Avaliação do uso de Lactococcus lactis produtores ou não da Proteína do choque térmico 65 como estratégia imunomodulatória em camundongos com alergia alimentar experimental à ovalbumina

Abstract

Food allergy is most frequently the result of IgE-mediated hypersensitivity reactions and is related to the failure of some regulatory mechanisms. It has been shown that Heat Shock Protein 65 (HSP65) is released during cellular injury and can increase inflammatory response. Based on this, we suggest that an oral pretreatment with HSP65, which could turn the mice tolerant to HSP65, could decrease signs of food allergy. To investigate this hypothesis, we induced oral tolerance to HSP65, through the ingestion of transgenic Lactococcus lactis (L. lactis)-secreting HSP65 before antigen sensitization. Food allergy was induced through subcutaneous injection with ovalbumin in aluminum hydroxide and challenged with the antigen containing diet for 7 days, in female mice BALB/c. The treatments consisted of oral ingestion (during 4 days) of L. lactis wild-type (WT), or L. lactis secreting HSP65, or only the medium M17 cultures, 7 days before the OVA sensitization. Both treatments reduced almost equally the majority of the food allergy observed signs. Compare to allergic group medium, animals from allergic groups treated with WT and HSP65 had reduction in serum anti-OVA IgE levels, intestinal eosinophils numbers, mucus production and IL-6 levels in the adipose tissue. We conclude that L. lactis could be a probiotic in potential. To investigate whether oral tolerance to HSP65 is involved in this response, new experiments with new protocols should be further addressed