that an intact hippocampal region is essential for the normal humoral immunity for the primary immune response in rats. Probably VHF region may be required for the secondary immune response as indicated by the alteration in IgG levels in these animals.

Production of IgY anti-mouse IgG antibodies from chicken eggs.

IgY technology offers several advantages over antibody production in mammals. In this study, we applied IgY technology for the production of anti-mouse IgG polyclonal antibodies and developed a FITC conjugate reagent. Two hens were immunized 3 times with mouse IgG, one via the pectoralis and the other via the calf muscles. Specific antibodies could be detected in the sera two weeks after the immunization, and maximum levels were reached at week 10. The hen which was immunized via the pectoralis muscle produced a much higher antibody response than the hen immunized via the calf muscle. In egg yolk, specific antibodies appeared 2 weeks after the first immunization, reached a plateau after week 11 and remained high until week 20. IgY were extracted from egg yolk by sodium sulfate precipitation. Approximately 40 mg of IgY could be extracted from a single egg. The extracted IgY was labeled with FITC. The so-produced antibody-FITC conjugate reacted to all mouse IgG isotypes and could be used to determine leukocyte sub-populations in blood samples by flow cytometry.

Determinação de autoanticorpos para antígenos da mielina no soro de pacientes HLA - DQB1*0602 com esclerose múltipla / Determination of autoantibody for myelin antigens in the serum of patients HLA - DQB1*0602 with multiple sclerosis

Esclerose múltipla (EM) é doença inflamatória desmielinizante do sistema nervoso central (SNC) de natureza autoimune, mediada por linfócitos Th1. A produção de autoanticorpos séricos para proteína básica da mielina (MBP), proteolipídeo PLP e sequência da glicoproteína de oligodendrócito MOG 92-106, foi determinada em 54 indivíduos saudáveis e 26 pacientes com EM expressando ou não o alelo de suscetibilidade HLA-DQB1*0602. Independentemente da expressão do alelo DQB1*0602, todos os pacientes apresentaram produção marcante (p< 0,0001) de autoanticorpos isotipo IgG para MBP e MOG 92-106, e do isotipo IgA para PLP e MOG 92-106. Os resultados sugerem que outros alelos HLA da classe II exerçam influência na suscetibilidade à EM e no reconhecimento imunológico dos antígenos encefalitogênicos, determinando o padrão de resposta autoimune e contribuindo na manutenção e/ou controle da inflamação no SNC

Interleukin-4 production in BALB/c mice immunized with Anisakis simplex

We investigated the interleukin (IL-4) levels in BALB/c mice immunized with Anisakis extract in single or multiple doses and in mice orally infected with a larva. From animals immunized maximum responses were obtained with the multiple doses with an only IL-4 peak. Conversely, in the mice inoculated with a larva per os, the IL-4 levels showed two peaks of different rates

Isotype specific immune responses in murine experimental toxocariasis

In this work, a murine experimental model of toxocariasis has been developed in BALB/c, C57BL/10 and C3H murine strains orally inoculated with 4,000 Toxocara canis embryonated eggs, in order to investigate the isotype-specific immune responses against excretory-secretory antigens from larvae. T. canis specific IgG+M, IgM, IgG, IgA, IgG1, IgG2a and IgG3 were tested by ELISA. The dynamics of the specific immunoglobulins (IgG+IgM) production showed a contrasting profile regarding the murine strain. Conversely to the results obtained with the IgM isotype, the IgG antibody class showed similar patterns to those obtained with IgG+IgM antibodies, only in the case of the BALB/c strain, being different and much higher than the obtained with IgG+IgM antibodies, when the C3H murine strain was used. The antibodies IgG+IgM tested in BALB/c and C57BL/10 were both of the IgM and IgG isotypes. Conversely, in the C3H strain only IgG specific antibody levels were detected. The IgG1 subclass responses showed a similar profile in the three murine strains studied, with high values in BALB/c, as in the case of the IgG responses

Evaluation of immunoglobulin G synthesizing plasma cells in periapical granuloma and cyst.

Immunoglobulin synthesizing plasma cells for IgG were quantitated in 20 periapical granulomas and 20 periapical cysts, using unlabelled antibody peroxidase-antiperoxidase complex method. Result showed that immunoglobulin G producing plasma cells were predominant in periapical cyst as compared with periapical granuloma. A statistical significant relation was observed between these two lesions.

Production of monoclonal antibodies to a tumor--associated antigen by spontaneous cell fusion.

Spontaneous cell fusion induced by the bacterium Haemophilus paragallinarum has been recently reported as an alternative technique to generate hybridomas producing monoclonal antibody (mAb). In order to investigate the advantages of this technique to produce anti-tumor monoclonal antibodies we performed comparative experiments between H. paragallinarum induced spontaneous cell fusion and polyethylene glycol (PEG) mediated fusion. Hybridomas producing monoclonal antibodies to an experimental murine lymphoma antigen, the Dalton's lymphoma associated antigen (DLAA) were generated and their sensitivity and specificity were ascertained. The spontaneous fusion yielded more number of stable and specific hybridomas than PEG mediated fusion. The results suggest the advantage of H. paragalinarum induced cell fusion for the simplified production of specific antitumor monoclonal antibodies.

Characterization of the mucosal and systemic immune response induced by Cry1Ac protein from Bacillus thuringiensis HD 73 in mice

The present paper describes important features of the immune response induced by the Cry1Ac protein from Bacillus thuringiensis in mice. The kinetics of induction of serum and mucosal antibodies showed an immediate production of anti-Cry1Ac IgM and IgG antibodies in serum after the first immunization with the protoxin by either the intraperitoneal or intragastric route. The antibody fraction in serum and intestinal fluids consisted mainly of IgG1. In addition, plasma cells producing anti-Cry1Ac IgG antibodies in Peyer's patches were observed using the solid-phase enzyme-linked immunospot (ELISPOT). Cry1Ac toxin administration induced a strong immune response in serum but in the small intestinal fluids only anti-Cry1Ac IgA antibodies were detected. The data obtained in the present study confirm that the Cry1Ac protoxin is a potent immunogen able to induce a specific immune response in the mucosal tissue, which has not been observed in response to most other proteins