Ciliated protists: a new source of molecules with antimicrobial activities

• Grant number: 22/00538-0
• Support type: Regular Research Grants
• Duration: June 01, 2022 - May 31, 2023
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal researcher: Marcus Vinicius Xavier Senra
• Grantee: Marcus Vinicius Xavier Senra
• Home Institution: Centro de Ciências Naturais e Humanas (CCNH). Universidade Federal do ABC (UFABC). Ministério da Educação (Brasil). Santo André , SP, Brazil
• Assoc. researchers: Lívia Seno Ferreira Camargo

Abstract

Ciliated protists (Ciliophora) are diverse (~8,000 formally described species) and ancestral (~1.1 billion years old) organisms, forming a monophyletic group of unicellular eukaryotes capable of colonizing almost any marine and terrestrial ecosystem, acting as top predators of bacteria and other microorganisms. Interestingly, even with this intimate coevolutionary history, there are no reports of lethal pathogens, suggesting that ciliates must have an efficient infection control mechanism. Indeed, several molecules with antimicrobial activity have been identified in ciliates; among them, some antimicrobial peptides (AMPs), small components of the humoral system of eukaryotes and prokaryotes, with potent activity against a variety of microorganisms, low toxicity to mammalian cells, susceptible to rational modeling, stable, and that rarely induce resistance gain in target organisms. Here, we propose to search the 200 or so ciliate genomes and transcriptomes available in public databases for new AMPs, using different bioinformatics tools. In a second step, we will overexpress the most promising AMPs in a heterologous system based on the microalgae Chlamydomonas reinhardtii; and conduct in vitro tests, with these purified AMPs, against a panel of bacteria and fungi, to validate the data obtained in silico and to establish a new method for large-scale production of AMPs, with application in human, veterinary and agricultural therapy, for the control of pathogens, including those resistant and multidrug-resistant to various conventional antibiotics; but also to meet the growing demand from the food and cosmetics industry for new, more efficient antimicrobial molecules for product preservation purposes. (AU)