AUTHOR=Giovati Laura , Santinoli Claudia , Mangia Carlo , Vismarra Alice , Belletti Silvana , D’Adda Tiziana , Fumarola Claudia , Ciociola Tecla , Bacci Cristina , Magliani Walter , Polonelli Luciano , Conti Stefania , Kramer Laura H. 

TITLE=Novel Activity of a Synthetic Decapeptide Against Toxoplasma gondii Tachyzoites

JOURNAL=Frontiers in Microbiology

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2018.00753

DOI=10.3389/fmicb.2018.00753

ISSN=1664-302X

ABSTRACT=<p>The killer peptide KP is a synthetic decapeptide derived from the sequence of the variable region of a recombinant yeast killer toxin-like microbicidal single-chain antibody. KP proved to exert significant activities against diverse microbial and viral pathogens through different mechanisms of action, but little is known of its effect on apicomplexan protozoa. The aim of the present study was to evaluate the <italic>in vitro</italic> activity of KP against <italic>Toxoplasma gondii</italic>, a globally widespread protozoan parasite of great medical interest. The effect of KP treatment and its potential mechanism of action on <italic>T. gondii</italic> were evaluated by various methods, including light microscopy, quantitative PCR, flow cytometry, confocal microscopy, and transmission electron microscopy. In the presence of KP, the number of <italic>T. gondii</italic> tachyzoites able to invade Vero cells and the parasite intracellular proliferation were significantly reduced. Morphological observation and analysis of apoptotic markers suggested that KP is able to trigger an apoptosis-like cell death in <italic>T. gondii</italic>. Overall, our results indicate that KP could be a promising candidate for the development of new anti-<italic>Toxoplasma</italic> drugs with a novel mechanism of action.</p>