Influence of Lactococcus lactis and expression of heat shock protein (HSP)-65 in the development of allergic process and behavior modulation in mice

Abstract

The prevalence of allergic diseases is continuously increasing. Asthma, food allergy, dermatitis, and systemic anaphylaxis are amongst the most common allergic diseases. The development of allergic processes occurs when regulatory mechanisms responsible for the phenomenon of immunological tolerance fail. The underlying mechanisms involved in the pathophysiology of classic allergic reactions have been well characterized, but little is known about its regulation. Ligands of Toll-like receptor (TLR)-4, such as bacterial endotoxins (e.g. LPS), may influence the development of allergies. However, the effect of endogenous ligands of TLR-4, such as heat shock proteins (e.g. HSP-65), in the modulation of allergic responses is not known. There is evidence that the intestinal microbiota can influence allergic reactions. Therefore, the oral administration of Lactococcus lactis expressing or not HSP-65 will be performed in a murine model of allergic asthma to investigate the effect of probiotics as well as HSP in the development of allergies. Nowadays it is known that allergic reactions influence the central nervous system (CNS), modulating behavioral aspects such as anxiety and depression. There is also evidence that microbiota can either directly modulate behavior or indirectly, via the interaction with immune system. Therefore, using the same model of allergic asthma, the effect of oral Lactococcus lactis expressing or not HSP-65 in the modulation of animal behavior will be studied. Thus, the present work will study the interactions between microbiota, immune and nervous systems, aiming to achieve potential alternatives for treatment and/or prevention of allergic diseases. (AU)