Inmunología: investigación actual

Abstracto

New Insights into Antimicrobial Peptides Isolated from Brazilian Natural Sources

Laura Cristina Lima Diniz and Pedro Ismael da Silva Junior

Antimicrobial Peptides or Proteins (AMPs) are components of the humoral response of the innate immune system. Representing a fast and effective initial barrier against pathogens, these molecules gained visibility as several began to be described as potent bioactive molecules. AMPs are generally amphypathic and cationic and have high hydrophobic properties at physiological pH, leading to different mechanisms of actions. Some of them may interact with negatively charged microbial membranes; others can penetrate the membrane and have intracellular targets. As these mechanisms occur due to charge-based interaction, these molecules generally act in an independent protein-binding manner, hindering the development of resistance mechanisms. Nowadays there is an urgent need to produce new antibiotics that can act over resistant bacteria/fungi. Thus, AMPs are very good candidates to substitute commercial antibiotics due to these physical-chemistry features and mechanism of action. Thus, our field of study on Butantan Institute is to identify AMPs from different natural sources, including chicken eggs, pineapple, garlic and invertebrates, such as kissing bugs, spiders, centipedes and scorpions among others. A wide broad of molecules have been isolated and had their antimicrobial potential confirmed. Serrulin from the scorpion Tityus serrulatus, Lacrain from the centipede Scolopendra viridicornis, Sarconesin from the fly Sarconesiopsis magellanica and Juruin from the spider Avicularia juruensis are some of the examples. Triatoma infestans, member of the Triatominae subfamily, popularly known as kissing bugs, feeds with blood and has a major role as Chagas disease vector. Regarding new researches related to AMPs in triatomines, few molecules have been identified so far, and no research on this area have been developed with T. infestans, and due to the fact that this insect survives in a highly infectious habitat during its life cycle, we were able to obtain new information of AMPs used by this insect.