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1.
J Allergy Clin Immunol Pract ; 9(1): 321-327, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33217614

RESUMO

BACKGROUND: Tree nut allergies affect an estimated 1% of the US population and is lifelong in 90% of allergic individuals. Oral immunotherapy (OIT) for food allergies is an effective method to induce desensitization in a majority of participants in trials of peanut, egg, and milk OIT. Limited trials using tree nut OIT have been reported, possibly due to the lack of standardized drug products. OBJECTIVE: Food products used in OIT are considered drugs by the Food and Drug Administration (FDA) because they are intended to modulate the individuals' immune responses to the food allergens. As such, OIT drug products must meet FDA standards for acceptable levels of microbes and undergo testing for allergenic proteins. We aimed to determine the suitability of walnut, cashew, hazelnut, and almond flours for use in OIT trials. METHODS: We employed gamma irradiation on commercially available walnut, cashew, hazelnut, and almond flours and tested their levels of microbial contamination, total protein, and allergen content, along with stability of these parameters over time. RESULTS: Our results demonstrate that irradiation of tree nut flours greatly diminishes the levels of total aerobic bacteria, mold, yeast, Escherichia coli, and Salmonella, whereas there are no substantial changes in total protein or allergen content. Importantly, the microbial levels, protein, and allergen content remained stable over a 24-month period. CONCLUSION: Irradiation of tree nut flours is a safe and effective method of processing to allow tree nut products to meet the FDA standards for OIT drug products.


Assuntos
Hipersensibilidade a Noz , Nozes , Administração Oral , Alérgenos , Dessensibilização Imunológica , Farinha , Humanos , Imunoterapia
2.
J Allergy Clin Immunol Pract ; 5(4): 1098-1104, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28132800

RESUMO

BACKGROUND: Oral immunotherapy (OIT) is an investigational therapeutic approach for the treatment of food allergies. Characterization of the drug product used in oral immunotherapy trials for peanut allergy has not been reported. OBJECTIVE: To quantify relative amounts of the major peanut allergens and microbial load present in peanut flour used in OIT trials and assess whether these parameters change over a 12-month period. We also anticipate that this report will serve as a guide for investigators seeking to conduct OIT trials under Food and Drug Administration-approved Investigational New Drug applications. METHODS: Densitometric scanning of Ara h 1 and Ara h 2 resolved on SDS-PAGE gels was used to assess allergen content in peanut flour extracts. Microbial testing was conducted on peanut flour under US Pharmacopeia guidelines for the presence of Escherichia coli, salmonella, yeast, mold, and total aerobic bacteria. In addition, aflatoxin was quantified in peanut flour. Reported results were obtained from 4 unique lots of peanut flour. RESULTS: Relative amounts of the major peanut allergens were similar between different lots of peanut flour and remained stable over a 12-month period. E coli and salmonella were absent from all lots of flour. Yeast, mold, total aerobic bacteria, and aflatoxin were within established US Pharmacopeia guidelines on all lots tested and remained within the criteria over a 12-month period. CONCLUSIONS: Peanut flour used as a drug product contains the major peanut allergens and has low levels of potentially harmful microbes. Both these parameters remain stable over a 12-month period.


Assuntos
Arachis , Dessensibilização Imunológica , Farinha/análise , Albuminas 2S de Plantas/análise , Aflatoxinas/análise , Alérgenos/análise , Antígenos de Plantas/análise , Bactérias/isolamento & purificação , Ensaios Clínicos como Assunto , Farinha/microbiologia , Fungos/isolamento & purificação , Glicoproteínas/análise , Humanos , Proteínas de Membrana , Hipersensibilidade a Amendoim/terapia , Proteínas de Plantas/análise
3.
J Allergy Clin Immunol ; 139(3): 882-888.e5, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27609653

RESUMO

BACKGROUND: Though peanut oral immunotherapy (OIT) is a promising investigational therapy, its potential is limited by substantial adverse events (AEs), which are relatively understudied. OBJECTIVE: A retrospective analysis was conducted, pooling data from 3 pediatric peanut OIT trials, comprising the largest analysis of peanut OIT safety to date. METHODS: We pooled data from 104 children with peanut allergy from 3 peanut OIT studies. We catalogued AEs from parental reports, daily symptom diaries, and dose escalations. We included events that were considered likely related to OIT and identified potential baseline predictors of higher AE rates using generalized linear regression models. RESULTS: Eighty percent of subjects experienced likely related AEs during OIT (72% during buildup and 47% during maintenance). Of these AEs, over 90% occurred while at home. Approximately 42% of subjects experienced systemic reactions, and 49% experienced gastrointestinal symptoms. Twenty percent of subjects dropped out, with half (10% of the overall group) due to persistent gastrointestinal symptoms. Baseline allergic rhinitis (AR) and peanut SPT wheal size were significant predictors of higher overall AE rates. SPT wheal size predicted increased gastrointestinal AEs, and AR predicted increased systemic reactions. Over the course of OIT, 61% of subjects received treatment for likely related AEs, 59% with antihistamines and 12% with epinephrine. CONCLUSIONS: Peanut OIT is associated with frequent AEs, with rates declining over time, and most graded mild. However, systemic reactions and intolerable gastrointestinal AEs do occur and are significantly associated with AR and peanut SPT wheal size, respectively. Further study is needed of predictive biomarkers and the overall risks and benefits of OIT.


Assuntos
Dessensibilização Imunológica/efeitos adversos , Hipersensibilidade a Amendoim/terapia , Adolescente , Criança , Pré-Escolar , Epinefrina/uso terapêutico , Feminino , Antagonistas dos Receptores Histamínicos/uso terapêutico , Humanos , Lactente , Recém-Nascido , Masculino , Ensaios Clínicos Controlados Aleatórios como Assunto , Rinite Alérgica/terapia
4.
J Allergy Clin Immunol ; 139(1): 173-181.e8, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27522159

RESUMO

BACKGROUND: Oral immunotherapy (OIT) is an effective experimental food allergy treatment that is limited by treatment withdrawal and the frequent reversibility of desensitization if interrupted. Newly diagnosed preschool children may have clinical and immunological characteristics more amenable to treatment. OBJECTIVE: We sought to test the safety, effectiveness, and feasibility of early OIT (E-OIT) in the treatment of peanut allergy. METHODS: We enrolled 40 children aged 9 to 36 months with suspected or known peanut allergy. Qualifying subjects reacted to peanut during an entry food challenge and were block-randomized 1:1 to receive E-OIT at goal maintenance doses of 300 or 3000 mg/d in a double-blinded fashion. The primary end point, sustained unresponsiveness at 4 weeks after stopping early intervention oral immunotherapy (4-SU), was assessed by double-blinded, placebo-controlled food challenge either upon achieving 4 prespecified criteria, or after 3 maintenance years. Peanut-specific immune responses were serially analyzed. Outcomes were compared with 154 matched standard-care controls. RESULTS: Of 40 consented subjects, 3 (7.5%) did not qualify. Overall, 29 of 37 (78%) in the intent-to-treat analysis achieved 4-SU (300-mg arm, 17 of 20 [85%]; 3000 mg, 12 of 17 [71%], P = .43) over a median of 29 months. Per-protocol, the overall proportion achieving 4-SU was 29 of 32 (91%). Peanut-specific IgE levels significantly declined in E-OIT-treated children, who were 19 times more likely to successfully consume dietary peanut than matched standard-care controls, in whom peanut-specific IgE levels significantly increased (relative risk, 19.42; 95% CI, 8.7-43.7; P < .001). Allergic side effects during E-OIT were common but all were mild to moderate. CONCLUSIONS: At both doses tested, E-OIT had an acceptable safety profile and was highly successful in rapidly suppressing allergic immune responses and achieving safe dietary reintroduction.


Assuntos
Dessensibilização Imunológica , Hipersensibilidade a Amendoim/terapia , Alérgenos/imunologia , Antígenos de Plantas/imunologia , Arachis/imunologia , Pré-Escolar , Método Duplo-Cego , Feminino , Humanos , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Lactente , Masculino , Hipersensibilidade a Amendoim/sangue , Proteínas de Plantas/imunologia
5.
Clin Transl Sci ; 8(5): 526-32, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25588691

RESUMO

PURPOSE: The Food and Drug Administration Expanded Access (EA) program and "Right-to-Try" legislation aim to provide seriously ill patients who have no other comparable treatment options to gain access to investigational drugs and biological agents. Physicians and institutions need to understand these programs to respond to questions and requests for access. METHODS: FDA EA programs and state and federal legislative efforts to provide investigational products to patients by circumventing FDA regulations were summarized and compared. RESULTS: The FDA EA program includes Single Patient-Investigational New Drug (SP-IND), Emergency SP-IND, Intermediate Sized Population IND, and Treatment IND. Approval rates for all categories exceed 99%. Approval requires FDA and Institutional Review Board (IRB) approval, and cooperation of the pharmaceutical partner is essential. "Right-to-Try" legislation bypasses some of these steps, but provides no regulatory or safety oversight. CONCLUSION: The FDA EA program is a reasonable option for patients for whom all other therapeutic interventions have failed. The SP-IND not only provides patient access to new drugs, but also maintains a balance between immediacy and necessary patient protection. Rather than circumventing existing FDA regulations through proposed legislation, it seems more judicious to provide the knowledge and means to meet the EA requirements.


Assuntos
Ensaios de Uso Compassivo/legislação & jurisprudência , Aprovação de Drogas/legislação & jurisprudência , Drogas em Investigação/uso terapêutico , Política de Saúde/legislação & jurisprudência , Acessibilidade aos Serviços de Saúde/legislação & jurisprudência , United States Food and Drug Administration/legislação & jurisprudência , Drogas em Investigação/efeitos adversos , Definição da Elegibilidade/legislação & jurisprudência , Humanos , Segurança do Paciente , Desenvolvimento de Programas , Medição de Risco , Fatores de Risco , Estados Unidos
6.
Clin Transl Sci ; 8(1): 48-51, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25387802

RESUMO

The Food and Drug Administration Amendments Act of 2007 (FDAAA 2007, US Public Law 110-98) mandated registration and reporting of results for applicable clinical trials. Meeting these registration and results reporting requirements has proven to be a challenge for the academic research community. Duke Medicine has made compliance with registration and results reporting a high priority. In order to create uniformity across a large institution, a written policy was created describing requirements for clinical trials disclosure. Furthermore, a centralized resource group was formed with three full time staff members. The group not only ensures compliance with FDAAA 2007, it also acts as a resource for study teams providing hands-on support, reporting, training, and ongoing education. Intensive resourcing for results reporting has been crucial for success. Due to implementation of the institutional policy and creation of centralized resources, compliance with FDAAA 2007 has increased dramatically at Duke Medicine for both registration and results reporting. A consistent centralized approach has enabled success in the face of changing agency rules and new legislation.


Assuntos
Centros Médicos Acadêmicos , Ensaios Clínicos como Assunto , Internet , Relatório de Pesquisa , Comitês Consultivos , Humanos , Investimentos em Saúde
7.
Diabetes ; 63(12): 4100-14, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24985350

RESUMO

Little is known about the molecular mechanisms underlying age-dependent deterioration in ß-cell function. We now demonstrate that age-dependent impairment in insulin release, and thereby glucose homeostasis, is associated with subtle changes in Ca(2+) dynamics in mouse ß-cells. We show that these changes are likely to be accounted for by impaired mitochondrial function and to involve phospholipase C/inositol 1,4,5-trisphosphate-mediated Ca(2+) mobilization from intracellular stores as well as decreased ß-cell Ca(2+) influx over the plasma membrane. We use three mouse models, namely, a premature aging phenotype, a mature aging phenotype, and an aging-resistant phenotype. Premature aging is studied in a genetically modified mouse model with an age-dependent accumulation of mitochondrial DNA mutations. Mature aging is studied in the C57BL/6 mouse, whereas the 129 mouse represents a model that is more resistant to age-induced deterioration. Our data suggest that aging is associated with a progressive decline in ß-cell mitochondrial function that negatively impacts on the fine tuning of Ca(2+) dynamics. This is conceptually important since it emphasizes that even relatively modest changes in ß-cell signal transduction over time lead to compromised insulin release and a diabetic phenotype.


Assuntos
Envelhecimento/metabolismo , Glicemia/metabolismo , Cálcio/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Transporte de Elétrons/fisiologia , Células Secretoras de Insulina/metabolismo , Mitocôndrias/metabolismo , Animais , Inositol 1,4,5-Trifosfato/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/genética , Fosfolipases Tipo C/metabolismo
8.
J Investig Med ; 62(5): 797-803, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24831858

RESUMO

OBJECTIVE: The objective of this study was to provide recommendations for provision of training for sponsor and investigators at Academic Health Centers. BACKGROUND: A subgroup of the Investigational New Drug/Investigational Device Exemption (IND/IDE) Task Force of the Clinical and Translational Science Award (CTSA) program Regulatory Knowledge Key Function Committee was assembled to specifically address how clinical investigators who hold an IND/IDE and thus assume the role of sponsor-investigators are adequately trained to meet the additional regulatory requirements of this role. METHODS: The participants who developed the recommendations were representatives of institutions with IND/IDE support programs. Through an informal survey, the task force determined that a variety and mix of models are used to provide support for IND/IDE holders within CTSA institutions. In addition, a CTSA consortium-wide resources survey was used. The participants worked from the models and survey results to develop consensus recommendations to address institutional support, training content, and implementation. RECOMMENDATIONS: The CTSA IND/IDE Task Force recommendations are as follows: (1) Institutions should assess the scope of Food and Drug Administration-regulated research, perform a needs analysis, and provide resources to implement a suitable training program; (2) The model of training program should be tailored to each institution; (3) The training should specifically address the unique role of sponsor-investigators, and the effectiveness of training should be evaluated regularly by methods that fit the model adopted by the institution; and (4) Institutional leadership should mandate sponsor-investigator training and effectively communicate the necessity and availability of training.


Assuntos
Comitês Consultivos/normas , Aprovação de Equipamentos/normas , Drogas em Investigação/normas , Desenvolvimento de Programas/normas , Pesquisa Translacional Biomédica/educação , Pesquisa Translacional Biomédica/normas , Educação/métodos , Educação/normas , Humanos , Desenvolvimento de Programas/métodos , Pesquisadores/educação , Pesquisadores/normas , Pesquisa Translacional Biomédica/métodos
9.
J Allergy Clin Immunol ; 133(2): 500-10, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24636474

RESUMO

BACKGROUND: The mechanisms contributing to clinical immune tolerance remain incompletely understood. This study provides evidence for specific immune mechanisms that are associated with a model of operationally defined clinical tolerance. OBJECTIVE: Our overall objective was to study laboratory changes associated with clinical immune tolerance in antigen-induced T cells, basophils, and antibodies in subjects undergoing oral immunotherapy (OIT) for peanut allergy. METHODS: In a phase 1 single-site study, we studied participants (n = 23) undergoing peanut OIT and compared them with age-matched allergic control subjects (n = 20) undergoing standard of care (abstaining from peanut) for 24 months. Participants were operationally defined as clinically immune tolerant (IT) if they had no detectable allergic reactions to a peanut oral food challenge after 3 months of therapy withdrawal (IT, n = 7), whereas those who had an allergic reaction were categorized as nontolerant (NT; n = 13). RESULTS: Antibody and basophil activation measurements did not statistically differentiate between NT versus IT participants. However, T-cell function and demethylation of forkhead box protein 3 (FOXP3) CpG sites in antigen-induced regulatory T cells were significantly different between IT versus NT participants. When IT participants were withdrawn from peanut therapy for an additional 3 months (total of 6 months), only 3 participants remained classified as IT participants, and 4 participants regained sensitivity along with increased methylation of FOXP3 CpG sites in antigen-induced regulatory T cells. CONCLUSION: In summary, modifications at the DNA level of antigen-induced T-cell subsets might be predictive of a state of operationally defined clinical immune tolerance during peanut OIT.


Assuntos
Dessensibilização Imunológica , Fatores de Transcrição Forkhead/imunologia , Tolerância Imunológica/imunologia , Hipersensibilidade a Amendoim/imunologia , Linfócitos T Reguladores/imunologia , Administração Oral , Adolescente , Adulto , Antígenos/imunologia , Arachis/efeitos adversos , Arachis/imunologia , Criança , Pré-Escolar , Células Dendríticas/imunologia , Método Duplo-Cego , Feminino , Humanos , Imunoglobulina E/sangue , Imunoglobulina G/sangue , Masculino , Metilação , Pessoa de Meia-Idade , Hipersensibilidade a Amendoim/terapia , Adulto Jovem
10.
J Allergy Clin Immunol ; 133(2): 468-75, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24361082

RESUMO

BACKGROUND: Although peanut oral immunotherapy (OIT) has been conclusively shown to cause desensitization, it is currently unknown whether clinical protection persists after stopping therapy. OBJECTIVE: Our primary objective was to determine whether peanut OIT can induce sustained unresponsiveness after withdrawal of OIT. METHODS: We conducted a pilot clinical trial of peanut OIT at 2 US centers. Subjects age 1 to 16 years were recruited and treated for up to 5 years with peanut OIT. The protocol was modified over time to permit dose increases to a maximum of 4000 mg/d peanut protein. Blood was collected at multiple time points. Clinical end points were measured with 5000-mg double-blinded, placebo-controlled food challenges once specific criteria were met. RESULTS: Of the 39 subjects originally enrolled, 24 completed the protocol and had evaluable outcomes. Twelve (50%) of 24 successfully passed a challenge 1 month after stopping OIT and achieved sustained unresponsiveness. Peanut was added to the diet. At baseline and the time of challenge, such subjects had smaller skin test results, as well as lower IgE levels specific for peanut, Ara h 1, and Ara h 2 and lower ratios of peanut-specific IgE/total IgE compared with subjects not passing. There were no differences in peanut IgG4 levels or functional activity at the end of the study. CONCLUSIONS: This is the first demonstration of sustained unresponsiveness after peanut OIT, occurring in half of subjects treated for up to 5 years. OIT favorably modified the peanut-specific immune response in all subjects completing the protocol. Smaller skin test results and lower allergen-specific IgE levels were predictive of successful outcome.


Assuntos
Dessensibilização Imunológica , Hipersensibilidade a Amendoim/terapia , Albuminas 2S de Plantas/imunologia , Administração Oral , Adolescente , Antígenos de Plantas/imunologia , Arachis/imunologia , Criança , Pré-Escolar , Método Duplo-Cego , Glicoproteínas/imunologia , Humanos , Imunoglobulina E/sangue , Lactente , Proteínas de Membrana , Hipersensibilidade a Amendoim/sangue , Hipersensibilidade a Amendoim/imunologia , Proteínas de Plantas/imunologia , Testes Cutâneos
11.
Clin Invest Med ; 36(6): E290-6, 2013 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-24309225

RESUMO

PURPOSE: This study highlights Warning Letter (WL) findings issued to sponsor-investigators (S-Is) by the Food and Drug Administration (FDA). METHODS: The online index of WLs issued from October 1, 2007 through September 30, 2012 was reviewed [1]. Through a manual screening process, letters were evaluated if specifically issued to 'clinical investigators', 'sponsors' or 'sponsor-investigators'. A particular focus was given to S-Is at Academic Health Centres (AHCs). Each letter was scored for the presence of violations in 40 general regulatory categories. RESULTS: A review of FDA WLs issued over a five-year period (FDA Fiscal Years 2008-2012) revealed that WLs to S-Is represent half of the WLs issued to all sponsors (16 of 32 letters). A review of these letters indicates that S-Is are not aware of, or simply do not meet, their regulatory responsibilities as either investigators or sponsors. In comparing total sponsor letters to those of S-Is, the most cited violation was the same: a lack of monitoring. A review of publicly available inspection data indicates that these 16 letters merely represent the tip of the iceberg. CONCLUSION: This review of the WL database reveals the potential for serious regulatory violations among S-Is at AHCs. Recent translational funding initiatives may serve to increase the number of S-Is, especially among Academic Health Centres (AHCs) [2]; thus, AHCs must become aware of this S-I role and work to support investigators who assume both roles in the course of their research.


Assuntos
Pesquisa Biomédica/legislação & jurisprudência , Bases de Dados Factuais , United States Food and Drug Administration , Correspondência como Assunto , Feminino , Humanos , Masculino , Estados Unidos
12.
J Investig Med ; 60(7): 987-94, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22847340

RESUMO

Clinical investigators in academic medical centers often perceive federal regulations as a significant obstacle to conducting clinical research. The regulatory authority of the Food and Drug Administration (FDA) extends to clinical studies of medical devices. Consequently, researchers wishing to conduct device research using FDA-approved as well as nonapproved devices must comply with federal regulations for investigational device exemptions (IDE) as described in Title 21 of the Code of Federal Regulations Part 812. FDA regulatory oversight is structured to match the risk to the subject to the risk of the device. Medical device studies can be categorized as follows: meeting exemption criteria, being a nonsignificant risk device, or being a significant risk device. All IDE studies must meet regulations for the protection of human subjects, but no additional federal filing on the part of the investigator is necessary for those that meet exempt criteria. Nonsignificant risk device studies require meeting abbreviated IDE regulatory requirements for the conduct of the study, but no previous FDA approval is required. Significant risk device studies require that the investigator also function as a sponsor and to file an IDE with the FDA for approval before starting. A sponsor-investigator filing an IDE follows the format and content described in 21 CFR 812.20. The study may begin 30 days after the date of submission receipt unless the FDA notifies the sponsor otherwise. While the IDE is active, the sponsor-investigator must meet the requirements for the conduct of the study and the required monitoring and reporting to the FDA.


Assuntos
Aprovação de Equipamentos/legislação & jurisprudência , Pesquisadores/legislação & jurisprudência , United States Food and Drug Administration/legislação & jurisprudência , Humanos , Estados Unidos
13.
Sci Signal ; 3(113): ra19, 2010 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-20234002

RESUMO

Parasympathetic stimulation of pancreatic islets augments glucose-stimulated insulin secretion by inducing inositol trisphosphate receptor (IP(3)R)-mediated calcium ion (Ca2+) release. Ankyrin-B binds to the IP(3)R and is enriched in pancreatic beta cells. We found that ankyrin-B-deficient islets displayed impaired potentiation of insulin secretion by the muscarinic agonist carbachol, blunted carbachol-mediated intracellular Ca2+ release, and reduced the abundance of IP3R. Ankyrin-B-haploinsufficient mice exhibited hyperglycemia after oral ingestion but not after intraperitoneal injection of glucose, consistent with impaired parasympathetic potentiation of glucose-stimulated insulin secretion. The R1788W mutation of ankyrin-B impaired its function in pancreatic islets and is associated with type 2 diabetes in Caucasians and Hispanics. Thus, defective glycemic regulation through loss of ankyrin-B-dependent stabilization of IP3R is a potential risk factor for type 2 diabetes.


Assuntos
Anquirinas/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Sistema Nervoso Parassimpático/metabolismo , Animais , Anquirinas/deficiência , Anquirinas/genética , Cálcio/metabolismo , Carbacol/metabolismo , Glucose/metabolismo , Immunoblotting , Secreção de Insulina , Camundongos , Microscopia de Fluorescência , Mutação de Sentido Incorreto , Polimorfismo de Nucleotídeo Único/genética , RNA Interferente Pequeno/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Risco
14.
Mol Immunol ; 45(11): 3059-64, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18471883

RESUMO

Mouse T-cell development is unfinished at birth and continues during the first month of life, when T cells exit from the thymus and colonize secondary hematopoietic organs to build up a peripheral T-cell repertoire. T-cell responses against beta-cell-derived autoantigens are initiated in the pancreatic lymph nodes (PLN) of non-obese diabetic (NOD) mice during the same time period. We hypothesized that the combined effect of T-cell development and T-cell activation against tissue-specific antigens would create unique TCR repertoires in two different lymph node stations in NOD mice. To test this hypothesis, we determined the length distribution of the third complementarity-determining region (CDR3) of the TCR in the PLN and the inguinal lymph nodes (ILN) of 10, 14, 18 and 22-day-old NOD females. The analysis of all the BV genes revealed significant perturbations of the repertoire between days 10 and 22 but with no statistical differences between the PLN and ILN repertoires. In contrast, when a set of BV chains were amplified using BJ-specific primers, several unique TCR perturbations were observed in the PLN compared to the ILN. We propose that the TCR repertoire in peripheral lymph nodes of NOD mice develops dynamically between 10 and 22 days of age as a result of a developmental process. On top of that development, the local environment may fine-tune that repertoire, possibly by means of stimulation of T cells by tissue-specific antigens presented by local APC.


Assuntos
Linfonodos/imunologia , Pâncreas/imunologia , Estado Pré-Diabético/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Animais , Animais Recém-Nascidos , Regiões Determinantes de Complementaridade/imunologia , Feminino , Camundongos , Camundongos Endogâmicos NOD , Fatores de Tempo
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