RESUMO
AIM: To determine the percentage of change and increment in glucose levels after a normal oral glucose tolerance test between 24 and 28 weeks of pregnancy. METHODS: We studied 3510 pregnant women who attended their obstetric delivery at a tertiary care hospital in Guadalajara, Mexico in 2018, according to characteristics and risk 1647 (47%) patients were screened for diabetes diagnosis using the oral glucose tolerance test, 501 patients reported normal values between their 24th and 28th week of pregnancy, only 400 patients had their fasting glucose level measured on the same day of their obstetric delivery, to be compared. RESULTS: Average age was 30 years, with an average of 25.3 weeks of pregnancy. The fasting serum glucose levels taken after 28 weeks of pregnancy and before the obstetrical delivery showed an increase of 1.1 mmol/L in women who develop gestational diabetes mellitus, in contrast to women who did not develop gestational diabetes mellitus after 28 weeks their blood glucose only increased on average 0.4 mmol/L. The incidence of gestational diabetes mellitus in the study population during 2018 was 32.7%. Patients who developed gestational diabetes mellitus after a normal oral glucose tolerance test had greater body mass index before the pregnancy and newborns had a higher weight than babies born to mothers without gestational diabetes mellitus. CONCLUSION: Changes in glucose levels after the oral tolerance test of normal glucose require strict monitoring, in that it was demonstrated that 3% of patients developed gestational diabetes mellitus after week 28 of gestation.
Assuntos
Diabetes Gestacional , Gravidez , Feminino , Humanos , Recém-Nascido , Adulto , Glicemia , Teste de Tolerância a Glucose , Parto , MéxicoRESUMO
In recent times, the primary approach to treating food allergies involved strict avoidance of the triggering allergen. Many considered this approach as lacking true treatment, leaving patients vulnerable to even small amounts or hidden sources of the allergenic food. Desensitization or Oral Tolerance Induction (OTI) is a studied method aiming for a lasting tolerance to the allergen. The ultimate goal is permanent tolerance, where allergic reactions won't reoccur after new exposure to the triggering allergen, following a period of abstinence. The research mainly focuses on allergen-specific immunotherapy, covering three routes: oral, sublingual, and epicutaneous immunotherapy. Milk, egg, and peanuts are the extensively studied foods due to their prevalence in allergies. The oral route is favored for inducing tolerance because ingestion of a food antigen by a non-allergic individual triggers an active immune response without causing an allergic reaction. The paradigm has shifted from recommending avoidance to early consumption strategies to prevent allergies. The period from 4 to 6 months of age is considered immunologically sensitive, where children with risk factors show increased allergic sensitization risk. Implementing these recommendations, considering family and community preferences, may reduce the burden of food allergies and healthcare costs.
Hasta hace poco, el enfoque principal para tratar las alergias alimentarias implicaba evitar estrictamente el alérgeno desencadenante. Este método a menudo se consideraba insuficiente, lo que dejaba a los pacientes vulnerables a pequeñas cantidades o fuentes ocultas del alérgeno. La desensibilización, o inducción de tolerancia oral, es un método emergente que se está investigando para el tratamiento de las alergias alimentarias. El objetivo final es conseguir una tolerancia permanente, previniendo reacciones alérgicas tras una nueva exposición al alérgeno tras un periodo de abstinencia. La investigación se ha centrado en la inmunoterapia con alérgenos específicos a través de tres vías: oral, sublingual y epicutánea. La leche, el huevo y el maní son los principales alimentos estudiados debido a su prevalencia en las alergias. Se prefiere la inducción oral porque la ingestión de una persona no alérgica induce una respuesta inmune sin desencadenar una reacción alérgica. La atención de pacientes se ha desplazado de evitar el alergeno a ofrecer estrategias de consumo temprano para prevenir las alergias. En este enfoque se considera crucial el rango de edad de 4 a 6 meses. Se necesita investigación continua para evaluar los detalles de la población, los efectos a largo plazo, la viabilidad y la seguridad de estas estrategias.
Assuntos
Dessensibilização Imunológica , Hipersensibilidade Alimentar , Criança , Humanos , Animais , Custos de Cuidados de Saúde , Leite , Alérgenos , Hipersensibilidade Alimentar/terapiaRESUMO
Oral tolerance is defined as a specific suppression of cellular and humoral immune responses to a particular antigen through prior oral administration of an antigen. It has unique immunological importance since it is a natural and continuous event driven by external antigens. It is characterized by low levels of IgG in the serum of animals after immunization with the antigen. There is no report of induction of oral tolerance to Bothrops jararaca venom. Here, we induced oral tolerance to B. jararaca venom in BALB/c mice and evaluated the specific tolerance and cross-reactivity with the toxins of other Bothrops species after immunization with the snake venoms adsorbed to/encapsulated in nanostructured SBA-15 silica. Animals that received a high dose of B. jararaca venom (1.8 mg) orally responded by showing antibody titers similar to those of immunized animals. On the other hand, mice tolerized orally with three doses of 1 µg of B. jararaca venom showed low antibody titers. In animals that received a low dose of B. jararaca venom and were immunized with B. atrox or B. jararacussu venom, tolerance was null or only partial. Immunoblot analysis against the venom of different Bothrops species provided details about the main tolerogenic epitopes and clearly showed a difference compared to antiserum of immunized animals.
Assuntos
Reações Cruzadas/imunologia , Venenos de Crotalídeos/imunologia , Tolerância Imunológica , Administração Oral , Animais , Anticorpos/sangue , Bothrops , Venenos de Crotalídeos/administração & dosagem , Feminino , Camundongos Endogâmicos BALB C , Nanoestruturas , Dióxido de Silício/química , Especificidade da Espécie , Venenos de Víboras/imunologia , ViperidaeRESUMO
Cutaneous leishmaniasis caused by L. braziliensis induces a pronounced Th1 inflammatory response characterized by IFN-γ production. Even in the absence of parasites, lesions result from a severe inflammatory response in which inflammatory cytokines play an important role. Different approaches have been used to evaluate the therapeutic potential of orally administrated heat shock proteins (Hsp). These proteins are evolutionarily preserved from bacteria to humans, highly expressed under inflammatory conditions and described as immunodominant antigens. Tolerance induced by the oral administration of Hsp65 is capable of suppressing inflammation and inducing differentiation in regulatory cells, and has been successfully demonstrated in several experimental models of autoimmune and inflammatory diseases. We initially administered recombinant Lactococcus lactis (L. lactis) prior to infection as a proof of concept, in order to verify its immunomodulatory potential in the inflammatory response arising from L. braziliensis. Using this experimental approach, we demonstrated that the oral administration of a recombinant L. lactis strain, which produces and secretes Hsp65 from Mycobacterium leprae directly into the gut, mitigated the effects of inflammation caused by L. braziliensis infection in association or not with PAM 3CSK4 (N-α-Palmitoyl-S-[2,3-bis(palmitoyloxy)-(2RS)-propyl]-L-cysteine, a TLR2 agonist). This was evidenced by the production of anti-inflammatory cytokines and the expansion of regulatory T cells in the draining lymph nodes of BALB/c mice. Our in vitro experimental results suggest that IL-10, TLR-2 and LAP are important immunomodulators in L. braziliensis infection. In addition, recombinant L. lactis administered 4 weeks after infection was observed to decrease lesion size, as well as the number of parasites, and produced a higher IL-10 production and decrease IFN-γ secretion. Together, these results indicate that Hsp65-producing L. lactis can be considered as an alternative candidate for treatment in both autoimmune diseases, as well as in chronic infections that cause inflammatory disease.
Assuntos
Proteínas de Bactérias/administração & dosagem , Proteínas de Bactérias/metabolismo , Chaperonina 60/administração & dosagem , Chaperonina 60/metabolismo , Tolerância Imunológica/efeitos dos fármacos , Lactococcus lactis/metabolismo , Leishmania braziliensis/efeitos dos fármacos , Leishmaniose Cutânea/tratamento farmacológico , Mycobacterium leprae/enzimologia , Administração Oral , Animais , Proteínas de Bactérias/genética , Chaperonina 60/genética , Citocinas/metabolismo , Feminino , Inflamação/tratamento farmacológico , Inflamação/imunologia , Lactococcus lactis/genética , Leishmaniose Cutânea/imunologia , Leishmaniose Cutânea/parasitologia , Camundongos , Camundongos Endogâmicos BALB C , Organismos Geneticamente Modificados/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/imunologia , Linfócitos T Reguladores/imunologiaRESUMO
The prevalence of food allergy has increased over the last 20-30 years, including cow milk allergy (CMA) which is one of the most common causes of infant food allergy. International allergy experts met in 2019 to discuss broad topics in allergy prevention and management of CMA including current challenges and future opportunities. The highlights of the meeting combined with recently published developments are presented here. Primary prevention of CMA should start from pre-pregnancy with a focus on a healthy lifestyle and food diversity to ensure adequate transfer of inhibitory IgG- allergen immune complexes across the placenta especially in mothers with a history of allergic diseases and planned c-section delivery. For non-breastfed infants, there is controversy about the preventive role of partially hydrolyzed formulae (pHF) despite some evidence of health economic benefits among those with a family history of allergy. Clinical management of CMA consists of secondary prevention with a focus on the development of early oral tolerance. The use of extensive Hydrolysate Formulae (eHF) is the nutrition of choice for the majority of non-breastfed infants with CMA; potentially with pre-, probiotics and LCPUFA to support early oral tolerance induction. Future opportunities are, among others, pre- and probiotics supplementation for mothers and high-risk infants for the primary prevention of CMA. A controlled prospective study implementing a step-down milk formulae ladder with various degrees of hydrolysate is proposed for food challenges and early development of oral tolerance. This provides a more precise gradation of milk protein exposure than those currently recommended.
Assuntos
Dessensibilização Imunológica/métodos , Hipersensibilidade a Leite/diagnóstico , Animais , Bovinos , Suplementos Nutricionais , Feminino , Humanos , Tolerância Imunológica , Lactente , Fórmulas Infantis/química , Recém-Nascido , Hipersensibilidade a Leite/terapia , Prebióticos/administração & dosagem , Gravidez , Hidrolisados de Proteína/administração & dosagem , Hidrolisados de Proteína/químicaRESUMO
The ocular surface is the part of the visual system directly exposed to the environment, and it comprises the cornea, the first refractive tissue layer and its surrounding structures. The ocular surface has evolved to keep the cornea smooth and wet, a prerequisite for proper sight, and also protected. To this aim, the ocular surface is a bona fide mucosal niche with an immune system capable of fighting against dangerous pathogens. However, due to the potential harmful effects of uncontrolled inflammation, the ocular surface has several mechanisms to keep the immune response in check. Specifically, the ocular surface is maintained inflammation-free and functional by a particular form of peripheral tolerance known as mucosal tolerance, markedly different from the immune privilege of intraocular structures. Remarkably, conjunctival tolerance is akin to the oral and respiratory tolerance mechanisms found in the gut and airways, respectively. And also similarly, this form of immunoregulation in the eye is affected by ageing just as it is in the digestive and respiratory tracts. With ageing comes an increased prevalence of immune-based ocular surface disorders, which could be related to an age-related impairment of conjunctival tolerance. The purpose of this review was to summarize the present knowledge of ocular mucosal tolerance and how it is affected by the ageing process in the light of the current literature on mucosal immunoregulation of the gut and airways.
Assuntos
Envelhecimento/imunologia , Córnea/imunologia , Oftalmopatias/imunologia , Células Caliciformes/imunologia , Mucosa Intestinal/imunologia , Mucosa Respiratória/imunologia , Animais , Humanos , Privilégio Imunológico , Tolerância Imunológica , Imunidade Inata , InflamaçãoRESUMO
Food allergies are usually managed by food avoidance. Hidden allergens in food, due to cross-contamination and/or allergenic additives added during production, place an important concern in today's increasing food allergy cases worldwide. Previous studies showed that the introduction of unacquainted food components, in an inflamed intestine, results in sensitization to this food. Thus, our aim was to evaluate the kinetics of multiple food allergy induction. Adult male C57BL/6 mice were divided into five groups, four of which were submitted to an intestinal inflammation induction protocol to peanuts. Egg white (OVA) diluted 1:5 v/v in distilled water was instilled by gavage 6h-before (PRIOR), concomitant (AT) and 6h-after (DURING) the onset of the peanut challenge diet. Positive control (POS CONT) and NEG CONT received saline per gavage. Finally, animals were challenged with subcutaneous injections of OVA. Results showed no changes in diet intake were observed. Anti-OVA polyisotypic IgG antibody titers significantly increased in AT. Flow cytometry revealed significant decrease in CD4+CD25+Foxp3+ and significant increase in TCD8+ in AT. Histomorphometrically, AT and DURING were classified as Infiltrative and Partial Destruction stages. PRIOR was classified as Infiltrative, while POS CONT was classified as Partial Destruction. NEG CONT was classified as Normal. Together, our results confirm that the introduction of unfamiliar food only a few hours before the initiation of a gut inflammation process is able to induce oral tolerance, however the introduction of a dietary protein concomitant to the onset or during an ongoing gut inflammation may induce multiple allergies.
Assuntos
Alérgenos/imunologia , Hipersensibilidade Alimentar/etiologia , Hipersensibilidade Alimentar/metabolismo , Gastroenterite/complicações , Tolerância Imunológica/imunologia , Alérgenos/administração & dosagem , Animais , Biomarcadores , Citocinas/metabolismo , Modelos Animais de Doenças , Suscetibilidade a Doenças/imunologia , Hipersensibilidade Alimentar/diagnóstico , Hipersensibilidade Alimentar/terapia , Humanos , Imunização , Imunoglobulina G/imunologia , Imunomodulação , Subpopulações de Linfócitos/imunologia , Subpopulações de Linfócitos/metabolismo , Camundongos , Especificidade de Órgãos/imunologia , Ovalbumina/imunologiaRESUMO
Oral tolerance is a physiological phenomenon described more than a century ago as a suppressive immune response to antigens that gain access to the body by the oral route. It is a robust and long-lasting event with local and systemic effects in which the generation of mucosally induced regulatory T cells (iTreg) plays an essential role. The idea of using oral tolerance to inhibit autoimmune and allergic diseases by oral administration of target antigens was an important development that was successfully tested in 1980s. Since then, several studies have shown that feeding specific antigens can be used to prevent and control chronic inflammatory diseases in both animal models and clinically. Therefore, oral tolerance can be classified as an antigen-specific form of oral immunotherapy (OIT). In the light of novel findings on mechanisms, sites of induction and factors affecting oral tolerance, this review will focus on specific characteristics of oral tolerance induction and how they impact in its therapeutic application.
RESUMO
Oral tolerance is defined as a specific suppression of cellular and humoral immune responses to a particular antigen through prior oral administration of an antigen. It has unique immunological importance since it is a natural and continuous event driven by external antigens. It is characterized by low levels of IgG in the serum of animals after immunization with the antigen. There is no report of induction of oral tolerance to Bothrops jararaca venom. Here, we induced oral tolerance to B. jararaca venom in BALB/c mice and evaluated the specific tolerance and cross-reactivity with the toxins of other Bothrops species after immunization with the snake venoms adsorbed to/encapsulated in nanostructured SBA-15 silica. Animals that received a high dose of B. jararaca venom (1.8 mg) orally responded by showing antibody titers similar to those of immunized animals. On the other hand, mice tolerized orally with three doses of 1 µg of B. jararaca venom showed low antibody titers. In animals that received a low dose of B. jararaca venom and were immunized with B. atrox or B. jararacussu venom, tolerance was null or only partial. Immunoblot analysis against the venom of different Bothrops species provided details about the main tolerogenic epitopes and clearly showed a difference compared to antiserum of immunized animals.
RESUMO
Oral tolerance is the physiological process that enables the immune system to differentiate between harmless dietary and microbiota antigens from pathogen derived antigens. It develops at the mucosal surfaces and can result in local and systemic regulatory and anti-inflammatory effects. Translation of these benefits to the clinical practice faces limitations involving specificity and doses of antigen as well as regimens of feeding. To circumvent these problems, we developed a recombinant Hsp65 delivered by the acid lactic bacteria Lactococcus lactis NCDO 2118 directy in the intestinal mucosa. Hsp65 is a ubiquitous protein overexpressed in inflamed tissues and capable of inducing immunoregulatory mechanisms. L. lactis has probiotic properties and is commonly and safely used in dairy products. In this study, we showed that continuous delivery of HSP65 in the gut mucosa by L. lactis is a potent tolerogenic stimulus inducing regulatory CD4+LAP+ T cells that prevented collagen-induced and methylated bovine serum albumin-induced arthritis in mice. Clinical and histological signs of arthritis were inhibited as well as levels of inflammatory cytokines such as IL-17 and IFN-γ, serum titers of anti-collagen antibodies and rheumatoid factor. Oral administration of L. lactis induced alterations in microbiota composition toward an increased abundance of anaerobic bacteria such as Bifidobacterium and Lactobacillus. Tolerance to HSP65 and arthritis prevention induced by the recombinant L. lactis was associated with increase in IL-10 production by B cells and it was dependent on LAP+ T cells, IL-10 and TLR2 signaling. Therefore, HSP65-producing treatment induced effective tolerance and prevented arthritis development suggesting it can be used as a therapeutic tool for autoimmune diseases.
Assuntos
Artrite/induzido quimicamente , Artrite/prevenção & controle , Proteínas de Bactérias/metabolismo , Colágeno/efeitos adversos , Proteínas de Choque Térmico/metabolismo , Lactococcus lactis/metabolismo , Soroalbumina Bovina/efeitos adversos , Administração Oral , Animais , Artrite/imunologia , Doenças Autoimunes/prevenção & controle , Proteínas de Bactérias/genética , Linfócitos T CD4-Positivos/imunologia , Citocinas/metabolismo , Modelos Animais de Doenças , Feminino , Microbioma Gastrointestinal , Proteínas de Choque Térmico/genética , Tolerância Imunológica , Mucosa Intestinal/imunologia , Lactococcus lactis/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Probióticos/administração & dosagem , Proteínas Recombinantes/metabolismoRESUMO
Alterations in the composition of the intestinal microbiota have been associated with development of type 1 diabetes (T1D), but little is known about changes in intestinal homeostasis that contribute to disease pathogenesis. Here, we analyzed oral tolerance induction, components of the intestinal barrier, fecal microbiota, and immune cell phenotypes in non-obese diabetic (NOD) mice during disease progression compared to non-obese diabetes resistant (NOR) mice. NOD mice failed to develop oral tolerance and had defective protective/regulatory mechanisms in the intestinal mucosa, including decreased numbers of goblet cells, diminished mucus production, and lower levels of total and bacteria-bound secretory IgA, as well as an altered IEL profile. These disturbances correlated with bacteria translocation to the pancreatic lymph node possibly contributing to T1D onset. The composition of the fecal microbiota was altered in pre-diabetic NOD mice, and cross-fostering of NOD mice by NOR mothers corrected their defect in mucus production, indicating a role for NOD microbiota in gut barrier dysfunction. NOD mice had a reduction of CD103+ dendritic cells (DCs) in the MLNs, together with an increase of effector Th17 cells and ILC3, as well as a decrease of Th2 cells, ILC2, and Treg cells in the small intestine. Importantly, most of these gut alterations precede the onset of insulitis. Disorders in the intestinal mucosa of NOD mice can potentially interfere with the development of T1D due the close relationship between the gut and the pancreas. Understanding these early alterations is important for the design of novel therapeutic strategies for T1D prevention.
Assuntos
Diabetes Mellitus Tipo 1/patologia , Mucosa Intestinal/anormalidades , Animais , Citocinas/metabolismo , Células Dendríticas/imunologia , Diabetes Mellitus Tipo 1/imunologia , Progressão da Doença , Disbiose/patologia , Feminino , Microbioma Gastrointestinal , Tolerância Imunológica , Mediadores da Inflamação/metabolismo , Mucosa Intestinal/patologia , Linfonodos/patologia , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos NOD , Muco/metabolismo , Pâncreas/metabolismo , Pâncreas/patologiaRESUMO
El síndrome de enterocolitis inducido por proteínas alimentarias es un síndrome de hipersensibilidad gastrointestinal a alimentos no mediado por inmunoglobulina E, que, en su forma aguda, se manifiesta con vómitos repetitivos, palidez e hipotonía, que puede acompañarse o no de diarrea y producir un cuadro grave de deshidratación y letargia. Una prueba de provocación oral controlada es, en ocasiones, realizada para confirmar el diagnóstico y el tratamiento consiste en la eliminación del alimento causante. Se presenta el caso de un lactante de 3 meses con varios episodios de síndrome de enterocolitis tras la toma de biberón de leche de fórmula de inicio con tolerancia de otra marca comercial. Se encontraron diferencias en los ingredientes de su composición que podrían ser el origen de la sensibilización.
Food protein-induced enterocolitis syndrome is a nonimmunoglobulin E mediated gastrointestinal food hypersensitivity that manifests as profuse, repetitive vomiting, pallor and hypotonia, often with diarrhea leading to severe dehydration and lethargy (sepsis-like symptoms) in the acute setting. An oral food challenge is sometimes performed to confirm the diagnosis and treatment consists of elimination of the food trigger(s) from the diet. We report a case of a 3-months-old infant with several episodes of food protein-induced enterocolitis syndrome after taking infant formula milk with tolerance of another trademark. Differences in the composition of its ingredients could be the cause of the sensitization.
Assuntos
Humanos , Masculino , Lactente , Proteínas Alimentares/efeitos adversos , Enterocolite/etiologia , Hipersensibilidade Alimentar/complicações , SíndromeRESUMO
Food protein-induced enterocolitis syndrome is a nonimmunoglobulin E mediated gastrointestinal food hypersensitivity that manifests as profuse, repetitive vomiting, pallor and hypotonia, often with diarrhea leading to severe dehydration and lethargy (sepsis-like symptoms) in the acute setting. An oral food challenge is sometimes performed to confirm the diagnosis and treatment consists of elimination of the food trigger(s) from the diet. We report a case of a 3-monthsold infant with several episodes of food protein-induced enterocolitis syndrome after taking infant formula milk with tolerance of another trademark. Differences in the composition of its ingredients could be the cause of the sensitization.
El síndrome de enterocolitis inducido por proteínas alimentarias es un síndrome de hipersensibilidad gastrointestinal a alimentos no mediado por inmunoglobulina E, que, en su forma aguda, se manifiesta con vómitos repetitivos, palidez e hipotonía, que puede acompañarse o no de diarrea y producir un cuadro grave de deshidratación y letargia. Una prueba de provocación oral controlada es, en ocasiones, realizada para confirmar el diagnóstico y el tratamiento consiste en la eliminación del alimento causante. Se presenta el caso de un lactante de 3 meses con varios episodios de síndrome de enterocolitis tras la toma de biberón de leche de fórmula de inicio con tolerancia de otra marca comercial. Se encontraron diferencias en los ingredientes de su composición que podrían ser el origen de la sensibilización.
Assuntos
Proteínas Alimentares/efeitos adversos , Enterocolite/etiologia , Hipersensibilidade Alimentar/complicações , Humanos , Lactente , Masculino , SíndromeRESUMO
Oral tolerance (OT) is characterized as a peripheral immune tolerance form, in which, mature lymphocytes in lymphoid tissues associated with mucosa, become non-functional or hypo responsive due to prior oral administration of antigen. OT is an important immunological phenomenon due to its therapeutic potential in inflammatory processes and others diseases. Here we evaluated leukotriene role in the induction of OT, as well as, the production of cytokines IL-5 and IFN-γ in leukotriene deficient animals (knock-out). Our results suggested that even in the presence of OT and leukotrienes absence, cytokine IFN-γ remains being secreted, which gives us an indication of immune system specificity and also that IFN-γ participates in various immune processes.
RESUMO
Vitamin A, a generic designation for an array of organic molecules that includes retinal, retinol and retinoic acid, is an essential nutrient needed in a wide array of aspects including the proper functioning of the visual system, maintenance of cell function and differentiation, epithelial surface integrity, erythrocyte production, reproduction, and normal immune function. Vitamin A deficiency is one of the most common micronutrient deficiencies worldwide and is associated with defects in adaptive immunity. Reports from epidemiological studies, clinical trials and experimental studies have clearly demonstrated that vitamin A plays a central role in immunity and that its deficiency is the cause of broad immune alterations including decreased humoral and cellular responses, inadequate immune regulation, weak response to vaccines and poor lymphoid organ development. In this review, we will examine the role of vitamin A in immunity and focus on several aspects of T cell biology such as T helper cell differentiation, function and homing, as well as lymphoid organ development. Further, we will provide an overview of the effects of vitamin A deficiency in the adaptive immune responses and how retinoic acid, through its effect on T cells can fine-tune the balance between tolerance and immunity.
Assuntos
Imunidade Celular , Linfócitos T/imunologia , Tretinoína/fisiologia , Imunidade Adaptativa , Animais , Diferenciação Celular/efeitos dos fármacos , Ensaios Clínicos como Assunto , Suplementos Nutricionais , Modelos Animais de Doenças , Células Epiteliais/efeitos dos fármacos , Humanos , Tolerância Imunológica , Linfócitos/efeitos dos fármacos , Organogênese , Células Th1/imunologia , Células Th17/imunologia , Células Th2/imunologia , Timo/efeitos dos fármacos , Deficiência de Vitamina A/sangue , Deficiência de Vitamina A/tratamento farmacológicoRESUMO
The induction of tolerance has been proposed as a therapeutic strategy for arthritis aiming to decrease progression of the pathology, probably by promoting suppressor mechanisms of the autoimmune response. This work aimed to confirm whether the treatment with vitamin D3 could synergize oral tolerance induced by hydrolyzed collagen peptides, in our experimental model of antigen induced arthritis in New Zealand rabbits. Clinical observation of the phenomenon indicates that simultaneous treatment with hydrolyzed collagen peptides and vitamin D3 was beneficial when compared with no treatment, for arthritic animals, and for arthritic animals that received treatment with only hydrolyzed collagen peptides or vitamin D3. Treatment with hydrolyzed collagen peptides caused diminished proinflammatory cytokine levels, an effect synergized significantly by the simultaneous treatment with vitamin D3. The anatomical-pathological studies of the animals that received both treatments simultaneously showed synovial tissues without lymphocytic and plasma cell infiltrates, and without vascular proliferation. Some of the synovial tissue of the animals of these groups showed a slight decrease in Galectin-3 expression. We propose that simultaneous oral treatment with vitamin D3 and hydrolyzed collagen peptides could increase the immunoregulatory effect on the process of previously triggered arthritis. We used articular cartilage hydrolysate and not collagen II because peptides best expose antigenic determinants that could induce oral tolerance. Oral tolerance may be considered in the design of novel alternative therapies for autoimmune disease and we have herein presented novel evidence that the simultaneous treatment with vitamin D3 may synergize this beneficial effect.
Assuntos
Artrite Reumatoide/tratamento farmacológico , Artrite Reumatoide/imunologia , Colecalciferol/administração & dosagem , Peptídeos/administração & dosagem , Administração Oral , Animais , Colágeno/química , Citocinas/imunologia , Feminino , Humanos , Coelhos , Membrana Sinovial/imunologiaRESUMO
BACKGROUND: Immunological tolerance refer to the inhibition of specific immune responsiveness and the ingestion of proteins previous to immunization is a reliable method to induce (oral) tolerance. Parenteral exposure to tolerated antigens, in adjuvant, trigger indirect and systemic effects that inhibits concomitant immune responses to other unrelated antigens and also decrease unrelated inflammatory responses. Interesting, intraperitoneal (i.p.) exposure to orally-tolerated proteins soon before an incisional linear skin wound improves the healing by primary intention in mice. An important clinical and surgical objective is to identify strategies to improve wound healing and reduce scarring. OBJECTIVE: To evaluate whether i.p. injection of an orally-tolerated protein improves wound healing by secondary intention and reduce scarring of full-thickness excisional skin injury. METHODS: C57Bl/6 mice were turned tolerant to ovalbumin (OVA) by drinking a solution containing OVA; seven days later, they received an i.p. injection of OVA plus Al(OH)3 adjuvant immediately before two full-thickness excisional skin wounds, under anesthesia. The wound healing process was evaluated macro and microscopically after H&E, toluidine blue and Gomori's Trichrome staining. The presence of granulocytes, macrophages, miofibroblasts, fibronectin, collagen I and collagen III was investigated by immunofluorescence and the levels of cytokines by flow cytometry or ELISA. Mice not tolerant to OVA were included as controls. RESULTS: The i.p. injection of OVA+Al(OH)3 in mice orally tolerant to OVA reduced the subsequent inflammatory response in the wound bed and the cutaneous scarring. There was a change in the pattern of collagen deposition making it more similar to the pattern observed in intact skin. In tolerant mice, mast cells and granulocytes (Ly-6C/G+), were reduced, while lymphocytes (CD3+) were increased in the wound bed. Time course analysis of Th1/Th2/Th17 cytokines and growth factors showed slightly differences between tolerant and control groups. CONCLUSION: Parenteral injection of an orally-tolerated protein has systemic consequences that impair the inflammatory response triggered by skin injury and reduce the cutaneous scarring.
Assuntos
Cicatriz/imunologia , Cicatriz/patologia , Tolerância Imunológica , Pele/imunologia , Pele/patologia , Cicatrização/imunologia , Administração Oral , Animais , Antígenos/imunologia , Biomarcadores , Colágeno/metabolismo , Citocinas/biossíntese , Modelos Animais de Doenças , Injeções Intraperitoneais , Masculino , Camundongos , Ovalbumina/administração & dosagem , Ovalbumina/imunologia , Pele/lesõesRESUMO
BACKGROUND: Ethanol (EtOH) consumption is able to disturb the ovalbumin (OVA)-oral tolerance induction by interfering on the function of antigen presenting cells (APC), down-regulating dendritic cells (DCs) and macrophages and up-regulating B-lymphocytes and their function, which results in an overall allergic-type immune status. In this study, the potential of a priori administration of Lactococcus lactis (LL) in avoiding loss of oral tolerance in EtOH-treated mice was investigated. METHODS: Female C57BL/6 mice received, by oral route, ad libitum wild-type (WT) LL or heat-shock protein producer (Hsp65) LL for 4 consecutive days. Seven days later, mice were submitted to short-term high-dose EtOH treatment. After 24 hours, stomach, intestine, spleen, mesenteric lymph nodes (mLN) specimens were collected for biomarkers analysis. Following EtOH-treatment protocol, a group of animals underwent single-gavage OVA-tolerance protocol and sera samples collected for antibody analysis. RESULTS: The ingestion of WT LL or Hsp65 LL is able to restore oral tolerance to OVA in EtOH-treated mice, by reducing local and systemic allergic outcomes such as gastric mast cells and gut-interleukin-4, as well as serum IgE. WT LL treatment prevents the decrease of mLN regulatory T cells induced by the EtOH treatment. Moreover, LL treatment preserves APC hierarchy and antigen presentation commitment in EtOH-treated mice, with conserved DC and macrophage activity over B lymphocytes in mLN and preserved macrophage activity over DC and B-cell subsets in the spleen. CONCLUSIONS: The present findings suggest that a priori ingestion of LL preserves essential mechanisms associated with oral tolerance induction that are disturbed by EtOH ingestion. Maintenance of mucosal homeostasis by preserving APC hierarchy and antigen presentation commitment could be associated with T-regulatory subset activities in the gastrointestinal tract.
Assuntos
Apresentação de Antígeno/imunologia , Etanol/administração & dosagem , Trato Gastrointestinal/imunologia , Tolerância Imunológica/imunologia , Lactococcus lactis , Administração Oral , Animais , Apresentação de Antígeno/efeitos dos fármacos , Feminino , Trato Gastrointestinal/efeitos dos fármacos , Tolerância Imunológica/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BLRESUMO
The aim of the present study was to investigate the effect of a protein-free diet in the induction of food allergy and oral tolerance in BALB/c mice. The experimental model used was mice that were fed, since weaning up to adulthood, a balanced diet in which all dietary proteins were replaced by amino acid diet (Aa). The absence of dietary proteins did not prevent the development of food allergy to ovalbumin (OVA) in these mice. However, Aa-fed mice produced lower levels of IgE, secretory IgA and cytokines. In addition, when compared with mice from control group, Aa-fed mice had a milder aversive reaction to the allergen measured by consumption of OVA-containing solution and weight loss during food allergy development. In addition, mice that did not have dietary proteins in their diets were less susceptible to induction of oral tolerance. One single oral administration was not enough to suppress specific serum Ig and IgG1 levels in the Aa-fed group, although it was efficient to induce suppression in the control group. The present results indicate that the stimulation by dietary proteins alters both inflammatory reactivity and regulatory immune reactivity in mice probably due to their effect in the maturation of the immune system.