Alergia alimentar - temporalidade X antigenicidade

• Autor(a) principal: Paschoal, Patrícia Olaya
• Data de Publicação: 2007
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal Fluminense (RIUFF)
• Texto Completo: https://app.uff.br/riuff/handle/1/17632
• topic: Alergia alimentar; Amendoim; Ovalbumina; Tolerância oral; Hipersensibilidade alimentar; Enteropatia inflamatória; Ovalbumina; Patologia Investigativa; Medicina; Food Allergy; Oral tolerance; Ovalbumin; Peanuts; CNPQ::CIENCIAS DA SAUDE::MEDICINA::ANATOMIA PATOLOGICA E PATOLOGIA CLINICA

INTRODUCTION: Mechanisms involved in the induction of oral tolerance or systemic immunization through the oral rout are still not completely clear. In our previous studies we have shown that when normal mice eat peanuts they become tolerant, and do not develop gut alterations. However, if they are immunized with peanut extract prior to a challenge diet containing peanuts they develop a chronic inflammation of the gut. AIMS: evaluate the influence of oral tolerance in a subsequent immunization to a non-related protein. Conversely evaluate the consequences of the introduction of a novel protein in the diet of animals presenting an inflamed gut. MATERIAL AND METHODS Adult, male and female C57BL/6J mice. In the first experiment, animals were submitted to oral tolerance induction protocol with peanut (A), OVA (O) and chow (R) prior to systemic immunization. Subsequently all groups were subdivided into three groups according to the antigen inoculated Peanut (1), Ova (2) and Saline (3). In the second experiment, control group - C1 was submitted to oral tolerance induction protocol (7 day oral exposure followed by 2 immunizations with 100ug of OVA) and C2 to immunization protocol with 100ug of OVA. The experimental group was immunized twice with 100ug of peanut extract. After that, they were exposed to a challenge diet for 30 days. During the challenge diet, the experimental group was divided into 5 other groups (E1-E5), which were all submitted to oral tolerance protocol. OVA feeding began 7 days prior to the challenge diet (E1) and on days 0, 7, 14 and 21, after initiating the challenge diet for groups E2, E3, E4 and E5 respectively. Oral exposure to a novel protein (OVA) in immune animals (peanut) prior to induction of gut inflammation (E1) led to low levels of systemic antibody titers when compared to the tolerant control group. Conversely, as off initial induction of inflammation, all groups that received OVA to drink presented high systemic antibody titers when compared to the immune control group and are significantly different from C1. Thus, when animals are given a novel protein in their diet while presenting an inflamed gut, they do not become tolerant to it, but become sensitized